Language：English   Publishing type：Research paper (scientific journal)  

Chlorophylls (Chl) are important pigments in plants that are used to absorb photons and release electrons. There are several types of Chls but terrestrial plants only possess two of these: Chls a and b. The two pigments form light-harvesting Chl a/b-binding protein complexes (LHC), which absorb most of the light. The peak wavelengths of the absorption spectra of Chls a and b differ by c. 20 nm, and the ratio between them (the a/b ratio) is an important determinant of the light absorption efficiency of photosynthesis (i.e., the antenna size). Here, we investigated why Chl b is used in LHCs rather than other light-absorbing pigments that can be used for photosynthesis by considering the solar radiation spectrum under field conditions. We found that direct and diffuse solar radiation (PAR_dir and PAR_diff, respectively) have different spectral distributions, showing maximum spectral photon flux densities (SPFD) at c. 680 and 460 nm, respectively, during the daytime. The spectral absorbance spectra of Chls a and b functioned complementary to each other, and the absorbance peaks of Chl b were nested within those of Chl a. The absorption peak in the short wavelength region of Chl b in the proteinaceous environment occurred at c. 460 nm, making it suitable for absorbing the PAR_diff, but not suitable for avoiding the high spectral irradiance (SIR) waveband of PAR_dir. In contrast, Chl a effectively avoided the high SPFD and/or high SIR waveband. The absorption spectra of photosynthetic complexes were negatively correlated with SPFD spectra, but LHCs with low a/b ratios were more positively correlated with SIR spectra. These findings indicate that the spectra of the photosynthetic pigments and constructed photosystems and antenna proteins significantly align with the terrestrial solar spectra to allow the safe and efficient use of solar radiation.

DOI： 10.1007/s10265-018-1052-7

Repository Public URL： http://hdl.handle.net/2324/2232316

Language：English   Publishing type：Research paper (scientific journal)  

Terrestrial green plants absorb photosynthetically active radiation (PAR; 400–700 nm) but do not absorb photons evenly across the PAR waveband. The spectral absorbance of photosystems and chloroplasts is lowest for green light, which occurs within the highest irradiance waveband of direct solar radiation. We demonstrate a close relationship between this phenomenon and the safe and efficient utilization of direct solar radiation in simple biophysiological models. The effects of spectral absorptance on the photon and irradiance absorption processes are evaluated using the spectra of direct and diffuse solar radiation. The radiation absorption of a leaf arises as a consequence of the absorption of chloroplasts. The photon absorption of chloroplasts is strongly dependent on the distribution of pigment concentrations and their absorbance spectra. While chloroplast movements in response to light are important mechanisms controlling PAR absorption,　they are not effective for green light because chloroplasts have the lowest spectral absorptance in the waveband. With the development of palisade tissue, the incident photons per total palisade cell surface area and the absorbed photons per chloroplast decrease. The spectral absorbance of carotenoids is effective in eliminating shortwave PAR (<520nm), which contains much of the surplus energy that is not used for photosynthesis and is dissipated as heat. The PAR absorptance of a whole leaf shows no substantial difference based on the spectra of direct or diffuse solar radiation. However, most of the near infrared radiation is unabsorbed and heat stress is greatly reduced. The incident solar radiation is too strong to be utilized for photosynthesis under the current CO2 concentration in the terrestrial environment. Therefore, the photon absorption of a whole leaf is efficiently regulated by photosynthetic pigments with low spectral absorptance in the highest irradiance waveband and through a combination of pigment density distribution and leaf anatomical structures.

DOI： 10.1007/s10265-017-0910-z

Other Link： http://link.springer.com/article/10.1007/s10265-017-0910-z

Repository Public URL： http://hdl.handle.net/2324/1936928

Language：English   Publishing type：Research paper (scientific journal)  

The physiological and anatomical responses of bryophytes to altered gravity conditions will provide crucial information for estimating how plant physiological traits have evolved to adapt to significant increases in the effects of gravity in land plant history. We quantified changes in plant growth and photosynthesis in the model plant of mosses, Physcomitrella patens, grown under a hypergravity environment for 25 days or 8 weeks using a custom-built centrifuge equipped with a lighting system. This is the first study to examine the response of bryophytes to hypergravity conditions. Canopy-based plant growth was significantly increased at 10×g, and was strongly affected by increases in plant numbers. Rhizoid lengths for individual gametophores were significantly increased at 10×g. Chloroplast diameters (major axis) and thicknesses (minor axis) in the leaves of P. patens were also increased at 10×g. The area-based photosynthesis rate of P. patens was also enhanced at 10×g. Increases in shoot numbers and chloroplast sizes may elevate the area-based photosynthesis rate under hypergravity conditions. We observed a decrease in leaf cell wall thickness under hypergravity conditions, which is in contrast to previous findings obtained using angiosperms. Since mosses including P. patens live in dense populations, an increase in canopy-based plant numbers may be effective to enhance the toughness of the population, and, thus, represents an effective adaptation strategy to a hypergravity environment for P. patens.

DOI： 10.1007/s10265-016-0879-z

Other Link： http://rdcu.be/m2wI

Repository Public URL： http://hdl.handle.net/2324/1936929

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/S0378-1127(02)00282-7

Other Link： http://dx.doi.org/10.1016/S0378-1127(02)00282-7

Language：English   Publishing type：Research paper (scientific journal)  

Other Link： http://www.jstor.org/stable/1552620

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DOI： 10.1046/j.1440-1703.1998.00251.x

Other Link： http://link.springer.com/article/10.1046%2Fj.1440-1703.1998.00251.x

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/BF02348523

Other Link： http://link.springer.com/article/10.1007%2FBF02348523

Language：English   Publisher：Elsevier  

Solar radiation (SR) is a critical environmental factor influencing plant ecophysiology and ecosystem dynamics, not merely as an energy source but through its spectral characteristics, including critical wavelength ratios (CWRs) that trigger photomorphogenic responses in plants, the diffuse fraction (DF), that affect light distribution within canopies, and the variability of SR. This study presents the Spectral Characteristics Index (SCI), a novel method that integrates spectral quality and energy flux to classify daily SR conditions. / Data were collected using a rotating shadow-band spectroradiometer. The study applied agglomerative hierarchical clustering (AHC) based on cumulative Euclidean distance matrices and identified five SR clusters ranging from clear (SCI-01) to overcast (SCI-05) conditions, with spectral shifts from red to blue. Significant differences in DF, global solar irradiance (GSI), and CWRs were observed across clusters (p < 0.0001, F > 27). / Given the challenges in obtaining comprehensive spectral data in certain regions, machine learning models replicated SCI clustering using easily accessible environmental variables (DF, GSI, variability, airmass, and vapor pressure). The support vector machine (SVM) model achieved 88.03 % validation accuracy and 94.29 % test accuracy, providing a practical alternative where spectral measurements are not available. While long-term data collection across various climatic zones could improve the validity and adaptability of SCIs to different geographical locations, the current model demonstrates high accuracy and efficiency. This innovative approach enhances the understanding of SR dynamics and advances ecological research on plant responses and ecosystem functions.

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

We have performed a lab-based hypergravity cultivation experiment using a centrifuge equipped with a lighting system and examined long-term effects of hypergravity on the development of the main axis of the Arabidopsis (Arabidopsis thaliana (L.) Heynh.) primary inflorescence, which comprises the rachis and peduncle, collectively referred to as the main stem for simplicity. Plants grown under 1 × g (gravitational acceleration on Earth) conditions for 20–23 days and having the first visible flower bud were exposed to hypergravity at 8 × g for 10 days. We analyzed the effect of prolonged hypergravity conditions on growth, lignin deposition, and tissue anatomy of the main stem. As a result, the length of the main stem decreased and cross-sectional area, dry mass per unit length, cell number, and lignin content of the main stem significantly increased under hypergravity. Lignin content in the rosette leaves also increased when they were exposed to hypergravity during their development. Except for interfascicular fibers, cross-sectional areas of the tissues composing the internode significantly increased under hypergravity in most types of the tissues in the basal part than the apical part of the main stem, indicating that the effect of hypergravity is more pronounced in the basal part than the apical part. The number of cells in the fascicular cambium and xylem significantly increased under hypergravity both in the apical and basal internodes of the main stem, indicating a possibility that hypergravity stimulates procambium activity to produce xylem element more than phloem element. The main stem was suggested to be strengthened through changes in its morphological characteristics as well as lignin deposition under prolonged hypergravity conditions.

DOI： 10.1007/s10265-024-01556-x

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Other Link： https://link.springer.com/article/10.1007/s10265-024-01556-x/fulltext.html

DOI： 10.1101/2024.06.18.599652

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Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

To determine the potential reduction of the seed productivity of Japanese black pine (Pinus thunbergii) by the western conifer seed bug (Leptoglossus occidentalis), two feeding experiments were conducted in the center of Kyushu Island, southwestern Japan, in fall of 2020. First, L. occidentalis individuals and a preharvested P. thunbergii cone were enclosed in a nonwoven fabric bag for 2 weeks, which yielded a mean filled seed rate of 18.8% compared with that of 35.6% in the control. Second, L. occidentalis individuals and harvested cones were enclosed in a plastic case for 1 week, affording a mean filled seed rate of 25.7% compared with that of 36.4% in the control. These results suggest that L. occidentalis feeding reduces the filled seed rate of P. thunbergii and damages the seed orchards of this species. Additionally, P. thunbergii seeds from cones damaged by L. occidentalis could be distinguished by their germination ability when sorted using an ethanol floatation technique. Overall, these findings suggest the importance of carefully monitoring L. occidentalis infestation in P. thunbergii seed orchards.

DOI： 10.1080/13416979.2023.2291343

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DOI： https://doi.org/10.1080/13416979.2023.2291343

Other Link： https://www.tandfonline.com/doi/full/10.1080/13416979.2023.2291343

Language：Japanese   Publishing type：Research paper (scientific journal)  

Photosynthetic response of trees to environmental stress in urban areas

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Microorganisms  

Typhulaceae Jülich is one of the cold-adapted fungal families in basidiomycetes. The representative genera, Typhula (Pers.) Fr. and Pistillaria Fr., are distinguished by the discontinuity between stems and hymenia in the former and the continuity in the latter (Fries 1821). This taxonomic criterion is ambiguous, and consequently, the view of Karsten (1882) has been widely accepted: Typhula develops basidiomata from sclerotia, while basidiomata develop directly from substrata in Pistillaris. However, Corner (1970) observed basidiomata of Pistillaria petasitis S. Imai developing from sclerotia in Hokkaido, Japan. We later recognized that P. petasitis basidiomata also emerged directly from substrates on the ground in Hokkaido. An aberrant form of Typhula hyperborea H. Ekstr. was found in Upernavik, West Greenland. This specimen had a stem-like structure on a Poaceae plant, and sclerotia developed on its tip. Similar phenomena were found in other Typhula species in Japan. In this study, we aimed to elucidate the life cycle plasticity in the genera Typhula and Pistillaria through the interactions between their ecophysiological potential and environmental conditions in their localities. We collected and prepared strains of the above fungi from sclerotia or basidiomata, and we elucidated the taxonomical relationship and determined the physiological characteristics of our strains. Our findings imply that both Typhula and Pistillaria have the potential to produce sclerotia as well as the capacity for mycelial growth at ambient air temperatures in each locality where samples were collected. These findings suggest that Typhula spp. develope basidiomata not only from the sclerotia dispersed by the basidiospores but also from mycelia generated by the spore germination, which formed basidiomata multiple times, depending on their growth environments.

DOI： 10.3390/microorganisms11082028

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Other Link： https://www.mdpi.com/2076-2607/11/8/2028

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Experimental Botany  

The mesophyll anatomical traits are essential factors for efficient light capture, CO2 diffusion, and hydraulics in leaves. At the same time, leaf hydraulics are governed by the xylem anatomical traits. Thus, simultaneous analyses of the mesophyll and xylem anatomy will clarify the links among light capture, CO2 capture, and water use. However, such simultaneous analyses have been scarcely performed, particularly on non-seed plants. Using seven fern species, we first showed that fern species with a large mesophyll thickness had a high photosynthetic rate related to high light capture, high drought tolerance, and low leaf hydraulic conductance. The chloroplast surface area (Sc) per mesophyll thickness significantly decreased with an increase in mesophyll thickness, which may increase light diffusion and absorption efficiency in each chloroplast. The photosynthetic rate per Sc was almost constant with mesophyll thickness, which suggests that ferns enhance their light capture ability via the regulation of chloroplast density.

DOI： 10.32615/ps.2023.017

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Other Link： https://ps.ueb.cas.cz/artkey/phs-202302-0010_variation-in-leaf-mesophyll-anatomy-of-fern-species-imposes-significant-effects-on-leaf-gas-exchange-light-cap.php

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1371/journal.pone.0275024

Other Link： https://doi.org/10.1371/journal.pone.0275024

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Microscopy  

Land plants have two types of shoot-supporting systems, root system and rhizoid system, in vascular plants and bryophytes. However, since the evolutionary origin of the systems are different, how much they exploit common systems or distinct systems to architect their structures are largely unknown. To understand the regulatory mechanism how bryophytes architect rhizoid system responding to environmental factors, we have developed the methodology to visualize and quantitatively analyze the rhizoid system of the moss, Physcomitrium patens in 3D. The rhizoids having the diameter of 21.3 µm on the average were visualized by refraction-contrast X-ray micro-CT using coherent X-ray optics available at synchrotron radiation facility SPring-8. Three types of shape (ring-shape, line, black circle) observed in tomographic slices of specimens embedded in paraffin were confirmed to be the rhizoids by optical and electron microscopy. Comprehensive automatic segmentation of the rhizoids which appeared in different three form types in tomograms was tested by a method using Canny edge detector or machine learning. Accuracy of output images was evaluated by comparing with the manually-segmented ground truth images using measures such as F1 score and IoU, revealing that the automatic segmentation using the machine learning was more effective than that using Canny edge detector. Thus, machine learning-based skeletonized 3D model revealed quite dense distribution of rhizoids. We successfully visualized the moss rhizoid system in 3D for the first time. High resolution refraction-contrast X-ray micro-CT using coherent X-ray optics successfully visualized 3D architecture of rhizoid system of moss, Physcomitrium patens, which is composed of cellular filaments having the diameter of 21.3 µm on the average, for the first time by using machine learning for segmentation.

DOI： 10.1093/jmicro/dfac041

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PLoS ONE  

The western conifer seed bug (WCSB, Leptoglossus occidentalis) is a pest of many pine species and is invasive worldwide. WCSB directly and indirectly deteriorates pine nut production by sucking seeds from cones. Currently, researchers think that WCSBs search for food by a combination of cues from visible light, infrared radiation, and chemicals such as monoterpenes. Some research revealed that WCSBs prefer larger cones, and it was thought that WCSBs suck seeds from and obtain more heat on larger cones. However, in early spring, we observed that most WCSBs gathered on male cones rather than on female cones and young cones. We hypothesized that male pine cones were warmer than female cones and needles, and WCSBs sucking male cones may receive more heat. To test these hypotheses, we measured spectral reflectance with a hyperspectral sensor and temperature of pine organs with tiny thermocouples, and the data were analyzed by a heat budget model. Our results revealed that male cones were significantly warmer and more reflective than female cones and needles, which may attract WCSBs. These results supported our hypothesis that WCSBs on male cones were warmer than those on other organs. This study will help further understanding of WCSBs and the adaptive value of pine cone colors.

DOI： 10.1371/journal.pone.0272565

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Other Link： https://doi.org/10.1371/journal.pone.0272565

Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Journal of Applied Earth Observation and Geoinformation  

A constant ratio of photosynthetically active radiation (PAR) to solar radiation (SR) (about 0.45–0.46) has been used in many ecological studies to convert SR into PAR by multiplication. The constant ratio is useful and convenient. However, there is no general agreement on whether the ratio is 0.45 or 0.46 and how distributed globally. Accordingly, many local empirical ratios have been reported. This study aims to demonstrate a global distribution of the ratio and its changing range. Thus, we created two simple empirical models to estimate the ratio based on the in-situ climatic data to achieve the aim. The models were created based on accurate data of SR and PAR observed using a direct and diffuse separation method at Tateno in Tsukuba, Japan. At three validation sites in Japan, the ratio could be estimated with an error within 3%, a considerable reduction from 15% in using a constant. The numerical model also produced the ratio within approximately 3% errors. Using the proposed model, we demonstrated that the annual mean of the ratio had a range from 0.409 to 0.477. The results will contribute to the uncertainty estimation when using a constant ratio.

DOI： 10.1016/j.jag.2022.102724

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society of Agricultural Meteorology of Japan  

Rice (<I>Oryza sativa</I> L.) quality and yield are degraded by high temperature, especially at the ripening stage after the heading of panicles. The effect is lethal when the panicle temperature (<I>T</I><SUB>p</SUB>) is excessively high; therefore, maintaining a low <I>T</I><SUB>p</SUB> is important to avoid deleterious impacts on the grains. Microclimatic factors and plant physiological elements determine the <I>T</I><SUB>p</SUB>. One determining factor is the color (or reflectance) of spikelets that constitute the panicle because it determines the absorption of shortwave radiation energy. An additional factor is the panicle position because it influences heat exchange by the wind and input energy from downward shortwave radiation. In this study, inter-strain differences in spikelet color and panicle height at heading were assessed. The <I>T</I><SUB>p</SUB> of strains differing in panicle color and panicle height were measured with thermocouples. In addition, to estimate the effect of each trait, we adopted a micrometeorological model. Panicle color was quantified using a hyperspectral sensor. Combining the spectral reflectance and spectral radiation, we assessed the effect of panicle color on <I>T</I><SUB>p</SUB>. The differences in panicle color and panicle position significantly affected <I>T</I><SUB>p</SUB>. The strain with a dark panicle had a maximum measured <I>T</I><SUB>p</SUB> about 1.8 °C higher than that of the strain with a light-colored panicle. The <I>T</I><SUB>p</SUB> of a strain with panicles at higher positions was up to 2.0 °C higher than that of a strain with panicles at lower positions. These relationships were consistent with the model estimates. When shortwave radiation was strong, the difference in <I>T</I><SUB>p</SUB> between strains showed a positive correlation, suggesting that the temperature difference was associated with shortwave radiation. Therefore, we concluded that rice strains with a brighter panicle color and low panicle position are less prone to deleterious impacts of high temperature because net radiation is reduced.

DOI： 10.2480/agrmet.D-21-00032

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Forest Research  

Although Chamaecyparis obtusa reduces soil pH and cation levels, limited information is available regarding their alterations after clear-cutting. We examined the soil pH and base cations on the upslopes and downslopes of individual trees and stumps of C. obtusa at two distances (0.5 m and 1.0 m) and three depths (0–5, 5–10, and 10–30 cm) in intact- and cut-tree plots. The soil pH was higher in the cut-tree plot than in the intact-tree plot, indicating the recovery of soil pH after clear-cutting. The recovery was more evident in the surface soils (0–5 cm) of downslope areas (0.5 m) than in other soil depths, which implies that the recovery of soil pH was caused by the lack of H+ supply from stumps after clear-cutting. The results of H+ (in H2O: water-soluble and KCl: exchangeable) suggested a lack of soluble H+ in the cut-tree plot. Soil Ca2+ and Mg2+ levels in the surface soil (0–5 cm) were 1.86-fold and 1.93-fold higher in the cut-tree plot than in the intact-tree plot, respectively, implying that the recovery of divalent cations after clear-cutting was caused by a reduction in cation loss through cation exchange with H+ derived from the stemflow. Collectively, soil pH and divalent cations were recovered after clear-cutting because the stemflow had ceased.

DOI： 10.1080/13416979.2022.2048987

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Urban Ecosystems  

We conducted on-site studies in Kyoto City, Japan, to evaluate the effect of air pollution by automobile gas exhaust on the leaf photosynthetic functions of four urban roadside tree species. Nitrogen oxides (NO and NO2) are major air pollutants that are related to automobile gas exhaust. The species-specific response of leaf photosynthesis to air pollution was obtained for single-year data, in which at the high air pollution sites, Rhododendron × pulchrum, Rhaphiolepis indica, and Prunus × yedoensis had a higher restriction of maximum photosynthesis (Amax), while the opposite trend was obtained for Ginkgo biloba. When the data were pooled across the years from 2007 to 2019 in R. pulchrum, the dose-dependent effect of NO and NO2 on photosynthesis became obvious, in which they decreased Amax and increased the long-term leaf water use efficiency. A spatial variability map for R. pulchrum showed a lower Amax and higher water use efficiency at the heavy traffic areas in Kyoto City, which suggests that R. pulchrum increased tolerance to air pollution and water stress at the expense of the leaf photosynthesis. This study revealed the importance of the evaluation of the species-specific response of photosynthesis to air pollution for the efficient use of urban trees, even in regions with relatively low atmospheric pollution levels such as < 40 ppb of NO or NO2.

DOI： 10.1007/s11252-022-01212-z

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Publishing type：Research paper (scientific journal)   Publisher：Trees - Structure and Function  

The spelling of the Latin name of the tree in the title of the paper is wrong. Wrong: Gingko Correct: Ginkgo

DOI： 10.1007/s00468-021-02213-9

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DOI： https://doi.org/10.2187/bss.35.32

Other Link： https://www.jstage.jst.go.jp/article/bss/35/0/35_32/_article/-char/en

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1007/s00468-021-02083-1

Other Link： https://link.springer.com/article/10.1007/s00468-021-02083-1

Language：English   Publishing type：Research paper (scientific journal)  

Key message: Seasonal variations in the leaf photosynthetic traits of an urban tree, Ginkgo biloba, were almost synchronized with the photoperiod. Non-stomatal limitations were a cue for photosynthesis in Ginkgo biloba. Photosynthetic functions, which are key traits in determining the carbon uptake of urban trees, exhibit significant seasonal variations in temperate zones. It is essential to clarify the seasonal dynamics of photosynthesis to evaluate the CO₂ uptake in urban areas. We investigated seasonal variations in the photosynthetic traits of Ginkgo biloba, which is a major urban deciduous tall tree often planted in Japan. Seasonal variations in the leaf photosynthetic traits, including the maximum photosynthesis rate, maximum carboxylation rate, and mesophyll and stomatal conductance, were well fitted to quadratic models, in which they peaked around the summer solstice and then declined with time. Seasonal variations in the environmental variables, such as photoperiod, temperature, and solar radiation, were compared to those of the leaf photosynthetic traits, in which the photoperiod explained well variations in the leaf photosynthetic traits. Seasonal variations in photosynthesis were largely governed by non-stomatal limitations, i.e., mesophyll and biochemical limitations. The high synchrony of the photoperiod and photosynthetic traits during leaf maturation may cause an enhancement in the daily carbon uptake of G. biloba leaves around the summer solstice, which has the longest photoperiod, and thus, will lead to an increase in the annual carbon uptake.

DOI： https://doi.org/10.1007/s00468-020-02033-3

Other Link： https://doi.org/10.1007/s00468-020-02033-3

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Key message: Canopy tree species with a large mean xylem vessel diameter has a high sensitivity of stomatal conductance to vapor pressure deficit in a wet tropical rainforest in Malaysia. Abstract: We investigated the diurnal variation of stomatal conductance to water vapor (g_s) and leaf water relations in nine tropical rainforest canopy tree species in Malaysia to investigate the sensitivity of stomatal conductance to VPD and its dependence on leaf water relations. We focused on the effect of wood anatomical properties on the stomatal sensitivity to VPD. Negative correlations were obtained between leaf-to-air VPD (VPD_leaf) and g_s for all species, in which interspecific variation was obtained for the sensitivity of g_s to VPD_leaf with the range of VPD_leaf being 1.2–5.9 kPa. The species with large mean xylem vessel diameter had high sensitivity of g_s to VPD_leaf. Although significant variations were obtained among the species for leaf water relations, such as relative water content at the turgor loss point (RWC_tlp) and water potential at the turgor loss point (Ψ_tlp), these water relations were not related to the stomatal sensitivity to VPD_leaf. In the wet tropical forest in the present study, VPD_leaf was the main regulator of g_s in the nine tree species. The high sensitivity of g_s to VPD_leaf in the trees with a large vessel area may contribute to the maintenance of an adequate leaf water status, e.g., high levels of Ψ_leaf, throughout the day, across a period of varying air temperature.

DOI： 10.1007/s00468-020-01998-5

Language：Japanese   Publishing type：Research paper (scientific journal)  

How plants grow under different gravity conditions besides 1 g:Perspectives from space experiments exploiting moss as a model organism

DOI： 10.24480/bsj-review.11a6.00178

Language：Japanese   Publishing type：Research paper (scientific journal)  

Terrestrial solar radiation environment and absorption characteristics of
photosynthetic pigments -Newscape from high-precision spectral solar radiation observation-

Language：English   Publishing type：Research paper (scientific journal)  

Soil water repellency (SWR) is a cause of low water infiltration, overland flow and soil erosion in mountainous coniferous plantations in Japan. The factors determining SWR intensity were investigated in two coniferous plantations of Chamaecyparis obtusa (Siebold et Zucc.) Endl. and Cryptomeria japonica (L.f.) D. Don, using intact tree plots and cut tree plots on the same hillslope. The SWR of Ch. obtusa plots was stronger than that of Cr. japonica plots. SWR intensity decreased after tree cutting. There were no significant differences in SWR upslope and downslope of individual trees/stumps for both tree species, though areas downslope of individual Ch. obtusa trees had higher SWR intensity than those upslope. SWR intensity and soil aggregate stability were positively correlated in the Ch. obtusa intact tree plot (r = 0.88, p < 0.01), whereas in the cut tree plot, this correlation was weak with no significance (r = 0.29, p = 0.41). Soil aggregate size had a non-significant influence on SWR intensity. These findings suggest that SWR intensity was not related to the soil aggregate size, but SWR intensity seemed have a role in soil aggregation in the Ch. obtusa intact tree plot. Destruction of soil aggregates could occur after tree cutting because of physical disturbances or increased input of different types of organic matter from other vegetation into soil. The presence of Ch. obtusa introduces a source of SWR, although uncertainty remains about how water repellency is distributed around soil aggregates. The distribution pattern of soil water content and soil hydraulic conductivity around Cr. japonica was related to other factors such as the litter layer and non-water-repellant soil.

DOI： 10.3390/f10090730

Language：English   Publishing type：Research paper (scientific journal)  

Standing trees influence the redistribution of soil water around the trunk and alter water movement under the canopy on hillslopes. We investigated soil properties around trees to clarify the effect of trees on soil hydraulic properties of soil surface layers on a slope. The intact tree and cut tree plots of two coniferous tree species, Cryptomeria japonica and Chamaecyparis obtusa, were considered in the northern part of Kyushu, Japan. The soil properties on the upslope and downslope of individual trees or stumps were compared. The soil near-saturated hydraulic conductivity (k_ns) on the upslope of individual trees and stumps was higher than that on the downslope for both species. Although the distribution patterns of k_ns were similar in all plots, the determinant factors of k_ns seemed to be different. In the Cr. japonica intact tree plot, more litter tended to accumulate on the upslope of individual trees, and it seemed to indirectly enhance k_ns. However, the results of the cut tree plot suggested that k_ns was affected by factors other than the litter layer biomass. In the Ch. obtusa intact plot, high water repellency of soil on the downslope of individual trees reduced k_ns. Organic matter tended to accumulate on the upslope of Ch. obtusa individual stumps and in combination with water repellency appeared to affect k_ns. Our findings showed that soil hydraulic conductivity was affected by the distance and direction from a tree on a slope and that the effect was maintained for a few years after cutting.

DOI： 10.1080/13416979.2019.1590967

Language：English   Publishing type：Research paper (scientific journal)  

Key message: Rhododendron × pulchrum avoided air pollution by adjusting its stomatal density, while Ginkgo biloba tolerated air pollution via a small stomatal density and high mesophyll thickness. Abstract: Information on the physiological mechanisms underlying species-specific photosynthetic responses to ambient air pollution is essential for enhancing the multiple services provided by urban trees. We conducted an on-site investigation of Rhododendron × pulchrum and Ginkgo biloba, which are the most common shrub and tall roadside tree used in Japan, in order to clarify their photosynthetic responses at sites with different air pollution levels in Kyoto city, Japan. The shrub tree R. × pulchrum and tall tree G. biloba exhibited contrasting responses to air pollution mainly from automobile exhaust gas. R. × pulchrum had a lower photosynthetic rate and stomatal conductance at high-pollution sites than at low-pollution sites, while no reductions were observed at high-pollution sites for G. biloba. The stomatal density of R. × pulchrum negatively correlated with atmospheric nitrogen oxides (NO and NO₂) concentrations. R. × pulchrum avoided the effects of air pollution by reducing stomatal density at high-pollution sites at the expense of reducing CO₂ uptake, while G. biloba appeared to have the ability to tolerate high air pollution levels by reducing the pollution load per mesophyll cell surface area with a low stomatal density and large mesophyll thickness. In conclusion, R. × pulchrum and G. biloba both acclimate to urban environments through an avoidance or tolerance strategy for air pollution by regulating stomatal and/or mesophyll morphologies.

DOI： 10.1007/s00468-018-1759-z

Other Link： https://doi.org/10.1007/s00468-018-1759-z

Language：English   Publishing type：Research paper (scientific journal)  

In populations of dioecious plants, the differences in the cost of reproduction between male and female plants can promote a male-biased sex ratio. In this study, we examine the macronutrient levels in tissues of the dioecious wetland shrub Myrica gale to identify the cost of reproduction for male and female plants and to examine the effect of nutrients on the apparent sex ratio at the ramet level. We examined plants across 12 populations of M. gale inhabiting bogs and fens in Japan. For each population, we used line transects to estimate the apparent sex ratio and measured the concentrations of nitrogen (N), phosphorus (P), and potassium (K) in the leaves sampled from male and female plants and in the fruits from female plants. For five of the populations, we calculated the flowering frequency, mortality, and the recruitment rate (as the rate of clonal propagation). We found that the proportion of females was positively affected, and the male bias of sex ratios reduced, by increases in P concentration in leaves sampled from female plants. Neither mortality nor recruitment was affected by sex or by the nutrient concentration (P, K). The flowering frequency was not affected by sex or by K concentration, but decreased with decreases in the P concentration measured in leaves. This study confirmed that reproduction in M. gale is P-limited. We found no distinct differences in the flowering frequency, mortality, or recruitment rate between the male and female plants.

DOI： 10.1007/s10265-018-1056-3

Other Link： https://doi.org/10.1007/s10265-018-1056-3

Language：English   Publishing type：Research paper (scientific journal)  

The photosynthetic and anatomical responses of bryophytes to changes in gravity will provide crucial information for estimating how these plant traits evolved to adapt to changes in gravity in land plant history. We performed long-term hypergravity experiments at 10g for 4 and 8 weeks using the moss Physcomitrella patens with two centrifuges equipped with lighting systems that enable long-term plant growth under hypergravity with irradiance. The aims of this study are (1) to quantify changes in the anatomy and morphology of P. patens, and (2) to analyze the post-effects of hypergravity on photosynthesis by P. patens in relation to these changes. We measured photosynthesis by P. patens for a population of gametophores (e.g., canopy) in Petri dishes and plant culture boxes. Gametophore numbers increased by 9% for a canopy of P. patens, with 24–27% increases in chloroplast sizes (diameter and thickness) in leaf cells. In a canopy of P. patens, the area-based photosynthesis rate (Acanopy) was increased by 57% at 10g. The increase observed in Acanopy was associated with greater plant numbers and chloroplast sizes, both of which involved enhanced CO2 diffusion from the atmosphere to chloroplasts in the canopies of P. patens. These results suggest that changes in gravity are important environmental stimuli to induce changes in plant growth and photosynthesis by P. patens, in which an alteration in chloroplast size is one of the key traits. We are now planning an ISS experiment to investigate the responses of P. patens to microgravity.

DOI： https://doi.org/10.1007/s12217-017-9565-6

Other Link： https://doi.org/10.1007/s12217-017-9565-6

Language：English   Publishing type：Research paper (scientific journal)  

Nitrogen (N) saturation of upland forests has been assumed to be a substantial N source downstream. However, removal processes of N, including assimilation and denitrification in the downstream area, have not been clarified. To evaluate the N removal processes, nitrate (NO3−) and organic N concentrations, as well as nitrogen isotope ratio (δ15N) and oxygen isotope ratio (δ18O) of NO3− were measured along three rivers of Tatara River Basin, Japan where upland forests have already been N-saturated. Geographic information system (GIS) based topographical analysis was also conducted to evaluate the land use as urban area in relation to topography. In two of the three rivers, NO3− concentrations did not increase from upstream to downstream, despite the potential non-point N sources of urban areas. In another river, NO3− concentrations rather decreased. The values of δ15N and δ18O of NO3− and organic N concentrations suggested the presence of denitrification and assimilation over N pollutants in the river whose watersheds have a lower percentage of urban area. The lower percentage of urban area could be explained by the lower topographic index. This study concluded that the NO3− leaching from upland N-saturated forests was substantially assimilated or denitrified in the downstream area.

DOI： 10.3390/hydrology4030043

Other Link： http://www.mdpi.com/2306-5338/4/3/43/htm

Repository Public URL： http://hdl.handle.net/2324/1936930

Language：English   Publishing type：Research paper (scientific journal)  

Long-term accurate data of photosynthetically active radiation (PAR) are needed because PAR is one of the standard environmental statistics needed to evaluate plant photosynthesis. Therefore, PAR observation sites are globally distributed, particularly in flux observation sites. Quantum sensors have been used for half a century to observe PAR; however, their accuracy is still uncertain. This study evaluates the accuracies of nine quantum sensor products by examining their spectral and cosine responses. On the basis of these data as well as reference spectrum data provided by our standard spectrometric measurement, we performed the following analyses: (1) a simulation of errors caused by the sensors’ non-ideal spectral response in three types of radiation inputs (open sky, forest canopy transmission, and forest canopy reflection), (2) a simulation of the errors caused by a complex combination of the sensors’ non-ideal spectral and cosine responses in three diurnal variation types of incident radiation (clear sky, partial clouds, and an overcast sky), and (3) an observation of the sensors’ long-term sensitivity degradation outdoors. Based on the results, we recommend two quantum sensors with minimal errors, LI-COR LI-190 encased in a weather-proof external housing with a glass dome and PREDE PAR-02D. The findings of this study contribute in establishing a long-term PAR observation protocol and should become a basis for quality checks and controls of PAR observation values that have previously been obtained worldwide.

DOI： 10.1016/j.agrformet.2017.01.011

Other Link： http://dx.doi.org/10.1016/j.agrformet.2017.01.011

Language：English   Publishing type：Research paper (scientific journal)  

In 2016, Ecological Research (ER) celebrated its 30th anniversary. ER’s goal is to be the leading ecological, evolutionary, and biodiversity journal in Asia. This article introduces the development of ER, improvements to its editorial system and their outcomes, and the strategies designed to achieve this goal. ER has already become a leading comprehensive and international publication as shown by statistical evidence and its strong editorial foundation. However, some members of the Ecological Society of Japan (ESJ) retain impressions of an old stereotype about ER. The discrepancy between the current status of the journal and its stereotype may explain why submissions from Japan remain static. A new article category for ER, Biodiversity in Asia, was created to encourage Asian studies. In addition, the Forum category is dedicated to promoting a broad understanding of the ESJ’s various activities. To promote open science, the proportion of open access articles in the journal is increasing. The publication of Data papers has been accelerated to improve the public availability of excellent open data sets. ER symposia and seminars provide good opportunities for members to participate. ER financially supports the invitation of scientists internationally to facilitate research exchanges with other countries and consequently promotes the internationalization of the ESJ. The ESJ is open to the world’s ecologists, and your participation in developing ER is welcome.

DOI： 10.1007/s11284-017-1457-0

Other Link： http://link.springer.com/article/10.1007/s11284-017-1457-0

Repository Public URL： http://hdl.handle.net/2324/1936932

Language：English   Publishing type：Research paper (scientific journal)  

As pioneer plants mosses are adaptable to extreme environments and are the first to colonize previously uncolonized land. Recently, we designed two centrifuges, MIJ-17 and MK-3, to investigate the effects of long-term cultivation under moderate hypergravity conditions on the growth of mosses. We examined the effects of the vibration generated by these centrifuges on the growth and morphological parameters of the moss Physcomitrella patens, because plants are generally sensitive to vibration. In MIJ-17, random vibration was detected by a micro three-axis acceleration sensor during centrifugation at 2, 5, and 10 G, whereas vibration was negligible in MK-3. Therefore, we compared the growth and morphological parameters of P. patens gametophores cultivated with MIJ-17 and MK-3 at 10 G. The vibration generated by MIJ-17 did not significantly affect the growth and morphological parameters of P. patens gametophores. Thus, we conclude that the vibration of MIJ-17 has a negligible impact on the growth of P. patens gametophores.

DOI： 10.2187/bss.31.9

Other Link： http://doi.org/10.2187/bss.31.9

Repository Public URL： http://hdl.handle.net/2324/1936936

Language：English   Publishing type：Research paper (scientific journal)  

Estimation of the current successional status of long-lived coniferous forests is difficult especially after several hundred years of human disturbance. However, in Cryptomeria japonica forest on Yakushima Island, the stumps generated by logging activities from the seventeenth to nineteenth centuries remain almost intact without intense rotting. From an inventory of these stumps and long-term monitoring of current stands for more than 25 years, we estimated the forest condition before logging and evaluated the current status of secondary succession. The size structure of Cr. japonica stumps suggested the stumps were composed of two different generations: the stumps of trees present before initiation of logging; and those of trees that regenerated after initiation of logging. In the current forest, the stem number of canopy species is decreasing and that of understory broad-leaved species is increasing. Regenerating Cr. japonica individuals are rare. Before the logging, the forest contained a larger number of larger Cr. japonica trees than the current forest. The results of monitoring the current forest suggested that all coniferous species, including Cr. japonica, were still undergoing self-thinning. The current Cr. japonica forest is in an intermediate stage of secondary succession, but the processes of succession are markedly different between the study plots, depending on their location or previous logging intensity.

DOI： 10.1080/13416979.2016.1273085

Other Link： http://www.tandfonline.com/doi/full/10.1080/13416979.2016.1273085

Language：English   Publishing type：Research paper (scientific journal)  

Stomatal regulation involves beneficial effects of pruning mulch and irrigation on leaf photosynthesis in Prunus yedoensis and Ginkgo biloba under moderate drought. G. biloba showed conservative water use under drought.
Abstract: Leaf photosynthesis is highly sensitive to soil water stress via stomatal and/or biochemical responses, which markedly suppress the growth of landscape trees. Effective irrigation management to maintain leaf photosynthesis and information on species-specific photosynthetic responses to soil water stress are essential for the sustainable management of landscape trees in Japan, in which summer drought often occurs. In order to investigate effective irrigation management, we used plants with moderate soil water stress as controls, and examined the effects of daily irrigation and pruning mulch on leaf photosynthesis in container-grown Ginkgo biloba and Prunus yedoensis, which are the first and second main tall roadside trees in Japan. Stomatal conductance was significantly increased by pruning mulch and daily irrigation, with similar increases in leaf photosynthesis being observed in P. yedoensis and G. biloba. In order to obtain information on species-specific photosynthetic responses to soil water stress, we compared the responses of leaf photosynthesis and leaf water status to reductions in soil water content (SWC) between the two species. G. biloba maintained a constant leaf water potential, leaf water content, maximum
carboxylation rate, and electron transport rate with reductions in SWC, whereas reductions were observed in P. yedoensis. We concluded that pruning mulch and irrigation effectively offset the negative impact of moderate water stress on leaf photosynthesis in summer in P. yedoensis and G. biloba via stomatal regulation, and also that G. biloba maintained its photosynthetic biochemistry and leaf water status better than P. yedoensis under severe water stress.

DOI： 10.1007/s00468-015-1312-2

Other Link： http://link.springer.com/article/10.1007%2Fs00468-015-1312-2

Language：English   Publishing type：Research paper (scientific journal)  

DOI： DOI: 10.1007/s11270-016-2906-z

Other Link： http://link.springer.com/article/10.1007/s11270-016-2906-z

Language：English   Publishing type：Research paper (scientific journal)  

The spectral distributions of light absorption rates by intact leaves are notably different from the incident solar radiation spectra, for reasons that remain elusive. Incident global radiation comprises two main components; direct radiation from the direction of the sun, and diffuse radiation, which is sunlight scattered by molecules, aerosols and clouds. Both irradiance and photon flux density spectra differ between direct and diffuse radiation in their magnitude and profile. However, most research has assumed that the spectra of photosynthetically active radiation (PAR) can be averaged, without considering the radiation classes. We used paired spectroradiometers to sample direct and diffuse solar radiation, and obtained relationships between the PAR spectra and the absorption spectra of photosynthetic pigments and organs. As monomers in solvent, the spectral absorbance of Chl a decreased with the increased spectral irradiance (W m-2 nm-1) of global PAR at noon (R2 = 0.76), and was suitable to avoid strong spectral irradiance (λmax = 480 nm) rather than absorb photon flux density (μmol m-2 s-1 nm-1) efficiently. The spectral absorption of photosystems and the intact thallus and leaves decreased linearly with the increased spectral irradiance of direct PAR at noon (Idir-max), where the wavelength was within the 450–650 nm range (R2 = 0.81). The higher-order structure of photosystems systematically avoided the strong spectral irradiance of Idir-max. However, when whole leaves were considered, leaf anatomical structure and light scattering in leaf tissues made the leaves grey bodies for PAR and enabled high PAR use efficiency. Terrestrial green plants are fine-tuned to spectral dynamics of incident solar radiation and PAR absorption is increased in various structural hierarchies.

DOI： 10.1007/s10265-016-0809-0

Other Link： http://link.springer.com/article/10.1007/s10265-016-0809-0

Language：English   Publishing type：Research paper (scientific journal)  

The precise measurement of incident photosynthetically active radiation (PAR) is crucial for the estimation of ecosystem vegetation productivity. However, reliable values of PAR are seldom measured routinely. Instead, it is sometimes estimated based on solar radiation (RS). One popular estimation method is by use of the conversion ratio PAR/RS. Depending on whether PAR is expressed in energy units (PE, W m−2) or photon units (PP, μmol m−2 s−1), there are two types of conversion ratios: PE/RS (unitless), or PP/RS (μmol J−1). Moreover, to translate PAR expressed in one unit to another, the ratio PP/PE (μmol J−1) is also important. However, past studies have not led to a general understanding of these ratios, mainly due to instrumental errors such as cosine errors. To reduce such errors, we developed a new PAR measurement system using grating spectroradiometers mounted on sun trackers to measure direct and diffuse PAR separately. This study aims to clarify the characteristics of these three ratios by the new precise measurement and radiative transfer simulation. We carried out measurements for one year in Tsukuba, Japan (36.05° N, 140.13° E). PE/RS increased with water vapor pressure (e) from 0.40 to 0.47. It increased with decreasing clearness index (kT), but did not strongly depend on solar zenith angle (θ). PP/RS also increased with e from 1.9 μmol J-1 to 2.2 μmol J-1. Its dependence on climatic factors was similar to that of PE/RS. PP/PE varied by about 3% around the value of 4.57 μmol J-1. This study implies that PAR can be estimated from RS and the conversion ratios with an error up to about 10%.

DOI： 10.1016/j.agrformet.2015.04.026

Other Link： http://www.sciencedirect.com/science/article/pii/S0168192315001306

Language：English   Publishing type：Research paper (scientific journal)  

To estimate the impact of atmospheric deposition on alpine ecosystems, we evaluated the interactions between atmospheric deposition and the Pinus pumila canopy close to the summit of Mt. Tateyama, Central Japan. We analyzed the chemical characteristics of rain, fog, and throughfall under the canopy in the summer time for 5 years. The concentrations of inorganic nitrogen and sulfate in precipitation at the summit (2839 m a.s.l.) were lower than at the base (13 m a.s.l.), but the total amounts deposited tended to be larger, because the precipitation was greater at the summit and highly concentrated fog water was deposited on the pine canopy. Large fluctuations in the quality and quantity of deposition were due to interannual variations in the meteorological conditions. About 80 % of NO3--N and NH4+-N (0.40 and 0.47 kg ha-1 month-1) from rain and fog were retained in the P. pumila canopy, and contributions from fog were twice those from rain. Considerable amounts of K+, Mg2+, and Ca2+ ions (0.97, 0.13, and 0.13 kg ha-1 month-1) were leached out from the canopy to the soil as throughfall. The leaching did not increase with rainfall, but increased as the duration of the fog and dew increased.

DOI： 10.1657/AAAR0013-126

Other Link： http://www.bioone.org/doi/10.1657/AAAR0013-126

Repository Public URL： http://hdl.handle.net/2324/1956688

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

Language：English   Publishing type：Research paper (scientific journal)  

Little research has examined whether forests reduce stream water eutrophication in agricultural areas during spring snowmelt　periods. This study evaluated the role of forests in ameliorating deteriorated stream water quality in agricultural areas, including pasture, during snowmelt periods. Temporal variation in stream water quality at a mixed land-use basin (565 ha: pasture 13%, forestry 87%), northern Japan, was monitored for 7 years. Synoptic stream water sampling was also conducted at 16 sites across a wide range of forest and agricultural areas in a basin (18.3 km2) in spring, summer and fall. Atmospheric nitrogen (N) and phosphorus (P) deposition were measured for 4 years. The results showed that concentration pulses of nitrate, organic N and total
P in stream water were observed when discharge increased during spring snowmelt. Their concentrations were high when silicate concentrations were low, suggesting surface water exported from pasture largely contributed to stream water pollution during snowmelt. Atmospheric N and P deposition (4.1 kgNha-1 y-1; 0.09 kg P ha-1 y-1, respectively) was too low to affect the background concentrations of N and P in streams from forested areas. Reduction of eutrophication caused by nutrients from pasture was mainly due to dilution by water containing low concentrations of N and P exported from forested areas, whereas instream reduction was not a dominant process. Results indicate that forests have a limited capacity to reduce the concentration
pulses of N and P in stream water during snowmelt in this study basin.

DOI： 10.1002/hyp.10189

Other Link： http://onlinelibrary.wiley.com/doi/10.1002/hyp.10189/abstract

Language：English   Publishing type：Research paper (scientific journal)  

We determined whether the apparent (M/Fl) sex ratio (male ramets/flowering ramets) and apparent reproductive ramet ratio (Fl/Li ratio; flowering ramets/living ramets) in 15 Myrica gale var. tomentosa populations varied with dissolved total nitrogen, dissolved total phosphorus, potassium, magnesium, calcium, or pH in the soil water. Our aim was to define the environmental factors affecting the M/Fl sex ratio and Fl/Li ratio of the populations. We also examined the habitat conditions of these populations by analyzing soil water chemistry and water dynamics. In 2007, 3 of the 15 populations had no females. The remaining 12 had significantly male-biased (M/Fl sex ratio = 0.59–0.97). Although we could not explain the absence of females by the current potassium levels alone, as potassium increased, so did the M/Fl sex ratio. As nitrogen increased and potassium decreased, Fl/Li ratio decreased. Our soil water chemistry analyses suggested that the potassium supply by soil surface erosion from flooding and the inflow of anthropogenic nitrogen were the important factors influencing the M/Fl sex ratio and Fl/Li ratio. Nitrogen management would be important in one of the endangered populations where inflow of nitrogen was the highest among 15 habitats.

DOI： 10.1007/s10265-012-0481-y

Other Link： http://link.springer.com/article/10.1007%2Fs10265-012-0481-y

Language：English   Publishing type：Research paper (scientific journal)  

To investigate the direct physiological effects of CNU (canopy nitrogen uptake), three mist solutions (control, N1, and N2 with 0.03, 13.1, and 32.7 kg NH4+-N·ha–1, respectively) were sprayed on Japanese red pine (Pinus densiflora Sieb. et Zucc.) seedlings three times a week for three months. Waterproof sheets protected the surface soil during misting to avoid adding N to the soil. The results show N mist treatments to foliage increased needle N availability in proportion to N dose, which was large enough to cause greater N and chlorophyll content in the needles. This suggests that N is rapidly absorbed, is directly assimilated by the needles, and is used in photosynthesis. These increases resulted in higher maximum net CO2 assimilation rates (Amax) and maximum quantum yield of PSII photochemistry (Fv/Fm) of pine seedlings and subsequently increased bud and root biomass. Increased root biomass reduced the sensitivity of the shoot-to-root ratio to increased N availability in the foliage. In conclusion, our study supported the idea that CNU should be taken into consideration when evaluating the impacts of elevated atmospheric N deposition on forest C sequestration and biomass allocation.

DOI： 10.1139/x2012-091

Other Link： http://www.nrcresearchpress.com/doi/abs/10.1139/x2012-091?journalCode=cjfr&#.UHt638UxqBk

Language：English   Publishing type：Research paper (scientific journal)  

This study evaluated whether nitrogen (N) saturated upland forests can degrade downstream water quality in the Tatara River Basin, northern Kyushu, western Japan. Our hypothesis is that elevated atmospheric N deposition degrades downstream water quality in a watershed containing N-saturated forests because a considerable amount of atmospherically deposited N passes into the streams without being retained. Synoptic stream water samplings were conducted at 23 sites across a wide range of land-use categories in the basin over 1 year. A long-term temporal analysis of downstream water quality over the last 30 years (1977–2007) was conducted and compared with long-term trends in related factors such as urban/agricultural activity, sewage wastewater treatment, atmospheric N deposition, and forest condition. The results showed that atmospherically deposited N to N-saturated forests can be a large enough non-point source of N leaving the watershed to impact downstream water quality. This was highlighted by the reduction in pollutant exports derived from urban/agricultural activities, an increase in atmospheric N deposition, and the maturation of coniferous plantation forests in the past 30 years. These have led to reductions in total phosphorus and organic nitrogen concentrations in downstream water, whereas downstream nitrate (NO3 −) concentrations increased over the last 30 years. The consequent increase in the downstream N:P ratio indicated P limitation. Reducing the NO3 − exports from N-saturated upland forests is suggested as a strategy to improve regional downstream NO3 − pollution, but involves intercontinental-scale action in reducing atmospheric N emissions.

DOI： 10.1007/s10021-011-9505-z

Other Link： http://link.springer.com/article/10.1007%2Fs10021-011-9505-z

Language：English   Publishing type：Research paper (scientific journal)  

The importance of fog precipitation in the alpine hydrological processes of Pinus pumila canopy was evaluated on Mt. Tateyama, central Japan. We observed rain and fog precipitation, throughfall, and wind direction and velocity at Jodo-daira (36.566°N, 137.606°E, 2840 m a.s.l.) for 3 years. During the snow-free period (August and September), mean monthly rain and fog precipitation was 0.45 mm h–1 and 0.14 mm h–1, respectively. The mean rainfall interception by P. pumila canopy was about 48%, which is higher than that of other forest canopies at lower altitudes. During rainfall, the dense canopy intercepts rain and the water evaporates from the needle surfaces. On the other hand, the canopy captured fog precipitation even in the absence of rainfall. The amount of throughfall increased with increasing fog deposition. Using δ18O and δD analysis, the mean contribution of fog water to the throughfall was estimated at approximately 35%, consistent with the result from direct measurement. These results indicate that P. pumila should have a significant influence on the local hydrological processes of the high mountain ecosystem. The large contribution of fog precipitation can be attributed to the high wind velocity and humidity of the Japan Alps.

DOI： 10.1657/1938-4246-44.1.143

Other Link： https://doi.org/10.1657/1938-4246-44.1.143

Repository Public URL： http://hdl.handle.net/2324/1956652

Language：English   Publishing type：Research paper (scientific journal)  

In long-term forest monitoring, tree crown condition has been visually rated to diagnose tree vigor and forest condition. However, visual estimates are subjective. A semiautomatic image analysis system, called CROCO, was developed to estimate crown condition quantitatively. CROCO calculates a DSO value which decrease with increasing crown transparency.
• Aims
This study aims to verify visual estimates objectively using CROCO and to assess characteristics of visual estimates and DSO values by comparing the effectiveness as indicators of radial growth.
• Methods
Crown condition of Abies mariesii was visually rated using a vitality index, and DSO values of the same trees were calculated.
• Results
When the top of the tree was intact, the trees with a higher vitality index showed a significantly higher DSO. Vitality index showed the strongest relationship with DBH increment for 8 years. DSO had a significant relationship with DBH increment by adding information of the crown top condition.
• Conclusion
Analysis of tree crown images is effective to verify visual estimates. Vitality index is a synthetic index involving factors affecting radial growth. DSO could be utilized similarly to vitality index, as an indicator of radial growth, by addition of information on crown size and/or shape.

DOI： 10.1007/s13595-011-0132-9

Other Link： http://www.springerlink.com/content/n731u4042kl03246/

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/10934529.2011.584505

Language：Japanese   Publishing type：Research paper (scientific journal)  

Influence of the load of long-range transported air pollutants on forest ecosystem: some examples in the Yakushima Island and Mt. Tateyama in Japan
Atsushi Kume, Koichi Watanabe, Osamu Nagafuchi, Hideharu Honoki

Repository Public URL： http://hdl.handle.net/2324/1961287

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10265-010-0346-1

Other Link： http://dx.doi.org/10.1007/s10265-010-0346-1

Language：Japanese   Publishing type：Research paper (scientific journal)  

Lichens of Ashoro Research Forest，Kyushu University -LSJ Field Excursion 2009
Yoshihito Ohmura，Shunji Takeshita & Atsushi Kume (ed.)

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

Tree species composition according to different slope direction and position on the slope in the cool temperate natural deciduous forests and larch plantations of Ashoro Research Forest.
Yuka Maeda，Takuo Hishi，Naoaki Tashiro，Tetsuya Mabuchi，Sachiko Inoue，Kei’ichiro Cho，Kohei Yamauchi，Taketo Ogata，Atsushi Kume

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11284-009-0647-9

Other Link： http://dx.doi.org/10.1007/s11284-009-0647-9

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11284-008-0574-1

Other Link： http://dx.doi.org/10.1007/s11284-008-0574-1

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11284-008-0557-2

Other Link： http://dx.doi.org/10.1007/s11284-008-0557-2

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/hyp.7264

Other Link： http://dx.doi.org/10.1002/hyp.7264

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.polar.2008.04.001

Other Link： http://dx.doi.org/10.1016/j.polar.2008.04.001

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.agrformet.2007.04.014

Other Link： http://dx.doi.org/10.1016/j.agrformet.2007.04.014

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10310-006-0250-7

Other Link： http://www.springerlink.com/content/uu757l7kx2w12764/

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11284-006-0151-4

Other Link： http://www.springerlink.com/content/2p78n3367065977p/

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10265-006-0265-3

Other Link： http://www.springerlink.com/content/f8j3l47423826r17/

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Other Link： http://www.scopus.com/scopus/record/display.url?view=basic&origin=resultslist&eid=2-s2.0-31544477207&sort=plf-f&src=s&nlo=&nlr=&nls=&imp=t&sid=4zziSH8uJm2cU9i4pVNrCYl%3a40&sot=br&sdt=a&sl=36&s=SOURCE-ID%2816556%29+AND+PUBYEAR+IS+2005&relpos=25

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10265-005-0211-9

Other Link： http://www.springerlink.com/content/nn6l544085784170/

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10310-004-0123-x

Other Link： http://www.springerlink.com/content/l03232468300p027

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1093/treephys/25.2.221

Other Link： http://treephys.oxfordjournals.org/cgi/content/short/25/2/221

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2151/jmsj.82.1589

Other Link： https://doi.org/10.2151/jmsj.82.1589

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/hyp.5746

Other Link： http://dx.doi.org/10.1002/hyp.5746

Language：English   Publishing type：Research paper (scientific journal)  

DOI： http://dx.doi.org/10.1657/1523-0430(2004)036[0395:SMBRRA]2.0.CO;2

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1023/B:WATE.0000015343.24509.19

Other Link： http://www.springerlink.com/content/u11r54831v6445qt/

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effects of the differences in canopy structure on the distribution of throughfall -a comparison of throughfall characteristics between the coniferous forest and the broad-leaved forest-.
Sato, Y., A. Kume, K. Otsuki & S. Ogawa
Journal of Japan Society of Hydrology and Water Resources 16 605-617 (2003)

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1657/1523-0430(2003)035[0377:CIDIDG]2.0.CO;2

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/S0929-1393(02)00158-0

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OSAMU NAGAFUCHI, SUGURU AKUNE, KAZUHISA YOSHIMURA, ATSUSHI KUME, SENICHI EBISE, KENSHI TETSUKA (2003)
Effect of acid deposition on the water quality formation of mountainous streams in the western part of Yakushima Island, a world natural heritage site. Journal of Japan Society on Water Environment 26 159-166.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/S0269-7491(01)00289-5

Other Link： http://www.sciencedirect.com/science/article/pii/S0269749101002895

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1046/j.0028-646x.2001.00236.x

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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DOI： 10.1016/S0269-7491(00)00091-9

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/PL00013969

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/PL00013942

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DOI： 10.1007/PL00009772

Other Link： http://link.springer.com/article/10.1007%2FPL00009772

Language：English   Publishing type：Research paper (scientific journal)  

Other Link： http://ci.nii.ac.jp/naid/110000035857/

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1751-8369.1998.tb00258.x

Other Link： http://onlinelibrary.wiley.com/doi/10.1111/j.1751-8369.1998.tb00258.x/abstract

Language：English   Publishing type：Research paper (scientific journal)  

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DOI： 10.1007/BF02347687

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Language：Japanese   Book type：Scholarly book

An Introduction to Environmental Biophysics, 2nd Edition

Other Link： http://www.morikita.co.jp/books/book/711

Repository Public URL： http://hdl.handle.net/2324/1001175065

Responsible for pages：ISBN 9784320058125   Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：General book, introductory book for general audience

DOI： 978-4-8299-8299-7107-9

Language：Japanese   Book type：General book, introductory book for general audience

Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：General book, introductory book for general audience

Repository Public URL： http://hdl.handle.net/2324/1001476369

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Repository Public URL： http://hdl.handle.net/2324/1001436292

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Language：Japanese   Book type：General book, introductory book for general audience

Language：Japanese   Book type：General book, introductory book for general audience

Language：Japanese   Book type：Scholarly book

Physiological Plant Ecology: Ecophysiology and Stress Physiology of Functional Groups

Language：Japanese   Book type：Scholarly book

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Let's publish English books!

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Venue：オンライン   Country：Japan  

地球の光環境は，入射日射と大気との相互作用によって，様々な波長成分の光から構成されている．このような光環境に対して植物はフィトクロムやフォトトロピン，クリプトクロム，UVR8，あるいは，クロロフィルa, bなどの色素を光受容体として利用し，気孔開閉や形態形成など様々な成長調節を行っている．利用される波長は主にUV-B，青色光と赤色光，そして近赤外波長FRであり，同一波長帯に複数の光受容体が存在する．その理由を明らかにするために地上の直達・散乱日射スペクトルデータを解析し，光受容体が得られる情報を検証した．その結果，青色光は晴天日の散乱放射や日陰環境，赤色光は直達日射に対応しており，正確な陸上の光環境のセンシングには赤色光と青色光の利用が不可欠であった．赤色光センサと青色光センサを持つことによって，植物は日陰における光合成有効放射強度を正確に判断することが可能となり，赤色センサとFRセンサを持つことによって，他の植物の葉に覆われている程度を正確に評価することが可能となる．青色光と赤色光に対する気孔の光応答，赤色光とFRに対する成長や発芽の光応答は，実際の野外の入射放射特性とよく対応している．一方，UVは拡散成分が卓越しており，異なった受光システムが必要であった．陸上植物の光受容体を進化させた主要な環境要因は，大気分子，オゾン層，大気水蒸気，植物の相互被陰であり，晴天日の光環境への適応が重要である．

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

イネは出穂から完熟にかけて穂色が緑色から黄色に変化するが，このような色の変化は，頴果表面の吸収・反射する波長帯の変化を示し，イネ科植物に広くみられる性質である．穂の温度は，主に周囲の気温と頴果の放射吸収によって決まるため，頴果色の変化は穂の温度に影響を与えると考えられる．本研究ではイネ頴果の色の変化が，穂温に及ぼす影響を定量的に評価した．2019年に11品種のイネの穂を，出穂から完熟に至るまで1週間間隔でサンプリングし，頴果の分光反射率とクロロフィル及びカロテノイドの量を測定した．そして，精密に測定された日射スペクトルを利用し，頴果の分光反射率との関係を調べた．その結果，出穂から完熟にかけて青色光域と赤色光域で反射率が上昇し，特に赤色光域の反射率が高まることが明らかになった．この変化はクロロフィルの分解によって生じ，カロテノイドによる着色ではなかった．晴天時の日射スペクトルを用いて吸収放射を計算すると，完熟期には，出穂直後と比較して，吸収する日射エネルギーが有意に減少することが示された．穂温推定モデル（吉本ら，2011）で穂温を計算すると，蒸散速度が低下する完熟時でも，反射率の上昇により穂温の上昇が0.5℃程度抑えられていることが示された．蒸散が限られる完熟時には日射エネルギーの吸収を抑えることが重要だと考えられ，穂色の変化は，穂温を調節する役割を担っていると判断された．

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

国際宇宙ステーションや小型衛星上における植物培養技術の開発においては，植物の成長状況を把握するための自動観測システムが必要とされる．植物の成長を非破壊的かつ自動的に評価する方法として，通常のRGB画像による評価に加えて分光情報を利用した近接リモートセンシングの適用が考えられる．宇宙空間においてはシステムの小型軽量化はもっとも重要な要素であり，小型マルチスペクトルセンサシステムが有望である．本研究では，マルチウェルプレート（MP）のような小さな培養空間で培養したヒメツリガネゴケ（Physcomitrella patens）における，基本的な成長パラメータと分光特性を解析し，実用的な観測システムへの応用について検討した．黒色の96穴MPを利用してヒメツリガネゴケを24時間明期で20℃のグロースチャンバー内で培養し，培養開始 3～10 週目にかけてハイパースペクトルセンサ（HSS）で撮影すると共に，群落内のコケ成長に関わるパラメータ量として茎葉体数（茎数），茎葉体の合計長さ（総茎長），茎葉体の葉数の合計（総葉数），および光合成色素量を測定した．HSS画像から，675 nmと 878 nmの反射率からコケ群落領域を抽出し，領域の平均反射スペクトルを求め，成長パラメータとの関係を解析した．その結果，クロロフィル含量について高い相関を持つ波長域の組み合わせが選択できた．また，ほかのパラメータについても推定できる可能性が示された．

Event date： 2020.8

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：オンライン   Country：Japan  

Today, the percentage of researchers whose second language is English is higher than that of researchers whose first language is English. As a result, a new language, SCIENTIFIC ENGLISH, is emerging. In this language system, complicated phrases and syntax are excluded, and simple and easy-to-understand expressions are selected. This webinar will cover practical techniques for creating English-language papers that can be submitted to international journals for researchers whose second language is English. Among researchers whose second language is English, there are researchers whose first scientific language is English and researchers whose second scientific language is English. For example, Japanese scientists often go through the process of learning and systematizing science in Japanese and translating it into English. Today, the ability of web-based translation systems has been greatly improved, and machine translation of SCIENTIFIC ENGLISH has reached a practical level. At this time, writing in the first language that is easy to translate is the key to improving the accuracy of machine translation. By asking a skilled human English editor to review such drafts, the manuscript writing efficiency and quality can be improved.

Event date： 2020.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：誌面発表   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：名古屋大学東山キャンパス全学教育棟・豊田講堂   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：誌面発表   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Other Link： http://id.nii.ac.jp/1696/00046409/

Event date： 2020.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Other Link： http://id.nii.ac.jp/1696/00046410/

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2019.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋大学東山キャンパス   Country：Japan  

We investigated the density of very fine roots (x < 0.5 mm in diameter) and the soil water content distribution in shallow soil depth (0–30 cm soil depths) along a slope with two different vegetation covers, Cryptomeria japonica, and Chamaecyparis obtusa. The results suggested that high densities of very fine root biomass and length around Ch. obtusa individual trees caused the water shortage in the soil surface layer; while the high soil water content around Cr. japonica individual trees seemed to be caused by other soil properties such as high soil hydraulic conductivity. We also found soil water content increased significantly around Ch. obtusa individual stumps in 5–30 cm depth, after one-year logging, while soil water content had an insignificant increase around Cr. japonica individual stumps in 0–30 cm depth than that corresponding tree species. These findings show dense very fine roots might impact on soil hydrological processes in Ch. obtusa plantations.

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉市文化センター   Country：Japan  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉市文化センター   Country：Japan  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学川内北キャンパス   Country：Japan  

植物は光合成によって二酸化炭素を吸収して酸素を供給するため，人間の宇宙滞在にとって重要である．中でも小型なコケ植物は，宇宙環境の限られた空間で栽培する上で有利であり，宇宙における様々な環境の違いが及ぼす影響を評価するのにも適している．すでに，ヒメツリガネゴケを過重力条件下で栽培すると，葉緑体が肥大化し，光合成速度や成長量が増加することが報告されている．成長量が増加することから，過重力応答には細胞増殖が関わっていることが予想される．そこで本研究では，過重力下でヒメツリガネゴケの重力応答メカニズムを探ることを目的とし，材料として，野生型および細胞周期制御に関わるサイクリン依存性キナーゼAの変異体cdka dkoを用いた．変異体と野生型とを富山大学の過重力栽培装置を用いて，1Gおよび10Gで，BCD培地，栽培温度23.5～27.1 ℃，光強度63μmol m–2 s–1 で8週間栽培した．栽培後，成長評価，形態観察，ガス交換測定による光合成速度測定，炭素安定同位体測定を行った．cdka dkoでは10G条件下で野生型とは異なる成長を示した．本発表では10G条件下で栽培した野生型，変異体を比較し，過重力応答との関係を考察する．

Event date： 2019.7

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Country：Japan  

Sustainable Journal Development: Collaborative publication of ecology journals in Japan

Event date： 2019.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：新潟コンベンションセンター　朱鷺メッセ   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟コンベンションセンター　朱鷺メッセ   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟コンベンションセンター　朱鷺メッセ   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：ポートアイランド（神戸国際会議場・神戸国際展示場2号館）   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：ポートアイランド（神戸国際会議場・神戸国際展示場2号館）   Country：Japan  

Event date： 2019.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Mechanical Properties of the Physcomitrella patens Gametophores Grown at 10 G

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/909649

Event date： 2018.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2018.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：琉球大学   Country：Japan  

Event date： 2018.10

Language：English   Presentation type：Oral presentation (general)  

Venue：琉球大学   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学片平キャンパス   Country：Japan  

クロロフィル（Chl）は植物にとって重要な色素であり，光を吸収して電子を放出することで光合成を駆動している．海洋の光合成生物は，Chl a，b，c，d，f　やフィコビリンなどのさまざまな光合成色素を利用しているが，陸上植物が利用しているのはChl aとbだけである．この2つのChlは光化学系複合体を形成するが，明るい環境ではChl bの割合が低下する．また，陸上植物の光化学系反応中心にはChl bは含まれていない．そのため，陸上植物のChl構成の均一性は，入射日射特性と関係があることが予想されるが，これまでその理由は明らかではなかった．そこで，各Chlの吸収スペクトルと日射スペクトルの関係を，エネルギーと光量子の観点から分光日射の実測データとの相関解析によって考察した．その結果，日射スペクトルに対してChl bはChl ａと相補的に働き，強い光から弱い光まで効果的に利用することができるのに対して，水中の生物のみが利用するChl cやd，あるいはフィコビリン類は，陸上の放射環境にはうまく適応していないことが示唆された。すなわち，陸上植物は，地上の光環境に適したChl aとbの組み合わせだけを利用するようになったと考えられる．この結果は，入射放射スペクトルに加えて，そのエネルギー強度が光合成に利用される色素の重要な選択圧となっており，惑星の置かれた環境によって，そこに生育する生物の色が大きく変化する可能性を示唆している．たとえば，太陽から地球の距離が現在よりも離れていれば，光合成生物の色はより暗くなっていくのに対して，より近づけば，光化学系からChl bが排除され，反応中心を保護するためのカロテノイドなどのフィルター色素の割合が高まることが予想される．また，宇宙船内などの人工光源環境下や新しい居住惑星環境では，それに応じた色素を持った光合成生物の開発が望まれるだろう．

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学片平キャンパス   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学片平キャンパス   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学片平キャンパス   Country：Japan  

コケ植物は幅広い環境適応能力を持ち、陸上植物として比較的小型で単純な組織を持ち培養も簡単なことから、宇宙実験材料として適していると考えられる。コケ植物の宇宙環境利用に向けて、まず地上において宇宙船内のさまざまな環境に対する応答を知ることは重要である。きぼう船内は微小重力環境であることはもとより、二酸化炭素（CO2）濃度も3000〜5000 ppmと地上のおよそ10倍となっている。そこで宇宙実験におけるヒメツリガネゴケ茎葉体の成長変化を評価するため、地上において重力とCO2環境の変化が成長に与える影響を調べている。我々は先に回転中心に光源を有する遠心装置を独自に開発し、長期間の連続光照射かつ過重力下での栽培を実現した。これまでの研究で最大2ヶ月間の過重力栽培（10 G程度まで）により1 G条件下に比べ植物体質量の増加、仮根の伸長、葉緑体の肥大、光合成活性の増加などが観察された。RNA-sequencingによる遺伝子発現解析では、122個と比較的少ない有意な発現変動遺伝子を検出した。GO解析により8個の転写因子が有意に変動していることが分かったが、このうち7個がいずれもAP2/ERFファミリーに属しており、これら転写因子が重力変化に対する応答に重要ではないかと考え解析を進めている。またCO2の影響に関しては、きぼう船内を想定した3000〜5000 ppmのCO2環境下での栽培により植物体数の増加、仮根の伸長が促進されていることを見出した。実際の宇宙船内においては植物体の成長に対して高CO2環境の影響が微小重力による影響と複合して観察されることが予想される。本発表では形態、生理学的な比較から高CO2環境が成長に及ぼす影響を考察する予定である。

Event date： 2018.9 - 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学川内北キャンパス   Country：Japan  

植物が光環境をどのように「感じて」「考えて」いるかを人間が直接理解することは難しい．外部環境変化に対する植物の反応を予測するためには，植物が利用しているであろう野外放射環境の把握という観点が必要である．陸上植物の光受容体としては，フィトクロムやフォトトロピン，クリプトクロムなどがある．また，クロロフィルa, bや他の色素も光検知色素として利用できる可能性がある．これらの光受容体を利用して植物が環境センシングする場合，単なる明るさ（エネルギー量）ではなく，ある特定波長同士の光量子数比率や方向性も重要な情報となり，近赤外域まで含めた環境中の方向性ハイパースペクトル情報が重要となる．晴天日の空の色と曇天日の空の色は異なるが，放射スペクトル的には1日の時間や標高や緯度によっても変化する．さらに，直達放射と散乱放射の色の違いは，放射スペクトル的には大きく異なる．そこで，野外の生物環境の放射環境を評価するために，直達・散乱日射スペクトルデータを元に，植物の光受容体が日射スペクトルから利用可能な情報を検証した．その結果，植物は直達日射よりかはむしろ散乱日射情報を利用している可能性が高いことが示唆された.

Event date： 2018.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：広島国際会議場   Country：Japan  

陸上植物の祖先は水中から陸上に進出する過程で重力に適応した，という表現を見かけることがある．しかし，地球の生物にとって，重力(加速度）は最も変動しにくい環境要因の1つであり，地上でも水中でも重力はほぼ1Gである．すなわち，陸上では重力によって生じる「浮力」が小さくなる．重力加速度と体積が同じ場合，浮力は物体のまわりにある水や大気（流体）の密度によって決まり，周囲の流体の密度が高いほど強い浮力が生じる。そのため，流体よりも密度の低い物体は，浮力によって重力とは反対方向に浮き上がる．たとえば，多くの海藻は気胞を持ち，浮力，すなわち重力を利用して水中で立体構造を形成する．一方，陸上では浮力の直接的な影響は非常に小さいため，立体構造の構築においては，一定の「重さ」を前提とした形態形成が行われている．陸上植物の形態形成では，個体成長においてアロメトリー則の一定性が幅広く成立していることが知られており，水通導と機械的強度の両方を満たすように，植物体全体で伸長成長と肥大成長が調節されている．細胞内の現象にも浮力は大きな影響を与えている。たとえば，密度が高くて「重い」デンプン粒が沈んだ方向が下であると細胞は判断するが，沈む速度は重力によって決まる．また，浮力は原形質流動にも影響している．地球の生物は1G環境に特化して適応しているが，異なった重力環境で解析することでその機構が明らかになる．

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島国際会議場   Country：Japan  

植物は光合成によって二酸化炭素を消費して酸素を供給するため，人間の宇宙環境への滞在に重要である．比較的小型なコケ植物は，宇宙環境の限られた空間で植物栽培する上で有利である．2019年に，国際宇宙ステーション（ISS）で微小重力実験を予定している．そこで，本研究ではISSでの微小重力実験下におけるヒメツリガネゴケの栽培環境を検討することを目的とした．ISSでは2ヶ月という限られた期間でヒメツリガネゴケを適切に成長させる必要があり，そのためには培地と栽培密度が重要である．まずBCD培地およびBCDAT培地で48日間ヒメツリガネゴケを栽培し，クロロフィル量，乾燥重量，光合成速度を比較した．そしてISSで使用する容器で3×4列および4×6列の密度で茎葉体切片を8週間栽培し，光合成速度を比較した．その結果，BCDAT培地の方が植物体のバイオマスとクロロフィル量が多く，一方，2種類の培地間で光合成速度に有意な差はなかった．また，3×4および4×6の密度で栽培したヒメツリガネゴケの光合成速度に有意な差はなかったが，4×6の密度で栽培した方がバイオマスは大きくなった．現在，コケ植物の重力応答のメカニズムを探るために過重力下で栽培したヒメツリガネゴケの変異体の解析も進めている．細胞周期制御に関わるサイクリン依存性キナーゼAの変異体では，野生型とは異なる成長を示した．その結果も併せて報告する．

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島国際会議場   Country：Japan  

宇宙での微小重力実験や遠心機を利用した過重力実験から，植物は重力屈性だけでなく抗重力反応と呼ばれる重力応答を示すことが分かってきた．維管束植物では，重力に依存して茎が太く短くなり，厚く頑強な細胞壁が形成されることが分かってきている．一方，原始的な陸上植物であるコケ植物の抗重力反応については，まだ不明な点が多く残されている．我々はこれまで，コケのモデル植物であるヒメツリガネゴケ（Physcomitrella patens）の茎葉体を用いて，過重力実験を行ってきた．その結果，過重力処理により茎が太く短くなるという維管束植物と同様の形態変化を示すものの，細胞壁の厚さはむしろ薄くなっており，維管束植物とは逆の反応を示した．そこで本研究では，ヒメツリガネゴケの茎葉体の力学的強度が過重力処理により実際に増加するのかどうかを調べた．10Gで25日間栽培した茎葉体を用いて，3点曲げ試験による力学的特性の解析を行った結果，曲げ硬さ及び座屈安全率が10G処理区で有意に高くなり，茎葉体の構造的強度が過重力環境下で実際に増加することが確かめられた．一方，茎葉体の弾性係数については1Gと10Gで有意な差は見られなかった．以上の結果から，ヒメツリガネゴケの茎葉体は，おそらく細胞壁の強度ではなく，茎を太くするなど，形態を変化させることで力学的強度を増加させているということが示唆された．

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島国際会議場   Country：Japan  

光合成の場である葉緑体は，周囲の光環境に応じて，細胞内の局在を変える．強光の下では，葉緑体は光を避ける為に，光と平行な細胞壁に沿って局在する（逃避反応）．それに対して，弱光下では，葉緑体は光の照射される場所に集まる（集合反応）．モデル植物において，逃避反応を欠く植物は強光下で生育することができず，集合反応を欠く植物は弱光下での生育が低下することから生存競争に勝てないと考えられ，葉緑体光定位運動は植物の生育において重要な役割を担う．一方，野外で生育する植物における葉緑体光定位運動の運動性は様々であり，その運動性は生育環境によって異なる．葉緑体光定位運動の運動性は，光環境がダイナミックに変化する林床に生育する植物にとって特に重要であると考えられるが，限られた知見しかない．林床の光環境は，林を構成する植物種によって大きく異なるため，本研究では，植生や気候帯の異なる日本各地の林床に生育する植物の葉緑体光定位運動を調べた．その結果，葉緑体光定位運動の運動性が高い植物種と運動性の低い植物種が存在することが分かった．また，葉緑体光定位運動の運動性の高い種の多くは，柵状組織細胞が四角形に近い細胞の形状を示していたのに対し，運動性の低い種の多くでは，細胞が逆円錐形の形状を示していた．本発表では，これらの知見に加えて，逆円錐形の柵状組織細胞の生理学的意義についても議論する．

Event date： 2018.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：広島国際会議場   Country：Japan  

現在の陸上植物が見せる形態や成長様式は，進化の中で植物が陸上での1 G環境に適応してきた結果である．植物は水中から陸上に進出し，その過程で浮力を失い重力に逆らい成長するため，リグニン合成能力を獲得し，頑丈な茎・幹や根を進化させてきた（抗重力反応）．一方で重力は地上において極めて安定な環境要因であり，その影響は，光，温度，水など変動が大きい環境要因と比べあまり研究されておらず，重力応答を調べるための適切な実験環境も少ない．　そこで私たちは，長期間植物を培養できる過重力栽培装置を開発した．また栽培スペースが小さくてすむ小型の陸上植物，コケ植物に着目し重力が与える影響を調べてきた．その結果ヒメツリガネゴケを長期間（1～2ヶ月）過重力栽培（1.1～10G）することで，予想外にも植物個体全体の成長速度が増加することを見出した．また地上部と地下部の成長バランスが変化し，とくに仮根の成長が促進されること，さらに葉緑体が大きくなり，光合成速度も高まること等の新たな知見を得た．また特定の転写因子群が過重力環境で有意に発現変動することも見出した．このように明瞭な重力応答を示すヒメツリガネゴケは，植物への重力影響を評価する上で優れた実験系であると考えられる．コケ植物は宇宙ステーションなど限られた空間での実験にも有利であり，コケ植物を用いた宇宙環境利用計画（スペース・モス）についても議論したい．

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2018.4

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Nagoya University Higashiyama Campus   Country：Japan  

Event date： 2018.4

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Nagoya University Higashiyama Campus   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：高知県高知大学朝倉キャンパス   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮城県仙台市東北大学青葉山新キャンパス   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌コンベンションセンター   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌コンベンションセンター   Country：Japan  

Event date： 2018.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/873926

Event date： 2018.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/873899

Event date： 2018.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/873896

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：総合地球環境学研究所（京都）   Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：総合地球環境学研究所（京都）   Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：すかっとランド九頭竜（福井市）   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2017.10 - 2017.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Hokkaido University   Country：Japan  

Event date： 2017.10 - 2017.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Hokkaido University   Country：Japan  

Event date： 2017.10 - 2017.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Hokkaido University   Country：Japan  

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：群馬会館   Country：Japan  

地球の陸上植物の葉の吸収スペクトルは，光合成有効放射波長域（PAR；400～700nm）で高い吸収率を示すが，近赤外放射波長域（NIR；750～1300nm）では非常に低い値を示す。このような特性は，リモートセンシングで陸上の植生割合を示すための植生指数（NDVI）などにも利用されており，高い普遍性を示す。その一方で，葉以外の器官はNIRを吸収し，ほぼ不透明である。また，陸上動物ではNIRの特異的な吸収率減少は見られず，爬虫類や昆虫類ではむしろ高い吸収率を示す場合がある。葉のNIR透過には，葉面のエネルギー吸収を抑制し，特に葉温や蒸散量を抑制する効果があるため，NIR吸収率の極端な低さ（落葉広葉樹や草本植物ではほぼゼロ！）は，何らかの選択圧の結果である可能性を示唆する。そこで，植物の葉のNIR吸収特性について，針葉樹，広葉樹，広葉草本，イネ科植物の21種類について解析し，PAR吸収特性との関係を解析した。その結果，針葉樹種とそれ以外の植物群で葉のNIR吸収特性が大きく異なっており，針葉樹種では，PARの吸収率の増加はNIRの吸収率のより急激な増加を伴っていた。この結果は，たとえば，針葉樹の黒い森（Schwarzwald）は，PARだけでなく，NIRについても「黒く」，寒冷な環境において葉温をより高く維持することに適している可能性が示唆された。寒冷地のコケ植物や地衣類の吸収特性を含めて考えると，地球の陸上植物のNIR吸収率は，気温の高さと日射の強さを反映している可能性があり，惑星環境に応じて変化しうることが推測された。

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：群馬会館   Country：Japan  

コケ植物は幅広い環境適応能力を持ち、陸上植物として比較的小型で単純な組織を持ち培養も簡単なことから、宇宙実験材料として適していると考えられる。そこで我々はコケ植物ヒメツリガネゴケを用いて宇宙環境がコケ植物の成長に及ぼす影響を検証し、それが他の陸上植物の宇宙環境における成長評価にも役立つものと考え研究を開始した。植物の宇宙環境利用に向けて、まず地上においてさまざまな宇宙環境変動に対する応答を知ることは重要である。宇宙では多くの環境因子が地上とは異なるが、本研究では重力と二酸化炭素（CO2）がヒメツリガネゴケの成長に与える影響を調べた。我々は回転中心に光源を有する遠心装置を独自に開発し、長期間の連続光かつ過重力下での栽培を実現した。これにより長時間の比較的弱い過重力に対する植物の応答を知ることができる。これまでの研究で最大2ヶ月間の過重力栽培（10 G程度まで）により1 G条件下に比べ植物体重量の増加、仮根の伸長、葉緑体の肥大、光合成活性の増加などが観察された。現在、次世代シーケンサーによるRNA-sequencingを実施し、過重力環境下における発現遺伝子の変動を解析している。これらの結果から比較的弱い過重力から微小重力までの変化が植物の成長に与える影響について考察する。またCO2の影響に関しては、きぼう船内を想定した3000〜5000 ppm CO2環境下での栽培により植物体の増加、仮根の伸長が促進されていることを見出した。このことから宇宙実験における植物体の成長にはきぼう船内のCO2環境による影響を合わせて考える必要がある。以上より過重力実験から推定される微小重力による影響と船内CO2環境の複合的な影響について考察する。

Event date： 2017.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：群馬会館   Country：Japan  

重力は、陸上植物にとって常に安定した刺激として存在し、植物の形態形成や成長、環境応答に不可欠な役割を果たしている。植物は水中から陸上に進出し、その過程で重力に逆らい大きく成長するため、リグニン合成能力を獲得し、体に機械的強度を与える支持組織を発達させ、頑丈な茎・幹や根を進化させてきた。この基盤が重力形態形成であり、抗重力反応である。現在の陸上植物で見られる、地上部と地下部の重量比や形態バランス、葉の内部構造、茎の肥大成長、リグニンの合成などは、5億年近い陸上植物進化の過程で水中での浮力を失い、陸上で1 Gという重力環境に適応してきた結果である。
このように植物の成長、形態などの適応は重力と密接に関係しているものの、地上において重力は極めて安定な環境要因であるため、その影響の検証は、光、温度、水、栄養素など不安定な環境要因と比べてあまり研究されておらず、適当な過重力実験環境もあまりない。重力は遠心力を利用して調節することが可能であるものの、通常の遠心装置では連続光を照射し、長期間栽培することは考慮されていない場合が多い。
そこで私たちは、安定した遠心力を加えながら植物の上方から光を照射し、長期間植物を培養できる過重力植物栽培装置を開発した。また栽培スペースが小さくてすむ小型の陸上植物、コケ植物に着目し長期間の過重力栽培実験を行うことにした。ヒメツリガネゴケは、実験室内での栽培条件が確立されており、また全ゲノム配列が決定され遺伝子データベースが整備されている。ゲノム編集技術など各種遺伝子機能解析技術も開発され、陸上植物の成長や環境応答、進化を研究するための代表的なモデル生物である。
このような特徴を持つヒメツリガネゴケを過重力植物栽培装置において、明条件下、さまざまな過重力ストレス(2.3, 4, 7.1, 10 G)下で長期栽培（1〜2ヶ月程度）したところ、予想外にも1 Gのコントロールに比べ植物個体数が増加し、したがって植物個体全体の成長量も最大約50%増加することを見出した。また地下部の器官である仮根の成長が促進され、その数も増えていた。一方、地上部の茎葉体は、背丈が低く横に太くなっていた。次にこのような成長量の増加がどのような原因により生じているのかを調べるため、成長量に大きな影響を及ぼすと考えられる光合成速度や二酸化炭素コンダクタンスを測定し、また細胞の大きさや数、細胞小器官の形態観察などを行った。その結果、過重力環境の長期栽培により面積当たりおよび乾燥重量当たりの光合成速度がそれぞれ増加しており、二酸化炭素コンダクタンスも増加していることが明らかになった。さらに葉緑体のサイズが1.4倍程度大きくなっており、細胞壁面に接する葉緑体の表面積が増加しているらしいことを見出した。以上の結果より、私たちは、過重力での長期栽培により、葉緑体のサイズが増大し、植物体内への二酸化炭素コンダクタンスが増加し、結果として単位面積当たりの光合成速度が高まり、成長量が増大したのではないかと考えている。現在、1 Gと10 Gの発現遺伝子をゲノムワイドに比較し、その違いを調査している。
本研究により植物が重力の変化に応じてどのように成長や形態を変化させるのか、そのしくみの１つを理解することができるであろう。またこのような過重力環境における成長促進能力は、通常の1 G環境下では潜在しており、本研究によりこのように植物に潜在している成長制御のしくみを新しく明らかにできるものと考えている。また本研究は、地上とは異なる宇宙重力環境で植物がどのように応答し成長するのかを理解し、さらに宇宙環境下で植物の栽培法を考える上でも重要な貢献ができると考えている。

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学 野田キャンパス   Country：Japan  

植物の葉の近赤外域（700～1400nm）の吸収率（αNIR）について，針葉樹，広葉樹，広葉草本，イネ科草本の21種類の葉の分光測定データ（Noda et al. 2013）を利用し，光合成有効放射（400～700nm）の吸収率（αPAR）との関係を解析した。日射の放射エネルギースペクトル（350～1650nm）に対する吸収率（αSolar）は，常緑針葉樹で高く（>0.6），イネ科草本で低かった（＜0.5）。また，常緑樹と落葉樹では，常緑樹のほうが高かった。αPARはイネ科草本以外では0.85～0.95で系統的な差は無かったが，αNIRは針葉樹では高く（＞0.2），広葉樹や草本では低かった（＜0.1）。針葉樹のαNIRはαPARと高い相関があり，αPARの増加に対してαNIR は2倍以上の増加率を示した。これは，葉緑体以外の組織による吸収の影響が大きいことを示唆した。一方，草本植物や落葉樹ではこのような相関は見られなかった。PAR光量子吸収あたりの日射エネルギー吸収を比較すると，針葉樹で大きく（0.28～0.32 J/μmol），落葉樹や草本で小さく，もっとも小さいのはイネ（0.254 J/μmol）であった。これらの結果は，針葉樹以外の植物では，日射からの熱吸収割合が最低値に近づくように収斂しているのに対して，針葉樹種ではむしろ光合成に利用しない放射成分も積極的に吸収している可能性を示唆した。針葉樹は広葉樹よりも「黒色」であり，このような放射吸収特性は高緯度の低温環境ではメリットがあると考えられた。

Event date： 2017.6 - 2017.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Matsue   Country：Japan  

Gravity is a fundamental environmental parameter for plant growth regulation on the terrestrial environment. 1-G is the constant throughout the biosphere of the Earth even under sea, though the effects of buoyancy are quite different. Therefore, it is not easy to distinguish the role of Gravity of the plant growth from other mechanical stresses. The creation of an altered gravity environment is essential for analyzing plant responses to increases in gravity. Hypergravity environments produced by centrifugation have provided a practical experimental system for angiosperms. However, these experiments were often performed under dark conditions with strong hypergravity (>30×g). Such experiments intended to reveal the effects of short and transient stress, rather than continuous stress, and did not include the process of photosynthesis. However, for a long term plant cultivation experiments, dynamic maintenance of gas-exchange process accompanying photosynthesis is one of the important matters in plant cultivation. The transport of gaseous molecules into and out of the leaf is largely driven by buoyancy, and both the force of gravity and the amount of supplied energy are main determinants. We quantified changes in plant growth and photosynthesis in the model plant of mosses, Physcomitrella patens, grown under a hypergravity environment for several 8 weeks using a custom-built centrifuge equipped with a lighting system. We found that the hypergravity treatments increased the growth rates of colonies as well as rhizoid length. In a canopy of P. patens, the area-based photosynthesis rate was increased. These results suggest that changes in gravity are important environmental stimuli to induce changes in plant growth and photosynthesis by P. patens, in which an alteration in chloroplast size is one of the key traits.

Event date： 2017.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

１．はじめに：地球温暖化により、極めて寒冷な環境条件で隔離的に生育する高山植物の展葉、開花、紅葉、落葉などの生物季節（フェノロジー）や分布域の変化が各地で報告されている。また、植物とそれを利用する昆虫や動物種ごとの異なる温度応答により生ずる活動時期のミスマッチなど、高山生態系の気候変動に対する脆弱性が危惧され、モニタリングの重要性が認識されている。多雪を特徴とする日本の高山帯においては積雪や消雪時期が生物の活動にとって重要な要因となる。そこで、消雪と植生フェノロジーを高頻度・高解像度で把握するため、山小屋などに自動撮影デジタルカメラを設置し定点観測を行ってきた。本研究では定点カメラの画像解析から、立山室堂と千畳敷における消雪時期と植生の展葉・紅葉フェノロジーの年変動を検出する。さらに、気象観測データを用いて、フェノロジーや紅葉の色付きと気象要因との関係性を解明することを目的とした。
２．方法：定点カメラにより2009-2016年に北アルプス立山室堂山荘（標高約2450ｍ）から雄山方面を撮影した約18000シーンと、2012-2016年に中央アルプス千畳敷（約2650ｍ）から極楽平方面を撮影した約11000シーンの画像を用いて解析を行った。これらの画像から画素毎に記録されているRGB三原色のデジタルカウント値を抽出し、統計的手法により積雪画素と非積雪画素に判別し、消雪過程を調べた。さらに、画像中に撮影されているナナカマドとダケカンバの画素について、RGBの合計値に対するGとRの割合をそれぞれ緑葉と紅葉の指標値として時系列変化を算出し、展葉や紅葉時期、紅葉の色の鮮やかさを定量的に評価した。
３．結果：立山室堂および千畳敷において、2015-2016年は最近数年間で最も積雪量が少なく気温が高めに推移したため融雪の進行が早く、例年と比較してそれぞれ約22日、38日早い消雪となった。それに伴って2016年は展葉が非常に早く、落葉性植物の生育期間は最長になった。紅葉時期については、例年は8月下旬から9月中旬の平均気温と高い相関を示したが、2016年は気温が高い割りに紅葉が早く、気温だけでは説明できなかった。そこで葉の寿命を考慮して、気温に加えて展葉時期を説明変数とした回帰式により紅葉時期の予測が可能になると考えられた。また2016年は紅葉の色付きが悪い傾向が見られたが、紅葉の色の鮮やかさの年変動には夏期の日射量や秋の最低気温などとの関係が認められた。このような定点カメラを用いた観測により、高山帯における消雪時期や植生フェノロジーを高い時空間解像度で検出し、多時期かつ多地点での客観的な比較が可能になった。今後、定点カメラを多地点で展開し、気象観測データと合わせた解析を進めることにより、気象要因による展葉や紅葉フェノロジーへの影響評価と将来予測が期待される。

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島大学郡元地区   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学早稲田キャンパス   Country：Japan  

植物の性表現は様々であり、雌雄異株植物はそのうち約4％を占める。この雌雄異株植物の性比はしばしば著しく偏り、集団の結実率に負の影響を与えることもある。その至近要因としては、生育地の光・水分・土壌の化学性などの環境要因が関与していると考えられる。メスは一般に、果実を生産するため繁殖コストが大きくなりやすく、ストレス条件下では開花を抑制したり、死亡率が高くなったりして、結果的に集団の性比がオスに偏ることがある。湿地性の雌雄異株植物であるヤチヤナギも、みかけの開花性比がオスに大きく偏る集団が存在し、土壌水中のKイオン濃度が低いほど、メスの割合が減少することが我々の研究から明らかになった。そこで本発表では、植物体内の養分濃度を測定し、集団間変異および性差を示すこと、さらに、養分濃度とみかけの開花性比との関係やメスの花序数に与える影響を明らかにした。調査地として、別寒辺牛（高層・林縁・中州）、弁天沼、茶内、兼金沼、キモントウ、生花苗、落石、ポー川、尾瀬（牛首・ヨッピ）の12集団から雌雄の葉および果実を4サンプルずつ採取し、N・P・K濃度を測定した。また開花調査、花序数計測調査を行った。ヤチヤナギは窒素固定植物で、クラスター根を形成することが知られている。葉内の養分濃度には大きな集団間変異がみとめられた。N濃度には性差がなかったが、P・K濃度はオスに比べてメスで低かった。また、葉に比べ、果実は非常に高いP・K濃度を示し、果実への投資負担が大きいことが明らかとなった。メスの葉内P・K濃度が低くなると集団中のみかけのメスの開花性比が下がったこと、またメスの葉内P濃度が低いほど、メスの花序数が減少していたことから、メスはP・Kが不足する状態では、開花頻度や開花する花序数が制限されている可能性が示された。

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学早稲田キャンパス   Country：Japan  

人類が宇宙ステーションや月・火星のような地球外天体に長期滞在する際には、食料生産機能とガス処理機能を持つ植物栽培システムの構築が重要課題であると考えられている。コケ植物はサイズが小さく、省スペースで容易にかつ大量に栽培でき、宇宙ステーションという限られたスペースで栽培する上で被子植物に比べて有利であると考えられている。一方で、宇宙ステーションは地球上とは重力が全く異なっており、コケ植物の生存や生育に大きな影響があらわれると考えられる。しかしながら、コケ植物における重力応答についてはほとんど明らかになっていない。
本研究では低速回転型の遠心装置と光源を組み合わせた過重力栽培装置MK3 (松倉) を使用し、長期にわたって重力を変化させて植物を栽培した。先行研究においては、10×g条件下でヒメツリガネゴケを栽培すると、茎葉体への分化促進、光合成速度の増加、葉緑体の肥大化等、これまで被子植物では得られていなかった新規な知見を得ている。本研究では過重力条件としてさらに6×gを加えることにより、先行研究で得られた結果を裏打ちし、陸上植物の成長や光合成の重力応答メカニズムを解明することを目的とした。
6×g条件下ではヒメツリガネゴケのシュートの伸長が有意に抑制された。一方で、1プラントボックス当たりの茎葉体数は6×g条件下で有意に増加し、乾燥重量も増加傾向であった。したがって、6×g条件下ではヒメツリガネゴケの茎葉体への分化が促進されることが示された。さらに、6×g条件下では植物体内CO2コンダクタンスが有意に増加し、光合成速度も有意に増加した。加えて、光合成が行われる場である葉緑体の大きさも6×g条件下では有意に肥大化していることが明らかになった。このような結果は、陸上植物における重力応答のメカニズムの解明につながり、将来的な宇宙空間における植物栽培システムの構築に貢献する。

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学早稲田キャンパス   Country：Japan  

人類が宇宙ステーションなどの環境で長期滞在するには、閉鎖生態系生命維持システムが必要になる。植物は光合成により二酸化炭素を消費し酸素を供給する。したがって、宇宙に長期滞在する環境において植物栽培システムは必要である。コケ植物は小型であり、省スペースかつ大量栽培が容易なので、宇宙ステーション内での栽培に有利である。また、コケ植物は高いストレス耐性と再生能力を持ち、宇宙環境でも生育可能と考えられる。しかし、地上と異なる重力環境下でのコケ植物の応答については明らかにされていない。そこで、本研究では、単純な体制を持ちストレスに対する成長応答が極めて明快であるヒメツリガネゴケを用いて過重力条件での形態変化を調べた。
　過重力条件を作り出すために、富山大学に設置されている過重力栽培実験装置（MK-3、松倉）を用いた。ヒメツリガネンゴケを地球上と同じ重力条件1×gおよび過重力条件6×g、10×gで直径7.5cmのプラントボックス内に4週間と8週間で栽培した。ヒメツリガネゴケを樹脂（Spurr resin kit）に固定包埋し、ミクロトーム（Leica EM UC6）で1000nmの切片を作成し、光学顕微鏡（BX51OLYMPUS、日本）観察しImageJで画像解析した。またミクロトームで60nmの切片を作成し、透過型電子顕微鏡JEM-1220 (日本電子データム株式会社)を用いて観察しImageJで画像解析した。
6×g 、10×g条件下で葉の葉緑体が肥大化し、重力に依存して増加率が上昇した。10×g条件下で生の茎の太さが増加した。6×g 、10×g条件下で葉の細胞壁の厚さ、中肋から先端までの長さおよび、茎の葉緑体の大きさ、細胞壁の厚さ、直径、細胞密度は変化しなかった。以上の結果から、過重力条件でヒメツリガネゴケを栽培すると葉緑体が肥大化し、大気から二酸化炭素の取り込みが促進されると考えられる。

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学早稲田キャンパス   Country：Japan  

近年，PLOS ONEやScientific Reports，またEcology and Evolution のように，査読された論文を著者あるいはスポンサーが出版料を支払って読者の費用負担無しにWeb掲載するスタイル（オープンアクセス電子ジャーナル，OA誌）の科学雑誌が急増しており，生態学会会員の執筆論文も多数掲載されるようになっています。また，生態学会の英文誌Ecological Researchについても，費用負担の面から現在OA誌化が検討されています。しかし，これまでのような論文出版形式とOA出版には，様々な違いがあるにもかかわらず，そのメリット・デメリットは多くの会員にあまり理解されていないのが現状です。さらに，昨年よりSpringer Nature（SP社）で開始されたSharedIt サービス（論文共有リンク）は，著者が論文をシェアすることをサポートするシステムで，既存の論文出版スタイルも大きく変革されつつあります。そこで，SP社のOA出版と国際的な出版の動向，2014年に新規にOA誌，Progress in Earth and Planetary Science (PEPS)を立ち上げた日本地球惑星科学連合の現状について各担当者に紹介していただき，生態学会としての今後の雑誌出版の将来展望についての議論を行います。来場者の皆さまの積極的な参加をお待ちしております。

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学早稲田キャンパス   Country：Japan  

光合成を行うほとんどの陸上植物の葉は緑色であり，地球上どの植生帯においてもほぼ同じ分光吸収・反射特性を示す．これは主に光化学系のアンテナ色素複合体を構成するクロロフィルaとbおよびカロテノイド類の分光吸収特性に依存しており，非常に一定である．一方，海洋環境では，深度に伴って卓越する青緑成分の弱光をうまく吸収できる色素を保持した多様な生物が存在し，光利用効率を高めていることが知られている．そのため，陸上植物の分光特性の均一性は，入射日射スペクトルとその強度に関係していることが予想されるが，これまでその理由は明らかではなかった．そこで，陸上植物の葉における日射吸収に及ぼす吸収スペクトルの影響を，エネルギーと光量子の観点から直達日射スペクトルの実測データと簡単な植物生理学的モデルによって考察した．色素レベルでは，クロロフィルの日射吸収効率は低かった。また，エネルギー含量の高い波長の短い光子（青～紫）はカロテノイド類が競合的にクロロフィルへの吸収を抑制していることが示唆された。さらに，クロロフィルなどの光吸収タンパク質によって構成される光化学系複合体は，直達放射のエネルギーが最も高くなる波長（550nm）の吸収を避ける特性を示し，これは個葉レベルの分光特性にも反映されていた。一方，柵状組織の発達は葉緑体レベルの光吸収の平準化に非常に大きな効果を持ち，細胞内での葉緑体の運動や葉緑体のクロロフィル含量の変化も熱収支調整に効果があった。大気CO2濃度に対して放射が強すぎる地球の陸上では，直達日射に対して吸収率の低い光合成色素を持ち，色素濃度と細胞構造の組み合わせによる吸収エネルギーの最適化が重要であることが示された．このことは，地球の陸上植物の光合成色素や光合成器官の運動特性・組織構造は，直達日射による強光を避けることから，安全かつ有効に利用できる方向に進化してきたことを示唆している．

Event date： 2017.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2017.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

A hypergravity experiment is useful to understand plant responses to gravity on Earth. We have developed two centrifuges equipped with a lighting system, named MIJ-17 and MK-3, to investigate the effects of long-term cultivation under moderate hypergravity conditions on the growth of the moss Physcomitrella patens. In the use of these centrifuges, however, a rigorous 1-G control experiment should be required especially in a long-term experiment, because several factors (vibration, pressure, gas circulation, humidity and temperature) are presumed to change during centrifugation in addition to gravity. The most difficult factor to control is vibration; there is no information available on the vibration generated during centrifugation. In the present work, we described the vibration properties generated by MIJ-17 and MK-3 using a three-axis micro acceleration sensor, and showed that distinct random vibration occurred in MIJ-17, but little in MK-3. We also demonstrated that the vibration in MIJ-17 at 10 G did not affect significantly on the growth and morphological parameters of P. patens gametophores, suggesting that the influence of centrifugal vibration may be negligible in experiments to investigate the effects of long-term hypergravity conditions (< 10 G ) on the growth of P. patens gametophores.

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/590481

Event date： 2017.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Developing a successive plant-cultivation system is crucial to secure a stable food supply in a long-term manned space exploration as a component of bio-regenerative life support system. It is necessary to clarify effects of altered gravity on the life cycle of plants because effects of space environment, including microgravity, on various processes of life cycle of plants are still largely unknown. Anatomical observation of supporting tissues of Arabidopsis peduncles obtained in the “Space Seed” experiment was performed in order to understand roles of gravity in the development of such tissues. In this experiment, plants were grown under either ground 1 G, artificial 1 G on orbit, or microgravity and harvested. Segments were excised from the peduncle of plants grown for 33 days, and fixed and embedded in resin. Morphological characteristics of the tissues composing peduncle were examined in cross sections. Additionally, X-ray microCT was performed using the basal part of the peduncle of plants, which had been grown for 62 days to complete their life cycle under each condition.

Event date： 2017.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙科学研究所相模原キャンパス   Country：Japan  

Gravity is one of the most important environmental signals in regulating plant growth and development. Microgravity conditions in space are thought to be useful to clarify the role of gravity in regulating plant growth. However, the opportunity for experiments in space, which provide microgravity conditions, is limited. On the other hand, long-term hypergravity conditions, a gravity of more than 1×g, can be produced easily on earth by centrifugation. We focused on the effects of gravity on mosses, and used the model plant, Physcomitrella patens because they have compact plant size and easy-to-grow, with high adaptation to severe environments such as in Antarctica with high UV levels. We investigated photosynthetic and developmental responses of P. patens to 8 weeks of hypergravity (6×g, 10×g). Plant density and plant dry mass were significantly increased under hypergravity (6×g, 10×g) compared to those under 1×g. Cell wall thickness of P. patens was not affected by hypergravity (10×g), which contrasts with that obtained for higher plants. On the other hand, numbers and sizes of chloroplasts of the leaves of P. patens were significantly increased under hypergravity (6×g, 10×g). Photosynthesis rate and internal CO2 conductance of P. patens were enhanced under hypergravity (6×g, 10×g).These results are new findings for the plant response to gravity, providing valuable information for plant adaptation to gravity in the land plant history, and for the construction of plant growth system in space.

Event date： 2016.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛知医科大学たちばなホール   Country：Japan  

陸上植物の葉は緑色であり，地球上どの植生帯においてもほぼ同じ分光吸収・反射特性を示す．これは主に光化学系のアンテナ色素複合体を構成するクロロフィルaとbの分光吸収特性に依存しており，植物種によらず非常に一定である．一方，海洋環境では，様々な分光吸収特性を持った生物が生存しており，水中の光環境と関係していることが知られている．そのため，陸上植物の分光特性の均一性は，入射日射の分光特性と関係があることが予想されるが，これまでその関係は明らかではなかった．そこで，陸上植物の葉における日射吸収に及ぼす吸収スペクトルの影響を，エネルギーと光量子の観点から分光日射の実測データと簡単な植物生理学的モデルによって考察した．その結果，大気CO2濃度に対して放射が強すぎる地球の陸上では，直達日射に対して吸収率の低い光合成色素を持ち，色素濃度と細胞構造の組み合わせによる吸収エネルギーの最適化が重要であることが示された．このことは，地球の陸上植物の光合成色素や光合成器官の運動特性・組織構造は，地球の日射・大気CO2濃度環境に高度に最適化されており，これらの条件が異なる環境では，異なった色や形態の光合成生物が進化することを示唆している．また，宇宙船内などの人工光源環境下では，それに応じた光合成生物の利用が適していると考えられる．

Event date： 2016.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛知医科大学たちばなホール   Country：Japan  

Event date： 2016.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎市民プラザ   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄コンベンションセンター   Country：Japan  

陸上植物の葉の日射吸収過程に及ぼす吸収スペクトルの影響を，エネルギーと光量子の観点から実測データと簡単なモデルによって考察した．葉に入射したエネルギーのうち，700nm よりも短波長の全体の45 ％程度を占める光合成有効放射（PAR）波長域の放射が吸収され，長波長の放射は吸収されない．個葉レベルのPAR 吸収はその平均吸収率が高いため，直達日射や散乱日射に対してほぼ波長依存性のない灰色体である．500nm よりも短波長のPAR 成分の20 ％以上はβカロチンやその他の非光合成色素によって吸収され，光化学系への余剰エネルギー流入が効果的に抑制されている．葉緑体の放射吸収量は，色素濃度とそれらの吸収スペクトル特性に強く依存している．葉緑体の定位運動による吸収放射量の調節は重要であるが，これは主に吸収率の高い青色光と赤色光でのみ効果があり，直達日射の最大エネルギー域の緑色光の吸収率は位置によらず常に低く抑えられている．単位入射放射あたりの有効吸収面積を増大して葉緑体のクロロフィル濃度に入射方向から勾配を付けることは，光吸収過程の平準化に大きな効果があり，柵状組織は構造的に有利である．光合成色素から葉緑体レベルまでのエネルギー収支は，吸収スペクトルによる調節が最も重要である．CO2 濃度に対して放射が強すぎる陸上では，直達日射の吸収率が低い光合成色素を持ち，濃度と構造の組み合わせによる吸収エネルギーの最適化が重要である．

Event date： 2016.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari Messe, Chiba   Country：Japan  

Non-point source nutrients, such as excess fertilizers from agriculture and human sewage water, are main cause of eutrophication of lakes, streams, and coastal areas. The upstream areas of suburbs of Fukuoka are covered with nitrogen-saturated forests, and supplied high concentration NO3 - river water to the downstream. Such nitrogen-saturated forests have large impact on the downstream water
quality (Chiwa et al., 2012), but less information was available of the mechanism of the changes in NO3- concentration from upstream to the downstream. The objectives of this study were to clarify (1) whether the nitrogen dynamics (the concentration of NO3-, δ15NNO3 and δ18ONO3) in the downstream were affected by the nitrogen-saturated forests in the upstream, (2) the influence of nitrogen runoff from agriculture and urban area in the downstream, and (3) the influence of the river gradient on denitrification. NO3- concentration and the stable isotopes, δ15NNO3 and δ18ONO3 were measured in the Tatara River Basin, located in northern Kyushu, western Japan. Water samples were mainly collected from branch rivers; Ino River, Sue River and Umi River. Deciduous mature forest dominates the ridges in the upstream, with paddy, farmland and urban dominating in the middle and downstream. Topographic Index (TI) was calculated by using Digital Elevation Model (DEM) with ArcGIS software. Our results showed that the NO3 - concentration in the upstream of three rivers (33.9-82.8 μmol/L) were higher than the other non-saturated forests. Lower δ18ONO3, higher NO3 - and δ15NNO3 in the downstream were be found in Sue River and Umi River. On the other hand, Ino River showed different trend that lower NO3- concentration, higher δ15NNO3 and δ18ONO3 concentration in the downstream. The higher NO3- concentration in the downstream in Sue River and Umi River was affected by the increasing agriculture and urban areas in the downstream. However, the NO3- concentration in the downstream of Ino River decreased with the increasing agriculture and urban areas. The average TI value showed no difference between rivers. However, the distribution of TI values in Ino River was different from other rivers. Ino River has smaller changes in gradient from upstream to downstream and fewer agriculture and urban areas in the downstream than the other two rivers. These differences could result in the higher probability of denitrification occurring and the lower NO3- loading in the downstream in Ino river. The nitrogen-saturated upstream forests in this watershed has large impact on the nitrogen sources to the downstream. In the areas with steeper gradient, the high concentration of nitrogen runoff was supplied to the agriculture and urban areas. On the other hand, in those areas with gentle gradient, the nitrogen loading in the downstream also decreased due to the gentle gradient of the watershed and it was suggested that the rate of denitrification and decrease NO3- concentration in the downstream was also high.

Other Link： http://www2.jpgu.org/meeting/2016/session/PDF/H-TT21/HTT21-P13_e.pdf

Event date： 2016.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：日本大学生物資源科学部（藤沢市）   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：日本大学生物資源科学部（藤沢市）   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台国際センター   Country：Japan  

Event date： 2015.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：総合地球環境学研究所（京都）   Country：Japan  

Event date： 2015.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2015.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：かんぽの宿　岐阜羽島   Country：Japan  

植物がどのように「感じて」「考えて」いるかを人間が直接理解することは難しい。外部環境変化に対する植物の反応を予測するためには、植物が感じている野外環境を生態研究者が把握していること、すなわち、植物が利用しているであろう野外情報の把握という観点が必要である。たとえば、人の目の感じる「色」は、放射のスペクトル分布や強度を忠実に反映したものというよりかは、進化的に重要な色（波長）や強度（光量子量）の反射放射情報を都合良く利用できるような「人間という生物固有」の情報である．他の構造の目を持った生物では、同じ放射特性を全く違った情報として解釈している。さらに、植物の光受容体は基本的に特定波長の光量子を吸収して量子的に「感じて」、その結果を直接的に遺伝子発現に利用できるため、検出感度は非常に高くなりうるし、情報処理様式も異なるだろう。たとえば，ある特定波長同士の比率や方向性も重要な情報となり、単なる明るさ（エネルギー量）だけでなく、近赤外域まで含めた環境中の方向性ハイパースペクトル情報が重要となる。晴天日の空の色と曇天日の空の色は異なるが、放射スペクトル的には1日の時間や標高や緯度によっても変化する。さらに、直達放射と散乱放射の色の違いは人間の目では区別がつかないが、放射スペクトル的には大きく異なる。そのため、野外の生物環境の放射環境、すなわち空の色を測定するためには直達放射と散乱放射を分けて、分光放射測定を行う必要がある。そこで、実際にそのような装置を作成し実測した結果，およびシミュレーションで検証した結果を紹介する。

Event date： 2015.9 - 2015.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道大学学術交流会館   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟市　朱鷺メッセ：新潟コンベンションセンター   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟市　朱鷺メッセ：新潟コンベンションセンター   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島大学郡元キャンパス   Country：Japan  

北アルプス立山地区はライチョウの生息密度が日本で最も高く，300羽余の生息が確認されている．ライチョウは盲腸を持ち植物食に適応し，無雪期は高山植物の葉や果実を主な餌とし，種子散布に及ぼす重要な役割も明らかにされている．餌資源として重要なガンコウランやコケモモなど8種類の木本植物の結実について2006年間からモニタリング調査を行った結果，いずれの種でも現地の平均気温と結実量の間には負の相関が確認され，温暖化が進行した場合のライチョウの餌資源への悪影響が示唆された．
ライチョウの摂餌，消化効率と高山植物の必要資源量を明らかにするために，摂餌する主要植物の水分量・可溶性有機物量，及び野外の新鮮な糞の含水率や含有成分，含有種子数を測定し，ライチョウ1羽が必要とする植物バイオマス量の推定を行った．果実や葉の推定吸収率は植物種で異なり49～84%となった．ガンコウランの葉は含水率が高く，水分量と可溶性有機物量とのバランスも良く，葉面積あたりの質量も他の植物に比べて大きかった．また，夏から秋にかけては栄養価の高い果実をつけるため，ガンコウランはライチョウにとって重要な摂餌植物であることが再確認された．
ガンコウランの葉の含水率から必要摂餌量を推定したところ，約60g/dayとなった．ライチョウの食痕から1回についばむガンコウランの葉面積は平均0.17cm2と推定され，1回のついばみ当たり約4.6mgの水分を摂取できると推定された．水摂取から推定されるガンコウランの摂餌葉面積は約1100cm2で，6700回程度ついばむ必要があるが，これは，既存の観察値とほぼ一致した．ガンコウランの平均葉面積指数は2.6m2/m2で，1日に必要なガンコウラン群落は430cm2となり，この値はエネルギー必要量から算出された結果とほぼ一致した．

Event date： 2015.3

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：鹿児島大学郡元キャンパス   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：文部科学省研究交流センター   Country：Japan  

市販測器がどのように開発・販売されているかについて意識されることは少ない．一部の大企業では，開発者が学会に参加して直接情報交換を行い，ノーベル賞を獲得してしまう場合すらあるが，フィールドで使用する比較的単純な測器の場合は，分野外の技術者が，センサ開発時の原著論文を参照せず，輸入品の見様見真似で開発・販売している事例は多い．結果として，設計や校正，宣伝内容が不適切であるなどの問題が生じている．このような現状を改善する上で，研究者と開発者の積極的な協力関係が非常に重要であることを，光量子センサを例として紹介する．

Event date： 2015.2

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：Asia Center for Air Pollution Research (ACAP)   Country：Japan  

A dense vegetation cover (canopy) intercepts a large proportion of bulk deposition and also efficiently captures fog precipitation. Under such conditions, most of the rain and fog deposition falls on the surface of canopy, not directly on the soil surface. Chemical properties of the water droplets are changed when they pass through the canopy. The accumulated dry deposition on the canopy surfaces is washed out by rain and fog, and several water-soluble plant nutrients are leached out from the leaf surfaces. Usually, K+, Mg2+, Ca2+ and other cations are leached from internal plant tissues. NO3-, NH4+ and other solutes, gases and particles are taken from leaf surfaces. Basically, dry and wet deposition is the main nutrient source of Japanese forest ecosystems. However, sometimes the interactions between leaf surface processes and deposition have harmful effects on the plant growth. High concentration of H2O2 in the fog and dew water is frequently observed in the forest areas and it may cause negative effects on the photosynthesis as similar as gaseous Ozone. Excessive leaching causes nutrient deficit and excessive deposition causes various disorders of plant growth. The physiological processes on leaf surfaces are important to understand the effects of air pollution on the Japanese forest ecosystem.

Event date： 2015.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙航空研究開発機構　相模原キャンパス   Country：Japan  

Toward microgravity experiments in moss: The emerging model land plant, Physcomitrella patens on International Space Station and more

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/549482

Event date： 2015.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙航空研究開発機構　相模原キャンパス   Country：Japan  

Toward microgravity experiments in moss: The emerging model land plant, Physcomitrella patens on International Space Station and more

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/549510

Event date： 2015.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇宙航空研究開発機構　相模原キャンパス   Country：Japan  

Toward microgravity experiments in moss: the response of hyper gravity environment of Physcomitrella patens

Other Link： https://repository.exst.jaxa.jp/dspace/handle/a-is/549484

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：総合地球環境学研究所（京都）   Country：Japan  

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2014.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Seoul   Country：Korea, Republic of  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡国際会議場   Country：Japan  

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山大学   Country：Japan  

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：明治大学　生田キャンパス   Country：Japan  

Event date： 2014.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Moscow   Country：Russian Federation  

Hypergravity experiments with plants have been mostly performed using a commercial centrifuge in the dark. In order to see longer-term effect of hypergravity on the development of plant shoots, however, it is necessary to carry out the experiments in the light. In the present study, we have set up a centrifuge equipped with lighting system, which supports long-term plant growth under hypergravity condition, in order to see long-term effects of hypergravity on the development of vascular tissues of inflorescence stems. Arabidopsis plants (Arabidopsis thaliana (L.) Heynh., Col-0), which were grown under 1 G conditions for 20-23 days and having the first visible flower bud, i.e., at Arabidopsis growth stage number 5 (according to Boys et al., 2001), were selected as the plant material. These plants were exposed to hypergravity stimulus at 10 G in a direction from the shoot to root for 10 days in the continuous light. Effects of hypergravity on growth of inflorescence stems, lignin content, and morphometrical parameters of the stem tissues were examined. As a result, the length of the inflorescence stem was decreased. Cross sectional area as well as cell number, and lignin content in the stem were increased under hypergravity. The length of basal internodes of the stem was decreased under hypergravity. In conclusion, the inflorescence stem was suggested to be strengthened through changes in its morphological characteristics as well as lignin deposition under long-term hypergravity conditions.

Other Link： http://adsabs.harvard.edu/abs/2014cosp...40E1390K

Event date： 2014.4 - 2014.5

Language：English   Presentation type：Oral presentation (general)  

Venue：パシフィコ横浜   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：大宮ソニックシティー   Country：Japan  

アジア大陸の工業・都市地域から放出されたNOxやSO2は，オゾン（O3）や非海塩性硫酸塩エアロゾル（SO42-）等に変化しながら，風によって日本に輸送されるため，大陸からの広域大気汚染においてはO3とSO42-の濃度変化が相関し，複合汚染として作用する．その影響は，離島や山岳域の大陸側に面した斜面で顕在化することが多い．屋久島のヤクタネゴヨウにおいてもO3濃度とSO42-負荷量との間には高い相関があり，冬季の濃度上昇期には針葉からのK+の溶脱量やエチレン放出が大幅に増大し，大きなストレス要因となっていた．富山県立山のハイマツ林冠では，針葉への霧や降雨の付着に伴い，窒素が葉面から吸収されると同時に，多量のK+やMg2+が葉面から溶脱し，特にK+は針葉の濡れ時間とSO42-負荷量に比例していた．貧栄養環境下においてSO42-負荷量は，樹体の栄養塩バランスに大きな影響を及ぼす可能性が高く，2006年までの負荷量の急増は日本の森林に大きな影響を及ぼした可能性が高い．一方，2006年以降，中国の大気汚染対策が進み，SO42-負荷量は減少傾向にあるが，O3濃度には変化が見られないため，森林への影響変化を注意深く見守る必要がある．

Event date： 2014.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：広島県国際会議場   Country：Japan  

植物がどのように「感じて」「考えて」いるかを人間が直接理解することは難しい。外部環境変化に対する植物の反応を予測するためには、植物が感じている野外環境を生態研究者が把握していること、すなわち、植物が利用出来るであろう野外情報の把握という観点が必要である。
たとえば、温度変動を植物がどのような生理学的メカニズムによって「感じて」いるのかは不明な点が多い。生物環境物理学的な立場から考えると、実際の植物に影響を及ぼしているのは植物表面の温度とエネルギーの出入りである。これは日射や周辺からの長波放射、大気や地中との熱交換、表面からの蒸散量などによって決まるものであり、必ずしも気温と良い対応を示さない。すなわち、野外の植物は、直接気温に反応するというよりかは、自身と外部環境とのエネルギー収支を、酵素反応や細胞内環境の変化、それに付随する遺伝子発現変化の総体として「感じて」いるため、単純な温度センサとしては扱いにくい。
一方、植物の光受容体は、基本的に特定波長の光量子を吸収して量子的に「感じて」、その結果を直接的に遺伝子発現に利用できるため、検出感度は非常に高くなりうる。ある特定波長同士の比率も重要な情報となるため、植物の光環境を評価するためには、単なる明るさ（エネルギー量）だけでなく、近赤外域まで含めた環境中のハイパースペクトル情報が重要となる。一方、植物がどの光量子信号を受容したかどうかを外部から直接的に判断することは困難であることが多く、光量子センサとしても扱いにくい。
時間制御の観点からは、受容された環境情報はデジタル信号として細胞内に生理的に積算して変換されて利用されることが多いため、アナログ的に発現しているように見えることも重要であろう（検知と記録が融合している）。
このような植物のハード－ソフトコンプレックスを理解して応用する上で，遺伝子発現データは非常に重要なツールになっている。

Event date： 2014.3

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：広島県国際会議場   Country：Japan  

Event date： 2013.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：総合地球環境学研究所（京都）   Country：Japan  

Event date： 2013.5

Language：English   Presentation type：Oral presentation (general)  

Venue：幕張メッセ国際会議場   Country：Japan  

Chubu-Sangaku mountainous area in central Japan is composed of mountains whose elevation is over 2500 m above sea level (a.s.l.). In the soil of this high elevation area, biological activity is inactive due to low air temperature and long snow cover, resulting in the slow decay of biomass, immobilization of nutrient, and depressing the material circulation. Wet and dry depositions in these mountainous ecosystems play an important role as nutrient supply. Wet precipitation on the forest ecological system partly adheres on leaves and branches, and water returns to the atmosphere by evaporation. The chemical composition of throughfall changes from the precipitation by interaction with tree and grass. Some elements are absorbed from crown. Further high elevation area is sensitive to materials transported from regional air pollution. However, there are a few geochemical and material-circulation studies on the mountainous ecosystem with high elevation.We have been studied ecological
and plant physiological studies on Mt. Tateyama, one representative Chubu-Sangaku mountainous area. The ecological system of Mt. Tateyama is important, since this mountain is strongly impacted from air-pollutants from the Asian continen as it faces the Sea of Japan, and is affected by global warming as the air temperature increases more than three times as the world average during recent 30 years. Sr is known as a powerful hydrological and ecological tracer but it is utilized as a fingerprint to understand plant physiology. This isotope is unique as it can quantitatively discriminate atmosphere-derived Sr from bedrock-derived Sr. In order to elucidate the material circulation system on the forest ecosystem in Tateyama, we sampled a variety of water (rainfall, throughfall, fog water, snow, groundwater, and dale water) and Siberian dwarf pine in Joudodaira, and determined their Sr isotope ratios. Our result shows that the 87Sr/86Sr ratio of groundwater (0.7068) and dale water (0.7070) are almost identical to that of soil and bed rock (0.7070), suggesting that Sr in the surface and ground water is largely derived bedrock through chemical weathering. This is consistent with that rainwater (0.7091) and fogwater (0.7090) have higher 87Sr/86Sr ratios. As this ratio is similar to seawater value (0.7092), Sr in precipitation is largely of sea-salt origin. It is notable that the 87Sr/86Sr ratio of dirty materials in snow is variable from 0.7095 to 0.7198. This high ratio suggests an incorporation of Asian dust particle whose 87Sr/86Sr ratio is around 0.720. The 87Sr/86Sr ratio of throughfall is 0.7094, indicating a contribution Asian dust Sr. The most notable feature is that Siberian dwarf pine (Pinus pumila) has high 87Sr/86Sr ratios (0.7099 in leaf and branch and 0.7097 in litter). Most alpine plants have lower 87Sr/86Sr ratios (0.707 of Gaultheria miqueliana and 0.708-0.7095 of others). This result demonstrates that Siberian dwarf pine is actively absorbing Asian dust particles.

Event date： 2013.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：岩手大学   Country：Japan  

Japanese forests are affected by various regional pollutants including ozone

Event date： 2013.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：静岡県コンベンションアーツセンター（グランシップ静岡）   Country：Japan  

植生のリモートセンシング，すなわち測定対象から離れた測器によって植生情報を集める技術は，利用可能な観測機器やシステム，そして画像処理システムの急激な広がりにともなって，生態学者にとって極めて重要な技術になってきている．しかし，リモセンの専門家と生態学者との間には基盤となる知識体系に大きな違いがあり，研究対象が同じにもかかわらず，相互交流はそれほど盛んではなかった．地球環境問題についてリモセンの専門家と地上の植生の専門家が一緒にプロジェクトを運営するようになっている現在，そのギャップを埋めていく必要がある．本シンポジウムは，現在の植生リモセン技術をできるだけ包括的に紹介し，植生を通じた様々な研究活動に対してどのようにリモセン技術が活用できるのか，効果的にリモセン技術を活用するにはどのような背景知識が必要となるのか，そして今後の方向性についての共通理解を深めることを目的としている．

Event date： 2013.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：総合地球環境学研究所（京都）   Country：Japan  

Event date： 2012.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌コンベンションセンター   Country：Japan  

日射は直達放射と散乱放射によって構成される．散乱放射のスペクトルは太陽高度や雲量によらず，470nm付近にピークを持ったほぼ一定の形状を取る．一方，直達放射のスペクトルは，太陽高度が高く入射エネルギー量が最大の時に530nm付近にピークを持つ．このような日射スペクトルに対して，Chl aの吸光スペクトルは最大直達放射を避け，Chl bの吸光スペクトルは散乱放射を効率的に利用するのに適している．

Event date： 2012.9

Presentation type：Oral presentation (general)  

Venue：兵庫県立大学姫路書写キャンパス   Country：Japan  

陸上植物の特徴は可視放射の中で550nmを中心とした緑色光を比較的吸収しないことで，その理由については多くの研究者が様々な説明を行ってきた（Nishio 2000, Terashima et al. 2009）.しかし，ほとんどの研究では，一定の平均的な日射スペクトル分布を想定しており，実際の日射スペクトルを考慮していない．日射は直達放射と散乱放射によって構成され，たとえば快晴時には可視放射の7割以上が直達放射となる．一方，完全曇天時には，ほぼ100%が散乱放射となる．放射スペクトルを比較すると，散乱放射では太陽高度や雲量によらず， 470nm付近にピークを持ったほぼ一定の形状を取るのに対して，直達放射では，太陽高度が低い時には700nm付近，高度が高まり入射エネルギー量が増加するにつれて530nm付近までピーク位置が移動していく．このような放射環境下で，高い光利用効率を得るという観点からChlの吸光スペクトルをみると，放射強度によらず常に一定の入射が見込まれる散乱放射波長のピーク位置に吸収極大を持つのが効率的であると考えられ，一方，不安定で過剰な放射として入射する直達放射による強光阻害を避けるには，530nmから650nmの放射を吸収せず，特に，最大エネルギー入射が想定される550nm付近の放射吸収を避けるのが最適である．すなわち，Chl aの吸光スペクトルは最大直達放射を避け，Chl bの吸光スペクトルは散乱放射を効率的に利用するのに適している．

Event date： 2012.3

Presentation type：Symposium, workshop panel (public)  

Venue：宇都宮大学   Country：Japan  

液相と気相の違い
都市や工業地域など人間活動が活発に行われている地域からは，大量の窒素酸化物（NOx）が放出され，様々な形で大気や生態系に影響を及ぼしている．ここで重要なことは，NOx自体の植物に対する毒性は低くいものの，NOxが水滴中に溶け込んだり，光化学変化することによって植物に対する影響が大きく変化することである．例えば，植物に新鮮な自動車排気ガスを吹きかけても光合成にはほとんど影響が生じないが，これを水に溶け込ませ，植物葉表面に霧状に噴霧すると，亜硝酸イオン（NO2-）の光化学分解により水滴中でOHラジカルが発生し，高濃度の場合，気孔に障害を与えて光合成活性を低下させる（Sakugawa et al. 2011）．OHラジカルの影響の有無は，マンニトールのようなOHラジカル消去物質を利用することで明確に判断でき，多環芳香族炭化水素による実験でもその効果が示されている（Oguntimehin et al. 2010）．NOラジカルの影響も示唆されているが（Kume et al. 2001；Sakugawa et al. 2011），これについては未解明である．

汚染源が近い場合
排気ガス由来のNOxや揮発性有機化合物（VOC）などの一次汚染物質（O3前駆物質）やH2O2などの二次物質が朝露や霧などの水滴中に集積され，光が当たることにより反応性が高いOHラジカルが発生する現象は，霧の発生しやすい都市近郊域や高速道路周辺で観測され，H2O2から鉄化学種共存条件でのフェントン反応で生成するOHラジカルによって，O3暴露による場合と同様の光合成蒸散機能の低下が生じることが多くの暴露実験によって示され（例えばKume et al. 2001; Nakatani et al. 2007），野外の汚染地域で感受性の高い樹種の枯死を引き起こすことがあることが観察されている（Kume et al. 2006）．一方，葉面上に沈着した大気汚染由来の窒素成分の多くは，葉面を通して植物体内に吸収され，光合成タンパクとして利用されるため，NOxの植物影響の評価は単純ではない．

広域汚染の場合
一次汚染物質は大気中を移動している間に日射によって光化学反応が進行し，O3が生成され，その濃度は風によって運ばれた周辺の郊外や山岳地域などで高くなる．O3が生成される過程でNO3-として水滴中に取り込まれたり，SO2が酸化されてSO42-として水滴中に取り込まれたりする場合には，酸性雨や酸性霧として植物体からの溶脱に影響する．富山県立山の観測では，頻繁に発生する霧水中にはSO2の重要な酸化剤であるH2O2が高濃度で度々検出され，夜間の露水中にも高濃度のH2O2が観測された（Watanabe et al. 2009）．室堂平（標高2450m）では，霧水中に100μMを超える非常に高濃度のH2O2が観測されており（Watanabe et al. 2010），酸性物質との複合効果による植生への影響も懸念される．H2O2はO3によって生成が促進され，広域汚染の影響で特に山岳域におけるO3濃度が増加していることから，野外におけるH2O2濃度の測定データの蓄積が求められている．日本のように，霧や露が生じやすい湿潤な環境では，森林へのO3影響評価において，気相と液相の両面からの影響評価が実体解明の鍵となるだろう．

引用文献
Kume et al. 2001 Harmful effects of radicals generated in polluted dew on　the needles of Japanese red pine. New Phytol 152: 53-58
Kume et al. 2006 Seasonal changes in needle water content and needle ABA concentration of Japanese red pine in declining forests on Mt. Gokurakuji, Hiroshima Prefecture, Japan. J Plant Res 119:231-238
Nakatani et al. 2007 Roles of hydroxyl radical generating/scavenging mechanisms in pseudo polluted dew in reducing the foliar CO2 assimilation rate and biomass production of Japanese red pine seedlings. Environ Exp Bot 60: 159-169
Oguntimehin et al. 2010 Simultaneous ozone fumigation and fluoranthene sprayed as mists, negatively-affected Cherry tomato. Ecotoxicol Environ Saf 73: 1028-1033
Sakugawa et al. 2011 Automobile exhaust gas as a source of aqueous phase OH radical in the atmosphere and its effects on physiological status of pine trees. Chemosphere 85: 812-819
Watanabe et al. 2009 Measurements of peroxide concentrations in precipitation and dew water in Toyama. Bull Glaciol Res 27: 1-5
Watanabe et al. 2010 Chemical characteristics of fog water at Mt. Tateyama, near the coast of the Japan Sea in central Japan. Water Air Soil Pollut 211: 379-393

Event date： 2012.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮大学   Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：龍谷大学瀬田キャンパス   Country：Japan  

McCree(1972)は，PAR（光合成有効放射）の評価に400～700nmのPPFD（光量子フラックス密度）を用いることで，実用的な評価が行えることを確認した．現在，様々なPARセンサが販売されているが，それらのセンサの材質や構造は様々であり，日射計などとは異なり国際標準も規定されていない．従来の植物生態学的な観点では，PARセンサは絶対値の測定よりかは，植生内外での相対強度の測定に用いられることが多く，絶対値精度が必要とされる場面は少なかった．しかし，近年のリモセン技術の発達や，群落観測の高度化によって，誤差数％以内の高精度なPAR地上観測が求められるようになり，様々な精度管理上の問題点が明らかになってきた．そこで，これまでのPARセンサの信頼性や問題点を確認し，国際的に通用するフィールド対応型PAR計測のガイドライン，すなわち，長期間, 高精度の地上観測を行うためのプロトコルを整備し提案することを目的として研究を進めた．まず，PARの校正基準として，慎重に校正・確認すれば市販のマルチスペクトルセンサ（Eko-MS700）が利用でき，全天日射のPAR/日射エネルギー比は，校正に利用できる程度に一定（約0.45）であることを明らかにした．次に，主な市販PARセンサを複数購入し，各社の試作品も含めて，実際に様々な野外環境（天候，植生タイプ）において測定し，ソーラーシミュレータによる測定結果も踏まえ問題点を解析した．その結果，測定精度に及ぼす最も影響の大きな要因はセンサの入射角特性（コサイン特性）であり，次に，センサ表面の汚れおよび拡散板・フィルタの劣化，そしてデータロガーの精度であった．一方，従来から問題として指摘されてきた分光感度特性の影響は植生内においても小さく，フィルター特性やセルタイプ（Siセル，GaAsセル）の違いにかかわらず，実質的な差は無かった．