Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Tsutomu Enoki Last modified date:2021.10.26

Associate Professor / Forest Science / Department of Agro-environmental Sciences / Faculty of Agriculture


Papers
1. Shimono K, Katayama A, Kume T, Enoki T, Chiwa M, Hishi T, Different responses of net primary production allocations and nitrogen use efficiency along a slope between a Moso bamboo and Japanese ceder forests, Shimono K, Katayama A, Kume T, Enoki T, Chiwa M, Hishi T, 10.1080/13416979.2021.1965280, 2021.08.
2. TaeOh Kwon, Hideaki Shibata, Ika Djukic, Sebastian Kepfer-Rojas, Inger Kappel Schmidt, Klaus Steenberg Larsen, Claus Beier, Björn Berg, Kris Verheyen, Jean Francois Lamarque6, Frank Hagedorn, Nico Eisenhauer and TeaComposition, Effects of climate and atmospheric nitrogen deposition on early to mid-term stage litter decomposition across biomes, Frontiers in Forests and Global Change, 10.3389/ffgc.2021.678480, 2021.07.
3. Hino Takafumi, Yuri Kanno, Shin Abe, Tetsuto Abe, Tsutomu Enoki, Toshihide Hirao, Tsutom Hiura, Kazuhiko Hoshizaki, Hideyuki Ida, Ken Ishida, Masayuki Maki, Takashi Masaki, Shoji Naoe, Mahoko Noguchi, Tatsuya Otani, Takanori Sato, Michinori Sakimoto, Hitoshi Sakio, Masahiro Takagi, Atsushi Takashima, Naoko Tokuchi, Shunsuke Utsumi, Amane Hidaka, Masahiro Nakamura, Assessing insect herbivory on broadleaf canopy trees at 19 natural forest sites across Japan, ECOLOGICAL RESEARCH, 10.1111/1440-1703.12215, 2021.03, We present the largest freely available herbivory dataset for Japan representing data collected from a network of 19 natural forest sites across the country. Sampled network sites were part of the Monitoring Sites 1000 Project organized by the Ministry of the Environment. Sites were located across a range of climate zones, from subarctic to subtropical, and broadleaf trees (both evergreen and deciduous) were targeted at each site. Litterfall traps were used to assess leaf damage caused by leaf-chewing insects in 2014 and 2015. Using a standardized protocol, we assessed herbivory on 117,918 leaves of 39 dominant tree species. Preliminary analyses suggest that insect herbivory increases with increasing latitude for deciduous broadleaf species. In particular, oak (Quercus crispula) and beech (Fagus crenata) were subject to increased insect herbivory with increasing latitude. In contrast, insect herbivory decreased with increasing latitude in evergreen broadleaf species. The latitudinal gradient of herbivory differed according to leaf type (i.e., evergreen or deciduous). This dataset offers excellent opportunities for meta-analysis and comparative studies of herbivory among various forest types. The complete dataset for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at ..
4. Stand condition of "Sasaguri-Kyudai-no-Mori"
"Sasaguri-Kyudai-no-Mori" in the Kasuya Research Forest, Kyushu University is the area open to the public from July 2009 under joint management of Sasaguri Town and Kyushu University. This area will be required to demonstrate not only educational and research function, but cultural, health and recreational functions. However, there is insufficient information on vegetation in the area. From May to September 2018, square plots (10m×10m) were set up at 15 locations in the area, and vegetation survey was conducted in each plot. Two gymnosperms species of two families, 65 angiosperms species of 37 families, in total, 67 woody plant species of 39 families were recorded. Based on the appeared woody plant species outside plots and the report of Yamauchi et al. (2012), five gymnosperms species of three families, 69 angiosperms species of 39 families, in total, 74 woody plant species of 42 families was confirmed. The tree layer was dominated by Toxicodendron succedaneum, Quercus serrata, Symplocos kuroki and Cinnamomum camphora. Taller Pinus×densithunbergii tree was rare. The shrub layer was dominated by Eurya japonica var. japonica. The shrub layer in the plots of north area was dominated by Podocarpus macrophyllus f. spontaneous and the trees could grow taller and expand its distribution to other area in the near future. As a whole stand, the generation of tree species was frequently present..
5. Effects of tree species difference of bedlog on the fruiting of Lentinula edodes mushroom : changes in bulk density and water content of bedlog
To investigate the effect of different species of log on Shiitake (Lentinula edodes) fruit body development, we compared the number and quantity of fruit bodies, and bulk density and moisture content of the log between Quercus acutissima and Quercus crispula. The quantity of fruit bodies developed from Q. acutissima was 1.5 times greater than that from Q. crispula at 6 years after sowing. Q. acutissima developed fruit bodies two months later than Q. crispula. Each fruit body developed from Q. acutissima was heavier than that from Q. crispula at the early stage of development, while there was no difference in the dry weight over the 6-year period between the two species. The bulk density of logs before sowing was greater in Q. acutissima than in Q. crispula. The bulk densities of both species decreased with time, and they were 42% of the initial value for Q. acutissima and 26% for Q. crispula after 5 years of sowing. There was no significant difference in the moisture content of logs before sowing, while the increase in moisture content after sowing was greater in Q. crispula than in Q. acutissima..
6. Seed collection in the Millennium Seed Bank project in Kyushu University Forest
The Millennium Seed Bank was established in 2000 at the Royal Botanic Garden, Kew in the United Kingdom to store seeds from all over the world for avoidance of plant species extinction. The Millennium Seed Bank is promoting an international conservation project "Millennium Seed Bank Partnership", and is working with collaborators in more than 95 countries on seed collections. In Japan, for the first time in 2018, Kyushu University Forest and Faculty of Science of the University of the Ryukyus participated in the Millennium Seed Bank Partnership for the first time, providing seeds and related data to the Millennium Seed Bank. In a two-year tree seed collection project carried out in 2018, 37 species for conservation and 72 species for germination test to evaluate the storage behavior were collected from the Kasuya, Ashoro and Shiiba Research Forests..
7. Carbon and nitrogen storage of dead woody debris in an abandoned Moso bamboo forest
Although it is reported that comparable carbon and nitrogen is stored in abandoned bamboo forests with neighboring broadleaved forest and Japanese cedar forests, coarse woody debris has not been considered in the estimate in bamboo forests. This study was aimed to understand contribution of woody debris on carbon and nitrogen storage in an abandoned Moso bamboo forest. For this aim, we examined carbon and nitrogen storage in woody debris (standing and downed culms), soil organic matter (litter layer and mineral soil) and aboveground and belowground biomass of bamboo. This study was conducted in Kasuya research forest of Kyushu University. Three study plots were established along a slope to consider spatial variation in woody debris. Carbon storage in standing and downed culms, litter layer and mineral soil were 11.2,13.8,2.7 and 17.1 Mg C ha-1, respectively. Woody debris accounted for 30.9 % of aboveground biomass of bamboo. Culm density of standing dead culms was 18 % of living culm density. Nitrogen storage in standing and downed culms, litter layer and mineral soil were 49.1,136.4,85.8 and 1468.2 kg N ha-1, respectively. Woody debris accounted for 56 % of aboveground biomass of bamboo. These results suggest that woody debris can affect carbon and nitrogen storage considerably, and therefore it is very important to evaluate the storage in the dead culms in an abandoned Moso bamboo forest..
8. Five years stand dynamics of reserved forests in Kasuya Research Forest
The ninth Kasuya Research Forest Management Plan (2015-2024) designated five reserved forests (Woody liana, Abies firma and Rhododendron farrenrae, Juniperus rigida, Diospyros japonica, and Castanopsis and Quercus). We surveyed the 5 years dynamics of stand structure and species composition of 20m × 20m monitoring plot established in each model forest. In woody liana reserved forest, tree and liana density decreased slightly, while the basal area did not change. In Abies firma and Rhododendron farrenrae, and Diospyros japonica reserved forests, tree density decreased slightly, while the basal area increased. In Juniperus rigida reserved forest, both of tree density and basal area increased largely. In Castanopsis and Quercus reserved forest, both of tree density and basal area decreased..
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10. Early Stage of Understory Recovery after a Forest Fire in a Larch Plantation in the Eastern Part of Hokkaido, Japan

The recovery of Sasa nipponica and regeneration of forest floor vegetation after a forest fire occurred in May 2015 were investigated in a larch (Larix kaempferi) plantation in the Ashoro Research Forest, Kyushu University. In July 2015 the coverage, height and biomass of recovered S. nipponica in the burned site were 83, 70 and 38% of those in the unburned site, respectively. In July 2016 and 2017, the coverage, height and biomass of S. nipponica in the burned site were not significantly different from those in the unburned site. The number of herbaceous and tree species emerged in the burned site was almost twice as many as that in the unburned site in 2016. The number was not different in 2017, while the species composition in the burned site was quite different between 2016 and 2017. The results of PERMANOVA showed that the forest fire formed a different plant community composition compared to that before the forest fire and the difference was maintained at least for two years after the wild fire.

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11. Effects of thinning on the aboveground net primary production of old Cryptomeria japonica plantation-comparison between stands with different thinning intensity..
12. Satoshi N. Suzuki, Mioko Ataka, Ika Djukic, Tsutomu Enoki, Karibu Fukuzawa, Mitsuru Hirota, Takuo Hishi, Tsutom Hiura, Kazuhiko Hoshizaki, Hideyuki Ida, Akira Iguchi, Yasuo Iimura, Takeshi Ise, Tanaka Kenta, Yoshifumi Kina, Hajime Kobayashi, Yuji Kominami, Hiroko Kurokawa, Kobayashi Makoto, Michinari Matsushita, Rie Miyata, Hiroyuki Muraoka, Tatsuro Nakaji, Masahiro Nakamura, Shigeru Niwa, Nam J. Noh, Takanori Sato, Tatsuyuki Seino, Hideaki Shibata, Ryo O. Suzuki, Koichi Takahashi, Tomonori Tsunoda, Tasuhiro Ustumi, Kenta Watanabe, Harmonized data on early stage litter decomposition using tea material across Japan, Ecological Research, 10.1111/1440-1703.12032, 34, 5, 575-576, 2019.09, © 2019 The Ecological Society of Japan Litter and soil organic matter decomposition represents one of the major drivers of carbon and nutrient cycling in a given ecosystem; however, it also contributes to a significant production of relevant greenhouse gasses. The Japanese archipelago spans several biomes (boreal-temperate-subtropical) and covers a large range of elevations and ecosystem types. Hence, the comprehension of this fundamental biogeochemical process in diverse ecosystems is crucial to maintain their ecosystem services. In this article, we have provided data on plant leaf decomposition from 33 research sites across Japan. At each site, standard litter material with different decomposition rates, rooibos tea and green tea were incubated for 90 days between 2012 and 2016 and the remaining mass was recorded. In total, 1904 bags were used. In addition, supplementary measurements of environmental variables essential for the interpretation of the collected data, such as soil and vegetation, were recorded. Plot-level averages of the remaining mass rates of bag contents after incubation ranged 0.17–0.51 for green tea and 0.54–0.82 for rooibos tea. Continued monitoring will also provide important insights into the temporal dynamics of litter decomposition..
13. Model Forests in Kasuya Research Forest: II..
14. The effect of forest treatment on the growth of Quercus crispula plantation for 27 years in eastern Hokkaido.
15. High frequency of discontinuous rings in evergreen and deciduous hardwood species in a temperate forest
© 2018 Tree age derived from annual-ring counts provides fundamental information on forest stands and individual trees in temperate forests. However, discontinuous growth in the trunk may cause inaccuracies in annual-ring counts, and the effect of radial growth rate and interspecific differences on discontinuous ring formation have not been evaluated in the same forest stand. We investigated the occurrence of discontinuous rings at the base of 435 tree trunk disks of 16 evergreen and 15 deciduous hardwood tree species growing in a temperate forest of Japan. The effects of tree age and radial growth rate on frequency of discontinuous rings and their interspecific differences were evaluated by a generalized linear mixed-effect model. Discontinuous rings were observed in 29 of the 31 species in 330 individuals, which is about 75% of the total number of individuals examined. The number of discontinuous rings proportionally decreased with the growth rate and increased with the tree age. On the other hand, the effects of the growth rate were different among species. The majority of species at the study site contained frequent discontinuous rings in the trunk base. Annual-ring counts from a single core would lead to underestimation of tree ages in this case. Stem disks or increment cores taken in multiple directions at ground level would be useful for accurate estimation of tree age in temperate hardwood forests..
16. Yuka Maeda, Naoaki Tashiro, Tsutomu Enoki, Rieko Urakawa, Takuo Hishi, Effects of species replacement on the relationship between net primary production and soil nitrogen availability along a topographical gradient: Comparison of belowground allocation and nitrogen use efficiency between natural forests and plantations, Forest Ecology and Management, 10.1016/j.foreco.2018.03.046, 422, 214-222, 2018.08, Changes in dominant plant species can influence the net primary production (NPP) via changes in species traits, including nitrogen use efficiency (NUE) and belowground allocation enhancing N uptake, as well as soil N availability. We investigated changes in above- and belowground NPP, N uptake, and NUE in response to changes in soil N in natural forests and plantations, with and without changes in species compositions among the environmental gradient, respectively. In plantations, NPP increased with increasing availability of soil N in the presence of constant NUE and the proportion of belowground NPP to total NPP. However, in natural forests, aboveground, belowground, and total NPP were high for the available middle range soil N. Belowground NPP and the proportion of belowground NPP to total NPP in natural forests was positively related to aboveground NPP. Both belowground NPP and soil N mineralization rates explained stand N uptake rates. These results indicated that belowground allocation might facilitate aboveground NPP with enhancement of N uptake by root allocation. Stand NUE decreased with soil N availability in natural forests and was stable in plantations, and resulted in lower production in natural forests and higher production in plantations under high soil N availability. The community weighted mean (CWM) of N resorption efficiency was positively related to NUE. The CWM of juvenile root growth, as reported previously for planted juveniles, was positively related to belowground NPP allocation. In addition, the ranges of CWMs were broader in natural forests than in plantations. This suggested that the different changes in NPP in response to changes in soil N between natural forests and plantations was due to the changes in leaf and root species traits via changing in species composition among sites. In conclusion, the present study showed that the changes in species specific traits in root growth and leaf N strongly affected the relationship between soil N availability and stand carbon and N dynamics..
17. Ayumi Katayama, Tsutomu Enoki, Tomonori Kume, Kyoichi Otsuki, Characteristics of soil respiration in upper and lower slope positions with different aboveground biomass: A case study in a Japanese cypress forest, Journal of Agricultural Meteorology, 10.2480/agrmet.D-17-00019, 74, 2, 63-70, 2018.04, Differences in aboveground biomass alonga slope position are often overserved because of varyinglevels of nutrient availability. Such differences can affect the spatial variation in soil respiration (Rsoil) via changes in biological factors (e.g., fine root biomass and litter mass), in addition to environmental factors. This study clarified the differences in Rsoil and the factors affecting Rsoil, between the upper and lower slope positions with contrastingaboveground biomass, within a small watershed covered by a Japanese cypress forest. The soil water content (SWC) was lower, whereas the soil temperature (Tsoil) and fine root biomass were higher in the upper plot (UP) than in the lower plot (LP). Rsoil was negatively correlated with SWC, but positively correlated with Tsoil and fine root biomass. These results gave rise to a positive effect of Rsoil on the UP. However, Rsoil was comparable between the plots. The results from a multiple linear regression model indicated that factors other than SWC, Tsoil, and fine root biomass increased Rsoil in the LP. We speculate that high litterfall could enhance Rsoil in the LP, as litterfall is an important source of decomposed respiration. The higher aboveground net primary production and lower fine root biomass in the LP suggest that more carbon was allocated aboveground and less carbon was allocated belowground, resultingin comparable Rsoil but different contribution of aboveground and belowground sources on Rsoil between the plots. It is considered that differences in phosphorus availability between the plots caused the different carbon allocation patterns, even at a small spatial scale of less than 100 m..
18. Aboveground biomass in managed and unmanaged bamboo forests for Phyllostachys pubescens and Phyllostachys bambusoides
本稿は,福岡演習林内の放棄モウソウチクおよびマダケ林に設置した,管理放棄したプロット(コントロール区)とタケノコ採取を行ったプロット(処理区)における4年間の地上部バイオマスのモニタリング結果を報告する。本研究の竹林の地上部バイオマスは両種とも,同じ福岡演習林内に生育する森林に比較すると低かった。コントロール区における新規稈数,および処理区におけるタケノコ採取数は明確な2年周期はなく,地上部バイオマス増加量は年変動が非常に大きかった。4年間の地上部バイオマス増加量平均値は森林と比較すると非常に高く,放棄竹林であっても生産性は森林よりも高いことが明らかとなった。一方,タケノコ採取により地上部バイオマスの減少が確認できたが,タケノコ採取数は減少しなかった。モウソウチク,マダケともに新規稈数の年変動が大きいことから,今後はさらに長期間のモニタリングが必要であることが示唆された。This report presents results of four-year monitoring of aboveground biomass in a control plot (i.e., abandoned forest) and a treatment plot (i.e., bamboo shoot harvested forest) for a Moso bamoboo forest (Phyllostachys eduli)) and a Madake bamboo forest (Phyllostachys bambusoides) in Kasuya research forest. Aboveground biomass in control and treatment plot was lower than broad leave forests in Kasuya Research forest. Two-year cycle for new culm and harvested bamboo shoot was not observed and inter-annual variation in aboveground biomass increment was very high. Aboveground biomass increment was higher than those for forests in Kasuya research forest, suggesting that abandoned bamboo forests have very high productivity. Bamboo shoot harvest decreased aboveground biomass, but did not affect number of harvested bamboo shoot. High inter-annual variation in new culms suggests that longer-time monitoring is necessary to examine dynamics of bamboo forest..
19. 榎木 勉, 菱 拓雄, 田代 直明, 温帯混交林における樹木の成長と死亡に隣接固体が及ぼす影響の30年間の変化, 九州大学農学部演習林報告, 99, 1-7, 2018.03, We compared the effects of tree size and the basal area of neighboring trees on the growth rate and mortality of individual trees over the past 30 years (1984-2014), before and after the increase of a sika deer population in a mixed conifer-broadleaf forest in the Shiiba Research Forest of Kyushu University in Japan. In the study site, sika deer (Cervus nippon) have reduced understory vegetation since the 1990s, denuding it since the 2000s. Most of the recruitment in the second half of the study period (1996–2014) consisted of tree species that sika deer cannot consume, such as Illicium anisatum and Pieris japonica subsp. japonica. Smaller trees had higher mortality throughout the study period. Neighboring trees affected the tree mortality significantly in the first half of the study period (1984–1996), while they did not significantly affect it in the second half. However, neighboring trees significantly affected the growth rate of trees throughout study period. Based on our findings, we speculate that an increase in sika deer population may have affected the competition between individual trees in the mixed forest. The effects of tree size and neighboring trees on mortality and growth varied depending on the growth form groups and the species.九州大学農学部附属宮崎演習林内の針広混交林において,樹木サイズと隣接個体の胸高断面積合計が樹木の成長と枯死に及ぼす影響を,シカの個体数が増加した30 年間の前期(1984-1996 年)と後期(1996-2014 年)とで比較した。本調査地では下層植生が1990 年代から衰退し,2000 年代ではほぼ消滅した。調査期間の後期に更新した樹木のほとんどは,シカが採食しないシキミとアセビであった。小径木は成長速度が遅く,枯死率が高い傾向が調査期間を通じて観察された。調査期間の前期では,隣接個体が枯死率に有意に影響を及ぼしていたが,後期では影響が見られなかった。一方,隣接個体の成長に及ぼす影響は調査期間を通じて観察された。以上の結果から,本調査地において,シカの個体数増加は樹木の個体間競争に影響を及ぼした可能性が示唆された。これらの影響は樹木の生活型や種によって異なっていた。.
20. Increase of sika deer population on plantation trees and understory in Kasuya Research forest of Kyushu University in Fukuoka Prefecture, Japan
ニホンジカの目撃頻度が長期間低かった福岡県犬鳴山地西部において,ニホンジカの近年の目撃数の増加を日中(2007年から2015 年)及び夜間(2010 年から2015 年)の林道における計測により把握するとともに,造林地での下層植生への食害との対応関係を解析した。ニホンジカの目撃数は2009 年から2013 年までの4年間で急激に増加し,2012 年には最大値の80% に達した。下層植生への食害は2011 年から,造林木への食害は2012 年からそれぞれ確認された。ニホンジカの目撃数は短期間で増加し,増加が始まってから3年後に造林木と下層植生への食害が顕在化する可能性が示された。The increase process in sika deer sighting number at forest road was measured in day time from 2007 to 2015 and night time from 2010 to 2015 in the western hillside of Inunaki mountain in Fukuoka Prefecture, Japan. The correspondence between the increase in the sighting number of sika deer (Cerbs nippon) and the occurrence of feeding damage in plantations were also analyzed. The sighiting number of Sika deer showed a maximum value in 2013 after four years of increase from 2009. In 2012, the sighting number had reached 80% of the maximum value. Feeding damage to the understory was detected in 2011 and the damage to the planted trees was confirmed in 2012. The sighting number of sika deer increased in a short period, and the feeding damaged the understory and planted trees in the next three years from the occurrence of the sighting number increased..
21. J W Ferry Slik, Janet Franklin, Víctor Arroyo-Rodríguez, Richard Field, Salomon Aguilar, Nikolay Aguirre, Jorge Ahumada, Shin-Ichiro Aiba, Luciana F Alves, Anitha K, Andres Avella, Francisco Mora, Gerardo A Aymard C, Selene Báez, Patricia Balvanera, Meredith L Bastian, Jean-François Bastin, Peter J Bellingham, Eduardo van den Berg, Polyanna da Conceição Bispo, Pascal Boeckx, Katrin Boehning-Gaese, Frans Bongers, Brad Boyle, Fabian Brambach, Francis Q Brearley, Sandra Brown, Shauna-Lee Chai, Robin L Chazdon, Shengbin Chen, Phourin Chhang, George Chuyong, Corneille Ewango, Indiana M Coronado, Jurgi Cristóbal-Azkarate, Heike Culmsee, Kipiro Damas, H S Dattaraja, Priya Davidar, Saara J DeWalt, Hazimah Din, Donald R Drake, Alvaro Duque, Giselda Durigan, Karl Eichhorn, Eduardo Schmidt Eler, Tsutomu Enoki, Andreas Ensslin, Adandé Belarmain Fandohan, Nina Farwig, Kenneth J Feeley, Markus Fischer, Olle Forshed, Queila Souza Garcia, Satish Chandra Garkoti, Thomas W Gillespie, Jean-Francois Gillet, Christelle Gonmadje, Iñigo Granzow-de la Cerda, Daniel M Griffith, James Grogan, Khalid Rehman Hakeem, David J Harris, Rhett D Harrison, Andy Hector, Andreas Hemp, Jürgen Homeier, M Shah Hussain, Guillermo Ibarra-Manríquez, I Faridah Hanum, Nobuo Imai, Patrick A Jansen, Carlos Alfredo Joly, Shijo Joseph, Kuswata Kartawinata, Elizabeth Kearsley, Daniel L Kelly, Michael Kessler, Timothy J Killeen, Robert M Kooyman, Yves Laumonier, Susan G Laurance, William F Laurance, Michael J Lawes, Susan G Letcher, Jeremy Lindsell, Jon Lovett, Jose Lozada, Xinghui Lu, Anne Mette Lykke, Khairil Bin Mahmud, Ni Putu Diana Mahayani, Asyraf Mansor, Andrew R Marshall, Emanuel H Martin, Darley Calderado Leal Matos, Jorge A Meave, Felipe P L Melo, Zhofre Huberto Aguirre Mendoza, Faizah Metali, Vincent P Medjibe, Jean Paul Metzger, Thiago Metzker, D Mohandass, Miguel A Munguía-Rosas, Rodrigo Muñoz, Eddy Nurtjahy, Eddie Lenza de Oliveira, Onrizal, Pia Parolin, Marc Parren, N Parthasarathy, Ekananda Paudel, Rolando Perez, Eduardo A Pérez-García, Ulf Pommer, Lourens Poorter, Lan Qie, Maria Teresa F Piedade, José Roberto Rodrigues Pinto, Axel Dalberg Poulsen, John R Poulsen, Jennifer S Powers, Rama Chandra Prasad, Jean-Philippe Puyravaud, Orlando Rangel, Jan Reitsma, Diogo S B Rocha, Samir Rolim, Francesco Rovero, Andes Rozak, Kalle Ruokolainen, Ervan Rutishauser, Gemma Rutten, Mohd Nizam Mohd Said, Felipe Z Saiter, Philippe Saner, Braulio Santos, João Roberto Dos Santos, Swapan Kumar Sarker, Christine B Schmitt, Jochen Schoengart, Mark Schulze, Douglas Sheil, Plinio Sist, Alexandre F Souza, Wilson Roberto Spironello, Tereza Sposito, Robert Steinmetz, Tariq Stevart, Marcio Seiji Suganuma, Rahayu Sukri, Aisha Sultana, Raman Sukumar, Terry Sunderland, Supriyadi, H S Suresh, Eizi Suzuki, Marcelo Tabarelli, Jianwei Tang, Ed V J Tanner, Natalia Targhetta, Ida Theilade, Duncan Thomas, Jonathan Timberlake, Márcio de Morisson Valeriano, Johan van Valkenburg, Tran Van Do, Hoang Van Sam, John H Vandermeer, Hans Verbeeck, Ole Reidar Vetaas, Victor Adekunle, Simone A Vieira, Campbell O Webb, Edward L Webb, Timothy Whitfeld, Serge Wich, John Williams, Susan Wiser, Florian Wittmann, Xiaobo Yang, C Yves Adou Yao, Sandra L Yap, Rakan A Zahawi, Rahmad Zakaria, Runguo Zang, Phylogenetic classification of the world's tropical forests., Proceedings of the National Academy of Sciences of the United States of America, 10.1073/pnas.1714977115, 115, 8, 1837-1842, 2018.02, Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world's tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: (i) Indo-Pacific, (ii) Subtropical, (iii) African, (iv) American, and (v) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests..
22. Tsutomu Enoki, Donald R. Drake, Alteration of soil properties by the invasive tree Psidium cattleianum along a precipitation gradient on O'ahu Island, Hawai'i, PLANT ECOLOGY, 10.1007/s11258-017-0742-x, 218, 8, 947-955, 2017.08, To test the effects of invasion by strawberry guava trees (Psidium cattleianum) on the forest soil ecosystem, we compared soil properties between pairs of adjacent native and P. cattleianum stands. We set up six study sites that had developed under different mean annual precipitation levels in the Ko'olau Mountains on the island of O'ahu, Hawai'i. Accumulated litter mass and soil pH decreased with precipitation in the native stands. Invasion by P. cattleianum increased the amount of litter and reduced the differences in soil water content and pH among the sites. We compared the decomposition process using the Tea Bag Index, which is determined by the difference in dry mass of commercially available green and rooibos teas in nylon mesh bags before and after 90 days of burial. Psidium cattleianum increased the initial litter decomposition rate irrespective of precipitation and other soil properties. On the other hand, P. cattleianum increased the long-term litter stabilization factor of the Tea Bag Index in wetter sites. The accumulation of litter was likely caused by indirect effects of P. cattleianum through the alteration of soil moisture properties. In summary, this study shows that invasion by P. cattleianum could alter the soil properties in both wet and mesic sites, suggesting the possibility of change in composition and/or function of decomposers..
23. Effects of sika deer on long-term stand dynamics of Abies-Tsuga forest in the Kyushu mountain range
九州大学宮崎演習林内の冷温帯針広混交林に1971年に設定した調査地を2013年に復元し,森林構造と種組成を再調査した。1971年に林床を被覆していたスズタケは2013年には完全に消失した。その他の下層の木本も,シカが摂食しないシキミとアセビ以外は消失した。樹高2m 以上の木本も種数,幹数とも大きく減少した。特に胸高直径5cm 未満の木本は幹数が20%程度まで減少した。胸高直径5cm 以上の針葉樹は,同サイズの広葉樹よりも成長速度が速かった。死亡率は落葉広葉樹が常緑針葉樹や常緑広葉樹よりも低かった。モミはツガよりも成長速度が速く,死亡率が高かった。モミの優占度はツガよりも大きかったが,今後はツガの優占度が増加するかもしれない。しかし,シキミとアセビ以外の新規加入がみられないため,さらに長期的にはシキミとアセビが優占する林分になる可能性がある。In 2013, we reestablished study plots established in1971 in a cool temperate mixed forest in the Shiiba Research Forest, Kyushu University. We identified the trees measured in the former study, and measured stand structure and species composition again. The understory had mostly been denuded by sika deer browsing in 2013, while Sasa borealis covered the forest floor thickly in 1971. The number of species and stems of trees taller than 2m in height also decreased largely. Especially, the stem numbers of trees smaller than 5cm in diameter at breast height (DBH) decreased up to 20%. The growth rate of conifer larger than or equal to 5cm in DBH was larger than those of broad-leaved trees. The mortality of deciduous trees was smaller than those of evergreen trees. The larger growth rate of Abies firma corresponded to the larger dominance of A. firma than Tsuga sieboldii. The low mortality of T. sieboldii suggested that the dominance of T. sieboldii would increase in the future. Further, the stand would be dominated by two species sika deer cannot consume, Illicium anisatum and Pieris japonica subsp. japonica, because no species other than the two species regenerated in the stands..
24. Model Forests in Kasuya Research Forest(1)
九州大学農学部附属演習林福岡演習林第9次森林管理計画書(2015~2024年度)において指定された見本林のうち,陣馬の大杉見本林とヌマスギ見本林について,2015 年度に設定と概要調査を行った。その結果,陣馬の大杉見本林では,高齢のスギが平均直径63cm,平均樹高29m,立木密度194本/ha だった。ヌマスギ見本林は,40年生で平均直径51cm,平均樹高21mだった。The ninth Kasuya Research Forest Management Plan (2015-2024) designated the conservation and monitoring of model forests in Kasuya Research Forest. In 2015, we surveyed the Jimba-no-oosugi (Cryptomeria japonica) model forest and Tacodium distichum model forests. The mean diameter at breast height, tree height and tree density in the Jimba-no-oosugi model forest were 63cm, 29m and 194 trees/ha, respectively. The mean diameter at breast height and tree height in the Tacodium distichum model forest were 51cm and 21m, respectively..
25. Forest dynamics during 8 years at the three monitoring plots for long-term forest dynamics in the Shiiba Research Forest.
九州大学農学部附属演習林宮崎演習林では,3ヵ所(合戦原,丸十,広野)に森林動態モニタリングプロット1ha(100m×100 m)が設定され,100年を超える長期的な計画のもと,胸高周囲長が15cm 以上の樹木を対象に継続して毎木調査が行われている。継続調査の初期8年間の森林動態を調べた結果,3プロットともに,立木密度は低下し,胸高断面積合計と総現存量は増加した。総現存量の年平均増加量は合戦原,丸十,広野のそれぞれで3.3, 3.9, 7.1 Mg/ha/yr で,3つのプロットの平均は4.8 Mg/ha/yr であった。立木密度の低下は胸高直径20cm 以下の小径木で多くみられた。また,胸高周囲長15cm 以上への新規加入個体はいずれのプロットでも枯損木本数を下回っていた。調査期間中,3つのプロットとも種構成や多様度指数に大きな変化はなかった。小径木の減少が継続すれば,現存量や生産量の減少が生じる可能性がある。Three 1 ha monitoring plots, which had named as Kasebaru, Maruju and Hirono, were established at different locations in Shiiba Research Forest. At these plots, the forest dynamics have been monitored under the plan lasting more than 100 years. During 8 years from the starting monitoring, stem densities decreased, and total basal area and total biomass stock increased at the all three plots. Average annual increments of total biomass were 3.3, 3.9 and 7.1 Mg/ha/yr, with the mean of 4.8 Mg/ha/yr, at Kasebaru, Maruju and Hirono, respectively. The decline in stem density was mainly due to mortality of the individuals which have less than 20 cm in stem diameter. The number of recruitment individuals with >15cm in girth at breast height was less than that of dead individuals with >15cm in girth at breast height at the all plots. During the 8 years, species composition and diversity index were not changed at the all plots. The long-lasting decline of small trees may result in the decline of forest biomass and productivity..
26. Tsutomu Enoki, Tsuneaki Yabe, Toru Koizumi, Changes in spatial patterns of sika deer distribution and herbivory of planted seedlings: a comparison before and after deer population control by culling, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-015-0515-0, 21, 2, 84-91, 2016.04, Sika deer (Cervus nippon) sometimes cause extensive damage to planted tree seedlings. To evaluate the effects of culling on the spatial distribution patterns of sika deer and browse damage to planted seedlings, we compared the data collected before and after experimental culling in a cool, temperate, mixed forest on Kyushu Island, Japan. Experimental culling, conducted in an area of 1 km(2), removed five, four and two sika deer in April, June and October 2011, respectively. During the year before culling, the spatial pattern of the number of sika deer caught on camera corresponded to the predicted sika deer density. Sika deer immediately browsed planted seedlings after the initial planting. The cumulative number of browsed seedlings increased over time, especially in winter. The spatial pattern of the cumulative number of sika deer caught on camera corresponded to that of browsed seedlings at the year's end. During the year when culling was conducted, the number of sika deer caught on camera decreased around the center of the study site where the culling was conducted and the number of browsed seedlings decreased. During the year following culling, the cumulative number of browsed seedlings was very similar to that in the year before the culling, while the same low number of sika deer was caught on camera. These results indicate that the effects of deer culling resulted in decreased levels of sika deer appearance and browse damage for more than 1 year and for several months, respectively..
27. Soil movement on forest slope with impoverished understory vegetation induced by sika deer grazing in Shiiba Research Forest, Kyushu University
Since around 1980, Sasa borealis (Hack.) Makino et Shibata on forest floor has been impoverished with increase in the density of sika deer (Cervus nippon) in the Shiiba Research Forest, Kyushu University. Understory vegetation in a considerable area of the Sampoudake-danchi had been eliminated for around 20 years. To evaluate the effects of the long term elimination of understory vegetation on the soil movement, we measured amounts of moved soil and of splashed soil with soil trap and splash cup, respectively, on slopes of the forest with and without S. borealis. The amounts of moved and splashed soils were smaller in the forest without S. borealis, though the amount of throughfall was larger. The ratio of gravel in the surface soil of the forest without S. borealis was larger than that with S. borealis. The larger amount of gravel is a reason of smaller amounts of the moved and splashed soils in the forest without S. borealis. The ratios of gravel in the moved and splashed soil were smaller than that of the surface soil. Long-term erosion of fine soil could create the higher ratio of gravel in the surface soil..
28. Dynamics of Sasa borealis (Hack.) Makino et Shibata community induced by the grazing of sika deer (Cervus nippon) : The change from 2003 to 2014 in Shiiba Research Forest, Kyushu University
九州山地中央部に位置する九州大学宮崎演習林(2, 915ha)において, 2003年と2014年にスズタケの健全度調査を行い, ニホンジカによる摂食がスズタケの分布に及ぼす影響を評価した。2003年では三方岳団地(2, 282ha), 萱原山団地(146ha)の大部分でスズダケが消失していたが, 津野岳団地(487ha)ではほとんどの林地でスズタケが生育していた。2014年には三方岳団地および萱原山団地において前回の調査時に消失していたスズタケが回復した場所はなかった。一方、津野岳団地においてはスズタケの衰退が進行し, 大部分でスズタケが消失していた。津野岳団地で実施したスポットライトセンサスの結果, 近年の同団地におけるニホンジカ個体数に急激な増加が見られており, そのことが津野岳団地での急激なスズタケの衰退に繋がったと考えられた。また, スズタケが残存する場所の地形的特徴や林分の特徴などを検討した結果, 標高が低く, 施業が近年実施された場所でスズタケが残る傾向にあった。The distribution patterns of Sasa borealis (Hack.) Makino et Shibata in the Shiiba Research Forest, Kyushu University (2,915ha) were compared between 2003 and 2014, to evaluate the effects of sika deer (Cervus nippon) on the forest floor vegetation. In 2003, S. borealis was not observed in most of Sampo-dake area (2,282 ha) and Kayahara-yama area (146 ha), while it was observed in most of Tsuno-dake area (487 ha). In 2014, S. borealis was declined in most of Tsuno-dake area. We recently obseved a rapid increase in sika deer density in the Tsuno-dake area on spotlight census. There was no area in which S. borealis recovered. S. borealis tended to remain in low elevation and in the area where silvicultural manipulation had been conducted during the period between the surveys..
29. Rieko Urakawa, Nobuhito Ohte, Hideaki Shibata, Kazuo Isobe, Ryunosuke Tateno, Tomoki Oda, Takuo Hishi, Keitaro Fukushima, Yoshiyuki Inagaki, Keizo Hirai, Nobuhiro Oyanagi, Makoto Nakata, Hiroto Toda, Tanaka Kenta, Megumi Kuroiwa, Tsunehiro Watanabe, Karibu Fukuzawa, Naoko Tokuchi, Shin Ugawa, Tsutomu Enoki, Asami Nakanishi, Nobuko Saigusa, Yukio Yamao, Ayumi Kotani, Factors contributing to soil nitrogen mineralization and nitrification rates of forest soils in the Japanese archipelago, FOREST ECOLOGY AND MANAGEMENT, 10.1016/j.foreco.2015.11.033, 361, 382-396, 2016.02, Nitrogen (N) is the primary limiting nutrient for forest production. Therefore, understanding how environmental factors affect N transformation rates is essential for the provision of sustainable ecosystem services. Because these factors are interlinked, it is important to consider direct and indirect structural relationships to better understand the factors contributing to N transformations. In this study, we analyzed the structural cause-effect relationships surrounding N transformations by structural equation modeling using a database containing net and gross N transformation rates and related soil chemical properties from 38 sites across the Japanese archipelago. The average net N mineralization and nitrification rates in the Japanese forest soils were 0.62 +/- 0.68 and 0.59 +/- 0.65 mg N kg(-1) d(-1), respectively, and gross N mineralization and nitrification rates were 4.22 +/- 3.59 and 0.98 +/- 0.68 mg N kg(-1) d(-1), respectively. Compared with previous large scale studies, net and gross N transformation rates in Japanese forest soils were considerably diverse despite their relatively small land area and were representative of temperate forest ecosystems. Structural equation modeling analysis showed that net N transformations were directly affected by gross N transformations, which in turn were significantly and directly affected by soil organic matter contents. Soil organic matter was significantly affected by organic layer amount, tree species and soil group. The effect of soil group was the greatest among these factors, suggesting that soil organic matter contents in Japanese forest soils were mainly influenced by soil parent materials. This was especially evident for Andosols, which are derived from volcanic sediments and contain large amounts of soil organic matter leading to high N transformation rates in the Japanese forest soils. Among the factors related to organic layers and mineral soil layers, soil organic matter content and organic layer amount, which represent substrate availability, had significant effects on gross and net N transformation rates. However, by refining the scale of the dataset using soil groups/soil parent materials, the influence of substrate quality and soil chemical properties on N transformations was suggested. From the current dataset, it was indicated that soil parent materials were the most important factor controlling the pattern of N transformations in the soil of Japanese forest ecosystems. This conclusion should be repeatedly refined considering the spatial distribution of factors such as climatic conditions and forest types with additional site datasets obtained from future surveys. (C) 2015 Elsevier B.V. All rights reserved..
30. Masaaki Chiwa, Shoko Ikezaki, Ayumi Katayama, Tsutomu Enoki, Topographic Influence on Plant Nitrogen and Phosphorus Stoichiometry in a Temperate Forested Watershed, WATER AIR AND SOIL POLLUTION, 10.1007/s11270-015-2701-2, 227, 1, 2016.01, Plant stoichiometry has been used to diagnose phosphorus (P) limitation caused by increased atmospheric nitrogen (N) deposition. Spatial variability of N/P stoichiometry within a forested watershed has not yet been evaluated. This study conducted synoptic sampling of leaf matter in 27 plots within a temperate forested watershed on low P availability rock (serpentine bedrock) with a moderately high atmospheric N deposition (16 kg N ha(-1) year(-1)) to assess the effects of spatial topographic variation on N/P stoichiometry. Leaf N and P concentrations and N/P ratios of Japanese cypress were assessed, and their spatial variations were evaluated across a catchment. Average leaf P concentration was low (0.66+0.16 mg g(-1)) across the sites, while leaf N concentration was high (13.0 +/- 1.5 mg g(-1)); subsequently, N/P ratios were high (21 +/- 5). In addition, the aboveground biomass growth of Japanese cypress positively correlated with litter P, implying the P limitation of Japanese cypress at the study site. Leaf P concentrations responded to the index of convexity (IC) values more than those of N. Subsequently, the N/P ratio correlated with IC, suggesting that N/P ratios are susceptible to topographic features. This could be partly caused by smaller spatial variability of N availability compared with P, owing to increased atmospheric N deposition. Thus, topography should be taken into consideration when diagnosing P limitation caused by N deposition..
31. Akira Kato, Hiroyuki Obanawa, Yuichi Hayakawa, Manabu Watanabe, Yoshio Yamaguchi, Tsutomu Enoki, Fusion between UAV-SFM and terrestrial laser scanner for field validation of satellite remote sensing, IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2015 2015 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2015 - Proceedings, 10.1109/IGARSS.2015.7326355, 2015-November, 2642-2645, 2015.11, Field tree measurement to collect ground truth data is labor intensive. To make it efficient to collect the field data in a large scale, Unmanned Aerial Vehicle is introduced in this study. An automated photogrammetric technique called Structure from Motion (SfM) is used to create 3D data out of photos collected by UAV. Tree structure created by SfM is compared with the 3D data obtained by several Terrestrial Laser Scanners to see the difference in vertical forest structure. Canopy structure is mainly captured by UAV-SfM and there is more point density around tree canopy than 3D data obtained by airborne laser. The point density of UAV around tree canopy is equivalent to that of TLS data, but tree trunk underneath the canopy cannot be reconstructed well, because the trunk is obscured by tree canopy and it is not visible on photos..
32. Accumulation patterns of soil carbon and nitrogen in a Japanese oak (Quercus crispula) plantation in eastern Hokkaido: Analyses using continuous 0-40 years old stands
本研究は0年生から40年生のミズナラ造林地において下層種であるミヤコザサを含む植生構造の造林後の林齢によって生じる変化が,土壌の炭素と窒素の蓄積,またC/N比に与える影響を評価した。下層種現存量は造林後7年目に極大値となる一山型分布を示した。一方上層種は調査期間中増加し続け,8年目以降は全ての林分において上層種が下層種を上回っていた。葉面積指数の変化から林冠の閉鎖が造林後12年目に起こっていた。林齢による土壌の炭素と窒素の蓄積は両方とも粗大有機物の集積するO層での変化が最も大きく,表層,深層の鉱質土の順に変化が小さくなった。O層で観察された変化は全て林分発達初期に起こっており,炭素蓄積量は造林後10年,窒素蓄積量は20年目まで増加した。O層の炭素蓄積量,および窒素蓄積量は上層木の着葉量との間に正の相関が見られた。O層の窒素蓄積量とC/N比は,下層種の現存量との間にそれぞれ負の相関,正の相関関係が見られた。一方,鉱質土層の窒素蓄積量はササの細根量と負の相関にあった。これらの結果から,林齢の増加に伴う林冠閉鎖や下層種の増減といった植生構造の変化が土壌の炭素および窒素の蓄積に影響を及ぼしていると考えられた。This study assessed the effect of the change in forest structure including understory vegetation of Sasa nipponica on soil C and N accumulation from 0 to 40-yr Japanese oak (Quercus crispula) plantation chronosequence. The peak of understory biomass was at 7 years after afforestation. Biomass of the overstory species linearly increased, and the biomass of overstory species was more than that of understory species after 8-yr. According to leaf mass index change along with stand age, canopy closure was occurred about 12 years after afforestation. The ranges of temporal changes in both soil C and N accumulations increased from surface to deep soil layers. The changes in C and N accumulation of O layer were large during early stage of stand development, and C and N accumulations increased until 10 years and 20 years after afforestation, respectively. Overstory leaf mass positively correlated with C and N accumulations in O layer. Understory biomass negatively correlated with N accumulation in O layer and positively correlated with C/N ratio. The N accumulations both in mineral soil 0-4 and 4-8cm in depth were negatively correlated with fine root mass of S. nipponica. The results suggested that change in vegetation structure such as canopy closure by overstory and dynamics of understory biomass affected soil C and N accumulations..
33. Drivers of soil N mineralization and nitrification rates in forest soils in the Japanese archipelago
[in Japanese].
34. Rieko Urakawa, Nobuhito Ohte, Hideaki Shibata, Ryunosuke Tateno, Takuo Hishi, Keitaro Fukushima, Yoshiyuki Inagaki, Keizo Hirai, Tomoki Oda, Nobuhiro Oyanagi, Makoto Nakata, Hiroto Toda, Tanaka Kenta, Karibu Fukuzawa, Tsunehiro Watanabe, Naoko Tokuchi, Tatsuro Nakaji, Nobuko Saigusa, Yukio Yamao, Asami Nakanishi, Tsutomu Enoki, Shin Ugawa, Atsushi Hayakawa, Ayumi Kotani, Megumi Kuroiwa, Kazuo Isobe, Biogeochemical nitrogen properties of forest soils in the Japanese archipelago, ECOLOGICAL RESEARCH, 10.1007/s11284-014-1212-8, 30, 1, 1-2, 2015.01, This data paper provides some biogeochemical nitrogen (N) properties and related chemical properties of forest soils from 39 sites throughout the Japanese archipelago. The data set was collected and analyzed under the GRENE (Green Network of Excellence) environmental information project and the ReSIN (Regional and comparative Soil Incubation study on Nitrogen dynamics in forest ecosystems) project. The sites cover 44A degrees 20'N to 26A degrees 50'N and the climate ranges from cool-temperate zone to subtropical zone. At each site, litter on forest floor and soil samples (three or four layers to 50 cm depth) were collected between August and November in 2010-2013 from five soil profiles. From the litter layer samples, the stocks and concentrations of total carbon (C) and N were measured. From the mineral soil samples, bulk density, pH (H2O), total C and N concentrations, net and gross rates of N mineralization, nitrification and concentrations of water-soluble substances were measured. The measurements are relevant for other biogeochemical N studies in forest ecosystems and the data set provides basic information on the N pool and fluxes with related chemical properties of forest soils across the Japanese archipelago. The average rates of net and gross N transformation at 20 A degrees C across the sites were 0.26 +/- A 0.47 mgN kg(-1) soil d(-1) for net N mineralization, 0.25 +/- A 0.45 mgN kg(-1) soil d(-1) for net nitrification, 4.06 +/- A 0.47 mgN kg(-1) soil d(-1) for gross N mineralization, and 1.03 +/- A 1.29 mgN kg(-1) soil d(-1) for gross nitrification (average +/- A SD)..
35. Application of Laser Remote Sensing to Forest Ecological Research.
Recent advances in laser technology enable us to capture detailed forest structures quickly and accurately. In the past, airborne laser has been used intensively to measure stand level attributes, such as average tree height, individual tree crowns, canopy cover, canopy stratification, and tree height growth. Using terrestrial lasers we can obtain more accurate stem volume and stem density by identifying the stem structure. Moreover, with the terrestrial laser, we can measure the upper part of stem and crown without human error, which was impossible using conventional ground-based manual measurement. LiDAR has contributed to various fields of forest ecosystem studies in estimating forest light and hydrological environments, predicting stand dynamics, and quantifying parameters for forest conservation. We expect that terrestrial lasers will be used more widely in forest ecological research to quantify physiological function of trees, large-scale, long-term monitoring of forest dynamics, as well as environmental assessment. This fine scale measurement technology has the potential to capture various structural attributes of forest ecosystems, which would allow us to understand and measure ecological processes quantitatively in forest ecosystems..
36. Rieko Urakawa, Hideaki Shibata, Megumi Kuroiwa, Yoshiyuki Inagaki, Ryunosuke Tateno, Takuo Hishi, Karibu Fukuzawa, Keizo Hirai, Hiroto Toda, Nobuhiro Oyanagi, Makoto Nakata, Asami Nakanishi, Keitaro Fukushima, Tsutomu Enoki, Yuichi Suwa, Effects of freeze-thaw cycles resulting from winter climate change on soil nitrogen cycling in ten temperate forest ecosystems throughout the Japanese archipelago, SOIL BIOLOGY & BIOCHEMISTRY, 10.1016/j.soilbio.2014.02.022, 74, 82-94, 2014.07, In temperate forest ecosystems, accelerated freeze-thaw cycles caused by winter climate change are expected to affect nitrogen (N) cycling in soils. Net N mineralization and nitrification rates were investigated via incubations of sieved soils transplanted from ten temperate forest ecosystems to two northern Japan sites with natural snowfall gradients. This was done to address: 1) how freeze-thaw cycles affect N mineralization and nitrification in temperate forest soils; 2) whether freeze-thaw cycles change the soil N transformation rates in the following growing season; and 3) which soil characteristics affect the response of the N transformation rates to freeze-thaw cycles. The effect of freeze-thaw cycles on inorganic N and dissolved organic carbon productions differed among soils, that is, some soils produced more inorganic N and dissolved organic carbon in the conditions imposed by freeze-thaw cycles than in the non-frozen treatment but the others did not. The response to the freeze(t)haw cycles was explained by soil microbial activity (gross N mineralization and nitrification rate) and soil fertility (inorganic N pools in the early spring and water soluble ions). Freeze-thaw cycles significantly increased N transformation rates in the following growing season, suggesting that winter climate change might also affect nutrient availability for vegetation and soil microbes in the growing season. The magnitude and frequency of freeze-thaw cycles were considered to be important indicators of N transformation rates during the growing season, suggesting that the higher intensity of freeze-thaw cycles in the original locations of soils changed the microbial communities and functions with high tolerance to freeze-thaw cycles; this resulted in greater N transformation rates in the following growing season. Microbial activity, soil fertility and climate patterns in the original locations of soils are believed to have an effect on the response to winter climate change and to cause large variability of soil response of N transformation rates to freeze-thaw cycles in both the dormant and growing seasons. (C) 2014 Elsevier Ltd. All rights reserved..
37. Tsutomu Enoki, Tohru Nakashizuka, Shin-ichi Nakano, Takeshi Miki, Yu-Pin Lin, Masahiro Nakaoka, Eri Mizumachi, Hideaki Shibata, Progress in the 21st century: a Roadmap for the Ecological Society of Japan, ECOLOGICAL RESEARCH, 10.1007/s11284-014-1140-7, 29, 3, 357-368, 2014.05, The primary goal of the 60th anniversary symposium of the Ecological Society of Japan (ESJ) was to re-examine the role of the Society. The first of five lectures, "Development of Long-term Ecological Research in Japan," discussed the increasingly important role of long-term and networked research studies. Ecological research in Asia faces many challenges, because Asia features natural and anthropogenic landscapes with highly diverse ecosystems. "Developing Strategies of the Ecological Society of Japan for Worldwide Societies of Ecology with Special Reference to Strategies for Asia" emphasized the role of ESJ in promoting ecological research and outreach in Asia. Ecosystem sustainability is a key issue in both the theory and practice of ecosystem management. A framework concept of an environmental and biodiversity cycle was proposed in the session "Linking Community and Ecosystem Dynamics" for understanding the mechanisms driving the sustainability of ecosystems. Ecosystem services are essential aspects of land use and conservation planning and management. "Integrating Models of Ecosystem Services and Land Use Changes" reviewed recently-developed models that simulate patterns of land-use change and analyze its effects on ecosystem services and also recommended future directions for collaboration among researchers. "Disaster Resilience and Coastal Ecology" highlighted the contributions of ecologists to evaluating the resilience of damaged coastal ecosystems and provided sound proposals to local communities and governments for rehabilitation plans. The past achievements and future directions of ESJ were discussed by the panelists and the audience in "Past and Future of the Ecological Society of Japan."..
38. Experimental transplant of Sasa borealis in Shiiba Research Forest, Kyushu University: clump growth and effect of prescribed burning.
かつて九州大学宮崎演習林(以下、宮崎演習林)ではスズタケ(Sasa borealis (Hack.) Makino et Shibata)がほぼ全域に繁茂していた。しかし、1980年代後半から密度や被覆面積の減少が見られ始め、2004年には宮崎演習林全体の面積の70%以上の場所でスズタケの衰退が確認された。宮崎演習林内でスズタケが絶滅した地域において、2010年に天然生林の林床にスズタケを移植し2013年までの変化を調査した。調査プロットの一部の林床に火入れを行い、プロットの周囲をシカ防護ネットで囲みスズタケを移植した。稈冠の幅(稈の広がりの直角2方向)と1株あたりの稈数、最大稈高、地際の株幅を一年に一回測定した。2013年3月において稈冠幅から求めた稈冠面積、稈数、株幅は初期値より大きく増加していた。稈高にはほとんど変化が見られなかった。火入処理は稈冠面積、稈数、稈高、株幅に影響を及ぼさなかった。.
39. Relationship between tree phenology and cumulative temperature in the Kasuya Research Forest, Kyushu University
九州大学農学部附属演習林福岡演習林では10林班に生育するコナラ(2個体)、ソメイヨシノ(1個体)、ケヤキ(1個体)、コブシ(1個体)の計5個体を対象に樹木フェノロジーを観測してきた。2004年から2010年にかけてデジタルカメラにより撮影された画像をもとに展葉および落葉の季節パターンを検討した結果、ケヤキの展葉期およびコナラの落葉期が他の種と比べて遅い傾向が見られた。いずれの調査木も展葉のほうが落葉よりも温度依存性が高く、落葉には風など温度以外の要因が影響していた。展葉期の温度依存性はソメイヨシノとコブシが高く、コナラとケヤキで低かった。We have been monitoring the tree phenology of five individual trees; Quercus serrata Murray (two trees), Cerasus x yedoensis (Matsum.) A. V. Vassil, Zelkova serrata (Thinb.) Makino and Magnolia kobus DC. in the Kasuya Research Forest, Kyushu University. We analyzed the patterns of foliation and defoliation using the image pictures taken from the ground. The foliation of Z. serrate and the defoliation of a Q. serrate tree were later than the other trees. The temperature dependence of foliation was larger than that of defoliation for all trees. The defoliation was affected by strong winds other than temperature. C. x yedoensis and M. kobus showed larger temperature dependence of the foliation comparing with Q. serrata and Z. serrata..
40. Relationship between tree phenology and cumulative temperature in the Kasuya Research Forest, Kyushu University
九州大学農学部附属演習林福岡演習林では10林班に生育するコナラ(2個体)、ソメイヨシノ(1個体)、ケヤキ(1個体)、コブシ(1個体)の計5個体を対象に樹木フェノロジーを観測してきた。2004年から2010年にかけてデジタルカメラにより撮影された画像をもとに展葉および落葉の季節パターンを検討した結果、ケヤキの展葉期およびコナラの落葉期が他の種と比べて遅い傾向が見られた。いずれの調査木も展葉のほうが落葉よりも温度依存性が高く、落葉には風など温度以外の要因が影響していた。展葉期の温度依存性はソメイヨシノとコブシが高く、コナラとケヤキで低かった。.
41. Tsutomu Enoki, Buntarou Kusumoto, Shuichi Igarashi, Kazuki Tsuji, Stand structure and plant species occurrence in forest edge habitat along different aged roads on Okinawa Island, southwestern Japan, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-012-0383-9, 19, 1, 97-104, 2014.02, We compared stand structure and plant species occurrence on the shoulders of 3-, 10- and 20-year-old roads in a subtropical evergreen broad-leaved forest to document temporal changes in edge effects of forest roads. We recorded 154 vascular species in the study plots, including 3 non-native species. We used generalized linear mixed models to analyze changes in forest structure and plant species composition in relationship to the distance from forest roads. The spatial patterns in stand structure at different distances from roads differed with road age. The large canopy openness on the edge of 3-year-old roads decreased with time after the construction. A progressive decrease in tree height on roadsides was observed after the road construction, suggesting tall trees could not withstand the dry and windy roadside environment. The edge effect on the canopy tended to be larger at higher elevation sites. The spatio-temporal pattern of species occurrence based on distance from roads differed by species. Typical pioneer species such as Schima wallichii and Eurya japonica increased along the edge, while less aggressive pioneer species and understory species decreased. As time passed after the road construction, some climax and understory species decreased at the forest edge, while other climax and understory species increased. The modeling methods proposed in this study could be applied to different roadside and edge study sites..
42. Akira Kato, Koji Kajiwara, Yoshiaki Honda, Manabu Watanabe, Tsutomu Enoki, Yoshio Yamaguchi, Tatsuaki Kobayashi, Efficient field data collection of tropical forest using terrestrial laser scanner, Joint 2014 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2014 and the 35th Canadian Symposium on Remote Sensing, CSRS 2014 International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2014.6946549, 816-819, 2014.01, Various remote sensing technologies are utilized to monitor tropical forest for REDD project. In developing countries, the accuracy of field measurement does not satisfy the quality required for the validation of satellite remotely sensed data. Therefore, we introduce the most portable laser sensor, SICK LMS511, to measure trees in the field of tropical forest and the semi-automatic process to derive tree parameters from the 3D point cloud is established to provide accurate forest inventory data. From the accuracy assessment of the portable laser system provided 3.61 cm of root mean square error (RMSE) of stem diameter and 0.50 m of RMSE of tree height measurement. The portable terrestrial laser sensor can be the standard technique to create forest inventory data for the field validation of satellite remote sensing..
43. Masaaki Chiwa, Tsutomu Enoki, Naoko Higashi, Tomo'omi Kumagai, Kyoichi Otsuki, The Increased Contribution of Atmospheric Nitrogen Deposition to Nitrogen Cycling in a Rural Forested Area of Kyushu, Japan, WATER AIR AND SOIL POLLUTION, 10.1007/s11270-013-1763-2, 224, 11, 2013.11, Japan has been receiving increasing levels of atmospheric nitrogenous pollutants from the East Asian continent over the last few decades, so it is critical to evaluate the impact of this increased atmospheric nitrogen (N) deposition on N cycling even in rural forests. This study evaluated the contribution of the current level of atmospheric N deposition to N cycling in a rural forested area. Bulk precipitation and stream water were collected during 2007-2011 at the Shiiba Research Forest (SRF) located in the central Kyushu mountain range of southern Japan. Litterfall was also collected to investigate the contribution of atmospheric N deposition to total N input (litterfall N+atmospheric N deposition). The results showed that atmospheric depositions of both nitrate (NO3-) and ammonium (NH4+) were a few times higher during 2009-2011 than in 1991. This could be the result of additional N deposition from the increased long-range transport of nitrogenous pollutants from the East Asian continent. The current level of annual N deposition (9.7 kg N ha(-1) year(-1)) at the SRF was comparable with that at many urban sites and was close to the reported threshold values causing N saturation in forest ecosystems. Although current atmospheric N deposition was an important component (23 %) of total N input (43 kg N ha(-1) year(-1)) at the SRF, the concentrations of NO3- in stream water were consistently low (<10 mu mol L-1). These results indicate that atmospheric N deposition is currently largely incorporated into forest ecosystems without excess N export from forested watersheds..
44. Validity of culling techniques for management of overabundant sika deer.
45. Relieving effects of sika deer culling on damage of planted seedling.
46. Flora of Kasuya Research Forest, Kyushu University
九州大学農学部附属演習林福岡演習林(以下, 福岡演習林)では1922年に現在の福岡県糟屋郡篠栗町および久山町に設置されてから現在まで森林の管理を継続的に行ってきた。しかし, 福岡演習林内の植物相については1934年以後報告が無くその後の植物相の変化は明らかでない。そこで本調査では福岡演習林の林班ごとの植物相を調べ77年間での変化を検討した。本調査で維管束植物は小葉植物2科3種, シダ類16科59種, 裸子植物4科7種, 被子植物87科353種で合計422種が確認され, 種組成は1934年の調査と大きく異なった。調査した440方形区において出現頻度の上位5種はテイカカズラ, ヒサカキ, シロダモ, ヤブニッケイ, ネズミモチだった。出現種数は多い順にキク科30種, バラ科22種, オシダ科19種, シソ科17種, マメ科14種だった。また18種の帰化植物が出現し, うち8種は環境省の指定する要注意外来生物であった。Kasuya Research Forest of Kyushu University, which is located in Sasaguri Town and Hisayama Town, Fukuoka Prefecture, has been managed the research forest since 1922. The first and only survey of the entire vegetation in the Research Forest was made in 1934. This study aimed to show the present vegetation of the forest and it's changes for 77 years. The survey was conducted in all 22 areas of the forest. The species composition was remarkably different from the previous survey. The flora of vascular plants recorded were 2 families of Lycopsids including 3 species, 16 families of Ferns including 59 species, 4 families of Gymnospermae including 7 species, and 87 families of Angiospermae including 353 species. Trachelospermum asiaticum, Eurya japonica, Neolitsea sericea, Cinnamomum tenuifolium and Ligustrum japonicum were dominant species. Family name and number of recorded species are as follows; 30 species of Asteraceae, 22 species of Rosaceae, 19 species of Dryopteridaceae, 17 species of Lamiaceae, and 14 species of Fabaceae. Eighteen naturalized species, which were not recorded in the previous survey, were recorded, and eight of them were designated as invasive alien species by the Ministry of the Environment..
47. Sou N. Matsunaga, Shigeru Niwa, Tomoki Mochizuki, Akira Tani, Dai Kusumoto, Yasuhiro Utsumi, Tsutomu Enoki, Tsutom Hiura, Seasonal variation in basal emission rates and composition of mono- and sesquiterpenes emitted from dominant conifers in Japan, ATMOSPHERIC ENVIRONMENT, 10.1016/j.atmosenv.2012.12.004, 69, 124-130, 2013.04, Biogenic volatile organic compounds (BVOCs) are known to play an important role in atmospheric chemistry due to their high reactivity and high emission rates. Therefore, in recent decades, many efforts have been made to estimate the emission rates, composition and allocation of the BVoCs. Monoterpenes (MNTs) and sesquiterpenes (SQTs) are major groups of BVOCs and mainly emitted from coniferous trees. There is quite a few reports discussing the seasonality of basal emission rate, which is a normalized emission rate at a set of standard conditions (e.g. temperature, light intensity), of the BVOCs. Three field measurements were conducted using branch enclosure techniques to determine MNTs and SQTs emission measured from mature trees of Ciyptomeria japonica and Chamaecyparis obtusa, which are the most dominant trees in Japan and account for about 40-50% of Japanese forest in leaf amount throughout the four seasons in southern Japan in 2010. The results are compared with the measurements for the same compound classes obtained at a suburban area of Tokyo, Japan in 2009. The seasonal variation in the basal emissions of MNTs from both tree species at Shiiba did not show significant seasonal changes. For both tree species, the variations in the basal emission of MNTs differ in the two sites, while those of SQTs showed relatively similar variations. Chemical composition of SQTs showed clear and continued seasonal variations, while MNTs did not show any clear seasonal variation for these tree species at both sites. It can be hypothesized that the emissions of BVOC classes (e.g. MNTs and SQTs) depend on leaf age. In this paper, we discuss about the seasonal variations in the basal emission rates and chemical compositions of BVOCs obtained from the two dominant coniferous tree species in Japan based on nine field measurement campaigns conducted at two different sites. (C) 2012 Elsevier Ltd. All rights reserved..
48. Sou N. Matsunaga, Shigeru Niwa, Tomoki Mochizuki, Akira Tani, Dai Kusumoto, Yasuhiro Utsumi, Tsutomu Enoki, Tsutom Hiura, Seasonal variation in basal emission rates and composition of mono- and sesquiterpenes emitted from dominant conifers in Japan, Atmospheric Environment, 10.1016/j.atmosenv.2012.12.004, 69, 124-130, 2013.04, Biogenic volatile organic compounds (BVOCs) are known to play an important role in atmospheric chemistry due to their high reactivity and high emission rates. Therefore, in recent decades, many efforts have been made to estimate the emission rates, composition and allocation of the BVOCs. Monoterpenes (MNTs) and sesquiterpenes (SQTs) are major groups of BVOCs and mainly emitted from coniferous trees. There is quite a few reports discussing the seasonality of basal emission rate, which is a normalized emission rate at a set of standard conditions (e.g. temperature, light intensity), of the BVOCs. Three field measurements were conducted using branch enclosure techniques to determine MNTs and SQTs emission measured from mature trees of Cryptomeria japonica and Chamaecyparis obtusa, which are the most dominant trees in Japan and account for about 40-50% of Japanese forest in leaf amount throughout the four seasons in southern Japan in 2010. The results are compared with the measurements for the same compound classes obtained at a suburban area of Tokyo, Japan in 2009. The seasonal variation in the basal emissions of MNTs from both tree species at Shiiba did not show significant seasonal changes. For both tree species, the variations in the basal emission of MNTs differ in the two sites, while those of SQTs showed relatively similar variations. Chemical composition of SQTs showed clear and continued seasonal variations, while MNTs did not show any clear seasonal variation for these tree species at both sites. It can be hypothesized that the emissions of BVOC classes (e.g. MNTs and SQTs) depend on leaf age. In this paper, we discuss about the seasonal variations in the basal emission rates and chemical compositions of BVOCs obtained from the two dominant coniferous tree species in Japan based on nine field measurement campaigns conducted at two different sites..
49. Efficiency and cost of nuisance deer population control in Ashoro Research Forest.
北海道足寄町に位置する九州大学北海道演習林において実施されたシカ有害鳥獣捕獲の実施状況を明らかにし, 捕獲期間中に目撃されるシカの群れ構成数の動向と捕獲効率や費用との関係について検討した。捕獲期間中, 延べ従事人数は282人, 延べ従事時間は742時間の有害鳥獣捕獲が実施され, 420回の目撃機会があり, 1,711頭を目撃し, 192頭を捕獲した。目撃機会あたり捕獲できる頭数はほとんどの場合1頭であったことから, 目撃機会あたりの群れ構成数が大きいほど取り逃しが増え警戒心の強いシカを生み出すことが懸念された。時間経過にともなう目撃頭数の変化は見られなかったが, 捕獲頭数は減少しており, 時間経過にともなう捕獲効率の低下が示唆された。有害鳥獣捕獲における収支額は一人あたり全体の平均で673円/時間であった。捕獲効率や収支状況は構成した班によって異なっていた。以上の結果から, 詳細なデータを元に捕獲の効果とコストを検証しながら最適な個体数調整の方法を模索していくことが重要であると考えられた。We evaluated the efficiency and cost of nuisance deer (Cervus nippon yesoensis) population control by shooting conducted in Ashoro Research Forest of Kyushu University. We also analyzed the relationships between the catch efficiency and the trend of the deer population size. 282 person (742 person-hours) were taken in the period of the population control. We found 1,711 deer on 420 opportunities for sighting of deer. In most cases, only one deer was captured per one sighting. The larger number of deer in a group sighted, the larger number of deer would be missed. It is concerned about increase in the vigilance of deer. The number of sighted deer per one opportunity did not change with time after the control started, while the efficiency of catch decreased. The balance payment of the population control was 673 yen/hour on average. The efficiency and cost differed with hunting group. The results of our study confirmed that it is important to explore the adequate method of the population control with evaluation of the efficiency and cost..
50. Monitoring plots for long-term forest dynamics in the Shiiba Research Forest.
九州大学農学部附属演習林宮崎演習林では3つの100m×100mの長期森林動態モニタリングプロット(合戦原, 丸十, 広野プロット)を設定し, 胸高周囲長15cm以上の樹木を対象にした林分情報の収集を行っている。2005年および2006年に行われた第1回目の調査の結果, シカの食害の影響をあまり受けていない合戦原プロットの直径頻度分布はL字型を示したが, 影響を強く受けてきた丸十プロットでは胸高直径10 cm以下の幹が少なかった。合戦原プロットのみに出現する種には小径木が多かった。これらの結果から, シカによる影響が森林構造および種組成にも及んでいる可能性が示された。比較的近年まで人為の影響を受けたと考えられる広野プロットはアカマツが優占し, 一山型の直径頻度分布を示した。We established three long-term forest dynamics monitoring plots (Kasebaru, Maruju and Hirono plot) in the Shiiba Research Forest, Kyushu University. We have been censussing for trees lager than 15cm in girth in the plots. The DBH (Diameter at Breast Height) frequency distribution was L shaped in the Kasebaru plot in which effects of sika deer (Cervus nippon) were not large, while frequency of trees smaller than 10cm in diameter was small in the Maruju plot in which effects of sika deer were extensive. DBH of the species only found in the Kasebaru plot was small. The results suggest that the effect of sika deer was appered in the difference in the stand structure and species composition. Pinus densiflora was dominant in the Hirono plot in which human impact exerted until recently. The DBH frequency distribution of P. densiflora was bell shaped..
51. Buntarou Kusumoto, Tsutomu Enoki, Yasuhiro Kubota, Determinant factors influencing the spatial distributions of subtropical lianas are correlated with components of functional trait spectra, ECOLOGICAL RESEARCH, 10.1007/s11284-012-0993-x, 28, 1, 9-19, 2013.01, Lianas are important vegetation components that control structure and function, especially in tropical and subtropical forests. To explore the spatial assembly mechanisms of a subtropical liana community, we tested the following hypotheses: spatial distributions of subtropical lianas are determined by forest structures and topographic features, which are surrogates for host/light availability and edaphic/water conditions, respectively, and these effects are mediated through species functional traits. We examined the spatial distribution of lianas in two plots (areas 9 and 16 ha) representing landscapes in an intact forest and a secondary forest, and analyzed spatial distribution pattern at the species level using a simple, spatially explicit model. We also examined the correlations between determinant factors for species distribution and species functional traits, including climbing habits, leaf traits and wood density. The spatial distribution of lianas was controlled mainly by topographic gradient. Most species had preferences for concave topographies, i.e., valley habitats. Any covariates related to the host (or to light) had little influence on the distribution of most liana species. Distributional responses to topography were different among species, and associated significantly with leaf nitrogen content and climbing habit, but not with wood density. The correlation between variation in habitat preferences and leaf economic spectrum suggests that an environmental filter for physiological response to topography is the important mechanism shaping the spatial patterns of this subtropical liana community..
52. Sou N. Matsunaga, Satoru Chatani, Seiji Nakatsuka, Dai Kusumoto, Katsuyoshi Kubota, Yasuhiro Utsumi, Tsutomu Enoki, Akira Tani, Tsutom Hiura, Determination and potential importance of diterpene (kaur-16-ene) emitted from dominant coniferous trees in Japan, CHEMOSPHERE, 10.1016/j.chemosphere.2012.01.040, 87, 8, 886-893, 2012.05, Reactive volatile organic compounds (VOCs) are known to affect atmospheric chemistry. Biogenic VOCs (BVOCs) have a significant impact on regional air quality due to their large emission rates and high reactivities. Diterpenes (most particularly, kaur-16-ene) were detected in all of the 205 enclosure air samples collected over multiple seasons at two different sites from Cryptomeria japonica and Chamaecyparis balsa trees, the dominant coniferous trees in Japan,. The emission rate of kaur-16-ene, was determined to be from 0.01 to 7.1 mu g dwg(-1) h(-1) (average: 0.61 mu g dwg(-1) h(-1)) employing branch enclosure measurements using adsorbent sampling followed by solid phase-liquid extraction techniques. The emission rate was comparable to that of monoterpenes, which is known major BVOC emissions, collected from the same branches. In addition, total emission of kaur-16-ene at 30 degrees C was estimated to exceed that of total anthropogenic VOC emissions. (C) 2012 Elsevier Ltd. All rights reserved..
53. The preserved and model forests of Shiiba Research Forest(V)
九州大学農学部附属演習林宮崎演習林第6次森林管理計画書(2006~2015年)で設定とモニタリングが指定されている学術参考保護林と見本林のうち,モミ・ツガ学術参考保護林,スギ長伐期大径木見本林,アカエゾマツ・トドマツ見本林,シラカンバ見本林を2010年度に設定し,20m×20mの調査プロットにおいて,環境省のモニタリングサイト1000に準拠した毎本調査を行った。今回は学術参考保護林と見本林の調査結果について報告する。The sixth Shiiba Research Forest Management Plan (2006-2015 years) designated the conservation and monitoring of characteristic forests in Shiiba Research Forest. In 2010, we settled the Abies firma and Tsuga sieboldii Preserved Forest, the Betula platyphylla Model Forest, In a 20 x 20m plot on each of the forest, we measured the tree species compositions and the density..
54. Height growth variation of planted Sciadopitys verticillata with tree size and the position on a slope
九州大学農学部附属演習林宮崎演習林では,コウヤマキの人工造林の可能性を探ることを目的として, 1987年からコウヤマキの繁殖試験を開始し,1992年に実生苗を植栽した。本研究では,このコウヤマキ植栽本を対象に1995年,2000年, 2011年にそれぞれ生存状態の確認と樹高の測定を行った。その結果,1995年の調査では,植栽本数561本のうち生存個体数は415本で枯死率は26%,2000年では枯死個体数は291本と減少し枯死率は48%であった。2011年では枯宛率の大量な変化はなかった。また,1995年調査時の平均樹高は20.5cmであり,2000年では62.5cm, 2011年では216.8cmであった。樹高頻度分布の歪度は1995年では正の値を示し,2000年で増加した後,2011年には減少して負の値を示した。1995年から2000年までの樹高成長量には,1995年の樹高と尾根からの距離が正の影響を与えていた。2000年から2011年までの樹高成長量には2以均年の樹高が正の影響を,尾根からの距離が負の影響を与えていた。In shiiba Research Forest, Kyushu University, to investigate the possibility of Sciadopitys verticillata plantation silviculture, we started a reproduction study Siadopitys verticillata in 1987, 5651 seedlings in April 1992. We recorded the survival and measured the stem height for all planted seedlings in 1995, 2000 and 2011. The mortalities were 26% and 48% in 1995 and 2000, respectively. The mortality did not change after 2000. Mean values of seedling height were 20.5cm, 62.5cm, and 216.8cm in 1995, 2000 and 2011, respectively. The seedling height growth rate, on the other hand, during 2000-2011, the distance negatively affected the height growth rate..
55. Height growth variation of planted Sciadopitys verticillata with tree size and the position on a slope
九州大学農学部附属演習林宮崎演習林では,コウヤマキの人工造林の可能性を探ることを目的として,1987年からコウヤマキの繁殖試験を開始し,1992年に実生苗を植栽した。本研究では,このコウヤマキ植栽木を対象に1995年,2000年,2011年にそれぞれ生存状態の確認と樹高の測定を行った。その結果,1995年の調査では,植栽本数561本のうち生存個体数は415本で枯死率は26%,2000年では枯死個体数は291本と減少し枯死率は48%であった。2011年では枯死率の大きな変化はなかった。また,1995年調査時の平均樹高は20.5cmであり,2000年では62.5cm,2011年では216.8cmであった。樹高頻度分布の歪度は1995年では正の値を示し,2000年で増加した後,2011年には減少して負の値を示した。1995年から2000年までの樹高成長量には,1995年の樹高と尾根からの距離が正の影響を与えていた。2000年から2011年までの樹高成長量には2000年の樹高が正の影響を,尾根からの距離が負の影響を与えていた。.
56. Initial growth of Chamaecyparis obtusa in rooted cutting and seedling planted in a high altitude area on the Kyushu Mountains
これまで九州大学宵崎演習林では実生によるヒノキ苗の植栽を行なってきたが、近年ではヒノキ苗においても挿し木品種苗が開発されている。本研究では、九州山地の高標高地域におけるヒノキ挿し木苗の有用性を検討するために、ナンゴウヒ、カミコウ2号の挿し本品種と実生苗を植栽し、初期6年聞の生残率と成長在比較した。実生苗はシカによる食害を強く受けたのに対し、挿木苗はほとんど食害を受けなかった。その結果、挿し木苗は実生苗に比べ生存率が高く、調査終了時の樹高も高くなった。We have been planted seedling for the plantation of Chamaecyparis obtuse in the Shiiba Research Rorest, Kyushu University. Recently, rooted cutting of C. obutusa has been developed. To investigate the usefulness of the root cutting of C. obtuse for the plantation in high elevation area on the Kyushu Mountains, we compared the survival ratio and growth rate between 2 rooted cutting cultivars, Nangouhi and Kamikou 2, and seedlings for initial 6 years. Two rooted cutting cultivars showed higher survival ratio and growth rate than seedlings. The rooted cuttings had littele damage by sika deer (Cervus nippon), while seedlings had severe damage..
57. Initial growth of Chamaecyparis obtusa in rooted cutting and seedling planted in a high altitude area on the Kyushu Mountains
これまで九州大学宮崎演習林では実生によるヒノキ苗の植栽を行なってきたが、近年ではヒノキ苗においても挿し木品種苗が開発されている。本研究では、九州山地の高標高地域におけるヒノキ挿し木苗の有用性を検討するために、ナンゴウヒ、カミコウ2号の挿し木品種と実生苗を植栽し、初期6年間の生残率と成長を比較した。実生苗はシカによる食害を強く受けたのに対し、挿木苗はほとんど食害を受けなかった。その結果、挿し木苗は実生苗に比べ生存率が高く、調査終了時の樹高も高くなった。.
58. The preserved and model forests of Shiiba Research Forest (5)
九州大学農学部附属演習林宮崎演習林第6次森林管理計画書(2006~2015年)で設定とモニタリングが指定されている学術参考保護林と見本林のうち,モミ・ツガ学術参考保護林,スギ長伐期大径木見本林,アカエゾマツ・トドマツ見本林,シラカンバ見本林を2010年度に設定し,20m×20mの調査プロットにおいて,環境省のモニタリングサイト1000に準拠した毎木調査を行った。今回は学術参考保護林と見本林の調査結果について報告する。.
59. Masae I. Ishihara, Satoshi N. Suzuki, Masahiro Nakamura, Tsutomu Enoki, Akio Fujiwara, Tsutom Hiura, Kosuke Homma, Daisuke Hoshino, Kazuhiko Hoshizaki, Hideyuki Ida, Ken Ishida, Akira Itoh, Takayuki Kaneko, Kaname Kubota, Koichiro Kuraji, Shigeo Kuramoto, Akifumi Makita, Takashi Masaki, Kanji Namikawa, Kaoru Niiyama, Mahoko Noguchi, Haruto Nomiya, Tatsuhiro Ohkubo, Satoshi Saito, Takeshi Sakai, Michinori Sakimoto, Hitoshi Sakio, Hirofumi Shibano, Hisashi Sugita, Mitsuo Suzuki, Atsushi Takashima, Nobuyuki Tanaka, Naoaki Tashiro, Naoko Tokuchi, Toshiya Yoshida, Yumiko Yoshida, Forest stand structure, composition, and dynamics in 34 sites over Japan, ECOLOGICAL RESEARCH, 10.1007/s11284-011-0847-y, 26, 6, 1007-1008, 2011.11, This data paper reports tree census data collected in a network of 34 forest sites in Japan. This is the largest forest data set freely available in Japan to date. The network is a part of the Monitoring Sites 1000 Project launched by the Ministry of the Environment, Japan. It covers subarctic to subtropical climate zones and the four major forest types in Japan. Forty-two permanent plots, usually 1 ha in size, were established in old-growth or secondary natural forests. Censuses of woody species a parts per thousand yen15 cm girth at breast height were conducted every year or once during 2004 to 2009. The data provide species abundance, survivorship and stem girth growth of 52,534 individuals of 334 tree and liana species. The censuses adopted common census protocol, which provide good opportunities for meta-analyses and comparative studies among forests. The data have been used for ecological studies as well as for the biodiversity reports published by the Ministry of the Environment..
60. Tsutomu Enoki, Takafumi Inoue, Naoaki Tashiro, Hiroaki Ishii, Aboveground productivity of an unsuccessful 140-year-old Cryptomeria japonica plantation in northern Kyushu, Japan, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-010-0226-5, 16, 4, 268-274, 2011.08, We measured the aboveground biomass, biomass increment and litterfall production of a 140-year-old, abandoned Cryptomeria japonica plantation in order to infer the effects of topography on biomass production. The plantation was unsuccessful and the naturally regenerated broad-leaved trees contributed 93.4% (374.2 Mg ha(-1)) of the total aboveground biomass (400.2 Mg ha(-1)). Comparing between different slope positions, aboveground biomass decreased downslope corresponding to the decrease in broad-leaved tree biomass. The biomass of C. japonica did not vary with slope position. Biomass increment and litterfall production of the broad-leaved trees also decreased downslope. However, litterfall production per unit biomass and aboveground net primary production per unit biomass increased downslope. Results of a path analysis showed that biomass increment of C. japonica decreased with increasing topographical convexity, whereas biomass and litterfall production of broad-leaved tree increased. Litterfall production of broad-leaved tree decreased with increasing biomass of C. japonica, suggesting that, despite their small biomass, the presence of residual C. japonica may have negative effects on the distribution and productivity of the broad-leaved trees. Our results indicated that total aboveground biomass of the study site was comparable to that of old-growth C. japonica plantations. We inferred that the variation in aboveground biomass of the broad-leaved trees was largely determined by the topography, while their productivity was affected by interactions with planted C. japonica..
61. 谷 晃, Volatile diterpene emission from dominant conifers in Japan, Biogeosciences Discussions, 8, 6681-6700, 2011.07.
62. The preserved and model forests of Shiiba Research Forest (4)
九州大学農学部附属演習林宮崎演習林第6次森林管理計画書(2006~2015年)で設定とモニタリングが指定されている学術参考保護林と見本林のうち, ヒノキ長伐期大径木見本林, カラマツ見本林, アカマツ・モミ・ツガ天然生見本林を2009年度に設定し, 20m×20mの調査プロットにおいて, 環境省のモニタリングサイト1000に準拠した毎木調査を行った。今回は見本林の調査結果について報告する。The sixth Shiiba Research Forest Management Plan (2006-2015 years) designated the conservation and monitoring of characteristic forests in Shiiba Research Forest. In 2008, we settled the Long Cutting Time Model Forest of Chamaecyparis obtusa, the Larix kaempferi Model Forest, the Naturally Regenerated Model Forest of Pinus densiflora, Abies firma and Tsuga sieboldii. In a 20 x 20m plot on each of the forest, we measured the tree species compositions and the density..
63. Shinjiro Fujii, Yasuhiro Kubota, Tsutomu Enoki, Long-term ecological impacts of clear-fell logging on tree species diversity in a subtropical forest, southern Japan, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-010-0191-z, 15, 5, 289-298, 2010.10, Defining the spatial arrangement and length of the cutting cycle in a logged area is crucial for reconciling potential conflicts between timber yields and maintenance of ecosystem services in natural forests. In this study, we investigated long-term impacts of clear-fell logging on timber production and tree species diversity in a subtropical forest on the Ryukyu Islands, using an individual-based simulation model. We assumed six logging scenarios defined by combinations of forest type and regeneration processes, which acted as surrogates for spatial scales of clear-fell logging. These scenarios were simulated under cutting cycles ranging from 20 to 150 years. Short-cutting cycles resulted in dominance by the sprouting species Castanopsis sieboldii. The compositional shift was accelerated by the lack of seed dispersal from surrounding forest areas. The simulations demonstrated that a sustainable logging regime maintaining both yield and tree species diversity requires a cutting cycle longer than 50 years. The simulation results also suggest that the trade-off between the recovery of tree species diversity and timber production is favored more in stands surrounded by mature forest than in isolated stands or stands surrounded by immature forest. Ecological risk assessments based on model simulations provide an alternative to current forest management practices that rely on empirical knowledge..
64. Shinjiro Fujii, Yasuhiro Kubota, Tsutomu Enoki, Long-term ecological impacts of clear-fell logging on tree species diversity in a subtropical forest, southern Japan, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-010-0191-z, 15, 5, 289-298, 2010.10, Defining the spatial arrangement and length of the cutting cycle in a logged area is crucial for reconciling potential conflicts between timber yields and maintenance of ecosystem services in natural forests. In this study, we investigated long-term impacts of clear-fell logging on timber production and tree species diversity in a subtropical forest on the Ryukyu Islands, using an individual-based simulation model. We assumed six logging scenarios defined by combinations of forest type and regeneration processes, which acted as surrogates for spatial scales of clear-fell logging. These scenarios were simulated under cutting cycles ranging from 20 to 150 years. Short-cutting cycles resulted in dominance by the sprouting species Castanopsis sieboldii. The compositional shift was accelerated by the lack of seed dispersal from surrounding forest areas. The simulations demonstrated that a sustainable logging regime maintaining both yield and tree species diversity requires a cutting cycle longer than 50 years. The simulation results also suggest that the trade-off between the recovery of tree species diversity and timber production is favored more in stands surrounded by mature forest than in isolated stands or stands surrounded by immature forest. Ecological risk assessments based on model simulations provide an alternative to current forest management practices that rely on empirical knowledge..
65. Mammals monitoring in Shiiba Research Forest.
宮崎演習林では2006年4月から職員が演習林内での業務や演習林への移動中において, 日中に目撃した哺乳類の種と数を記録している。本報告では調査当初から2009年3月までの哺乳類の結果をまとめた。調査期間中に目撃された哺乳類は, ヒメネズミ(Apodemus argenteus)1匹, ニホンジカ(Cervus nippon)1973頭, ノウサギ(Lepus brachyurus)7匹, ホンドテン(Martes memlampus memlampus)7匹, ニホンアナグマ(Meles meles anakuma)4匹, ホンドタヌキ(Nyctereutes procyonoides viverrinus)3匹, ムササビ(Petaurista leucogenys)1匹, ニホンモモンガ2匹(Pteromys momonga), イノシシ(Sus scrofa)25頭, ホンドキツネ(Vulpes vulpes japonica)1匹の10種類で合計頭数は2024頭だった。業務1回あたりの哺乳頭目撃数1.6頭となった。シカの目撃数は1月, 5月, 12月に少なかった。宮崎県のレッドデータブックにおいて絶滅危惧1B類に指定されているニホンモモンガ2匹と準絶滅危惧に指定されているムササビ1匹を確認した。本報告から目撃数のモニタリング調査が低コストで技術的な難易度が低く, 複数の記録者でも継続して実施できる有効な手法であることが示された。Reports of mammal sightings in Shiiba Research Forest from April 2008 to March 2009 was analyzed. The name of species and the numbers were recorded during the daily activity of forest staffs. One Apodemus argenteus, 1973 Cervus nippon, Seven Lepus brachyurus, seven Martes memlampus memlampus, four Meles meles anakuma, three Nyctereutes procyonoides viverrinus, one Petaurista leucogenys, two Pteromys momonga, 25 Sus scrofa and one Vulpes vulpes japonica were witnessed by the staffs. P. momonga and P. leucogenys have been designated endangered species of Miyazaki Prefecture. 1.6 head mammals were recorded on each operation. Sighting number of C. nippon changed seasonally and decreased on January, May and December in the three years. Low difficulty and cost of sighting investigation would enable the long-term mammal monitoring..
66. An introduction to forest permanent plot data at Core and Subcore sites of the Forest and Grassland Survey of the Monitoring Sites 1000 Project(News)
モニタリングサイト1000は環境省生物多様性センターの事業であり、そのうち森林・草原調査では、樹木、地表徘徊性甲虫、鳥類を指標生物群として定め、2004年よりモニタリング調査を行っている。本稿では、コアサイト・準コアサイトで取られた樹木に関するデータ(毎木調査データ)が研究・教育・保全政策などに広く活用されるよう、その概要を紹介し、データの活用方法について提案する。.
67. The preselved and model forests of Shiiba research forest (3)
九州大学農学部附属演習林宮崎演習林第6次森林管理計画書(2006~2015年)で設定とモニタリングが指定されている学術参考保護林と見本林のうち,シナノキ学術参考保護林,ヒコサンヒメシャラ・マンサク学術参考保護林,ヒメコマツ・アカマツ学術参考保護林,レンゲツツジ学術参考保護林を2008年度に設定した。レンゲツツジ学術参考保護林を除く3カ所の学術参考保護林で,20m×20mの調査プロットにおいて環境省のモニタリングサイト1000に準拠した毎木調査を行った。その結果,樹種数・個体数とも最も多かったヒメコマツ・アカマツ学術参考保護林では20種151個体が出現し,樹種数・個体数の少なかったシナノキ学術参考保護林では11種45個体が生育していた。.
68. Protection effect of three obstruction nets from animals for Cryptomeria japonica seedling.
宮崎演習林では1985年頃から新植地の苗木に対するシカの食害が目立つようになり, 市販の有害獣防護ネットの設置を継続している。本報告ではスギの新植地において形状の異なる3種のネットを設置し, 4年後にその獣害防除効果を比較した。その結果, ネットで囲わなかった苗木と比較してネットで囲った苗木の食害率は低かった。一方, 枯死率と成長量にはネットの効果や, ネットの形状による差は認められなかった。Three types of obstruction net for animals were placed around Cryptomeria japonica seedlings in Shiiba Research Forest, which have intensive deer feeding problem to seedling for around 25years. After four years protection, feeding rate for seedling was lower in the nets than outside. There was no significant difference between each net type for growth rate and dieback rate of seedling..
69. Shinjiro Fujii, Yasuhiro Kubota, Tsutomu Enoki, Resilience of stand structure and tree species diversity in subtropical forest degraded by clear logging, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-009-0151-7, 14, 6, 373-387, 2009.12, Subtropical forests in the Ryukyu Islands have been degraded by silvicultural practices, and thus their structural attributes are being shifted to other states dominated by a few tree species. This study clarified the mechanisms of the change, and examined the effect of clear logging on the resilience of a subtropical forest. Sprouting regeneration and typhoon disturbance were introduced into an individual-based model, SEIB-DGVM, for describing stand development and succession. The regeneration dynamics from young secondary to old-growth stands were reproduced fairly well with the model. Sprouting recruitment produced high stem density at the beginning of stand development, which caused a self-thinning trajectory following the -3/2 power law. In the late development stage after 70 years, tree species diversity fluctuated because of the regenerative response of sprouting species and the facilitatory effect of typhoon disturbance on the coexistence of subordinate species. The death of canopy trees because of typhoon disturbances reduced the dominance of Castanopsis sieboldii, and depressed its dominance in the understory. Consequently, the understory species could establish by virtue of fallen canopy trees, and tree species diversity increased at the stand level. Clear logging experiments in the model revealed that species diversity deteriorated, especially in the stand dominated by sprouting species. Resilience of subtropical forests was determined by initial species composition before clear logging. Our simulation results suggest that repeated logging drives subtropical forests with high species diversity to a stand monopolized by C. sieboldii..
70. Ikue Murata, Sigefumi Saruki, Katsuyoshi Kubota, Sachiko Inoue, Naoaki Tashiro, Tsutomu Enoki, Yasuhiro Utsumi, Susumu Inoue, Effects of sika deer (Cervus nippon) and dwarf bamboo (Sasamorpha borealis) on seedling emergence and survival in cool-temperate mixed forests in the Kyushu Mountains, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-009-0131-y, 14, 5, 296-301, 2009.10, Effects of sika deer (Cervus nippon) and dwarf bamboo ("sasa;" Sasamorpha borealis) on seedling emergence and survival were investigated in cool-temperate mixed forests in the Kyushu mountain range, Japan. We compared the effects of sika deer between two sites with different sika deer densities. One site (no-sasa forest) has sparse cover of S. borealis and a high density of sika deer, and the other site (sasa forest) has dense cover of S. borealis with a low density of sika deer. In the no-sasa forest, more seedlings emerged and the survival rate of the seedlings was higher compared with the sasa forest. Compared with the sasa forest, the canopy in the no-sasa forest was more open, the organic layer was shallower and drier, the mean daily soil temperature was higher, and soil temperature fluctuated more widely. Those environmental parameters did not differ between unfenced and fenced plots. The comparison between the sasa and no-sasa forests suggested that removal of S. borealis by sika deer had an indirect positive effect on seedling emergence and survival. However, the fenced-plot experiments indicated that sika deer inhibited seedling emergence and survival. These contradictory conclusions could result from the much larger negative effects of S. borealis on seedling emergence and survival compared with the effects of sika deer browsing..
71. Ikue Murata, Sigefumi Saruki, Katsuyoshi Kubota, Sachiko Inoue, Naoaki Tashiro, Tsutomu Enoki, Yasuhiro Utsumi, Susumu Inoue, Effects of sika deer (Cervus nippon) and dwarf bamboo (Sasamorpha borealis) on seedling emergence and survival in cool-temperate mixed forests in the Kyushu Mountains, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-009-0131-y, 14, 5, 296-301, 2009.10, Effects of sika deer (Cervus nippon) and dwarf bamboo ("sasa;" Sasamorpha borealis) on seedling emergence and survival were investigated in cool-temperate mixed forests in the Kyushu mountain range, Japan. We compared the effects of sika deer between two sites with different sika deer densities. One site (no-sasa forest) has sparse cover of S. borealis and a high density of sika deer, and the other site (sasa forest) has dense cover of S. borealis with a low density of sika deer. In the no-sasa forest, more seedlings emerged and the survival rate of the seedlings was higher compared with the sasa forest. Compared with the sasa forest, the canopy in the no-sasa forest was more open, the organic layer was shallower and drier, the mean daily soil temperature was higher, and soil temperature fluctuated more widely. Those environmental parameters did not differ between unfenced and fenced plots. The comparison between the sasa and no-sasa forests suggested that removal of S. borealis by sika deer had an indirect positive effect on seedling emergence and survival. However, the fenced-plot experiments indicated that sika deer inhibited seedling emergence and survival. These contradictory conclusions could result from the much larger negative effects of S. borealis on seedling emergence and survival compared with the effects of sika deer browsing..
72. Effect of understory vegetations on species richness of oribatid mites in abandoned Chamaecyparis obtusa plantation within Ochozu watershed
We investigate effect of understory vegitation on species diversity of oribatid mites in warm-temperate Japanese cypress plantation. Four understory types were selected, uncovered with understory (C), covered mainly with evergreen broad leaved understory (E), with deciduous broad leaved understory (D) and with sasa bamboo understory (S). In all the sites, the dominance of canopy Japanese cypress is more than 90% in total basal area. We observed 2654 individuals and 121 taxa of adult oribatid mites. Species richness and Shannon-Wiener diversity index (H') of oribatid mites is higher in E, D, and S than in C. The difference in species composition was higher between C and the others, E, D and S than among E, D and S. Though the dominance of understory was quite low in forest plantation, the effect of understory on species richness of oribatid mites should be important in mono-dominant cypress plantation..
73. The preserved and model forests of Shiiba Research Forest (2)
九州大学農学部附属演習林宮崎演習林第6次森林管理計画書(2006~2015年)で設定とモニタリングが指定されている学術参考保護林と見本林のうち, サワグルミ・オヒョウ学術参考保護林, アカマツ学術参考保護林, ツクシシャクナゲ学術参考保護林, ツクシアケボノツツジ学術参考保護林, ブナ学術参考保護林を2007年度に設定し, 20m×20mの調査プロットにおいて環境省のモニタリングサイト1000に準拠した毎木調査を行った. その結果, 各調査プロットで12~26種の樹種が存在し, 胸高周囲長15cm以上の個体が39~145本生育していることが明らかになった.The sixth Shiiba Research Forest Management Plan (2006-2015 years) designated the conservation and monitoring of characteristic forests in Shiiba research forest. In 2007, we settled The Pterocarya rhoifolia and Ulmus lociniata Preserved Forest, the Pinus densiflora Preserved Forest, the Rhododendron degronianum subsp. heptamerum Preserved Forest, the Rhododendron pentaphyllum var. pentaphyllum Preserved Forest and Fagus crenata Preserved Forest. In a 20 × 20m plot in each of the forest, we measured the tree species compositions and the density. Each plot had numbers between 12 and 26 species and 39 and 145 individuals more than 15cm boundary length at 1.3m height..
74. Tsutomu Enoki, Moeko Ueda, Daisuke Nanki, Rempei Suwa, Akio Hagihara, Distribution and stem growth patterns of mangrove species along the Nakara River in Iriomote Island, Southwestern Japan, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-008-0094-4, 14, 1, 51-54, 2009.02, We examined variations in stand structure and tree growth of a mangrove forest along two gradients: from the river mouth to upper stream and from the riverside to inland, along the Nakara River, Iriomote Island, Japan. Bruguiera gymnorrhiza (L.) Lamk. occurred throughout the intertidal area, though Rhizophora stylosa Griff. and Kandelia candel (L) Druce did not occur upstream. Basal area and maximum tree height of B. gymnorrhiza decreased downstream. The growth rate in stem diameter of B. gymnorrhiza decreased downstream in relation with the soil salinity. The basal area and the maximum tree height of B. gymnorrhiza increased with the distance from the riverside. R. stylosa increased in stem diameter and growth rate toward the riverside..
75. Variation of tree size of Pinus densiflora with difference in the initial growth rate:Effects of age and topography.
76. Takafumi Inoue, Tsutomu Enoki, Naoaki Tashiro, Kotaro Sakuta, Susumu Inoue, Effects of topography and planted trees on the distribution of naturally regenerated broad-leaved trees in a 140-year-old Cryptomeria japonica plantation in northern Kyushu, Japan, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-008-0095-3, 13, 6, 365-371, 2008.12, We investigated factors affecting the distribution of naturally regenerated broad-leaved trees in a 140-year-old Cryptomeria japonica plantation. We used path analysis to examine the relationship among microtopography, the biomass of planted trees, and the biomasses of canopy and subcanopy trees of broad-leaved species. The study plot was divided into three topographic types (ridge, slope, and valley), and we discuss how the different topographic types are affected. For all topographic types, the biomass of canopy trees of broad-leaved species decreased with convexity. For slope and valley topographies, the biomass of subcanopy trees of broad-leaved species also decreased with convexity. For ridge topography, the biomass of subcanopy trees of broad-leaved species increased with the biomass of planted trees, and decreased with the biomass of canopy trees of broad-leaved species. These results suggest the effects of microtopography on the biomass of subcanopy trees were much larger than the effects of canopy trees for slope and valley topographies, while the effects of microtopography were smaller for ridge topography..
77. Buntarou Kusumoto, Tsutomu Enoki, Yasushi Watanabe, Community structure and topographic distribution of lianas in a watershed on Okinawa, south-western Japan, JOURNAL OF TROPICAL ECOLOGY, 10.1017/S0266467408005452, 24, 675-683, 2008.11, We investigated spatial distribution of lianas, and examined relationships between distribution and topography in a secondary forest on the northern part of the main island of Okinawa, south-west Japan. All lianas with a stem diameter exceeding 2 cm at a point 1.3 m from the root were inventoried. and stem diameter and root position were measured within a small watershed (16.0625 ha). Geographical information systems (GIS) were used to divide the watershed into 257 cells in total, each cell being 25 m x 25 m. Three topographic parameters were measured in each cell: slope angle. slope aspect and relief. In total, 930 stems from 20 species of lianas were recorded. Distribution of all liana stems and 14 of 15 species analysed were biased toward concave sites. Abundance of total lianas was higher in concave sites than in convex sites. Our results suggest that distribution and abundance of lianas are strongly affected by topography, and that lianas tend to be distributed in sites with more water and nutrients, which are formed by relief in the Okinawa forest. Factors affecting stem density differed among species..
78. The preserved and model forests of Shiiba Research Forest (1)
宮崎演習林に学術参考保護林が指定され60年以上が経過した。その間,自然林保全区への編入や名称の変更など様々の経緯を辿ってきた。しかし,その経緯の詳細な記述や調査記録はほとんど残っていないのが現状である。今回,第6次森林管理計画書(2006~2015年)の編成を期に学術参考保護林と見本林が大幅に拡充された。これは,本演習林の特徴的な植生を中心に特定の林相を比較的小面積で保全し,教育研究に供することが目的である。今回は学術参考保護林と見本林の設置計画と調査方法ならびに調査結果について報告する。.
79. Buntarou Kusumoto, Tsutomu Enoki, Contribution of a liana species, Mucuna macrocarpa Wall., to litterfall production and nitrogen input in a subtropical evergreen broad-leaved forest, JOURNAL OF FOREST RESEARCH, 10.1007/s10310-007-0046-4, 13, 1, 35-42, 2008.02, Annual amounts of litterfall and nitrogen input by litterfall were measured in a subtropical evergreen broad-leaved forest to examine the contribution of a liana species, Mucuna macrocarpa Wall., to the spatial heterogeneity of litterfall production and nitrogen input. The total litterfall in the study plot was 7.1 t ha(-1) year(-1). The amount of litterfall varied with topography and was greatest at the valley bottom and decreased toward the ridges. Macuna macrocarpa litterfall was absent on the ridges although it accounted for the largest percentage, 32%, of total leaf litter production in the valley. Nitrogen input by litterfall was 69 kg ha(-1) year(-1) in the plot. Nitrogen input by litterfall was also largest at the valley bottom and decreased toward the ridges. Leaf litter of M. macrocarpa had approximately twice the nitrogen concentration of litterfall of other species. Macuna macrocarpa accounted for 42% of nitrogen input by leaf litter in the valley. The abundance and the high nitrogen concentration of M. macrocarpa intensified differences in the amount of litterfall and nitrogen input by litterfall between valleys and ridges. It was concluded that a liana species, M. macrocarpa, can contribute to the spatial heterogeneity of litterfall and may subsequently affect nutrient cycling in a subtropical evergreen broad-leaved forest on Okinawa Island..
80. A beginning of LTER in Japan : A approach from forest science.
81. Topography-dependent Pattern of Tree Species Distribution on Different Spatial Scales in a Subtropical Evergreen Broad-leaved Forest
I evaluated the difference in the topography-dependent pattern of tree species distribution in a subtropical evergreen broad-leaved forest in the northern part of Okinawa Island. The values and spatial patterns of relief and slope changed with the difference in the spatial scale. The slope and relief had significantly positive relationships between the different scales. The rank of median for the slope and relief of the quadrat in which tree species occurred was not so different with the spatial scale. On the other hand, variable topography-dependent patterns of each tree species distribution were detected on different spatial scales. Castanopsis sieboldii trees clumped in a small convex area (5 mx5 m) both on large convex and concave areas (35 mx35 m), though they distributed on more convex slopes on every spatial scale. Schima wallichii trees distributed on steeper and more concave slopes than C. sieboldii on every spatial scale. With an increase in the tree sizes, C. sieboldii trees distributed on gentler and more convex slopes, while S. wallichii did not show such a significant pattern. The topography-dependent patterns of tree species distribution could be from the topographic structure of the study plot, in addition to being from the results of the tree population response to the topography..
82. Topography-dependent Pattern of Tree Species Distribution on Different Spatial Scales in a Subtropical Evergreen Broad-leaved Forest.
I evaluated the difference in the topography-dependent pattern of tree species distribution in a subtropical evergreen broad-leaved forest in the northern part of Okinawa Island. The values and spatial patterns of relief and slope changed with the difference in the spatial scale. The slope and relief had significantly positive relationships between the different scales. The rank of median for the slope and relief of the quadrat in which tree species occurred was not so different with the spatial scale. On the other hand, variable topography-dependent patterns of each tree species distribution were detected on different spatial scales. Castanopsis sieboldii trees clumped in a small convex area (5 m×5 m) both on large convex and concave areas (35 m×35m), though they distributed on more convex slopes on every spatial scale. Schima wallichii trees distributed on steeper and more concave slopes than C. sieboldii on every spatial scale. With an increase in the tree sizes, C. sieboldii trees distributed on gentler and more convex slopes, while S. wallichii did not show such a significant pattern. The topography-dependent patterns of tree species distribution could be from the topographic structure of the study plot, in addition to being from the results of the tree population response to the topography..
83. A Beginning of LTER in Japan : Approach from Forest Science.
84. Xu, X, Shibata, H, Enoki, T, Decomposition patterns of leaf litter of seven common canopy species in a subtropical forest: dynamics of mineral nutrients., Journal of Forestry Research, 10.1007/s11676-006-0001-9, 17, 1, 1-6, 17:1-6, 2006.03.
85. T Enoki, H Kawaguchi, T Nakashizuka, AA Hamid, Growth pattern and leaf morphology of Shorea parvistipulata saplings in a tropical reclin forest of Sarawak, Malaysia, JOURNAL OF TROPICAL ECOLOGY, 10.1017/S0266467404002020, 21, 215-218, 2005.03.
86. XN Xu, E Hirata, T Enoki, Y Tokashiki, Leaf litter decomposition and nutrient dynamics in a subtropical forest after typhoon disturbance, PLANT ECOLOGY, 10.1023/B:VEGE.0000029319.05980.70, 173, 2, 161-170, 2004.08, Decomposition of typhoon-generated and normal leaf litter and their release patterns for eight nutrient elements were investigated over 3 yr using the litterbag technique in a subtropical evergreen broad-leaved forest on Okinawa Island, Japan. Two common tree species, Castanopsis sieboldii and Schima wallichii, representative of the vegetation and differing in their foliar traits, were selected. The elements analyzed were N, P, K, Ca, Mg, Na, Al, Fe and Mn. Dry mass loss at the end of study varied in the order: typhoon green leaves > typhoon yellow leaves > normal leaves falling for both species. For the same litter type, Schima decomposed faster than Castanopsis. Dry mass remaining after 2 yr of decomposition was positively correlated with initial C: N and C: P ratios. There was a wide range in patterns of nutrient concentration, from a net accumulation to a rapid loss in decomposition. Leaf litter generated by typhoons decomposed more rapidly than did the normal litter, with rapid losses for N and P. Analysis of initial quality for the different litter types showed that the C: P ratios were extremely high (range 896 - 2467) but the P: N ratios were < 0.05 (range 0.02 - 0.04), indicating a likely P-limitation for this forest. On average 32% less N and 60% less P was retranslocated from the typhoon-generated green leaves than from the normal litter for the two species, Castanopsis and Schima. An estimated 2.13 g m(-2) yr(-1) more N and 0.07 g m(-) (2) yr(-1) more P was transferred to the soil as result of typhoon disturbances, which were as high as 52% of N and 74% of P inputted from leaf litter annually in a normal year. Typhoon-driven maintenance of rapid P cycling appears to be an important mechanism by which growth of this Okinawan subtropical forest is maintained..
87. T Enoki, A Abe, Saplings distribution in relation to topography and canopy openness in an evergreen broad-leaved forest, PLANT ECOLOGY, 10.1023/B:VEGE.0000029336.80225.f0, 173, 2, 283-291, 2004.08, We examined the spatial distribution of saplings in relation to topography and stand structure in a subtropical evergreen broad-leaved forest in the northern part of Okinawa Island, Japan. The distributions of most species were influenced mainly by topography but also by canopy openness. Species were arranged along a topographical gradient from concave areas with low canopy openness to convex areas with high canopy openness. Canopy species were arranged along a gradient from unstable fertile areas to stable infertile areas. Species occurring mostly in convex areas had a narrower distribution range than those in concave sites. Thus, habitat heterogeneity provided by topography and stand structure appears to be important factors for maintaining high species diversity in the understory of this subtropical evergreen broad-leaved forest..
88. XN Xu, T Enoki, D Hirata, Y Tokashiki, Pattern and chemical composition of fine litterfall in a subtropical forest in northern Okinawa Island, Japan, BASIC AND APPLIED ECOLOGY, 10.1078/1439-1791-00149, 4, 3, 229-237, 2003.06, The aim of this work was to analyze the pattern and chemical composition of litterfall and to investigate relationships between the contents of nutrient elements in senescent and fresh mature leaves of two dominant species: Castanopsis sieboldii and Schima wallichii, in two forest sites differing in edaphic condition on the northern Okinawa Island, Japan. In this subtropical forest, the mean annual rates of litterfall (including premature litter generated by windstorm) were 684 and 737 g m(-2) yr(-1) at site A and B, respectively. The leaf litter contributed 67% of annual total litterfall. The peak leaf fall occurred in March. Woody litter showed no particular pattern, and its peak fall varied with windstorm. The mean annual nutrient inputs by fine litterfall were, respectively, N 80.1, P 3.2, K 25.8, Ca 58.6 and Mg 17.1 kg ha(-2) yr(-1) at site A; and N 80.6, P 2.9, K 20.7, Ca 65.9 and Mg 17.8 kg ha(-2) yr(-1) at site B. A marked seasonal variability was observed in the concentrations of N, P and K, with no important differences for Ca and Mg, in leaf litter for the two dominants. N, P and K were retranslocated to other tree organs and Ca, Mg, Mn and Al were accumulated in mature leaves. The comparison between leaf litter and fresh mature leaves suggests that the analysis of leaf litter cannot substitute for that of living leaves to evaluate the nutritional status of the species studied for essential elements N, P and K. However, the index of nutrient use efficiency in litterfall can be used as an indicator of soil nutrient conditions. We found site-dependent and between-species differences in nutrient content and nutrient remobilization. The nutrient cycling in this subtropical forest follows a pattern similar to tropical forests, with inefficient within-stand use of N and more efficient cycling of P..
89. T Enoki, Microtopography and distribution of canopy trees in a subtropical evergreen broad-leaved forest in the northern part of Okinawa Island, Japan, ECOLOGICAL RESEARCH, 10.1046/j.1440-1703.2003.00549.x, 18, 2, 103-113, 2003.03, The spatial distribution of trees in relation to topography was investigated using two topographic indices, slope steepness and slope configuration, in a 4-ha plot In a subtropical evergreen forest in the northern part of Okinawa Island, Japan. Most species showed an aggregated distribution and patch size was related to various microtopographical features, including small ridges and valleys. In a cluster analysis based on the dissimilarity of each species' distribution, the species were divided into three major clusters. A significant correlation between the dissimilarity and the distance between each species on the axis of the two topographic indices indicated that species association was, in part, explained by the topographic indices. I suggest that species distributed on steep and concave slopes regenerate depending on disturbances such as landslides on unstable topography, whereas species distributed on ridges and upper slopes regenerate depending on the canopy gap. A number of species that were less abundant in the 4-ha plot occurred in the riparian area near a stream, where the density of more abundant species was low. The results of this study Support the existence of habitat niche divergence related to topography in a subtropical evergreen broad-leaved forest..
90. 呉 立潮, 新里 孝和, 西端 統宏, ほか3名, 榎木 勉, 平田 永二, 沖縄におけるイタジイ優占の常緑広葉樹林の萌芽更新(2)萌芽の位置と成長, 琉球大学農学部学術報告, 48, 48, 153-163, 2001.12, 本論文は亜熱帯照葉樹林地帯において、森林の循環利用のための人為干渉跡地の天然更新とくに萌芽更新システムに関する研究の一環をなす。天然林皆伐地5年後の根株に発生した萌芽枝の位置と成長に関する研究が、沖縄島北部に位置する琉球大学農学部附属与那演習林のイタジイの優占する常緑広葉樹林で実施された。萌芽枝の15.8%は根株の上部に、84.2%は下部に位置するものであった。これはほとんどの萌芽枝が根株の上部よりも下部に発生することを示している。萌芽位置は樹種によって異なる特性をもち、62種のうち、16種は下部に位置する萌芽枝のみであった。相対的に、1種は上部に位置する萌芽枝のみが見られ、2種は萌芽枝のない枯死根株で、43種は上部だけでなく下部に位置する萌芽枝も形成した。ほとんどの樹種は下部に発生したが、7種は、上部に位置する萌芽枝が下部のそれより平均胸高直径と平均樹高とも明らかにより高い値を示した。根株の胸高直径の大きさと萌芽成長に関して、萌芽林の平均胸高直径と平均樹高の解析から胸高直径で3区分できることが認められた。これは萌芽更新に際して伐採前に適切な胸高直径の立木が存在することを指示しているもので、実験地では萌芽更新のための立木の適切な胸高直径は10.0~25.5cmであった。伐採前の立木の胸高直径や樹種による萌芽の特性を知ることは、天然更新施業法における素材生産と多様な森林生物の保全の調和を基調とする萌芽更新システムに関して重要な指針を提示する。.
91. 徐 小牛, 平田 永二, 渡嘉敷 義浩, 榎木 勉, 篠原 武夫, 沖縄島北部における常緑広葉樹林とリュウキュウマツ林の土壌の理化学性比較, 森林立地, 10.18922/jjfe.43.1_1, 43, 1, 1-8, 2001.08, 林相の違いが土壌の養分特性に及ぼす影響について検討するために,沖縄島北部における常緑広葉樹林及びリュウキュウマツ林の鉱質土壌層の理化学的性質を調べた。常緑広葉樹林の土壌有機炭素及び全Nは,マツ林との差が認められなかった。表層土壌のpH及び交換性Ca^<2+>は,マツ林が高く,交換性Al^<3+>及び有効性Pは,逆に常緑広葉樹林の方が高くなっていた。また,交換性K^<+>及びNa^<+>は,両者ほとんど差がなかった。土壌pHは,常緑広葉樹林では下層にいくほど高くなるが,マツ林ではほぼ一定となった。物理性については,表層土壌の容積重は,常緑広葉樹林の方が小さかった。孔隙組成から見ると,常緑広葉樹林では粗孔隙率が細孔隙率より高く,マツ林では逆に細孔隙率が高くなっていた。しかしながら,下層(B2層)土壌の理化学的性質については,常緑広葉樹林とマツ林に違いが見られなかった。クラスター分析による解析では,林相の違いが,表層土壌の性質に大きく影響することが示唆された。.
92. Xiaoniu Xu, Eiji Hirata, Yoshihiro Tokashiki, Takeo Shinohara, Structure and species diversity of subtropical evergreen broad-leaved forest in northern Okinawa Island, Japan, Journal of Forest Research, 10.1007/BF02767094, 6, 3, 203-210, 2001.08, The structure and tree species diversity of a subtropical evergreen broad-leaved forest in northern Okinawa Island, Japan, were studied. Enumeration of the six sampling plots revealed an average density of 5,580 individuals with DBH ≥ 3.0 cm/ha, having an average basal area of 55 m2 ha -1. The large-size trees of DBH ≥ 20 cm contributed 10% of the total individuals, and 49% of the total basal area. The forest showed a high diversity of tree species, which is comparable to some tropical rain forests. A total of 54 overstory species of 24 families and a total of 63 understory species of 26 families were identified in the six sampling plots. Fagaceae and Theaceac were the most important families: Castanopsis sieboldii, Schima wallichii and Distylium racemosum were the most important species. The diversity index and equatability index of species were 4.15 and 0.72 for the overstory plots, and 4.72 and 0.79 for the understory subplots, respectively. The diversity index for the overstory was significantly correlated to the total basal area of trees over 20 cm DBH (p <
0.05) and the importance value of C. sieboldii (p <
0.001). while for understory, the diversity index was not correlated to the structural parameters (all p>
0.16). The size distribution pattern and age structure indicated differences in regeneration strategies for canopy dominants. In population dynamics of the succession process. C. sieboldii and D. racemosum were self-maintaining types, and S. wallichii was a gap- or opening-dependent type..
93. 新里 孝和, 呉 立潮, 西端 統宏, ほか3名, 榎木 勉, 平田 永二, 沖縄島におけるイタジイ優占の常緑広葉樹林の萌芽更新(1)根株の枯死と腐朽に関する研究, 琉球大学農学部学術報告, 47, 47, 145-157, 2000.12, 与那演習林の天然生広葉樹林における皆伐5年後の天然更新の状況を調査した。調査根株は62種、1,893個体であった。全根株の20.2%は枯死し、萌芽枝が発生した根株のうち29.7%が健全、26.5%が部分腐朽、23.6%が枯死根株であった。根株の腐朽状態は樹種と胸高直径によって違いがみられた。枯死率は樹種、生活形による有意差が認められたが、斜面の位置と方位による差はなかった。枯死率と胸高直径の直径の関係は明らかでなかった。調査樹種のうち、2種は生存株が16種は枯死株がみられず、44種は生存株も枯死株もみられた。枯死率は37種が20.0%以下、16種が20.0%以上50.0%以下、9種が50.0%以上であった。沖縄島におけるイタジイの優占する常緑広葉樹林皆伐跡地の天然更新は主として萌芽によるものと考えられた。.
94. Tsutomu Enoki, Hideyuki Kawaguchi, Initial nitrogen content and topographic moisture effects on the decomposition of pine needle, Ecological Research, 10.1046/j.1440-1703.2000.00363.x, 15, 3, 425-434, 2000.09, The effects of litter quality and site characteristics on the decomposition process were investigated using a litterbag method. Pine needle litters with differing nitrogen concentrations (0.8, 0.6 and 0.4%) were placed on the upper and lower slopes of a Pinus thunbergii Parl. plantation. After both 3 and 6 months, the mass of decomposing litter with the lower nitrogen concentration was larger than the litter with higher nitrogen concentrations. After 9 months, there were no significant differences in the litter mass remaining, regardless of the initial nitrogen concentration. Moisture content in the litter was always higher on the lower slope, although the mass of litter was smaller. Nitrogen concentration of the decomposing litter increased linearly with accumulated mass loss. The increase in nitrogen concentration of decomposing litter was greater on the lower slope, but this increase did not differ between initial nitrogen concentrations. The nitrogen release from the decomposing litter with higher initial nitrogen concentration was larger than the release from litter bags with lower nitrogen concentrations. This result suggests that there may be positive feedback between soil nutrient availability, litter quality and nutrient release from decomposing litter at the intraspecific level..
95. X. Xu, Y. Tokashiki, E. Hirata, T. Enoki, K. Nogami, Ecological studies on subtropical evergreen broad-leaved forest in Okinawa, Japan : Litter production and nutrient input, Journal of Forest Research, 10.1007/BF02762394, 5, 3, 151-156, 2000.09.
96. Stream water chemistry of university forests over Japan.
Extensive research on forest stream water chemistry gives important information in understanding the effects of environmental changes in forest ecosystems. The chemical properties of stream water from 45 forested watersheds in university forests over Japan were investigated in June, 1998. The average pH was 7.1 (maximum 8.1, minimum 6.1). The average electric conductivity (EC) was 64 (maximum 178, minimum 19) μS/cm. The EC of stream water in Okinawa and Sado Island sites tended to be high because the effects of sea salt. Except for the island sites, EC had a positive correlation with pH, summation of cation and alkalinity (mostly HCO3-). This suggests that the water showed a high EC value and a high pH value caused by the consumption of proton (H+) in streams where carbonate weathering brings a high cation concentration. The NO3-concentration in the Kanto mountainous region sites was high compared with the concentration of other sites. In Gunma sites, the relationships between NO3-and Ca2+concentration had a close positive correlation. It was considered that exchangeable Ca2+in the surface soil was discharged due to the increase of H+produced by nitrification..
97. T Enoki, H Kawaguchi, Nitrogen resorption from needles of Pinus thunbergii Parl. growing along a topographic gradient of soil nutrient availability, ECOLOGICAL RESEARCH, 10.1046/j.1440-1703.1999.141280.x, 14, 1, 1-8, 1999.03, To examine the relative importance of nutrient resorption in increasing the nutrient-use efficiency of Pinus thunbergii Parl., we investigated the nitrogen contents of green and senescent needles of P. thunbergii trees growing at five positions along a slope (LS, lower slope; TR, transitional site; MS, middle slope; US, upper slope; RG, ridge) and found that soil nitrogen availability tended to decrease upslope. Nitrogen concentration in green and senescent needles decreased upslope. Nitrogen resorption efficiencies (percentage change in nitrogen content between green and senescent needles) increased upslope from 43 to 77% with decreasing soil nitrogen availability. Nitrogen resorption efficiency was related to green needle dry mass per unit length, but there was no clear correlation between nitrogen resorption efficiency and nitrogen content in green needles. We concluded that the increase in nitrogen resorption efficiency of P. thunbergii enhanced the nitrogen-use efficiency as a response to the low nitrogen availability..
98. 徐 小牛, 榎木 勉, 渡嘉敷 義浩, 平田 永二, 沖縄本島北部における天然生常緑広葉樹林のリターフォール及びそれによる養分還元量について, 琉球大学農学部学術報告, 45, 45, 195-208, 1998.12, 沖縄本島北部の琉球大学農学部附属与那演習林で, 天然生常緑広葉樹林のリターフォール量とそれによる養分還元量の季節変化を, 1996年5月から1998年2月までの2年間にわたって調べた結果, 以下のことが明らかになった。年間のリターフォール量は, 一年目には7328∿12700 kg ha^<-1>, 二年目に5577∿8073 kg ha^<-1>で, 年間の差が大きかった。これは, 台風の影響によるものと思われる。リターの内訳をみると, 落葉量, 落枝量, 生殖器官の落下量およびその他の平均割合が, それぞれ63.7%, 28.2%, 1.4%, 6.7%となった。リターフォールの年間量の平均値と林分構造との関係をみると, 平均直径, 平均樹高, ヘクタール当たり本数及び材積とは比較的高い相関が認められたが, ヘクタール当たり断面積との間には相関がなかった。リターフォールによる年間養分還元量は, 窒素61.3∿128.2 kg ha^<-1>, リン2.8∿6.0 kg ha^<-1>, カリウム20.8∿44.5 kg ha^<-1>, カルシウム40.0∿117.9 kg ha^<-1>, マグネシウム13.3∿28.3 kg ha^<-1>, いおう7.0∿14.6 kg ha^<-1>, ナトリウム8.4∿17.2 kg ha^<-1>, アルミニウム8.6∿16.6 kg ha^<-1>, マンガン2.6∿5.4 kg ha^<-1>, 鉄0.6∿1.4 kg ha^<-1>であった。しかし, 微量元素の銅, 亜鉛, モリブデン, コバルト及びホウ素の還元量は極めて少なかった。また, 養分還元量は8月に最も多く, 年間量の19.3%∿38.3%を占め, 1月には最も少なくて, 僅か年間量の1.2%∿2.0%であった。養分還元量は3月から8月までの間に集中し, この6か月間で年間総量の70%以上を占めた。リターフォールの養分含有率はプロット間に違いがみられたが, これは立地条件の違いのほかに樹種構成の変化とも関係しているものと思われる。.
99. 徐 小牛, 渡嘉敷 義浩, 榎木 勉, 平田 永二, 沖縄本島北部における天然生常緑広葉樹林のA0層の有機物及び養分集積量について, 琉球大学農学部学術報告, 45, 45, 185-193, 1998.12, 沖縄本島北部の天然生常緑広葉樹林における地表(A_0層)に集積する有機物および養分について,22プロットでリターを採取(1996年7月∿8月)して測定した結果,およそ次のことが明らかとなった。1. A_0層の有機物集積量は,12Mg ha^<-1>で,その内,有機炭素が6Mg ha^<-1>を占めた。2. A_0層中の養分集積量は, 全窒素が84.1∿258.5kg ha^<-1>, リンが1.7∿10.4kg ha^<-1>, カリウムが9.0∿37.0kg ha^<-1>, カルシウムが60.0∿230.3kg ha^<-1>, マグネシウムが15.0∿29.7kg ha^<-1>, ナトリウムが1.9∿15.9kg ha^<-1>, いおうが8.78∿20.1kg ha^<-1>, アルミニウムが17.8∿132.5kg ha^<-1>, 鉄が5.3∿77.0kg ha^<-1>, マンガンが2.0∿16.9kg ha^<-1>で,微量元素の銅,亜鉛,ほう素,モリブデン,コバルトは極めて少ないことがわかった。3. 各元素の集積量と有機物集積量の関係について検討した結果,炭素,窒素,リン,カリウム,カルシウム,マグネシウム,いおう,ナトリウム,アルミニウムおよび亜鉛の10元素に0.51∿0.94のかなり高い相関(P<0.05,t-test)が認められた。4. 土壌型は,有機物集積量及び養分集積量への影響が大きく,弱乾性黄色土(Y_c)よりも,乾性黄色土(Y_B)の方が多くなることが明らかとなった。.
100. 徐 小牛, 榎木 勉, 渡嘉敷 義浩, 平田 永二, Xu Xiaoniu, Enoki Tsutomu, Tokashiki Yoshihiro, Hirata Eiji, 沖縄本島北部における天然生常緑広葉樹林のリターフォール及びそれによる養分還元量について, 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus, 45, 195-208, 1998.12, 沖縄本島北部の琉球大学農学部附属与那演習林で, 天然生常緑広葉樹林のリターフォール量とそれによる養分還元量の季節変化を, 1996年5月から1998年2月までの2年間にわたって調べた結果, 以下のことが明らかになった。年間のリターフォール量は, 一年目には7328∿12700 kg ha^<-1>, 二年目に5577∿8073 kg ha^<-1>で, 年間の差が大きかった。これは, 台風の影響によるものと思われる。リターの内訳をみると, 落葉量, 落枝量, 生殖器官の落下量およびその他の平均割合が, それぞれ63.7%, 28.2%, 1.4%, 6.7%となった。リターフォールの年間量の平均値と林分構造との関係をみると, 平均直径, 平均樹高, ヘクタール当たり本数及び材積とは比較的高い相関が認められたが, ヘクタール当たり断面積との間には相関がなかった。リターフォールによる年間養分還元量は, 窒素61.3∿128.2 kg ha^<-1>, リン2.8∿6.0 kg ha^<-1>, カリウム20.8∿44.5 kg ha^<-1>, カルシウム40.0∿117.9 kg ha^<-1>, マグネシウム13.3∿28.3 kg ha^<-1>, いおう7.0∿14.6 kg ha^<-1>, ナトリウム8.4∿17.2 kg ha^<-1>, アルミニウム8.6∿16.6 kg ha^<-1>, マンガン2.6∿5.4 kg ha^<-1>, 鉄0.6∿1.4 kg ha^<-1>であった。しかし, 微量元素の銅, 亜鉛, モリブデン, コバルト及びホウ素の還元量は極めて少なかった。また, 養分還元量は8月に最も多く, 年間量の19.3%∿38.3%を占め, 1月には最も少なくて, 僅か年間量の1.2%∿2.0%であった。養分還元量は3月から8月までの間に集中し, この6か月間で年間総量の70%以上を占めた。リターフォールの養分含有率はプロット間に違いがみられたが, これは立地条件の違いのほかに樹種構成の変化とも関係しているものと思われる。Litter fall and the nutrient returns in a forest were studied. The results obtained from five plots in natural evergreen broadleaved forests at Northern Okinawa Island in the period May 3,1996 to May 1,1998. Annual rates of total litter fall ranged from 7328 to 12700kg ha^<-1> a^<-1> in the first year, and from 5577 to 8073kg ha^<-1> a^<-1> in the second year, with great variation between the two years being related to the effects of the stronger typhoon No. 12 from August 11 to 12,1996. And the foliage litter fall contributed the greatest amount, about 63.7% averagely ranging from 54.6 to 78.8% of the total litter mass, and peaked in March and August, respectively. The results from this investigation indicated that the annual mean litter fall rate was positively correlated with stem volumes, mean D.B.H. and mean height of the stand, however, was negatively correlated with the stand density and neither related to the stand basal area. The annual amounts of nutrient returned by litter fall in the sampling stands were, N from 61.3 to 128.2kg ha^<-1> a^<-1>, P from 2.8 to 6.0kg ha^<-1> a^<-1>, K from 20.8 to 44.5kg ha^<-1> a^<-1>, Ca from 40.0 to 117.9kg ha^<-1> a^<-1>, Mg from 13.3 to 28.3kg ha^<-1> a^<-1>, S from 7.0 to 14.6kg ha^<-1> a^<-1>, Na from 8.4 to 17.2kg ha^<-1> a^<-1>, Al from 8.6 to 16.6kg ha^<-1> a^<-1>, Fe from 0.6 to 1.4kg ha^<-1> a^<-1>, and Mn from 2.6 to 5.4kg ha^<-1> a^<-1>, respectively. However, the annual nutrient returns for microelements such as Cu, Zn, Mo, Co and B were very little. Within the annual cycle, monthly nutrient fall was the most in August and the least in January, and the former was 12∿31 times more than the latter. Spring and summer (from March to August) was most important, accounting for over 70% of the nutrients..
101. Tsutomu Enoki, Hideyuki Kawaguchi, Goro Iwatsubo, Nutrient-uptake and nutrient-use efficiency of Pinus thunbergii Parl. along a topographical gradient of soil nutrient availability, Ecological Research, 10.1007/BF02523784, 12, 2, 191-199, 1997.08, To examine responses of a plant species to nutrient availability, we investigated changes in soil nutrient availability, litterfall production and nutrient content in litterfall along a topographic gradient in a Pinus thunbergii Pad. plantation. Responses were evaluated in terms of three efficiency indices: (i) nutrient-uptake efficiency (the ratio of nutrient return in litterfall to soil nutrient availability)
(ii) nutrient-use efficiency (the ratio of litterfall mass to nutrient return in litterfall)
and (iii) nutrient-response efficiency (the ratio of litterfall mass to soil nutrient availability). These indices can distinguish the ability of a species to acquire nutrients and its ability to use them in litterfall production. Nitrogen and phosphorus availabilities in soil were lower in upper slope positions. The three efficiencies were higher in upper slope positions and negatively correlated with soil nutrient availability for both nitrogen and phosphorus. An increase in nutrient-response efficiency was achieved by both increases in nutrient-uptake and nutrient-use efficiencies..
102. Tsutomu Enoki, Hideyuki Kawaguchi, Goro Iwatsubo, Topographic variations of soil properties and stand structure in a Pinus thunbergii plantation, Ecological Research, 10.1007/BF02347787, 11, 3, 299-309, 1996.12, Soil properties and above- and belowground forest structure were studied across various topographies in a 20-year-old Pinus thunbergii Parl. plantation on Mt Tanakami, Japan. The soil properties and stand structure varied greatly with slope position from ridge top to valley floor. Soil thickness, fine soil content and soil moisture content were greater in lower slope positions. The amount of organic carbon in the forest floor was greater in upper slope positions. The organic carbon content in the mineral soil was slightly greater in lower slope positions. These changes in soil properties suggested an upslope decrease in decomposition rate and water and/or nutrient availability. The aboveground structure of P. thunbergii was more developed at lower slope positions. The mean stem diameter, height and volume of P. thunbergii increased downslope with decreasing tree density. However, fine root biomass increased greatly upslope. This inverse relationship between tree height and fine root biomass indicated morphological plasticity of P. thunbergii in exploiting environmental heterogeneity. Variations in soil- plant interactions in the stand along various topographics caused spatial heterogeneity in the accumulation pattern of organic matter in plants and the soil..
103. Seasonal pattern of diameter growth of Pinus thunbergii in an erosion control forest on Mt. Tanakami.
104. A study on the decline of Pinus thunbergii in an erosion control forest on Mt. Tanakami.
105. Decomposition rates of Pinus thunbergii needle litter related to litter nitrogen content and slope positions..
106. Relationship between litterfall and soil nitrogen in a Pines thunbergii plantation on Mt. Tanakami.
107. Accumulation pattern of soil organic matter and distribution of fine root in a Pinus thunbergii plantation on Mt. Tanakami..
108. Effects of Site Conditions on Natural Regeneration in a Pinus thunbergii Plantation on Mt. Tanakami.
Spatial distributions of natural regenerating trees were measured in a Pinus thunbergii plantation on Mt. Tanakami, Japan. Most of species showed a contagious distribution, while distribution patterns of trees differed among the species. The effects of site conditions on the distribution pattern of regenarating trees were analyzed by the multiple regression method. Relative light intensity, moisture content of soil and distance from the mother tree were measured as factors of site conditions. P. thunbergii, P. densiflora and Quercus serrata favored drier conditions. The demand of P. thunbergii and P. densiflora for light was notably greater than other species. Excepting these three species, deciduous broad-leaved species showed more demand for light and moisture than evergreen. The distribution of saplings and seedlings of barochores, anemochores, and coppicing species was especially clustered near their mother trees..
109. Structure and composition of Pinus thunbergii plantation on wasted site..