«（落葉樹の根圏動態に対する高CO2とO3及び高窒素負荷の影響に関する研究） Wang Xiaona 王 晓娜 Division of ...»
Another possibility may be related to inheritance (Fujimoto et al. 2006, 2008), there are many similar expression patterns of characters between Japanese larch and F1.The more stable diversity of F1 than its parents indicated some dominated species in ECM community. S. grevillei was only one species survived, which made symbiosis with F1 after two growing seasons with high loading of N and P. This finding revealed that F1 undergoes symbiosis to a greater degree with S. grevillei than either of its parent larches (Zhou et al. 2002; Qu et al. 2003, 2004). These results proved a specific species of ECM with F1 for survival in high N conditions.
There was no distinct effect on biomass of aboveground by N and P treatment,
but the root biomass was reduced for F1 by high P loading. However, there was no impact on P uptake in imbalance nutrient condition (e.g. high N loading). The high P concentration in needles of F1 with N loading proved its high capacity and efficient uptake of P (Goldstein 2013). All of these owed to its benefit relationship of ECM symbiosis, contributing to a relative greater biomass than its parents.
Additionally, the different level of specialization to host plants is well known, with some ECM fungal species associated with a phylogenetically wide range of host plants while others are more specific to a narrow host range (den Bakker et al. 2004).
Many ECM fungi have multiple hosts while most host plants can also associate with many unrelated ECM fungi (Bruns et al. 2002). These ECM have been called as “generalists.” Generalist fungi might be more successful than specialists for long-distance dispersal in a spatially variable environment (Roy et al. 2013) as there is less host plant restriction. For example, among ECM fungi, a super-generalist Cenococcum geophilum, associates with virtually all ECM plant species (LoBuglio
1999) in many contrasting habitats world-wide. Contrarily, Suilloid group which is composed of Suillus, Rhizopogon, Truncocolumella, Gomphidius, and Chroogomphus, is the largest group of ECM fungi that exhibits this degree of host specificity, that is almost entirely restricted to hosts in the Pinaceae (Bruns et al. 2002).
The advantages of being specialists are less obvious, but if specialization provides greater physiological compatibility with the targeted host plant, it could result in greater competitive ability for the host or greater access to the host’s resources (Bruns et al. 2002). Therefore, I study ECM fungi with investigation of generalist and specialist species
5.3 Perspective In this study, root dynamics and ECM symbiosis were intensively investigated under elevated CO2/or O3 and N deposition. After the investigation of root dynamics and
ECM symbiosis in chapter 2-4, I obtained some important ecological information for afforestation with birch and larch species. However, one thing must be sure that, all the influences cannot be easily attributed to the individual environmental factor. The interactions of these factors are encouraged to detect for deep understanding of forest ecosystem under changing environment. There are still several aspects needed to be
conducted in further study:
1) The understanding of fine root dynamics various greatly depending on the root diameter or a root position in branching system. It is important to classify the different root orders and find their different behaviors at each location of the root systems.
2) The characteristics of root differ with its function, some pioneer roots and other roots are functional contributor for nutrient cycling in forest ecosystem. But how much difference of their contributions, and when and how their functions change, these are the essential parts that should be revealed in relation to changing environment, such as elevated CO2, O3 and high N loading.
3) The ECM symbiosis with a host plant has been evaluated by several studies.
This special relationship may be changed by ways of plasticity of short root, and further result in the function variation. To understand the morphology type of short root with ECM is highlighted in the near future.
Undoubtedly, it is still hard to conduct a root research because root is a hidden half of plants (e.g. Eshel and Beeckman 2013). Root research has lots of difficulties may be due to its unique trait, therefore it is challengeable and frontier for us like soil scientist as Olson suggested “Soil-The Final Frontier” (Special issue of Science 204, 11 June 2004). Most significantly, it is valuable and meaningful for any tiny contribution or further step on this research filed.
ACKNOWLEDGMENTSHow time flies, this has been the fourth winter I stay in Hokkaido and now I draw a period and put an end to my dissertation.
First of all, I am deeply appreciating the China Scholarship Council for their financial support during my study in aboard. I thank you very much for all Chinese people for giving me the chance.
At this moment, so many people appear in my mind. The most catchy one is three year ago-myself. In the late summer 2011, with a backpack and a luggage I came to Sapporo after the graduation of Beijing Forestry University. Within the next three and half years, deeply I have fallen in love with this mysterious and beautiful country. Getting acquaintance with here, the lovely people and their lives pasted a deeply impression in my mind.
At that time as a freshman, I started sailing an uncharted course to pursue my doctorate in forest science, especially plant ecophysiology field. Three and half year later, I have been rewarded with valuable expertise and become a specialist in some degree. I would like to express my special appreciation and thanks to my advisor, Dr. Takayoshi Koike, Professor of Silviculture and Forest Ecological Studies of Hokkaido University for his guidance.
I also thank Dr. Masato Shibuya and Dr. Hideyuki Saito for their continuous encouragement and Dr. Tomomi Marutani (Dean) for good friendship in creating MOU between Beijing Forestry University and School of Agriculture of Hokkaido University in 2013.
I am deeply grateful for the continuous support of group chair of Forest Resources Science, Professor Yuzo Sano for guiding me to final examination in PhD defense, Professor Heljä-Sisko Helmisaari for her kindhearted guidance in root dynamics study during my research stay at University of Helsinki, Professor Ryusuke Hatano for his guidance in Soil Science, Dr. Yutaka Tamai for Forest Micro-biology in general, Dr. Toshihiro Watanabe for his excellent guidance in Plant Physiology and Nutrient Dynamics and Dr. Tatsuro Nakaji for analysis of the root growth with an use of rhizotron. Give my sincerely thanks to them for reviewing my thesis writing and giving me relative comments. Moreover, a special thanks hand to Dr. Elena Paoletti (Institute of Sustainable Plant Protection, National Research Council of Italy) and Professor Art Chapperlka (Auburn University, U.S.A.) for their scientific improvement on Chapter 3 and 4, respectively. I
appreciate all of them for their kind guidance and support to my study and graduate carrier.
I would pass my thanks to Dr. Makoto Watanabe (JSPS fellow, now Tokyo University of Agriculture and Technology), Dr. Yasutomo Hoshika (Eco-research and JSPS fellow, Institute of Sustainable Plant Protection, National Research Council of Italy), Dr. Yosuke Matsuda (Mie Universiy), Dr. Matthew D. Wallenstein and Dr. Akihiro Koyama (Colorado State University, U.S.S), Dr. Laiye Qu (Research Center for Eco-Environment Sciences, Chinese Academy Sciences, China) and Dr. Qiaozhi Mao (Southeast University, China). I gained great help from them on my experiment work, data discussion, and other daily help. Extra gratitude I would like to give to Dr. Xiufeng Wang (Hokkaido University), everything I got and learned from her is more than a teacher to student. Her warm care and deeply consideration for all Chinese students is no less than a gracious mother.
Along the journey, the most enjoyable thing is to meet and harvest a great friendship with like-minded people. Dr. Jaana Leppälammi-Kujansuu and Mr. Tommy Y. Chan (University of Helsinki), they two always cheer me up, and make a colorful and funny life for my study. Thanks for the companion. I owe especially deep thanks to Ms. R. Yamakawa, Ms. S. Fujita, Mr. D.G.
Kam, Mr. E. Agathokleous, Ms. C. Shi, Mr. F. Meng (Nankai University) and all members of Silviculture and Forest Ecological Studies as well as Mr. K, Ichikawa, Prof. F. Satoh and all the member of Hokkaido University Forests for their kind support on my study. Moreover, I really appreciate my friends, Dr. Wang Chunying, Dr. Fan Min, Dr. Li Li, Dr. Ou Wei and other good friends. They gave me the strongest support for all my study, and inspire me during the depressed period.
I hardly find adequate word to express my gratefulness to my dearest family members, my mother, father and brother. They sacrificed and put up lots of things during my study oversea. The most sorrowful matter is my beloved grandma who raised me up had been left us forever. My parents suffered all the pain without telling me, they were afraid to let me know, considering the deep sad may disturb my study. I know the truth one year later after my brother’s wedding. It is greatest guilt for me. I wish her happy live in another world. I dedicate this thesis to my family for their meticulous care and great love.
REFERENCES Aber, J.D. and Melillo, J.M. (2001) Terrestrial Ecosystems. Saunders College Publishers, Philadelphia, Pennsylvania.
Adams, M.B. and Oneill, E.G. (1991) Effects of ozone and acidic deposition on carbon allocation and mycorrhizal colonization of Pinus-taeda L seedlings.
Aerts, J.D., Mellilo, J. M., Nadelhoffer, K. J., McClaugherty, C.A. and Pastor, J.
(1992) Fine root turnover in forest ecosystems in relation to quantity and form
of nitrogen availability: A comparison of two methods. Oecologia, 66:
Agathokleous, E., Saitanis, C.J. and Koike, T. (2015) Tropospheric O3, the nightmare of wild plants: A review study. Journal of Agricultural Meteorology, (in press).
Agerer, R. (1987-1993) Colour Atlas of Ectomycorrhizae. Einhorn-Verlag, Schwa
Agerer, R. (2001) Exploration types of ectomycorrhizae - A proposal to classify ectomycorrhizal mycelial systems according to their patterns of differentiation and putative ecological importance. Mycorrhiza, 11: 107-114.
Agerer, R., Hartmann, A., Pritsch, K., Raidl, S., Schloter, R., Vrerma, R. amd Weigt, R. (2012) Plants and their ectomycorrhizosphere: Cost and benefit of symbiotic soil organisms. In: Matyssek, R. et al. (eds.) Growth and Defence in Plants. Springer Ecology Studies, 213-242.
Akasaka, M., Tsuyuzaki, S. and Hase, A. (2007) Annual growth of invasive Larix kaempferi seedlings with reference to microhabitat and ectomycorrhizal colonization on a volcano. Journal of Plant Research, 120: 329-336.
Akimoto, H. (2003) Global air quality and pollution. Science, 302: 1716-1719.
Alves, L., Oliveira, V.L. and Silva, G.N. (2010) Utilization of rocks and ectomycorrhizal fungi to promote growth of Eucalypt. Brazilian Journal of
Microbiology, 41: 676-684.
Andersen, C.P. (2003) Source-sink balance and carbon allocation below ground in plants exposed to ozone. New Phytologist, 157: 213-228.
Anderson, I.C. and Cairney, J.W.G. (2007) Ectomycorrhizal fungi: exploring the mycelial frontier. Fems Microbiology Reviews, 31: 388-406.
Andersson, P. and Majdi, H. (2005) Estimating median root longevity at sites with
long winter time - Does median reflect the root turnover? Plant and Soil, 276:
Andrew, C. and Lilleskov, E.A. (2009) Productivity and community structure of ectomycorrhizal fungal sporocarps under increased atmospheric CO2 and O3.
Ecology Letters, 12: 813-822.
Aquino, M.T. and Plassard, C. (2004) Dynamics of ectomycorrhizal mycelial growth and P transfer to the host plant in response to low and high soil P availability.
Fems Microbiology Ecology, 48: 149-156.
Araki, M., Watanabe, M., Saito, H., Shibuya, M. and Koike, T. (2012) Effect of nitrogen deposition on growth of birch seedlings and ectomycorrhizal
development with/without phosphorous treatments. Boreal Forest Research, 62:
65-66 (in Japanese).
Arnone, J.A., Zaller, J.G., Spehn, E.M., Niklaus, P.A., Wells, C.E. and Körner, Ch.
(2000) Dynamics of root systems in native grasslands: effects of elevated atmospheric CO2. New Phytologist, 147: 411-411.
Ashmore, M.R. (2005) Assessing the future global impacts of ozone on vegetation.
Plant, Cell and Environment, 28: 949-964.
Auge, R.M., Moore, J.L., Sylvia, D.M. and Cho, K.H. (2004) Mycorrhizal promotion of host stomatal conductance in relation to irradiance and temperature.
Bakker, M.R., Jolicoeur, E., Trichet, P., Augusto, L., Plassard, C., Guinberteau, J., and Loustau, D. (2009) Adaptation of fine roots to annual fertilization and
irrigation in a 13-year-old Pinus pinaster stand. Tree Physiology, 29: 229-238.
Baxter, J.W. and Dighton, J. (2005) Phosphorus source alters host plant response to ectomycorrhizal diversity. Mycorrhiza, 15: 513-523.
Bellemain, E., Carlsen, T., Brochmann, C., Coissac, E., Taberlet, P. and Kauserud, H.
(2010) ITS as an environmental DNA barcode for fungi: an in silico approach reveals potential PCR biases. BMC Microbiology, 10:189.
Bidartondo, M.I., Ek, H., Wallander, H. and Soderstrom, B. (2001) Do nutrient additions alter carbon sink strength of ectomycorrhizal fungi? New Phytologist, 151: 543-550 Bielenberg, D.G. and Bassirirad, H. (2005) Nutrient acquisition of terrestrial plants in a changing climate. In: Bassirirad, H. (eds) Nutrient acquisition by plants - an ecological perspective. Springer-Verlag, Berlin, pp. 311-330 Blum, U. and Tingey, D.T. (1977) A study of the potential ways in which ozone could
reduce root growth and nodulation of soybean. Atmospheric Environment, 11: