DISSERTATION RESEARCH: Nutrient Controls on Epiphyte Communities in Tropical Forests

氮供应经常限制森林生产力。固氮地衣与蓝细菌的光合伙伴（蓝藻）作为附生植物生长在森林冠层中，有可能为森林贡献大量的氮，但控制其丰度的因素知之甚少。在低多样性的夏威夷山地雨林进行的长期施肥试验表明，当寄主树木的磷供应较高时，附生蓝藻最丰富、最多样化，表明土壤磷可能通过冠层固氮间接决定附生植物群落组成和氮输入。研究人员将扩大这项研究，以调查土壤磷是否也控制着马来西亚婆罗洲基纳巴卢山高度多样化的热带森林的冠层附生植物群落。该研究将有助于理解陆地土壤与林冠过程之间的联系以及林冠固氮在整个森林养分循环中的作用。

Nitrogen supply frequently limits the forest productivity. Nitrogen-fixing lichens with a cyanobacterial photosynthetic partner (cyanolichens) growing as epiphytes in forest canopies have the potential to contribute significant amounts of nitrogen to forests, but the factors controlling their abundance are poorly understood. Long-term fertilization experiments in low-diversity Hawaiian montane rainforests indicate that epiphytic cyanolichens are most abundant and diverse when phosphorus supply to host trees is high, suggesting that soil phosphorus may indirectly determine epiphyte community composition and nitrogen inputs via canopy nitrogen fixation. The investigator will expand this research to investigate whether soil phosphorus also controls canopy epiphyte communities in highly diverse tropical forests on Mt. Kinabalu in Malaysian Borneo. This research will contribute towards understanding both the links between terrestrial soil and canopy processes and the role of canopy nitrogen fixation in whole-forest nutrient cycles.