Dissertation Research: Role of the Arbuscular Mycorrhizal Fungi Community in Pasture Recolonization by a Tropical Forest Tree

了解影响废弃地森林更新的因素是陆地植物生态学家长期追求的目标，也是热带森林保护面临的主要挑战。在更新景观中，菌根真菌群落是一个经常被忽视的因素，它可能影响森林更新率和植物种类组成。本论文的研究将采用野外研究、温室实验和分子分析相结合的方法，研究热带森林片断和牧场菌根真菌群落组成的差异，以及这些差异是否会对热带森林树木在牧场上建立苗木产生影响。本研究的主要目的是确定(1)森林和邻近牧场的菌根真菌种类组成是否不同，(2)热带林木林木和牧草育苗的菌根种类组成是否不同，以及(3)森林和牧场的菌根真菌对苗木寄主的生长益处是否不同。拟议的研究结果对人类影响的热带生态系统中森林树种的牧场重新定居、森林更新和植物和真菌多样性的维持具有重要意义。

9902064PowerUnderstanding factors which influence forest regeneration in abandoned agricultural lands is a longstanding goal of terrestrial plant ecologists and a key challenge for tropical forest conservation. The mycorrhizal fungi community is an often-overlooked factor which may influence forest regeneration rates and plant species composition in regenerating landscapes. This dissertation research will use a combination of field studies, greenhouse experiments and molecular analyses to examine differences in mycorrhizal fungi community composition between tropical forest fragments and pastures, and whether these differences have consequences for seedling establishment in pastures by a tropical forest tree. Principal objectives of the research are to determine (1) whether species composition of mycorrhizal fungi differs between forest fragments and adjacent pastures, (2) whether species composition of mycorrhizae differs between forest- and pasture-grown seedlings of a tropical forest tree, and (3) whether mycorrhizal fungi of forest and pasture differ in their growth benefit to seedling hosts. Results of the proposed research have implications for pasture recolonization by forest tree species, forest regeneration and maintenance of plant and fungal diversity in human-impacted tropical ecosystems.