ESJ64 oral L01-07

日本生態学会第64回全国大会 (2017年3月、東京) 講演要旨
ESJ64 Abstract

一般講演（口頭発表） L01-07 （Oral presentation）

Is habitat association of karst tree species related to nonstructural carbohydrates in leaves, stems and roots?

*Nalaka GEEKIYANAGE（Tropical Forest Resources and Environments Laboratory, Division of Forest and Biomaterial Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake 606-8502, Kyoto, Japan, Department of Plant Science, Faculty of Agriculture, Rajarata University, Anuradhapura 50000, Sri Lanka）, Uromi Goodale（Plant Ecophysiology and Evolution Group, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning 530005, Guangxi, China）, Imeña Valdes（Plant/Animal Interaction Laboratory, Department of Biological Sciences, Florida International University, 11200 SW 8th St, Miami, FL 33199, USA）, Kunfang Cao（Plant Ecophysiology and Evolution Group, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning 530005, Guangxi, China）, Kaoru Kitajima（Tropical Forest Resources and Environments Laboratory, Division of Forest and Biomaterial Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake 606-8502, Kyoto, Japan）

Habitat association is a central theme in tropical forest community ecology. Karsts, the jagged limestone hills in Southwestern China, create contrasting availability of edaphic resources across topography. Karst tree species show a strong habitat affinity to a particular topographic position. We examined how non-structural carbohydrate (NSC) concentrations in leaves, branches and roots vary across 13 common tree species specialising in four karst habitats during the dry season, and whether leaf NSC concentrations were related to other leaf traits. Soil moisture contents decreased with increasing elevation. Species in the hilltops had higher concentrations of simple sugars in leaves than those in lower slopes. But, no clear differences in the concentrations of starch in roots and branches were observed among habitat specialization types. Leaf sugar concentrations showed a strong positive correlation with leaf mass per area. High accumulation of leaf sugar and investment on leaf structural mass by hilltop species may affect adaptive strategies for dryer and nutrient poor habitats. Our findings provide some novel insights into niche assembly process and species coexistence in tropical forests at fine scale environmental gradients such as observed in tropical karst forests.