林业科学2012，Vol.48Issue(7)：14-22,9.
荔波喀斯特森林4种木本植物水分来源的稳定同位素分析
Stable Isotope Analysis of Water Sources of Four Woody Species in the Libo Karst Forest
摘要
Abstract
Ecosystems in the karst region of southwest China are very fragile due to thin soil layer and intensive infiltration capacity of rock fracture, which result in a very limited amount of water storage for plant uptake. Water retention in the soil zone and shallow fractured rock zone (subcutaneous) is a key factor for plant growth. Distinction of water sources taken by karst plants is a challenging task for botanists and hydrologists but is needed for ecosystem management. In this study, stable isotope analysis was used to investigate water sources for plants because of no isotopic fractionation during water uptake by terrestrial plants. We selected several dominant plant species in three forests of mostly primary forest, secondary forest and bush covers at the Maolan national nature reserve of karst ecosystem in a small catchment of Libo, south Guizhou of China. Proportions of water sources for plant uptake were determined by the 5D and S"0 values of plant stem water, and water taken from soil layers and the subcutaneous zone. The analysis reveals that water was mainly taken from the soil layers and to less degree the subcutaneous zone as well. In October with scarce precipitation, plants in the bush and primary forest were prone to take more water from subcutaneous zone, while plants from secondary forest were prone to take more water from the upper layer of soil. Different species had different water use strategies, Lindera communis took a larger proportional water from the subcutaneous zone, suggesting deeper roots. However, Platycarya longipes extracted more percentage of water from the s upper soil water because of its shallower roots.关键词
氢氧稳定同位素/木本植物/水分来源/表层岩溶带水Key words
stable isotopes/woody plants/soil water/subcutaneous water分类
农业科技引用本文复制引用
容丽,王世杰,俞国松,邓晓琪,冉景丞..荔波喀斯特森林4种木本植物水分来源的稳定同位素分析[J].林业科学,2012,48(7):14-22,9.基金项目
中国科学院战略性先导科技专项(XDA05070400) （XDA05070400）
贵州省优秀科技教育人才省长专项资金项目(黔省专合字[2007]33号) （黔省专合字[2007]33号）
贵州省自然科学基金项目(黔科合J字[2008]2063号) （黔科合J字[2008]2063号）
国家自然科学基金面上项目(30872007). （30872007）
