喀斯特季节性雨林植物叶片碳同位素组成及水分利用效率 / Foliar stable carbon isotope composition and water use efficiency of plant in the Karst seasonal rain forest

研究喀斯特季节性雨林不同生境代表性树种及同一树种不同生境下叶片 δ １３Ｃ 值及 水分利用效率（ＷＵＥ），丰富喀斯特季节性雨林物种生态位分化及物种共存理论，可为喀斯特 地区石漠化治理树种选择及配置提供参考．结果表明： 喀斯特季节性雨林树种叶片 δ １３Ｃ 值的 范围为 － ３４． １３‰ ～ － ２９． ６９‰，平均值为 （ － ３１． ４０ ± １． １９）‰， ＷＵＥ 的范围为 ９． ０８ ～ ５８． ７６ μｍｏｌ·ｍｏｌ －１ ，均值为 ４１．７９ μｍｏｌ·ｍｏｌ －１ ，低于更高纬度的亚热带和暖温带森林，但高于更低 纬度的热带雨林和同一纬度的非喀斯特季节性雨林；从洼地到山顶，随着干旱指数的增加，不 同生境代表性树种的水分利用效率逐渐增大；同一树种 δ １３Ｃ 值和 ＷＵＥ 也是从洼地到山顶逐 渐增高．树种水分利用效率除了与气候等因子相关外，还与植物所处生境的地质背景、水分可 利用性相关．同一气候条件下，喀斯特区植物的水分利用效率要高于非喀斯特区、干旱生境植 物的水分利用效率高于湿润生境，说明不同的水分利用效率是喀斯特地区植物适应不同生 境、实现多物种共存的策略之一．

To enrich niche partition and species coexistence theory in karst seasonal rain forest, and provide reference for species selection and configuration for rocky desertification control, we examined foliar stable carbon isotope composition (δ¹³C) abd water use efficiency (WUE) of the representative species in different habitats and the same tree species in different habitats.  The results showed that foliar δ¹³C value in karst seasonal rain forest ranged from -34.13% to -29.66%, with a mean value of (-31.40±1.19)%.  WUE ranged from 9.08-58.76 μmol · mol^-1, with a mean value of 41.79 μmol · mol^-1.  Both of them were lower than subtropical and warm temperate forests at higher latitude, but higher than tropical rain forests at lower latitude and non-karst seasonal rain forests at the same latitude.  The foliar δ¹³C value and WUE of representative species gradually increased with the increases of drought index from the depression to the top of the mountain.  The foliar δ¹³C value and WUE of the same tree species increased with altitude.  The results indicated that water use efficiency of tree species was not only related to climate factors, but also related to the geographical background and water availability of the habitat.  The water use efficiency of plants in karst area was higher than that in non-karst area, and was higher in dry habitat than in wet habitat under the same climactic condition.  It showed that having different water use efficiencies was one of the strategies for plants in karst area to adapt to different habitats and maintain species coexistence.  

Abstract in Chinese and English; article in Chinese only.