热带雨林片断植物叶温边缘效应的初步分析

在西双版纳地区一块面积为 3hm2 热带干性季节性雨林片断的南向林缘 ,观测了林内至林外水平样带上的植物叶温及其它小气候要素 .结果表明 ,植物叶温的边缘效应影响范围从林内 2 0m至林外 16m ,这种水平变化梯度尤以林缘附近 (林内 12m至林外 8m)最大 .从林内至林外 ,植物叶温 (Tl)依次表现出气温 (Ta)型 (Ta>Tl)、中间型 (Ta=Tl)和辐射型 (Tl>Ta) .探讨了植物叶温与气温的关系 ,并讨论了植物叶温边缘效应的生态学影响 .

Plant temperature edge effects of tropical rain-forest fragment in Xishuangbanna

Edge is an important landscape feature of fragmented tropical forest landscapes in Xishuangbanna, Southwest China. Little is known about the edge effect of plant temperature that plays a key role in growth and development of plants. The primary objective of this study is to characterize the changes in plant leaf temperature from a forest interior to the outside. Leaf temperatures and other microclimatic elements were measured along a transect extending from the interior to the open field at south facing edge of a 3 hm 2 tropical dry seasonal rainforest fragment in Xishuangbanna. The findings showed that the influence range of edge effect of the leaf temperature ( T l) was 20 m into the forest and 16 m into the open field from the edge. The greatest horizontal change in the leaf temperature occurred near the edge ranging from -8 m to 12 m into the interior. From the interior to the open, the leaf temperature was found, comparing with air temperature ( T a), to show three categories of air temperature pattern ( T a> T l), middle pattern( T a= T l) and radiation pattern ( T a< T l). The relations of T l to T a were created at the interior, the edge and the open. The ecological impacts of the edge effect of the leaf temperature were also discussed.