沙地灌丛的“肥岛”和“虫岛”形成过程、特征及其与生态系统演替的关系

Formation process and characteristics of “Fertile island” and “Arthropod island” in desertified shrub land and their relations to ecosystem succession

沙地灌丛"肥岛"和"虫岛"均具有突出的生态功能,二者相互作用对于生态系统的演化具有重要作用。草地灌丛化和流动沙地固定化均可促使沙地灌丛"肥岛"和"虫岛"的形成,并且灌丛"肥岛"与放牧管理间存在密切相关,而灌丛"虫岛"与灌丛林龄密切相关。沙地灌丛"肥岛"和"虫岛"是相伴而生,相辅相成,而且作为反馈,灌丛"虫岛"可以进一步促成"肥岛"的形成,加速生态系统的演化过程。今后应从以下方面加强研究:(1)灌丛"虫岛"的形成机制及其对灌丛的反馈作用。(2)基于灌丛种与林龄的灌丛"虫岛"与放牧管理的关系。(3)灌丛"土-草-肥-虫-节肢动物-微环境-微生物"为一体的微宇宙实验的控制研究。(4)利用灌丛"虫岛"的形成、指示类群的辨识以及生态系统演替过程的长期观察与分析,来确定草地中可能存在的最佳人工灌丛林管理方式。

Shrub-covered ＂Fertile island＂and ＂Arthropod island＂in desertified land have special ecological implications,and their interactions contribute much to the succession of ecosystems. There is a close relationship between ＂Fertile island＂and grazing management,and between ＂Arthropod island＂and shrub age. Both kinds of islands are usually combined together.＂Arthropod island＂facilitates the formation of＂Fertile island＂in feedback,which could improve the succession process of ecosystems. Future studies should be focused on the following fields：（ 1） The formation mechanism of ＂Arthropod island＂and their feedback to the microhabitats.（ 2） The relationship between＂Arthropod island＂and grazing management in light of shrub species identity and stand age.（ 3） Controlled microcosm experiments with consideration of soil,vegetation,arthropod,microhabitat,and microbe influenced by shrub canopy and identity.（ 4）＂Arthropod island＂formation and bioindicators,and their relations to ecosystem succession,which are essential for the management of artificial shrub land.