科尔沁沙地植被恢复系列上群落演替与物种多样性的恢复动态

通过对科尔沁沙地植被恢复系列上不同阶段的群落取样,研究了植被恢复过程中群落物种组成、物种多样性的变化过程.在演替时间分别为1年、3年、5年、12年、20年和30年的群落中,物种丰富度分别为7、11、17、14、28和30种,而物种多样性指数分别为1.458 8、2.610 0、3.108 4、1.696 8、3.738 6、3.639 6.在生活型结构上,一年生植物的种类数量占绝对优势,但随着演替进展,多年生植物的种类数量增加且单种植物的优势度超过了一年生植物,表明多年生植物在群落功能维持中占据重要地位.随演替进展,来自不同科属的植物增加.藜科植物在演替过程中种类数量较为稳定,特别是在演替早期藜科植物占有很高的优势度.禾本科种类随演替进展不断增加,且在群落中的优势度逐渐上升.总体上,随演替进展群落种类组成与物种多样性增加,群落生态优势度下降,而均匀度增加,群落趋向稳定.

DYNAMICS OF SPECIES DIVERSITY OF COMMUNITIES IN RESTORATION PROCESSES IN HORQIN SANDY LAND

In this paper species composition and species diversity of communities with different succession times were studied in restoration processes. Our results showed that species richness is 7, 11, 17, 14, 28 and 30 in the communities, of which the succession time is 1, 3, 5, 12, 20 and 30 years, while the species diversity index is 1.458 8, 2.610 0, 3.108 4, 1.696 8, 3.738 6 and 3.639 6 respectively. For life form composition of all communities along the restoration succession series, annual herbaceous plants are dominant, but species number of perennials increases and the dominance of one species is more than that of annuals as succession proceeds. Species number of Chenopodiaceae is stable and their dominance in the community is high, especially in early successional stages. Species number of Gramineae increases continuously along the succession gradient and their importance in community also increases. Ecological dominance declines gradually, while community evenness increases progressively along with succession. In a relatively short time of 30 years the environment of sandy land shifted successfully from mobile sandy land to fixed sandy land, and species composition and community structure improved greatly. This research provided test and sample for the possibility of vegetation restoration under natural condition, as well as a practical pathway for the protection of biodiversity. The most important thing is to stop irrational use of land so that the natural ecological processes of vegetation recovery such as dispersal, inhabitation and propagation can be accomplished continually under stable environments.