对中欧草地系统演替的17年量化研究(英文)

本文旨在用17年的观测数据检验三个有关草地系统演替的假设:(1)物种多样性在演替早期不断增加;(2)伴随着演替的推进,样方植物群落间的相似度逐渐增加(样方间的差异度随着演替不断降低);(3)在演替早期,植物群落的物种组成有趋同之势。包括植物群落的总体发展、Shannon多度与均度、Bray-Curtis差异度和群落周转率在内的量化统计结果显示:经过早期5年的演替,各样方的物种多样性表现出快速的趋同,多度均值逐渐由8增加至25个物种;同时,所有样方的物种总数由23增加至55个物种,标准方差由4.6降至0.3。此外,样方间的差异度逐渐降低,物种多度与组成呈明显的趋同。停止除草的一个重要效应是,人工设置的由1到16个物种的多样性梯度因物种入侵至多度较低的样地而减弱。

A Seventeen-Year Quantitative Study of Succession in Central European Grassland

The objective of this paper is to test three main hypotheses in grassland succession by using 17-year observational data： （i） species diversity increases during early pioneering stages; （ii） the similarity rate of experimental plant communities increases along with the succession process （dissimilarity rate among plots decrease with succession age）;and （i i） plant communities in different ifeld plots converge towards a quite similar composition during the initial years of succession. Results draw from quantitative statistics which including： the general development of plant communities, Shannon’s H and E, Bray-Curtis dissimilarity and community turnover, indicate that after first 5 years of succession, species diversity rapidly becomes alike among all the plots. The average species number in al plots increased constantly from 8 to 25. Meanwhile, the total species number for al plots increased constantly from 23 to 55, accompanied by a steady decrease in Standard Deviation （S.D.） from 4.6 to 0.3. Additional y, dissimilarity of al stands in species composition decreased, indicating a clear trend towards a rapid convergence in species richness and composition. The most important effect of cessation of weeding is that the artiifcial diversity gradient from 1 to 16 species gets diminished by immigration in species poor plots.