中文摘要：

在2004～2011年对宁夏盐池人工封育区内各样地群落植被进行样方调查,通过分析调查数据研究不同封育年限对群落组成、植被特征值及物种多样性的影响,进而为草场恢复和下一步的开发利用提供理论依据。研究表明：随着封育年限的延长,封育区形成了以黑沙蒿（Artemisia ordosica Krasch）和刺沙蓬（Salsolaruthenica Iljin）为优势种的植被群落;通过对历年地表植被多样性指数的分析,各指数高峰值和低峰值出现周期性变化且周期为5年,这说明干旱半干旱地区人工封育草场的封育周期为5年。

英文摘要：

In order to study the effects of different enclosure and different years on the plant characteristic values and species diversity,quadrate method was used to investigate plant growth during the growing season from 2004 to 2011 in three sample plots in the fencing area of Yanchi County,Ningxia Hui Autonomous Region.The results showed that with the extension of the enclosure years,Artemisia ordosica Krasch and Salsola ruthenica Iljin become dominated species of vegetation.Through the analysis of vegetation diversity index in recent years,peak value and low peak of each index showed a regular cycle of 5 years.This showed that the period of artificial enclosure was 5 years in arid and semi-arid region.