Abstract:

In this study we assessed the recovery of desert steppe ecosystem in Yanchi Country, an arid and sandstorm area of Ningxia province by using VOR (vigor, organization, resilience) and CVOR (condition, vigor, organization, resilience) evaluation index and other 4 kinds of plant diversity indexes (Patrick index, Simpson index, Shannon-Wiener index and Alatalo index). The results showed that:the Patrick index of all testing plots was higher than 20. And in southern Yanchi, the Patrick index was higher than it in the middle and in the north. Significant differences were found between Patrick index, Simpson index, Shannon-Wiener index and Alatalo index at the level of 0.05. According to correlation analysis, only R index showed significantly correlation with VOR index (P<0.01), and Condition index (C), Organization index (O), Resilience index (R) were all significantly correlated with CVOR index (P<0.01). Both VOR and CVOR indexes showed that the condition of grassland in middle and southern Yanchi was in the level of "healthy". In northern Yanchi, VOR index showed that the grassland condition was in the "unhealthy" level, while it was in the "warning" level by the assessment of CVOR index. The recovery of grassland in northern Yanchi county needs more work to do.

Key words: Grassland ecosystem, Health assessment, VOR index, CVOR index

摘要：

本研究运用VOR和CVOR生态系统健康评价模型，结合Patrick多样性指数、Simpson优势度指数、Shannon-Wiener丰富度指数和Alatalo均匀度指数，对宁夏干旱风沙区荒漠草原的生态系统恢复状况进行了评估。结果表明：盐池县荒漠草原各监测点Patrick多样性指数均高于20，盐池县南部高于中部和北部。各监测点Simpson优势度指数、Shannon-Wiener丰富度指数和Alatalo均匀度指数均存在显著差异（P<0.05）。恢复力（R）与VOR指数极显著正相关（P<0.01），草地基况（C）、组织力（O）和恢复力（R）与CVOR指数极显著正相关（P<0.01）。VOR指数和CVOR指数对盐池县中部和南部草地健康状况评价结果一致，为“健康”状态，VOR指数评价北部草地处于“不健康”状态，CVOR指数评价为“警戒”状态，盐池县北部草地恢复工作有待加强。

关键词: 草地生态系统, 健康评价, VOR指数, CVOR指数