摘要
封育是退化草场恢复的重要措施之一,封育的效果在一定程度上取决于土壤中种子库的状况。以毛乌素沙地西南缘宁夏盐池县的退化草场为研究对象,采用相似性分析和排序方法对封育和未封育草场土壤种子库的特征及其与地上植被间关系进行了研究,结果表明无论封育区还是未封育区,土壤种子库中的种子主要分布于0～5cm的土层,6～15cm土层的种子数很少;封育区土壤种子库的物种丰富度大于未封育区,物种多样性则表现为H值较大,而D值较小,总体上看封育措施可以提高地上植被和土壤中种子的种类和数量,一些一年生植物、中生植物和盐生植物开始出现在地面或土壤种子库中。地上植被和土壤种子库间的相似性分析结果则表明相同措施同一土层间种子库中等相似,而不同土层间还是存在着一些差异。由于封育措施导致了植被样方的相似性较低,然而土壤种子库间的相似性仍然较高,两者间是否存在着一定程度的滞后效应有待于进一步研究。
exclosure is considered as one of effective measures for degraded rangeland restoration, and its effectiveness is influenced by soil seedbank conditions to the extent. This research was conducted in degraded rangeland at the southwestern edge of the Mu Us sandland, Yanchi county, Ningxia, the soil seedbank features and its relation to vegetation was analyzed using similarity analysis and ordination method, the results show that seeds within soil distribute mainly in 0-5 cm soil layer, less seeds in 6-15 cm soil layer in exclosed and non-exclosed rangeland, for seeds in exclosed soil, species richness and diversity index H are higher, while D is lower, exclosure measure, generally speaking, can increase plant species and amount of vegetation and seeds in soil, some annual plants, mesophytes and halophytes appears in the soil or surface. The similarity analysis with non-metric MDS method reveals that exclosure results in lower similarity among vegetation quadrats, this difference, however, doesn＇t reflect from soil seedbank, the lag effect between soil seedbank and vegetation should be focused on in further study.
出处
《生态环境》
CSCD
北大核心
2007年第2期533-537,共5页
Ecology and Environmnet
基金
国家"十五"科技攻关项目(2005BA517A04)
国家自然科学基金项目(30571529)
关键词
封育
土壤种子库
地上植被
退化草场
宁夏盐池
exclosure
soil seedbank
above-ground vegetation
degraded rangeland
Yanchi county
