宁夏四儿滩湿地-干草原群落交错带边缘效应研究

Edge effect of wetland and arid grassland community ecotone in Siertan wetland in Ningxia

以宁夏哈巴湖自然保护区四儿滩湿地为研究对象,于2011年和2012年7～8月份采用样线调查法对湿地-干草原生境梯度按东、西、南、北4条样线进行湿地植被调查,采用SPASS数量分类和植物群落结构指数研究并分析湿地-干草原交错带边缘效应.结果表明:四儿滩湿地植物群落分为沼泽植被、草甸植被、干草原植被3个类型;四儿滩湿地植物群落结构指数除群落均匀度指数外,生态优势度、丰富度和物种多样性在东、西、北3个方向均是交错带最大,其次是旱生带,湿生带最小,南样线因受人为因素影响略有不同;四儿滩湿地-干草原交错带不同方向群落结构差异较大,除群落均匀度外,其余各项植物群落结构指数均是北样线最大,东样线最小.造成不同样线间边缘效应差异的主要因素是人为干扰程度和地形抬升程度不同.

The edge effect of plant communities was investigated in a wetland-dry grassland ecosystem at Siertan wetland in Yanchi county, Ningxia. Four transects lines were set up in July to August of 2011and 2012 along the biotope gradient in four directions- east, south,west and north for vegetation survey. The data were analyzed with SPASS. The vegetation in Siertan wetland was classified into three vegetation types- halophytic marsh vegetation , meadow vegetation and grassland vegetation. Base on the calculation of the community structure indices, the edge effect was studied and revealed distinct differences among those three vegetation zones along each transect line except for the south line. The ecotone had the highest richness indices （R） ,diversity indices （SW） and ecological dominance （SP） except evenness indices （E）. As for the four transect lines, the north ecotone scored higher in each community structure indices except for the evenness indices than the others did, and the east was less. The edge effect difference between different transect lines were because o f the human disturbance and topography uplift.