围栏封育下华北半干旱草原植物生态位研究

为查明围栏封育条件下华北半干旱草原植物生态位格局及变化,于河北坝上地区红松洼国家级自然保护区设置100 m×100 m围栏监测固定大样地,采用样方法对封育区和放牧区植被生长状况进行调查,运用生态位理论对围栏内外主要植物的生态位宽度、生态位重叠值和生态位相似比例进行测算.结果表明:披针叶苔草(Carex lanceolata)在围栏内外的生态位宽度均为最大.披针叶苔草、裂叶蒿(Artemisia tanacetifolia)、地榆(Sanguisorba officinalis)、毛茛(Ranunculus japonicus)、珠芽蓼(Polygonum viviparum)等生态位宽度较大物种之间具有较高程度的生态位重叠.这些物种的生态位相似比例也较高;而生态位宽度较小的物种其生态位相似比例较小.表明生态位宽度与生态位重叠值、生态位宽度与生态位相似比例之间存在一定的线性关系.

Study on Plant Niche under Fencing Measures in the Semi-arid Grassland of North China

In order to find the plant niche pattern of grassland in the semi-arid grassland of North China, a 100 m×100 m enclosure fixed sampling plot in the Hongsongwa Natural Reserve of Chengde was set up, and the fencing measure area and continuous grazing area were studied with the quadrat method.The niche breadths, niche overlaps and niche proportional similarities of plants were calculated in both areas using the theory of niche. The results showed that the niche breadth of Carex lanceolata Boott was the largest in both tested areas.The niche overlaps among the species with broad niche breadths were much greater, such as Carex lanceolata, Artemisia tanacetifolia, Sanguisorba officinalis, Ranunculus japonicas, Polygonum viviparum. The niche proportional similarity among these species with broad niche breadths was much greater,whereas the niche proportional similarity among the species with small niche breadths was lower.These results showed that there were linear relationships between niche breadths and niche overlaps, as well as niche breadths and niche proportional similarities.