松嫩退化草地三种优势植物群落对封育的响应

Three dominant species communities response to grazing excluded in Songnen degraded grassland

封育是退化草地恢复的一种有效途径,为了解松嫩退化草地对封育的响应,2002年在吉林省长岭县境内选取三个地点的退化草地进行了封育改造.2006年对围栏内外羊草(Aneurolepidium chinensis)、芦苇(Phragmites communis)、虎尾草(Chloris virgata)三种优势群落的调查发现:封育四年后,围栏内各群落的植被盖度、群落高度、各建群种的密度、地上部分生物量均显著高于围栏外,尤其是围栏内的羊草群落已经接近了未退化草地羊草群落的水平,说明封育能有效地保护和恢复地上植被.封育后,围栏内外各群落土壤的理化性质并没有显著差别,均劣于未退化的羊草群落.可见,退化草地生态系统完全恢复所需的时间要超出仅恢复草地植被结构的时间.

Many papers have reported that grazing excluded by fencing was a effective way to restore degraded grassland,but little research is reported on it in Songnen grassland. Based on the reason,in 2002 years, selected three sites to restore using fence in which the grassland vegetation is destroyed in Changling county,Jilin province. Surveyed the Chloris virgata community, Phragmites communis community,Aneurolepidium chinensis community which were advantaged inside and outside the fence in 2006,the results showed that., four years after grazing excluded,the species numbers of communities were increased,the plant cover,plant height, density of constructive species and aboveground biomass of the communities in fence were higher than them outside the fence,especially Phragmites communis community in fence which had almost reached the level of the Phragmites communis grassland community. So it shows that grazing excluded for four years using fence can protect and restore vegetation effectively. After grazing excluded, the soil chemical and physical characters of the communities inside and outside the fence were not different markedly,which were bad compared with Phragmites commuhis grassland community. So it shows that it will take more time to restore the degraded grassland ecosystem completely than to restore the grassland vegetation barely.