围栏封育下山地灌草丛草地植被植物多样性与生物量的研究

Diversity and Biomass of Shrub-grasser Vegetation of Mountain Grassland under Enclosure

2006年3月,以云南省永胜县内干热河谷地区的退化草地为研究对象,在2004年设置的围栏封育区和对照区内,对植物的盖度、密度、频度、高度以、地上生物量及植物物种多样性进行了调查和研究。结果表明,围栏封育后退化草地的植被盖度明显变化,盖度总体变化趋势为:轻度退化围栏封育区>轻度退化对照区>重度退化围栏封育区>重度退化对照区。群落多样性总体表现同盖度的表现一样。群落均匀度指数、丰富度基本上与群落多样性指数呈正相关。群落的生态优势度指数与群落多样性指数呈负相关。围栏封育区地上生物量均高于对照,生态和经济效益明显。随着退化程度加剧,分布在各层的植物根量越来越少,地下根系具有浅层化特点。

In 2004, the enclosure area of badly and slightly degenerated grassland of xerothermic valley in Yongsheng county of Yunnan province were made. The changes of biodiversity, above-ground biomass, coverage, density, frequentness, and height were investigated in March, 2006. The result is that the coverage of degenerating grassland which have been enclosed has obvious change. The enclosure area of slightly degenerating grassland showed the more coverage than others and control. And it showed a good development. There is positive correlation between Evenness index, the richness index and the community diversity index, while negative correlation between the community diversity index and ecological dominance index. The biomass of the enclosure area were higther than control. It showed the good benefits of ecological and economic from enclosure of the degenerating grassland. The below-ground biomass at different soil layers decreased with root-systems displaying increased shallowness with increasing degradation levels.