长期围栏封育对中天山草地植物群落特征及多样性的影响

Effects of enclosure on plant diversity and community characteristics in pasture of Middle Tianshan Mountain

以中科院新疆巴音布鲁克草原生态站25年围封样地为对象,研究亚高山草原、亚高山草原化草甸和亚高山草甸化草原的植物群落特征及物种多样性。结果表明,长期围封对3种草地类型草地植被盖度、平均高度、地上生物量均有不同程度的提高,围栏内生物量与植株高度均表现为亚高山草原化草甸>亚高山草甸化草原>亚高山草原;3种草地类型围栏内外生物量和植被盖度差异呈极显著(P<0.01),且亚高山草原化草甸和亚高山草甸化草原围栏内外植物高度差异极显著(P<0.01)。围封25年后,围栏外的群落丰富度指数和优势度指数均高于围栏内,而均匀度指数围栏内均高于围栏外。

Three types of artificial grasslands fenced for 25 years in Middle Tianshan Moutain were used to examine the effects of enclosure on vegetation characteristics and plant diversity. The results showed that after long-term enclosure, the coverage, height and above ground hiomass were improved remarkably inside of fence than those of the outside in three types of grasslands. The above ground biomass and plant average height in the fenced meadow in three types of grasslands decreased in the following order： sub-al- pine prairie meadow〉sub-alpine meadow prairie〉sub-alpine prairie. The differences of above ground bio-mass and plant coverage between the fenced meadow and the grazed meadow were significant （P〈0.01）. In sub-alpine prairie meadow and sub-alpine meadow prairie, the plant average height showed significant difference between inside and outside of the fence （P〈0. 01）. After fencing for 25 years, the richness index and diversity index were higher outside of the fence than that of the inside in three types of grass-lands; however, the evenness index had the opposite result.