高寒草甸草地与其退化产物——“黑土滩”生物多样性和群落特征的初步研究

A PRELIMINARY STUDY ON BIOLOGICAL DIVERSITY AND FEA COMMUNITIES IN ALPINE MEADOW AND ITS DETERIORATIVE REST LT-"BIACK SOIL BEACH"

依据草地退化特征将高寒草甸草地退化产物——"黑土滩"草地划分为6个等级,研究了各级草地的物种多样性和植物群落特征。中度退化的"黑土滩"草地(秃斑地面积占27.6%)物种多样性和均匀性较大,为3.234和1.115。随草地退化程度的加大,秃斑地面积比例和毒杂草比例有明显增加的趋势(P<0.01);原生植被嵩草属植物优势度和草地活根量(30cm)趋于明显减少(P<0.01);群落产量在各级草地内变化不明显。其中,重度退化和极度退化的"黑土滩"草地嵩草优势度分别为14%和1%,30cm 土层活根量分别为1662.0g/m^2和1338.7g/m^2。

According to the deteriorative features of alpine meadow,the 6 grades'black soil patch'grassland were divided.The each grade species diversity and features of plant communities were studied respectively. The results showed that the indexes of species diversity(3.234)and evenness(1.115)of moderate deteriorative'black soil patch'(area of barren patch occupy 27.6%)were bigger than others.By increasing deteriorative grade to a high level,the area ratio of barren patch and the ratio of poisonous weeds had significantly increased(P<0.01),but the dominance of Kobresia of original vegetation and underground living phytomass(30cm)had significantly decreased(P<0.01),and the yield of communities in every grade grassland had not obviously changed.The dominances of Kebresia of'black soil patch'of the severe and extreme deteriorative grassland were 14% and 1% respectively,the underground living phytomas in 30cm soil layer were 1662.0g/m^2 and 1388.7g/m^2 resp.