黄土高原地区不同类型天然草地群落学特征

摘要：根据气候-植被特征，选取森林草原、典型草原和荒漠草原3种不同草地类型的封育和放牧草地进行群落特征研究，旨在分析黄土高原天然草地的群落分布规律。结果表明，荒漠草原的盖度、平均高度、个体数和物种数均显著低于其他两类草地（P≤0.05），森林草原的样方内个体数和平均高度显著高于典型草原，而后者则在盖度和物种数上优于前者；群落生物量表现为典型草原＞森林草原＞荒漠草原,且各草地类型之间差异显著（P≤0.05）；荒漠草原的多样性明显低于其他两个草地类型，典型草原和森林草原的物种多样性表现相类似。通过利用方式间的比较发现，封育措施对荒漠草原的植物群落结构有一定的改善作用，对于典型草原和荒漠草原，封育措施增加了其盖度和平均高度，但未达到显著水平（P≤0.05）。

Community characteristics of different types of grassland in the Loess Plateau

Abstract： Based on climate vegetation characteristics, enclosed and grazed grassland within 3 different grassland types which were forest grassland, typical grassland and desert steppe were selected for community characteristics analysis. The results showed that, coverage, average height, individual number and species number in desert steppe were significantly lower than that of the other two types of grassland (P≤0.05). Individual number and average height in forest grassland were significantly higher than that of typical grassland, however, coverage and species number in the latter were superior to the former. Community biomass showed significant difference among three grasslands types, and ranged as typical grassland>forest grassland>desert steppe (P≤0.05). For species diversity, rich index and evenness index, diversity index of desert steppe are obviously lower than that of the other two grassland types; In addition, enclosure has improved plant community structure in desert steppe to a certain extent; for typical grasslands and desert steppe, enclosure improved coverage and average height but not statistics significance.