巴丹吉林沙漠边缘地区植被特征

通过在巴丹吉林沙漠野外植被调查，描述了植被的生活型和群落的空间分布特征，分析了植被多样性、优势度及均匀度指数，并探讨了历年来气候变化对植被分布的影响。结果表明：（1）巴丹吉林沙漠植物种类较少，可分为小乔木、灌木、小灌木、半灌木、多年生草本和一年生草本6类生活型。其中灌木种类最为丰富，小乔木最少。（2）巴丹吉林沙漠东南一带物种丰富度和多样性高于西北一带，南缘地区植被群落分布及植被群落多样性亦均高于北缘地区。（3）近53 a巴丹吉林沙漠气温发生显著变化，蒸发量增加。南缘地区增温而降水减少。这种变化对于以水分为主导因子的沙漠地区植被发育来说极为不利，有加剧沙漠南缘荒漠化的威胁。

Vegetation Characteristics in the Marginal Areas of the Badain Jaran Desert

The article is based on the vegetation investigation in Badain Jaran Desert. It described various life forms of vegetation and the spatial distribution of community, then analyzed the index of vegetative diversity, dominance and evenness. We also discussed the impact of climate changes on vegetation distribution over the years. The results showed that:(1) The plant species in Badain Jaran Desert were lacking. It can be divided into 6 life forms:small trees, shrubs, small shrubs, subshrubs, perennial herbs and annual herbs. Among them, shrubs had the most abundant species, and small trees had the least. (2) Species richness and diversity in southeast area were higher than the northwest area of the Badain Jaran Desert. The distribution and diversity of vegetation communities in the southern margin were also higher than the northern margin. (3) In recent 53 years, the temperature of Badain Jaran Desert has changed dramatically, and the evaporation of water increased. Temperature increased and precipitation decreased in southern margin. The changes in desert where water is the dominant factor of the vegetation development is extremely disadvantageous. It's likely to intensify the threat of southern margin desertification.