辽西北半干旱风沙区疏林地群落特征研究

Research on woodland community characteristics of semi-arid sandy area in the northwest of Liaoning

辽西北半干旱风沙区属森林草原过渡带,是气候变化敏感区和生态系统脆弱区,为揭示该区域疏林地木本植物群落结构特征及其变化规律,对该地区的植物群落特征进行调查研究,结果表明:样地内木本植物共有19种,其中乔木12种,灌木6种,藤本1种,隶属于14科18属;植物组成上属于温带植物区系,并混有亚热带成分;加杨、野生山里红和家榆是该群落的优势种,但郁闭度小;优势树种中加杨和家榆的径级结构分别近似于正态分布和双峰分布,高度结构呈偏正态分布(如野生山里红)或正态分布(如家榆);群落及各优势种均为聚集分布,物种类型较为单一,且分布不均匀,多样性小。

The northwest semi-arid sandy area belongs to forest steppe ecotone. This area is sensitive to climate change and ecological system is fragile area. In order to reveal community structure characteristics of woody plant in this open forest land and its law of change, the plant community characteristics in the area were investigated. The results showed that： there were 19 species of woody plants in the plot, including 12 species of arbor, 6 species of shrub and 1 species of liane, belonging to 14 families and 18 genera. Flo- ristic characteristic of the community belongs to North temperature flora, including some subtropical elements. Populus canadensis, Crataeguspinnat^ta and Ulmuspumila are the dominant species in communities, but with small canopy density; diameter structure of dominant species of Populus canadensis and Ulmus pumila were approximate to normal dislribution and bimodal dislribution, height structure were partial normal distribution such as Crataegus pinnatifida or normal distribution such as Ulmus pumila; Commurfity and the dominant species were aggregated; object type was relatively single, with uneven distribution, and small diversity.