科尔沁沙地刺榆群落的结构特征

对科尔沁沙地刺榆（Hemiptelea davidii）群落的种类组成及其生态类型结构进行了调查.结果表明：研究区刺榆林不存在灌木层；其乔木层可划分为2个亚层，上、下层高度分别为4.05~7.86和2.05~3.20 m；林下共有32种草本植物，隶属13科27属，以禾本科、豆科和菊科为主；研究区有11个植被分布区型，其中，蒙古-东北-兴安-华北分布区型种类最多（34.38%），其次为东北-华北分布区型（12.5%）.在3个水分生态类型中，中生植物最多，占59.37%，中旱生类型和旱生类型分别占25%和15.63%.在6个生活型中，地面芽植物最多（31.25%）. 刺榆群落具有温带草原的典型生活型特征.

Ecology and biology of Gazella subgutturosa: Current situation of studies

An investigation was made on the species composition and eco-type of Hemiptelea davidiicommunity on Kerqin sandy land. The results showed that in study area, no shrub layer existed in H. davidiiforest, while arbor layer could be divided into two sub-layers, with a height of 4.05-7.86 m for the upper layer, and of 2.05-3.20 m for the lower layer. In the community, there were 32 herbal species belonging to 27 genera of 13 families and dominant by Poaceae, Fabaceae and Compositae, and 11 areal types, among which, the species number in Mongolian Northeastern China-Dahuricia-North China areal type was the highest (34.38%), followed by that in Northeastern China-North China areal type (12.5%). Among three water ecological types, mesophytes occupied 59.37% of the total, and mesoxerophytes and xerophytes occupied 25% and 15.63%, respectively. Hemicryptophytes had a larger amount in six life forms, accounting for 31.25% of the total. H. davidii community had the typical life form characteristics of temperate steppe.