中国戈壁针茅草原的分布、群落特征和分类

戈壁针茅(Stipa tianschanica var. gobica)草原主要分布于荒漠草原区的石质丘陵或石质山坡, 向东可以分布在典型草原区的石质丘陵或山地, 向西也可以分布在荒漠区的石质山坡上。该研究调查了中国戈壁针茅草原的主要植被类型, 通过对115个样地的样方数据分析, 量化描述了这一草原类型的主要植物群落特征。结果表明, 中国戈壁针茅草原共有维管植物272种, 隶属于38科127属; 其中裸子植物3种, 隶属于1科1属; 被子植物269种, 隶属于37科126属, 物种数大于等于10种的科为: 菊科、禾本科、豆科、蔷薇科、百合科、藜科、石竹科; 戈壁针茅草原植物区系的生活型谱以地面芽植物为主, 共178种植物, 占总种数的65.44%; 水分生态类型以旱生植物为主, 共120种, 占总种数的44.12%; 植物区系地理成分上以东古北极分布种和亚洲中部分布种(含其变型)最多, 分别为82种和80种, 占总种数的30.14%和29.41%; 盖度等级划分上以0.1%-1.0%的盖度最多, 共174种, 占总种数的63.97%; 恒有度等级划分上以I级(0-20%)的物种数最多, 共258种植物, 占所有植物种数的94.85%。基于群落调查数据, 按照群落-外貌分类原则, 将戈壁针茅群系划分为8个群丛组106个群丛。

Distribution,community characteristics and classification of Stipa tianschanica var. gobica steppe in China

Aims Stipa tianschanicavar. gobica steppe is mainly distributed on the rocky slopes or rocky hills of desert steppe region, and can also be found in rocky hills or mountains of the typical steppe area eastwardly and some rocky slopes of the desert region westwardly. The main vegetation types of S. tianschanicavar. gobica steppe in China were investigated in this paper, and based on the 115 plot samples, the characteristics of the main desert steppe plant communities from the main vegetation types were quantitatively described. And the results showed that: according to the quadrat data, 272 seed plants belonging to 38 families and 127 genera (including the subspecies, varieties and forms) were recorded in the S. tianschanicavar. gobica steppe of China, among which there were 3 gymnosperm species belonging to 1 families and 1 genera, and 269 angiosperm species belonging to 37 families and 126 genera. The families having more than 10 species were Compositae, Poaceae, Leguminosae, Rosaceae, Liliaceae, Chenopodiaceae and Caryophyllaceae respectively. Hemicryptophyte, with a total of 178 species is the dominant life form in S. tianschanicavar. gobica steppe, which accounted for 65.44% of the total species. As for the ecological type of water, xerophytes was the dominant plants, with a total of 120 species, accounting for 44.12% of all species. East Palaeo-North element areal-type (including 82 species) and Middle Asia element (included the variants) areal-type (including 80 species) were the major floristic elements, containing 30.14% and 29.41% of the total species. The coverage of 0.1%-1% was the dominant level in the cover class distribution of the species, including 63.97% of the total species. The constancy degree of I (0-20%) was the dominant level in the constancy degree distribution of the species in S. tianschanicavar. gobica steppe, containing 94.85% of all the species. In accordance with the classification principle of community-appearance, Form. S. tianschanicavar. gobica was divided into 8 S. tianschanicavar. gobica steppe association groups, and 106 associations were divided from these 8 association groups based on community survey data.