阿尔泰狗哇花型退化草地植物功能群特征初探  

Preliminary study on characteristics of plant functional types in deteriorated Heteropappus altaicus grassland

作　　者：林丽[1] 龙瑞军[2] 赵成章[3] 李以康[1] 张法伟[1] 王溪[1] 王洪君[4] 

机构地区：[1]中国科学院西北高原生物研究所,青海西宁810008 [2]兰州大学草地农业科技学院,甘肃兰州730020 [3]西北师范大学,甘肃兰州730070 [4]吉林省农业科学院,吉林长春130124

出　　处：《草业科学》2009年第6期35-40,共6页Pratacultural Science

基　　金：世界银行/全球环境基金项目"退化草原植被恢复与碳固定之间的研究"(052456CHA-GS-Y-4);国家自然基金重点项目(30730069)

摘　　要：采用空间序列代替时间序列的方法．以石羊河上游重度放牧条件下形成的阿尔泰狗哇花型退化草地及其原生群落（阿尔泰针茅Stipa krylovii＋扁穗冰草Agropyron cristatum一冷篙Artemisia frigida＋阿尔泰狗哇花Heteropappusaltaicus）为研究对象．对2种草地植物功能群的季节动态特征进行初探。结果表明：草地退化使禾本科牧草的平均盖度、密度和高度依次降低20．4％～33．6％、24．0％～34．6％、36．2％～59．9％．而杂类草的平均盖度、密度和高度依次升高18．1％～63．0％、26．7％～82．8％、6．9％～80．8％；由此推断随时间推移．禾本科功能群较杂类草空间拓殖速率降低．在群落中的地位下降．此特征与功能群所处的退化阶段无关；禾本科功能群在原生植被中始终保持优势地位．而在退化草地中其地位在7月上旬后被杂类草取代．导致群落成员型发生改变。造成该区草地退化的主要原因很可能同放牧干扰与植物功能群季节生长特性相叠加有关，家畜选择性采食和践踏的双重作用，降低了禾本科功能群对资源空间占有的能力．为杂类草生长提供更多的资源空间．造成了杂类草生长势更强．导致其在群落中地位上升。最终形成以杂类草为景观的退化草地。The method of spatial-temporal substitution was used to study the characteristics of plant functional types in deteriorated Heteropappus altaicus grassland caused by heavy grazing and its original vegetation community （Stipa krylovii ＋ Agropyron cristatum--Arternisia frigida ＋ H. altaicus） in the upstream of Shiyang River. The results showed that the coverage, density and height of gramineous plants decreased in deteriorated grassland, and their variation ranges were 20. 4% to 33.6%, 24.0% to 34.6% and 36.2% to 59.9% respectively, while those of forbs increased and the variation ranges were 18.1% to 63.0%, 26.7% to 82.8% and 6.9% to 80.8% respectively. It meant that the horizontal growth ability of plants in gramineous group decreased compared with those in forbs group and its role in community was weakened. This feature was not related with the deterioration phase. The plants in gramineous group kept their dominant role in original community, but they were replaced by forbs after mid July in deteriorated grassland. The main reasons for plant community deterioration might be the over-grazing and the growth characteristics of the plant functional types because the selective grazing and trampling of livestock reduced the resource occupying ability of gramineous plants and supply more resources to forbs and finally formed the deteriorated grassland.

关 键 词：退化草地 植物功能群 石羊河上游 

分 类 号：S812[农业科学—草业科学]