退化草地阿尔泰针茅生殖株丛与非生殖株丛的空间格局  

Spatial pattern of sexual plants and vegetative plants of Stipa krylovii population in alpine degraded grassland

作　　者：任珩[1] 赵成章[1] 高福元[1] 石福习[1] 张茜[1] 

机构地区：[1]西北师范大学地理与环境科学学院甘肃省湿地资源保护与产业发展工程研究中心,兰州730070

出　　处：《生态学报》2012年第21期6909-6916,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(40971039;91125014);甘肃省科技支撑计划项目(1011FKCA157);甘肃省高校基本科研业务费项目;西北师范大学知识与科技创新工程项目(nwnu-KJCXGC-03-66)资助

摘　　要：生殖株丛与非生殖株丛的空间格局是株丛自身特性和植物种内、种间关系综合作用的结果。采用草地群落学调查与点格局分析方法,在祁连山北坡高寒退化草地设置4个退化梯度,每个梯度内随机设置3个2 m×2 m的样方,分析了0—100cm空间尺度上阿尔泰针茅(Stipa krylovii)种群生殖与非生殖株丛的生物量、高度和空间格局。结果表明:未退化草地中,阿尔泰针茅生殖与非生殖株丛均出现聚集格局,且分布于不同的尺度区间;草地退化过程中,生殖与非生殖株丛聚集格局出现重叠且重叠的空间尺度发生转换,从18—19 cm、54—68 cm转换为45—78 cm;生殖株丛空间格局以聚集分布为主,聚集格局尺度随生物量和株高增加而增大;非生殖株丛以聚集和均匀分布为主,聚集格局尺度随生物量和株高下降而减小,均匀格局尺度增大。在干扰活动影响下,生物量分配和株高的转变是种群空间格局发生尺度转换的关键因素,反映了退化草地植物种群繁殖与更新的适应性途径。Spatial pattern is important in plant ecology as it affected the dynamics of plant populations, communities and ecosystem processes, which can reveal the dynamic and stability of population and community structure. Stipa krylovii, the zonal vegetation in alpine degraded grassland, has a great significance for understanding reproductive strategies of grassland resources with studies on spatial pattern of sexual plants and vegetative plants of S. krylovii population. In this study for two main aims ： First, to describe the scale transformation of spatial pattern along with the different plot ; Second, to analyze the effect of aboveground biomass and plant height on the spatial pattern. Study sites locates in the Ma Changtan grassland in SuNan country of the north Qilian Mountain （38°47＇22. 1＂-38°52＇11＂ N, 99°45＇11.7＂--99°57＇41.2＂ E）. In early August, 2011, we recorded aboveground biomass, plant height and fine-scale （0--100 cm） spatial pattern of sexual plants and vegetative plants of S. krylovii population from 2 m×2 m grids （2 cm×2 cm quadrats） in four plots under four kinds of degradation gradients： no degradation, light degradation, moderate degradation and heavy degradation. The measured value and the value of upper and lower envelopes were calculated by the Visual Fortran 6.5 based on the coordinate getting by GetData Graph Digitizer 2.22, the point pattern analysis and Monte Carlo stochastic simulation method were used to quantitatively analyze spatial pattern, the excel software was used to construction, the number of Monte Carlo stochastic simulation was 20 times with the step of 2 cm. The results showed that ： （ 1 ） Under no degradation conditions, the spatial pattern of sexual plants and vegetative plants were aggregated at different scale, the sexual plants were aggregated at 94-- 100 cm scales, the vegetative plants were aggregated at 22--46 cm scales. （2） In the process of natural pasture degeneration, along with the aboveground biomass and plant height

关 键 词：阿尔泰针茅 株丛 空间格局 株高 地上生物量 祁连山北坡 

分 类 号：S812[农业科学—草业科学]