高寒退化草地不同海拔梯度狼毒种群分布格局及空间关联性  

Spatial distribution and spatial association of Stellera chamaejasme population in the different altitude in in degraded alpine grassland

作　　者：高福元[1] 赵成章[2] 卓马兰草 

机构地区：[1]郑州师范学院,郑州450044 [2]西北师范大学地理与环境科学学院,兰州730070 [3]甘肃民族师范学院,甘南747000

出　　处：《生态学报》2014年第3期605-612,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(91125014)

摘　　要：在石羊河上游高寒退化草地,应用点格局分析方法,按狼毒个体分枝数设置Ⅰ级株丛(1—10枝)、Ⅱ级株丛(11—20枝)、Ⅲ级株丛(21—30枝)、Ⅳ级株丛(30以上)4个株级,研究了不同海拔高度各株级狼毒的空间分布格局及关联性,并统计了狼毒种群的大小组成。结果表明:随海拔升高Ⅰ、Ⅱ级狼毒株丛个体数减少,Ⅲ、Ⅳ级狼毒株丛个体数增多;Ⅲ、Ⅳ级狼毒株丛在各海拔梯度上主要以随机分布为主,Ⅰ、Ⅱ级狼毒株丛在低海拔地区小尺度上表现为聚集分布,随海拔升高聚集强度增强,聚集尺度减小,在较大尺度上表现为随机分布;Ⅰ级狼毒株丛与Ⅲ、Ⅳ级狼毒株丛、Ⅱ级狼毒株丛与Ⅳ级狼毒株丛小尺度上表现为正关联关系,随海拔升高正关联关系发生的尺度减小。狼毒种群对环境变化具有明显的响应机制,可通过相互之间的庇护作用、减少繁殖、减弱种内竞争以及提高聚集强度实现生存繁殖。Stellera chamaejasme L spread threatens productivity, conservation and ecological sustainability in wide range of meadows and grasslands on the Tibetan Plateau of China, it has become one of the most serious weeds threatening a widerange of grasslands, which were grazed heavily. In recent years, distribution of the Stellera chamaejasme have expanded and there formed severe degraded grassland in some high altitude area. Therefore, it is extremely important to understand their biologic characters of the population distribution that are in the different altitude. It is critical for revealing the cause and mechanism of population diffusion. The experiments were conducted in degraded alpine grassland in the upper reaches of Shiyang river, Gansu Province, China.In August 2012, at the same aspect and slope of the sample by selecting different altitudes（2700-3000 m） , every 100 meters to set up a plot, set up four plot, plot area of 2 m×2 m, with 1 mX 1 m sample box （box-like area of the small squares 10 cm × 10 cm） placed 4 times at a certain order of sampling, record every individual branches, ground projection and relative position, setted up Ⅰ degree cluster（ 1-10 branches）, Ⅱ degree cluster （11-20 branches）, m degree cluster （21-30 branches） , Ⅳ degree cluster （above 30 branches） under Stellerachamaejasme branch number. The measured value L（d） 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, Origin 7.5 was used as the plot software, this plot in the lower left comer coordinate origin to the intersection, using the step of 5 cm, the number of Monte- Carlo stochastic simulation is 20 times, dashed line are the 95% confidence envelops for the same process. The results showed that ： Ⅰ , Ⅱ degree Stellera chamaejasme cluster reduced, Ⅲ, IV degree Stellera chamaejasme cluster increased with the altitude escalate; Ⅲ Ⅳ degree Stellera chamaejasme cluster mainly random distribut

关 键 词：狼毒种群 空间分布格局 空间关联性 斑块 石羊河上游 

分 类 号：S812[农业科学—草业科学]