摘要
空间分布格局、空间关联性对尺度具有较强的依赖性,种群在不同的尺度上往往表现出多种空间分布格局和空间关联性。在黑河上游高寒退化草地,采用点格局分析方法,研究了小尺度上狼毒(Stellera chamaejasme)种群的分布格局和空间关联性。结果表明:小尺度上随着种群的发育,狼毒种群的空间分布格局由聚集分布逐渐向随机分布过渡;两个形体大小程度越接近的种群之间,空间关联性越有可能表现为正关联,随着种群的共同发育,空间关联性逐渐向不显著过渡,形体大小差异程度越大,则越有可能表现为负关联,而较大尺度上空间关联性趋于复杂化。种群个体之间的相互庇护促使狼毒个体的数量不断增长,并通过种内竞争使斑块不断扩张,狼毒种群合作与竞争机制的相互转变实现了种群的扩散。
Spatial distribution pattern,spatial association has a strong dependence on the scale,population in different scales often shows a variety of spatial pattern and spatial association.Stellera chamaejasme widely distributed in northen grassland in China,and the population has assumed a spreading tendency,so understanding the relation inside population as well as intra plant,inquiring the coexist mechanism of Stellera chamaejasme population and improving the diffusion principle which were siginficant to understand diffusion mechanism of poisonous weed in aird area.In Auvip,2009,station a 4 m×4 m plot in Kangle grassland(38°47′15.8″ N,99° 43′ 35.9″ E) Sunan Country in the upper reaches of Heihe,Gansu Province,China.We recorded every one's specific location,at last,323 Stellera chamaejasme plants were been counted in the plot.In our eexperiment,four grades were divided by shoot number of Stellera chamaejasme cluster,i.g: cluster gradeⅠ,Ⅱ,Ⅲ and Ⅳ,among which 244 individual plants was on Ⅰ level and accounted for 75.5% of the total,50 individual plants was on Ⅱ level and accounted for 15.5% of the total,20 individual plants was on Ⅲ level and accounted for 6.2% of the total,9 individual plants was on Ⅳ level accounted for 2.8% of the total.Calculating the measured value L(d) and the value of upper and lower envelopes by the Visual Fortran 6.5 based on the coordinate getting by GetData Graph Digitizer 2.22,the plot software was Origin 7.5.The results showed as follows: with the development of population,the spatial distribution pattern transfered from clumped to random gradually at fine-scale,theⅠgrade population showed clumped pattern at 0-1.35 m scale,it was clumped pattern at the 1.35-1.68 m scale and it was regular pattern at 1.68-2 m scale,Ⅱ grade population showed two spatial distribution patterns,it showed clumped pattern between 1.48 and 1.52,it was random pattern at other scale,Ⅲ and Ⅳ grades population showed random at all scale.The spatial association between plants will turn from positive to negative if their size differences are enlarged increasing,with the growth of population,the spatial association gradually transferred to non-significant.Then spatial association tended to complex at more bigger scale.So a clearer recognition be acquired by researching the distributing process of Stellera chamaejasme population,the population experienced six stage: form patchs-patchs disintegrate-form new patchs-merge patchs-patchs disintegrate-individuals died,the shelter among individuals promoted the increasing of population quantity,at the same time,which enlarged the patch by intracompetition,so the Stellera chamaejasme population has beening occupied more space and resources,finally the transformation between cooperation and competition completed population diffusion.
出处
《干旱区地理》
CSCD
北大核心
2011年第3期492-498,共7页
Arid Land Geography
基金
国家自然科学基金(40971039)
国家十一五科技支撑计划项目(2007BAD46B07)
关键词
狼毒种群
空间分布格局
空间关联性
斑块
黑河上游
Stellera chamaejasme population
spatial distribution pattern
spatial association
patch
upper reaches of Heihe
