摘要
利用Ripley’s K函数以及蒙特卡罗（Monte Carlo）随机模拟方法，定量分析了4种放牧强度——无牧、轻牧（1．33只羊／hm^2）、中牧（4．00只羊／hm^2）、重牧（6．67只羊／hm^2）下星毛委陵菜（Potentilla acaulis）种群的小尺度空间格局及其随尺度的变化规律；研究了放牧对星毛委陵菜种群空间格局的影响；并以放牧条件下星毛委陵菜的生活史特征、生态适应对策以及群落内植物种间的相互作用为基础，探讨产生和维持这些格局的机理，研究表明：（1）放牧对星毛委陵菜种群空间格局有显著影响，同一放牧强度下星毛委陵菜种群在不同尺度上的空间格局存在显著差异．（2）无牧条件下，星毛委陵菜种群在0～96cm尺度上表现为集聚分布，在96～100cm尺度为随机分布；轻牧条件下，星毛委陵菜种群在0～92cm尺度上表现为集聚分布，在92～100cm尺度为随机分布；中牧条件下，星毛委陵菜种群在0～72cm尺度上表现为集聚分布，在72～100cm尺度为随机分布；重牧条件下，星毛委陵菜在20～22cm尺度上表现为集聚分布，在15～17cm、23～28cm和46～50cm尺度为均匀分布，在0～15cm、17～20cm、22～23cm、28～46cm和50～100cm上为随机分布．（3）同一放牧强度下，随着尺度的增大，星毛委陵菜种群由集聚分布趋向于随机分布；且转变为随机分布时的尺度随着放牧强度的增大而逐渐缩小．这与星毛委陵菜生物学特性和种群对放牧压力的生态适应对策密切相关．（4）在0～100cm尺度上，星毛委陵菜种群的集聚强度随着放牧强度的增大而逐渐减小，即：无牧〉轻牧〉中牧〉重牧．（5）放牧活动改变了决定群落结构的有关过程的相对重要性．这些研究结果将为在放牧活动干扰下草原群落的演替提供理论依据．
Using Ripley＇s K function and Monte - Carlo random simulation methods, the fine - scale spatial patterns of Potentilla acaulis were quantified under four grazing intensities： no grazing, light grazing （ 1.33 sheep/hm^2 ） , medium grazing （4.00 sheep/hm^2 ） and heavy grazing （6.67 sheep/hm^2 ）. The effect of grazing on the spatial patterns was studied. Based on life circle characteristics and strategies of ecological adaptation of P. acaulis and interspecific interaction in the community, the mechanisms generating and maintaining these patterns were explored. The results showed that： （ 1 ） Grazing would greatly affect the spatial patterns of P. acaulis, which changed with increasing of scales even under the same grazing intensity ; （2） Under non-grazing condition, P. acaulis was aggregated at the scale of 0～96 cm, but randomly distributed at 96 ～ 100 cm; under light-grazing condition, it was aggregated at 0 ～92 cm, but randomly distributed at 92 ～ 100 cm; under medium-grazing condition, it was aggregated at 0～72 cm, but randomly distributed at 72 ～ 100 cm; under heavy-grazing condition, it was aggregated at 20 ～22 cm, regularly distributed at 15 ～ 17 cm, 23 ～28 cm and 46 ～ 50 cm, and randomly at 0 ～ 15 cm, 17～20 cm, 22～23 cm, 28～46 cm and 50 ～ 100 cm; （3） At the same grazing intensity, the spatial pattern of P. acaulis changed from aggregation to random distribution with the scale increasing. The scale, where the spatial pattern of P. acaulis changed, decreased with grazing intensity increasing; （4） At 0 ～ 100 cm scales, the aggregation intensity of P. acaulis decreased with the increasing of grazing intensity, that is, no grazing 〉 light grazing 〉 medium grazing 〉 heavy grazing; （5） The grazing activity changed relative importance of processes determining the community structure. Fig 2. Ref 24
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2006年第3期308-312,共5页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(No.30270249)
中国科学院知识创新项目(KSCX2-SW-107
KSCX-1-08)~~
关键词
星毛委陵菜
放牧强度
小尺度
空间格局
生态适应对策
Potentilla aeaulis
grazing intensity
fine scale
spatial pattern
strategy of ecological adaptation
