摘要
在内蒙古草原区中部的克氏针茅草原,连续4年(2006-2009年)进行了夏秋季划区轮牧实验;利用摄影和地理信息系统相结合方法,研究了不同放牧强度对植物群落和种群格局的生态作用效应。摄影图像和测定数据的分析结果表明,在不同放牧实验小区形成了大小不一、结构不同的群落斑块,并显示出不同放牧强度与放牧周期的植物群落及种群斑块结构的生态梯度格局。在不放牧的围封对照小区内(G5)保持原有的克氏针茅群落斑块和羊草群落斑块,二者的斑块数量、斑块面积之比、斑块的植物组成与生物量都比较稳定;在不同放牧强度的实验小区(G1、G2、G3),群落斑块的数量、面积、种群结构、植物多度、株丛冠幅、生物量等都形成了相对应的梯度差异。不同放牧强度导致克氏针茅群落与种群斑块的不同破碎化程度和植物个体(株丛)小型化。适度放牧使得斑块结构与生物量表现出中度干扰下植物补偿性生长的效应。结果表明植物群落斑块结构与种群格局的变化是草原植物群落演替过程中种群拓殖与衰退的基本形式,也是生态演替的机制。
A continuous period of four years （2006-2009 years） rotational grazing experiment was carried out on Stipa krylovii steppe in the central part of Inner Mongolia in the summer and autumn.With combination of photography and geographic information systems,we had studied ecological effects of grazing on the distribution pattern of plant populations and communities in different grazing intensities experimental plots.The photographic images and experimental data showed that there had formed patches with different sizes and structures in different grazing areas,also the gradient sequence of communities and population and plant production were caused by a different cycle and intensity of grazing.However,the patches in no-grazing enclosed control area（G5） were still original Ass.S.krylovii and Ass.Leymus chinensis.The percentage of the number and area of patches、the plants composition and above-ground biomass were all relatively stable in G5.In different grazing intensity experiments plots（G1、G2、G3）,there formed different gradient on the number,area,population structure,plant abundance,circumference and above-ground biomas.Ass.S.krylovii and population patch become fragmentation and individual plant become miniaturization due to different grazing intensity.Moderate grazing makes the patch structure and above-ground biomass emerge in the effects of compensatory growth of plants.This study showed that the changes of plant patch structure in community and population pattern were the basic for population colonization and recession during grassland succession,and also the mechanism for the succession of grassland plant communities.
出处
《草业学报》
CSCD
北大核心
2010年第3期6-13,共8页
Acta Prataculturae Sinica
基金
现代农业产业技术体系建设专项及公益性行业(农业)科研专项(No.200903060)
国家自然科学基金项目(No.30360016,No.40861002)资助
关键词
克氏针茅草原
放牧强度
摄影图像分析
植物群落与种群格局
Stipa krylovii steppe
grazing intensity
photographic image analysis
plant community and population pattern
