高寒退化草地狼毒与赖草种群空间格局及竞争关系

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 高寒退化草地狼毒与赖草种群空间格局及竞争关系 DOI: 10.5846/stxb201112031850 作者: 作者单位: 西北师范大学地理与环境科学学院,西北师范大学地理与环境科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金 (91125014,40971039);甘肃省生态经济重点学科资助 Spatial pattern and competition relationship of Stellera chamaejasme and Aneurolepidium dasystachys population in degraded alpine grassland Author: Affiliation: College of Geography and Environment Science,Northwest Normal University,College of Geography and Environment Science,Northwest Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:种群空间格局的尺度转换效应反映了植物种内、种间竞争关系的变化过程。采用草地群落学调查与点格局分析方法,在祁连山北坡阿尔泰针茅草原,分析了干扰状态下狼毒(Stellera chamaejasme)和赖草(Aneurolepidium dasystachys)种群的空间格局及竞争关系。结果表明:随着草地退化过程加剧,狼毒种群空间格局由聚集分布转变为非聚集分布,反映了协作转向竞争的种内个体间关系;赖草种群以聚集格局为主,体现了种内相互协作的个体间关系;二者空间关联性存在正相关、不相关和负相关的转换过程,正相关尺度逐渐缩小,负相关仅在重度退化草地出现,种群间关系表现为由协作转向竞争且竞争强度逐渐增大。干扰状态下,种群空间格局的尺度转换效应影响植物种内、种间的竞争关系及强度,反映了退化草地物种应对干扰的更新途径。 Abstract:Human activities are affecting the habitat, which decrease the number of habitats and recede the quality. The biggest threat to species diversity worldwide is the loss of suitable habitat. Human activities affect species dynamics and further influence species diversity by changing habitat. Species evolvement at different types of habitat is very complex, so there is an urgency to understand species responses to human-caused habitat degradation. Spatial pattern and competition relationship are important in plant ecology as they affected the dynamics of plant populations, communities and ecosystem processes, which can reveal the dynamic and stability of population and community structure. Stellera chamaejasme and Aneurolepidium dasystachys are the main species in alpine degraded grassland, have a great significance for understanding reproductive strategies of grassland plant resources with studies on spatial pattern and competition relationship of S. chamaejasme and A. dasystachys. In this study for two main aims: First, to describe the scale transformation of population's spatial pattern and spatial association along with the different plot; Second, to analyze the competition relationship and competition intensity of S. chamaejasme and A. dasystachys. 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, four experimental plots were established by the community characteristics and S. chamaejasme population characteristics. At the same time, we recorded fine-scale (0-100 cm) spatial pattern and spatial association of S. chamaejasme and A. dasystachys population from 2 m×2 m grids (2 cm×2 cm quadrats) in different plot. The point pattern analysis and Monte Carlo stochastic simulation method were used to quantitatively analyze spatial pattern and competition relationship. The results showed that: (1) In the process of natural pasture degeneration, the spatial patterns of S. chamaejasme were aggregated at 53-58 cm and 63-100 cm scales under no degradation and light degradation conditions, and subsequently random or regular under moderate degradation and heavy degradation conditions, which meant that the intraspecific relationship converted mutualism into competition within different plot. (2) The spatial patterns of A. dasystachys were aggregated within four plots, which meant that intraspecific mutualism was the most important competition relationship of A. dasystachys in the process of natural pasture degeneration. (3) The spatial association of S. chamaejasme and A. dasystachys population changed on the different scale and degradation gradient. Under no degradation and light degradation conditions, the positive correlation was shown at 8-20 cm and 66-71 cm scales; under moderate degradation conditions, there was no significant correlation as a whole and the scale ranges was from 0 cm to 100 cm; under heavy degradation conditions, negative correlation was shown at 16-28 cm scales. It reflected that the interspecific relationship converted mutualism into competition. The scale transformations of population's spatial pattern, as well as the spatial association, are not only the antecedent conditions affecting changes of competition relationship, but also the critical factors of population's competition intensity. It may reflect the adaptive approach of regeneration and reproduction when S. chamaejasme and A. dasystachys population face the outside interference. 参考文献 相似文献 引证文献