...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Ecological research >Quantitative evaluation of species composition dissimilarity within a community and among communities
【24h】

Quantitative evaluation of species composition dissimilarity within a community and among communities

机译：社区内部物种组成不相似性的定量评估

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

It is often necessary to perform quantitative comparisons and assessments of species composition among plant communities under various land use conditions and landscapes, as well as among plant communities at different stages of restoration or degradation in arid grasslands. In landscapes composed of a number of plant communities, in which many quadrats for a survey are set in each community, the species composition in each quadrat is measured using community variables, such as the presence/absence data (i.e., binary variable), biomass, cover, the number of individuals, or the frequency of occurrences (i.e., quantitative variables) of each species per quadrat. In this study, we defined two types of species composition dissimilarity in vegetation surveys: between different communities and within each community which were calculated based on the species composition of each quadrat, using the Bray-Curtis index. The second type dissimilarity occurs incidentally among quadrats (or micro-sites) even in a community with a relatively uniform structure. Both dissimilarity measures take values from 0 to 1, where larger values indicate larger dissimilarities, and the quadrat-to-quadrat variation in dissimilarity also indicates the degree of heterogeneity in the spatial pattern of species composition. Quantifying dissimilarity between and within communities remains a challenge in ecological applications. We proposed a new model to quantify community dissimilarity and applied this model to a grassland vegetation survey dataset. Quantitative variables resulted in more precise measures of community structure than binary variable. The advantages of our model relative to other broadly used community structure metrics based on the Jaccard and Sorensen indices were discussed.
机译：通常需要在各种土地使用条件和景观下的植物群落中进行定量比较和评估植物群落，以及在干旱草原的恢复或降解的不同阶段的植物群落中。在由许多植物社区组成的景观中，其中在每个社区中设置了许多调查的四足动物，每个Quadrat中的物种组成使用社区变量测量，例如存在/不存在数据（即二元变量），生物量每个Quadrat的每个物种的每个物种的覆盖，个人数量或出现的频率（即定量变量）。在这项研究中，我们在植被调查中定义了两种类型的物种组成不相似性：使用Bray-Curtis指数，在不同的社区和每个社区内基于每个四边形的物种组成来计算的。即使在具有相对均匀的结构的群组中，即使在具有相对均匀的结构的群组中，第二种类型的异化也偶然地发生在Quadrats（或微型位点）中。两个不同的措施从0到1取得值，其中较大的值表示较大的差异，并且差异的四边形曲线变化也表明物种组合物的空间模式中的异质性程度。量化社区之间的异化仍然是生态应用中的挑战。我们提出了一种新的模型来量化社区不同，并将这种模型应用于草地植被调查数据集。定量变量导致社区结构的更精确度量而不是二进制变量。讨论了我们的模型的优势，相对于其他基于Jaccard和Sorensen指数的其他广泛使用的社区结构指标。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号