• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Variation in forest richness, density, and size is explained by environmental gradients from the plot to landscape scale.
【24h】

Variation in forest richness, density, and size is explained by environmental gradients from the plot to landscape scale.

机译：森林丰富度，密度和大小的变化可以通过从地块到景观尺度的环境梯度来解释。

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

A spatial gap exists between fine scale forest census plot dynamics and coarse scale landscape processes. Patterns observed at the plot scale do not necessarily continue outside plot boundaries and how such patterns scale across the landscape remains poorly understood. The sparse geographic extent of census plot data and the prohibitive cost of high resolution remote sensing remain the largest obstacles to extending the study of plot scale dynamics across the landscape, however this situation is changing rapidly and methods must be developed to integrate new data and close this spatial gap. The research presented in this dissertation utilizes plot level census data to study how plant richness, density and size vary across environmental gradients and presents a methodological framework for 1) predicting species richness where no plot data currently exists, 2) investigating guild level differences between plant growth forms in relation to resource gradients and 3) studying how forests vary across environmental gradients at the continental scale. The methodology utilizes spatial and non-spatial modeling to identify associations between plant richness, density and size at the plot scale. These associations are used to predict forest dynamics at the landscape scale and study forest structure at the continental scale.;First, the findings provide evidence that increased tree species richness is associated with environmental heterogeneity in both the canopy and hydrologic environment. These associations explain nearly half of the variation in tree species richness and are used to make hectare scale predictions of tree species richness on Barro Colorado Island, Panama. Secondly, there is strong evidence of habitat filtering along resource gradients of light and water caused by guild level differences between plants. In particular, free-standing plant guilds are non-randomly arranged along the hydrologic gradient with short understory trees and shrubs clustered in wetter environments and midstory and canopy level trees clustered in drier environments. Finally, when compared to climatic predictors, topography and terrain slope in particular appear to be exerting strong controls on forest structure across Mesoamerica. Taller forests occur on steep slopes, high elevation, on well drained soils and these effects are insensitive to land cover, biome and spatial scale.
机译：精细森林普查动态与粗略景观过程之间存在空间差距。在地块比例上观察到的图案不一定会在地块边界之外继续，并且这种图案在整个景观上的缩放方式仍然知之甚少。人口普查地块数据的稀疏地理范围和高分辨率遥感的高昂成本仍然是扩大对整个地块的地块尺度动态研究的最大障碍，但是这种情况正在迅速改变，必须开发方法以整合新数据并关闭这个空间上的差距。本文利用地块普查数据研究植物丰富度，密度和大小如何随环境梯度变化，并提出了一种方法框架：1）预测目前没有地块数据的物种丰富度； 2）调查植物之间行会水平差异与资源梯度有关的增长形式； 3）研究森林在大陆范围内跨环境梯度的变化。该方法利用空间模型和非空间模型来识别地块尺度上植物丰富度，密度和大小之间的关联。这些关联被用来在景观尺度上预测森林动态并在大陆尺度上研究森林结构。首先，这些发现提供了证据，表明树种丰富度的增加与冠层和水文环境中的环境异质性有关。这些关联解释了树木物种丰富度近一半的变化，并用于对巴拿马巴罗科罗拉多岛的树木物种丰富度进行公顷尺度的预测。其次，有强有力的证据表明，由于植物之间行会水平的差异，生境会沿着光和水的资源梯度进行过滤。特别是，独立的植物行会沿着水文梯度非随机地排列，在潮湿的环境中聚集了矮小的林下树木和灌木，在较干燥的环境中聚集了中层和冠层树木。最后，与气候预测指标相比，特别是地形和地形坡度似乎对中美洲的森林结构施加了强有力的控制。较高的森林生长在陡坡，高海拔，排水良好的土壤上，这些影响对土地覆盖，生物群落和空间规模不敏感。

著录项

  • 作者

    Fricker, Geoffrey Andrew.;

  • 作者单位

    University of California, Los Angeles.;

  • 授予单位 University of California, Los Angeles.;
  • 学科 Geography.;Ecology.
  • 学位 Ph.D.
  • 年度 2015
  • 页码 136 p.
  • 总页数 136
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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