Doctoral Dissertation Research: Disturbances and Tree Species Diversity Along the Elevational Gradient of a Subtropical Montane Forest

该项目将评估阿根廷西北部亚热带山地森林的树种多样性如何受到各种空间尺度干扰的影响，以及干扰机制如何与海拔梯度相关。据推测，在高海拔的森林中，频繁的火灾维持了低多样性。在低山林中，小尺度林隙的出现促进了高多样性。高山林和低山林之间多样性的突变被认为是由扰动制度的变化引起的，这种变化反映了潜在的物理环境梯度和植被对这些梯度的响应的影响。研究方法将包括在林分和景观尺度上的干扰制度的树木生态记录，与竹覆盖有关的树木补充的空间和时间格局，林分尺度的多样性测量，以及利用遥感绘制低山林和高山林之间的界限。这些结果将提供有关气候变化和干扰制度中人为变化如何影响生物多样性的信息。

Grau, Hector R U. of Colorado, Boulder This project will assess how tree species diversity is affected by disturbances across a range of spatial scales, and how disturbance regimes are related to elevational gradients in subtropical montane forests in northwestern Argentina. It is hypothesized that in the higher montane forest, low diversity is maintained by frequent fire. In the lower montane forest, high diversity is promoted by the occurrence of small-scale treefall gaps. Abrupt changes in diversity between the higher and lower montane forest are believed to be caused by shifts in disturbance regimes that reflect the influences of both the underlying physical environmental gradients and vegetation responses to these gradients. Research methods will include dendroecological records of disturbance regimes at a stand and landscape scale, spatial and temporal patterns of tree recruitment in relation to bamboo cover, stand-scale measures of diversity, and the use of remote sensing to map the limit between lower and higher montane forests. The results will yield information on how climatic change and anthropogenic changes in disturbance regimes affect biodiversity.