RUI: Biogeographical Impacts of Recent Bark Beetle Epidemics on Cavity-Nesting Birds in Arizona.

生物地理学将地理学的空间方法与生态学的功能方法结合起来，观察生态过程中空间模式的起源和后果。生物地理学家研究生态模式（空间和时间）和进程（如干扰和物种分布）之间的关系。该研究项目将探讨人类活动对野生动物及其栖息地需求之间关系的原因和后果。具体来说，这项研究将确定最近树皮甲虫爆发对亚利桑那州北部洞穴筑巢鸟的影响。本项目的目标是：(1)描述美国西南部黄松林中被树皮甲虫杀死的树干（站立的死树）的空间格局、密度、腐烂率和动态；(2)通过比较树皮甲虫爆发时杀死的树枝和个体死亡率，根据这些树枝的特征预测洞巢鸟使用树枝的概率；(3)建立被树皮甲虫杀死的树枝数据库，将其添加到我们的火灾杀死的树枝动力学模型中，以检验生态假设并为森林管理者提供指导。这项研究将通过模拟鸟类在一系列干扰尺度上的空间格局，从个体死亡到景观尺度上的死亡率，来推进生物地理学理论。本计划将透过加强本科生实验室的基础设施及促进研究与本科教育的整合，加强文科本科学院的研究环境。研究区域将包括最近经历树皮甲虫爆发的未燃烧的西南黄松林和没有树皮甲虫爆发的未燃烧地区。收集的野生动物数据将包括挖掘洞穴的数量、自然洞穴的数量、觅食的证据和野生动物的直接观察。收集的树木数据将包括增加的岩心样本、绘制的位置、种类、直径、高度、顶部状况、折断状况、树皮覆盖、空洞、枯枝、瘦削、基部面积和腐烂等级。该项目将评估空间结构和格局，并协助评估干扰对景观的影响。此外，通过栖息地建模，量化结构模式将有助于评估这些景观如何影响鸟类的丰度和分布。该生物地理研究的直接应用包括森林管理决策，如在西南黄松森林的回收采伐和恢复工作中保留的障碍数量和障碍的空间格局。确定从砍断到砍伐的转换率对于预测野生动物栖息地的可用性具有重要意义。了解哪些树或障碍将保持最长的时间，并最常被洞穴筑巢者使用，将为确定需要更换多少活树和制定未来的障碍管理计划提供指导。

Biogeography unites the spatial approach of geography with the functional approach of ecology, viewing the origins and consequences of spatial patterns on ecological processes. Biogeographers investigate relationships between ecological patterns (spatial and temporal) and processes, such as disturbances and species distributions. This research project will explore the causes and consequences of human activity on relationships between wildlife and their habitat requirements across a range of scales. Specifically, this study will determine effects of recent bark beetle outbreaks on cavity nesting birds in northern Arizona. The objectives of this project are to: (1) describe spatial patterns, density, decay rates, and dynamics of bark beetle-killed snags (standing dead trees) in ponderosa pine forests of the American Southwest; (2) predict the probability of snag use by cavity nesters based on these snag characteristics comparing snags killed in bark beetle outbreaks vs. individual mortality; and (3) develop a database of bark beetle-killed snags to add to our fire-killed snag dynamics model in order to test ecological hypotheses and provide guidelines for forest managers. This research will advance biogeographical theories through modeling bird spatial patterns across a range of disturbance scales, from individual killed snags to landscape-scale mortality. This project will strengthen the research environment at an undergraduate liberal arts college through enhancing the infrastructure of the undergraduate labs and promoting the integration of research and undergraduate education. The study area will include unburned southwestern ponderosa pine forest that recently experienced bark beetle outbreaks paired with unburned areas without bark beetle outbreak. Wildlife data collected will include the number of excavated cavities, the number of natural cavities, evidence of foraging, and direct wildlife observations. Tree data collected will include increment core samples, mapped locations, species, diameter, height, top condition, snag condition, bark cover, cavities, dead limbs, lean, basal area, and decay class. The project will assess spatial structure and patterns and assist in evaluating effects of disturbances on landscapes. In addition, quantifying structural patterns will help to evaluate how these landscapes affect abundance and distribution of birds at present and into the future through habitat modeling. Direct applications of this biogeographic research include forest management decisions such as the number of snags and spatial pattern of the snags to retain in salvage logging and restoration efforts in southwestern ponderosa pine forests. Determining the transition rate from snag to fallen log is important for predicting availability of wildlife habitat. Knowing which trees or snags will remain standing longest and are most used by cavity nesters will provide guidance in determining how many live tree replacements are needed and in developing future snag management plans.