Doctoral Dissertation Research: Disturbance Interactions in a Rocky Mountain Subalpine Forest

最近的研究突出了自然干扰对许多森林生态系统发展的重要性。 科罗拉多森林的特点是大规模的干扰与历史的回报间隔往往短于优势树种的寿命。 因此，干扰是这些森林发展的一个重要因素。 火灾和大风是非常重要的干扰形式，反复影响科罗拉多森林的结构和功能。 1997年，一场大风暴吹倒了科罗拉多西北部Zirkel山荒野及其周围1万多公顷的森林，提供了一个难得的研究机会。 本研究的目的是调查四个主要因素对林分风干扰敏感性的影响：（1）林分的火灾历史;（2）林分的物种组成;（3）林分的风干扰历史;（4）林分的地形特征。 本研究将结合联合收割机传统的树木年代学技术与分析采用地理信息系统（GIS），研究火灾和风干扰制度之间的相互作用，在这科罗拉多亚高山森林。 将在实地收集数据并输入地理信息系统进行描述性分析。 将使用多元回归和其他多元统计分析这些数据，以将林分对风害的敏感性与这四类环境因素联系起来。 这项研究将量化火灾和大规模吹伐在亚高山森林中的作用，并深入了解不同干扰之间的相互作用如何决定森林结构，组成和健康。 这些见解将使森林管理在自然干扰的限度内。 由于全球气候变化可能会增加灾难性大风的频率和强度，因此了解大规模排污对森林生态系统的影响可能特别重要。 因此，这项研究将指导这些森林的管理决策，不仅产生重要的空间信息干扰亚高山森林，但也解决了很大程度上悬而未决的问题，如何网站的以前的干扰历史影响其对未来干扰的反应。 地理信息系统为生态系统过程的空间分析提供了新的机会。这项研究将结合联合收割机地理信息系统为基础的分析与完善的树木年表程序，已被用于森林动态的时间分析。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。

Recent research has highlighted the importance of natural disturbances in the development of many forest ecosystems. Colorado forests are characterized by large-scale disturbances with historical return intervals often shorter than the life span of dominant tree species. Disturbances therefore are an important factor in the development of these forests. Fire and high winds are very important forms of disturbance that repeatedly have affected the structure and function of Colorado forests. In 1997 a major windstorm blew down over 10,000 hectares of forest in and around the Mount Zirkel Wilderness in northwestern Colorado, providing a rare research opportunity. The objectives of this study are to investigate the effect of four main factors on susceptibility for forest stands to wind disturbance: (1) a stand's fire history; (2) a stand's species composition; (3) a stand's wind disturbance history and; (4) a stand's topographic characteristics. This study will combine traditional dendrochronological techniques with analyses employing a geographic information system (GIS) to study the interactions between fire and wind disturbance regimes in this Colorado subalpine forest. Data will be collected in the field and entered into the GIS for descriptive analysis. These data will be analyzed using multivariate regression and other multivariate statistics to relate stand susceptibility to wind damage to these four categories of environmental factors. This study will quantify the roles of fire and large-scale blowdowns in subalpine forests and lend insight into how interactions among different disturbances determine forest structure, composition, and health. These insights will allow management of forests to be within the limits that result from natural disturbances. The effects of large-scale blowdowns on forest ecosystems may be especially important to understand since global climate change may increase the frequency and intensity of catastrophic winds. This research therefore will guide management decisions of these forests by not only yielding important spatial information about disturbances in subalpine forests but also by addressing the largely unanswered question of how a site's previous disturbance history affects its response to future disturbances. Geographic information systems provide new opportunities for the spatial analysis of ecosystem processes. This research will combine GIS-based analyses with well-established dendrochronological procedures that have been used for temporal analysis of forest dynamics. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.