Doctoral Dissertation Research: Human Disturbance and Site Factors Influencing Spatial Patterns of Forest Regeneration

小行星9405356 地理学家、生态学家和其他科学家对人类与环境相互作用的复杂动力学的研究往往集中在自然系统的初始扰动上，但现在越来越多的注意力正在转向理解人类活动和自然过程在随后时期的关系。 被清除的森林地区的再生是这些复杂的相互作用特别明显的一个主题。 这篇博士论文的研究项目将比较密歇根州上半岛的森林再生模式，在那里，茂密的森林被砍伐和火灾在19世纪世纪后期清除。 其中一些地区经历了积极的再生，而其他地区仍然是“树桩草原”，基本上没有树木。 该项目将侧重于影响这种差异再生的因素以及植被模式对当前土壤发育过程的影响。 在清理前通过检查土地总局的测量记录确定森林组成模式之后，将利用航空摄影绘制组成均匀的同时期林分的地图。 将在森林组成、土壤质地、土壤肥力和土层发育的抽样地点进行实地观察。 这些数据将与小气候数据和历史来源的信息一起进行沿着分析，以确定各种自然和人为因素如何影响不同地点的再生过程。 将通过观察不同地点土壤中某些营养物质的移动情况，分析植物形态与土壤发育过程之间的关系。 该项目将提供关于特定自然和人为因素在森林地区持续变化动态中的重要性的宝贵信息，并将解决有关改变土壤成分和质量的过程的重要问题。 作为博士论文改进奖，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研究生涯。

9405356 SCHAETZL Studies by geographers, ecologists, and other scientists of the complex dynamics of human-environmental interaction have tended to focus on the initial disturbance of natural systems, but increasing attention now is being given to understanding how the processes through which human activities and natural processes relate during subsequent periods. The regeneration of forest areas that have been cleared is one topic for which these complex interactions are especially apparent. This doctoral dissertation research project will compare patterns of forest regeneration in the Upper Peninsula of Michigan, where dense forests were cleared by logging and fires in the late 19th Century. Some of these areas have experienced active regeneration, while others remain "stump prairies" that essentially are devoid of trees. The project will focus both on the factors that have influenced this differential regeneration and on the impacts of vegetative patterns on current soil- development processes. Following identification of patterns of forest composition before clearance through examination of General Land Office survey records, contemporary stands of homogeneous composition will be mapped using aerial photography. Field observations will be made in a sample of sites of forest composition, soil texture, soil fertility, and soil horizon development. These data will be analyzed along with microclimatic data and information from historical sources to identify the determine how various natural and human factors influenced regeneration processes in different sites. Analyses of relationships between vegetative patterns and soil-development processes will be undertaken through observations of the movement of selected nutrients through the soil in different locations. This project will provide valuable information about the importance of specific natural and human factors in the ongoing dynamics of change in forested regions, and it will address import ant questions regarding processes that alter the composition and quality of soils. As a doctoral dissertation improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.