DISSERTATION RESEARCH: Application of Phytolith Analysis to Infer Vegetation and Disturbance Regime Changes Over the Past 200 Years.

历史生态学是一个研究领域，旨在通过综合历史记录（即人类档案）和生物数据中的信息来描述生态系统随时间的变化。历史生态学的研究方法涵盖了广泛的时间尺度；然而，过去200年的生物学证据有限，需要新的方法。本研究旨在通过将人类档案与土壤植物体分析相结合，扩大生物数据在推断过去200年植被变化方面的应用。植物岩是植物细胞的微观化石，当植物腐烂时沉积到土壤中。这项研究将利用植物岩来描述西部牧场植物群落的变化，并记录过去200年里发生火灾的频率。这些新技术将通过提供与土地利用和气候变化相关的植被变化的历史信息，使从事西部两种广泛存在且高度退化的牧地类型——山艾草草原和小松柏林地的土地管理人员和研究人员受益。对历史条件的了解有助于指导管理决策和修复工作。此外，该研究将对历史生态学的科学领域做出重要贡献。

Historical ecology is a field of study that seeks to describe changes in ecosystems over time by synthesizing information from historical records (i.e., the human archive) and biological data. Methods used in historical ecology cover a wide range of time scales; however, biological evidence for the last 200 years is limited and new approaches are needed. This research seeks to expand the use of biological data for inferring vegetation changes in the last 200 years by combining the human archive with soil phytolith analysis. Phytoliths are microscopic fossils of plant cells that are deposited into soils when plants decay. This research will use phytoliths to characterize plant community changes in western rangelands and document the frequency of fires that occurred within the past 200 years. These new techniques will benefit land managers and researchers working in sagebrush steppe and pinyon-juniper woodlands, two widespread and highly degraded rangeland types in the West, by providing historical information on vegetation change as related to land use and climate change. An understanding of historical conditions helps guide management decisions and restoration efforts. In addition, this research will contribute significantly to the scientific field of historical ecology.