RUI: Assessing Change in Aquatic Resources Using a Historical Data Base: Effects of Land Use on Lakewater Chemistry and Plankton Biodiversity

本研究的重点是利用历史资料，考察和记录30个湖泊的土地利用与湖水化学特征和浮游植物生物多样性之间的关系。将为30个水体中的每个水体收集三套历史资料。第一组数据将包括对1934年、1970年、1990年和欧洲人定居前每个湖泊的硅藻浮游植物区系的详细分析。植物区系将使用铅210年代沉积物岩心的微化石残留物来确定。第二组数据将包括同一时期的湖水化学分析，这些分析来自实际的化学记录和/或古湖泊学推断模型。第三组数据将包括1934年、1970年和1990年根据高分辨率航空照片、历史地图和其他存档的土地使用记录确定的每个周围流域的土地使用情况。这三组数据将用于将每个湖泊的化学和生物状况的变化与三个时期的土地使用的测量变化联系起来：欧洲人的到来到20世纪30年代，30年代到70年代，对水生生态系统造成人为压力的主要原因之一是由于土地利用变化引起的集水区径流溶质含量的增加。尽管如此，人们对不断变化的土地覆盖模式对接收水体的影响知之甚少。详细的历史记录的可用性，加上从沉积物记录中提取数据的能力，为分析土地利用对水生生态系统的影响提供了难得的机会。从一种土地利用类型到另一种土地利用类型的变化如何改变附近水体的基本理解，将为湖泊管理提供有力的工具。本研究概述的历史记录整合可以作为其他地理区域类似项目的样板。

The focus of this study is to utilize historical information in order to examine and document relationships between land use and the character of lakewater chemistry and phytoplankton biodiversity in a suite of 30 lakes. Three sets of historical information will be assembled for each of the 30 waterbodies. The first set of data will consist of a detailed analysis of the siliceous algal phytoplankton flora for each lake for 1934, 1970, 1990, and for pre-European settlement. The floras will be determined using microfossil remains from lead-210 dated sediment cores. The second set of data will consist of lakewater chemical analyses from the same time periods assembled from actual chemical records and/or inferred from paleolimnological inference models. The third set of data will consist of land use determinations for each surrounding watershed for 1934, 1970 and 1990, derived from high resolution aerial photographs, historical maps and other archived land use records. The three sets of data will be used to correlate changes in the chemical and biological status of each lake with measured alterations in land use for three time periods, the arrival of Europeans to the 1930s, the 1930s to 1970s, and the 1970s to 1990s. %%% One of the primary causes of anthropogenic stress on aquatic ecosystems is the increase in solute content of runoff from catchment basins caused by a change in land use. Despite this fact, the impacts that changing land cover patterns have on receiving waterbodies are poorly understood. The availability of detailed historical records coupled with the ability to extract data from the sediment record offers a rare opportunity to analyze the effects of land use on aquatic ecosystems. A fundamental understanding of how changes from one type of land use to another could alter a nearby waterbody would provide a powerful tool for lake management. The integration of historical records, as outlined in this study, could serve as a model for similar projects in other geographic regions.