Collaborative Research: Long-Term Fire Regimes in Eastern North America

年全球气候变化最显著的影响之一， 接下来的两个世纪可能是增加的频率和/或 温带森林的火灾强度。 自然火灾状况 在很大程度上是未知的，这使得很难推测 火灾制度对快速气候变化的反应。 的影响 对森林组成和结构的影响可能具有重要意义 对气候的反馈效应通过其对循环的影响 温室气体 过去的1000年提供了一个例子， 北美东部的快速气候变化可以作为 了解气候变化时火的作用的基础。 森林的转变可能是变化的结果 在火灾状态或气候变化。 零 假设火制度没有改变整个 东北部落叶针叶混交林交错带 在过去的2500年里，美国将受到考验。 一种获得长期火灾历史的新方法将是 在这项研究中使用。 地层中的个别火灾 记录将使用岩石薄片确定， 每年层状（纹状）湖泊沉积物，以产生长期的 火灾频率 该方法将被应用到一个网络， 在我们的研究区域内有着纹状沉积物的小湖泊。 的 各个站点将提供一种评估以下方面作用的方法： 火对不同气候条件下森林变化的影响， 植被环境。 合并后的数据集将建立 火灾状况和森林的广泛时空格局 在次大陆范围内参与气候变化的成分。 结果将有助于评估未来气候变化， 自然生态系统。

Among the most dramatic effects of global climate change of the next two centuries may be the increased frequency and/or intensity of fires in temperate forests. Natural fire regimes are largely unknown, making it difficult to speculate on the response of fire regimes to rapid climate change. The influence of fire on forest composition and structure might have important feedback effects on climate through its effects on the cycling of greenhouse gases. The last 1000 years provides an example of rapid climate change in eastern North America that can serve as a basis for understanding the role of fire when climate changes. Forest transitions may have occurred as a consequence of changes in the fire regime or changes in the climate. The null hypothesis that the fire regime has not changed across the ecotone of deciduous and mixed conifer forest in eastern North America during the last 2500 years will be tested. A new method of obtaining long-term fire histories will be used in this research. Individual fires in the stratigraphic record will be determined using petrographic thin sections of annually laminated (varved) lake sediments to produce long-term fire frequencies. The method will be applied to a network of small lakes with varved sediments across our study area. The individual sites will provide a means for assessing the role of fire for influencing forest changes in different climatic and vegetation settings. The combined data set will establish the broad spatial and temporal patterns of fire regimes and forest composition that attend climate change at a subcontinental scale. Results will facilitate evaluation of future climate change on natural ecosystems.