Vegetation dynamics and paleoclimate in western Canada

可能对自然生态系统和人类社会产生负面影响的环境扰动很多，目前公众的注意力主要集中在气候变化上，有时还关注地震和海啸等历史事件。自1976年以来，我的研究计划继续强调研究加拿大西部过去发生的(数千年来)环境影响，目的是更好地了解气候变化、地震、森林火灾和火山喷发等扰动的长期影响，并利用这些知识帮助预测未来对自然系统的影响。我的合作者和学生与我合作开展了各种研究项目，这些项目都提供了与过去扰动相关的植被变化的信息。由于植被可以很好地反映气候条件，过去温度和湿度的变化通常可以从植物化石数据中重建出来。这些古数据可以帮助检查基于计算机的气候模型的准确性，并为大气和海洋中反复出现的气候变化提供长时间序列。这些数据在公园、林业、渔业和文化资源的管理中也很重要，并为研究原住民历史提供环境背景。这里提出的研究旨在为以下事件提供新的见解：公元前南部的地震频率，育空和公元前最后一次冰河时代的植物覆盖变化和气候，以及加拿大大型食草动物(如猛犸象、马和巨型野牛)灭绝的原因。覆盖过去1000年的高分辨率研究有望从每年分层的沉积物和泥炭沼泽中发现快速气候变化的模式。这些将提供加拿大西部快速环境变化的更多细节，并有助于实现气候变异性的国际研究目标。

Environmental disturbances that can negatively  affect natural ecosystems and human societies are many, with current public attention focussed primarily on climate changes, and sometimes on epsiodic events like earthquakes and tsunamis.  My research program since 1976 continues to emphasize studying past occurrences (over thousands of years) of environmental impacts in Western Canada, with the aim of better understanding the long-term effects of disturbances such as climate changes, earthquakes, forest fires and volcanic eruptions, and using this knowledge to help predict future impacts on natural systems.  My collaborators and students work with me on a variety of research projects that all provide information on vegetation changes associated with past disturbances. Since vegetation is a good "proxy" for climatic conditions, past changes in temperature and moisture can often be reconstructed from fossil plant data. Such paleo-data can help check the accuracy of computer-based climate models and provides long time series for recurring climate changes in the atmosphere and oceans.  These data are also important in the management of parks, forestry, fisheries, and cultural resources as well as providing an environmental context for investigations of First Nations history.The research proposed here is designed to provide new insights into events like  earthquake frequency in southern B.C., plant cover changes and climate during the last Ice Age in the Yukon and B.C., and causes of extinctions of large grazing animals such as mammoths, horses, and giant bison in Canada. High-resolution studies covering the past 1,000 years are expected to detect patterns of rapid climate change from annually layered sediments and peat bogs. These will provide greater details of rapid environmental changes in Western Canada, and also contribute to international research objectives into climate variability.