Dissertation Research: Future changes in California bird communities projected from century-scale resurveys

这个项目将研究为什么加州的鸟类出现在不同的地方比他们100年前。 这些信息将用于预测鸟类将如何应对未来气候和栖息地的变化，从而更好地制定保护计划。研究人员将利用一个独特的历史资源：从1900年到1945年，在加州的每个主要生态区域进行的鸟类系统调查。这些调查是在经历了气候变化、农业发展和城市化的地点进行的。洛杉矶地区的30个地点将被重新调查。 由此产生的数据将被添加到已经在内华达州、海岸山脉、中央谷和莫哈韦沙漠重新调查的290个地点的数据集中。鸟类如何对每个地点的变化作出反应的措施将用于预测未来对气候和土地利用变化的反应。这项研究将加深我们对气候和土地利用变化如何影响鸟类的理解。具体来说，它将测试土地利用的变化是否会加剧气候变化带来的问题，或者是否会帮助一些鸟类生活在它们原本会避免的地方。该项目是重要的保护规划，并将提供培训和指导的两个students.This研究将使用一个独特的历史资源（20世纪初的世纪由约瑟夫Grinnell和他的同事进行的鸟类调查），结合当代reserveys量化气候和土地利用变化的影响如何改变鸟类分布在加州。这些措施将用于预测未来气候和土地利用变化情景下的鸟类分布。在农业发达的中央谷的30个地点以及在内华达州、海岸山脉和莫哈韦沙漠的260个相对受保护的地点已经完成了重新调查。该项目将重新调查洛杉矶地区的另外30个地点，提供一个衡量鸟类如何应对比当前数据集所代表的更大的变暖和城市化的措施。通过量化在过去的世纪鸟类居住的变化是如何驱动的气候和土地利用协变量，本研究将预测鸟类对未来情景的气候和土地利用变化的直接措施的时间变化的基础上。预测将用于探索哪些鸟类群体预计将在未来经历范围扩大或缩小，以及这是否会导致创建无模拟鸟类群落。

This project will examine why birds in California occur in different places than they did 100 years ago. This information will be used to predict how birds will respond to future changes in climate and habitat, enabling better conservation planning. Researchers will make use of a unique historic resource: systematic surveys of birds conducted in every major ecological region of California from 1900 to 1945. These surveys were conducted at sites that have since experienced changes in climate, agricultural development, and urbanization. Thirty sites in the Los Angeles area will be re-surveyed. The resulting data will be added to a dataset of 290 sites already re-surveyed in the Sierra Nevada, Coast Ranges, Central Valley, and Mojave Desert. Measures of how birds have responded to changes at each site will be used to predict future responses to climate and land use change. This study will enhance our understanding of how combined changes in climate and land use impact birds. Specifically, it will test whether changes in land use exacerbate problems from climate change or help some birds to live in places they would have otherwise avoided. This project is important for conservation planning and will provide training and mentoring of two students.This study will use a unique historical resource (early 20th century bird surveys conducted by Joseph Grinnell and colleagues) in conjunction with contemporary resurveys to quantify how the effects of climate and land-use change have altered bird distributions in California. These measures will be used to project bird distributions under future scenarios of climate and land-use change. Re-surveys have already been completed at 30 sites in the agriculturally-developed Central Valley, and 260 relatively protected sites in the Sierra Nevada, Coast Ranges, and Mojave Desert. This project will re-resurvey an additional 30 sites in the Los Angeles area, providing a measure of how birds have responded to greater warming and urbanization than is represented in the current dataset. By quantifying how changes in bird occupancy over the past century are driven by climate and land-use covariates, this study will then project bird responses to future scenarios of climate and land-use change based on direct measures of temporal change. Projections will be used to explore which groups of birds are expected to experience range expansions or contractions in the future, and whether this will result in the creation of no-analog bird communities.