SG: Distinguishing between core and transient species: new insights into the determinants of species richness

了解生物多样性如何以及为什么在全球范围内变化是生态学长期关注的焦点，也是许多保护工作的基本关注点。然而，简单地计算一个地区的物种数量可能并不能准确地反映生物多样性，因为在一个地区观察到的许多物种并不经常在那里出现。通过分析过去四十年来在北美近500个地点的志愿观鸟者收集的数据，发现大多数鸟类可分为两类：核心物种，几乎每年都会在一个地点观察到，以及很少观察到的过渡物种。核心鸟类的数量与当地气候和植被的关系最为密切，而迁徙鸟类的数量则在生境多样化且不受气候影响的地区最多。该项目将评估核心物种和瞬变物种之间这种区别的普遍性，以及这种区别对于理解包括鸟类、哺乳动物、蝴蝶、植物、鱼类、浮游生物和潮间带无脊椎动物在内的广泛分类群和生态系统中的物种多样性模式的重要性。这项研究的结果将对生物多样性决定因素的基础和应用理解以及生态群落如何响应气候和土地利用变化产生影响。将为一名研究生提供研究培训和职业指导。与北卡罗来纳大学数学与科学教育中心和大学预科项目合作，将开展公共宣传活动，吸引中学生，包括来自代表性不足群体的很大一部分学生。大学预科项目是一个以探究为基础的项目，旨在丰富和鼓励女性和在科学和数学职业中代表性不足的少数民族在科学和数学方面的学习。这种推广的一个产品将是在北卡罗来纳植物园展出的解释性展示。这些研究人员还将提供结构化的讲习班，以提高各级科学家的计算和数据管理技能。

Understanding how and why biodiversity varies across the globe is a long-standing focus of ecology and is a fundamental concern of many conservation efforts. However, simply counting the number of species in an area may not give an accurate representation of biodiversity because many of the species observed in an area do not occur there regularly. By analyzing data collected over the past forty years by volunteer birders at almost 500 locations across North America, it was found that most bird species fall into one of two categories: core species that are observed almost every year at a site, and transient species that are observed only rarely. The number of core bird species was most strongly related to local climate and vegetation, whereas the number of transient bird species was greatest in regions with a diversity of habitats, independent of climate. This project will assess the generality of this distinction between core and transient species, and the importance of that distinction for understanding patterns in species diversity across a broad range of taxonomic groups and ecosystems including birds, mammals, butterflies, plants, fish, plankton, and intertidal invertebrates. Results from this research will have implications for both basic and applied understanding of the determinants of biodiversity, and for how ecological communities will respond to climate and land use change. Research training and career mentoring will be provided for one graduate student. In conjunction with the University of North Carolina's Center for Mathematics and Science Education and the Pre-College Program, public outreach activities will be developed that engage middle school students, including a large proportion from underrepresented groups. The Pre-College Program is an inquiry-based program of enrichment and encouragement in science and mathematics for women and minorities underrepresented in scientific and mathematical careers. One product of this outreach will be an interpretive display exhibited at the North Carolina Botanical Garden. The researchers will also provide structured workshops to improve the computational and data management skills of scientists of all levels.