LTER Cross-site: Collaborative Research - Assessing the Geographic and Temporal Consistency of Life History and Demographic Patterns: A Long-term, Multi-site Comparison

[00:87078]生态学家日益认识到自然系统中空间变异性的重要性，这种认识导致了LTER网络的建立。然而，我们对单个物种的人口统计的空间变化知之甚少，这在应用生态学和基础生态学方面都造成了一个重要的知识缺口。由于缺乏涵盖大量地理范围内多个人口的全面人口统计研究，造成了两个普遍问题。首先，种群生物学家被迫从单个种群中发现的种群动态和生活史模式推断出那些发生在物种范围遥远地区的种群。这种外推在保护生物学、比较生活史分析和气候变化预测中很常见，目前对单个物种的人口统计中实际存在多少空间变化知之甚少。第二个问题是什么设定了物种的范围限制。虽然气候的生理影响通常是众所周知的，但由于缺乏大规模的人口统计学研究，因此不太清楚种群动态如何在接近范围限制的情况下变化，因此不清楚人口统计学表现差与其他提出的因素（如超种群动态）在多大程度上决定了物种的分布限制。因此，我们几乎没有理由建立关于物种范围如何随着气候变化而变化的机械预测。

0087078DoakEcologists increasingly understand the importance of spatial variability in natural systems, a recognition that led to the creation of the LTER network. However, we still know surprisingly little about spatial variation in the demography of individual species, creating an important gap in knowledge for both applied and basic ecology. The paucity of full demographic studies that span multiple populations across substantial geographic scales creates two general problems. First, population biologists are forced to extrapolate from the population dynamics and life history patterns found in single, well-studied populations to those occurring in distant parts of a species range. Such extrapolation is commonplace in conservation biology, comparative life history analysis, and climate change predictions, and is currently done with little understanding of how much spatial variation actually exists in the demography of individual species. Second is the question of what sets the range limits of species. While the physiological effects of climate are often well-known, the lack of broad-scale demographic studies makes it less clear how population dynamics vary near range limits, and thus the extent to which poor demographic performance versus other proposed factors, such as metapopulation dynamics, determine the distributional limits of species. As a result, we have little ground for building mechanistic predictions about how species ranges will shift as climate changes.