A predictive approach to the continental distributions of species

物种在地球上的分布非常不均匀。 是什么决定了物种的空间分布？ 为什么有些地方的物种比其他地方多？ 为什么范围大小不同？ 人类活动如何影响环境容纳物种的能力？ 这些都是关于自然生态系统的最基本的问题。 他们的答案对于预测全球气候变化和栖息地改变的影响至关重要。我的研究的长期目标是：1）记录生物多样性地理分布的主要模式; 2）确定生物多样性与环境特征之间的预测关系; 3）提出并测试简单的，基于过程的模型，准确预测这些变化。 我的研究有四个主要主题：** 主题一：我实验室的早期工作表明，物种丰富度的大范围地理变化与当代气候密切相关。 这些相关性可能反映了一种因果联系，因为它们准确地预测了不同时间和其他地理区域的丰富度变化。 我们已经测试并拒绝了几个关于潜在机制的假设，但我们还没有确定产生自然界生物多样性变化的过程。为了确定这些过程，我计划开发和测试大陆生物地理模型，灵感来自麦克阿瑟和威尔逊的岛屿生物地理平衡理论（ETIB）。 ETIB在概念上和管理上都取得了丰硕的成果。 我和我的学生将假设类似的限制在大陆上物种的地理范围。 使用模拟模型，我们将从这些假设中得出生物多样性的预测模式，并将预测结果与美洲哺乳动物和鸟类多样性的观察模式进行比较。 此外，我们将测试我们假设的约束条件是否在自然界中观察到。** 主题二：我们还建议测试人类活动（例如，气候变化和自然栖息地的迁移）影响景观尺度上的物种分布和物种丰富度。 在以前的工作中，我们发现，50%的天然森林和50%的人类占主导地位的土地覆盖的混合物最大限度地提高鸟类的生物多样性在南部安大略。 在这里，我们将测试这种关系是否适用于其他生物群落和其他类群。 ** 主题三：上述研究是根据对自然界模式的统计描述进行的。 然而，这些模型的预测能力很少被测试。 从它们中得出的推论可能是不正确的。 我们建议审查，并重新评估的预测准确性发表的论文在地理学。* 主题四：最后，我希望以专著的形式对可预测的生态学模式的生态学文献进行综合。 我们可以预测生态系统的结构和功能吗？

Species are distributed very unevenly over the Earth. What determines the spatial distributions of species? Why are there more species in some places than in others? Why do ranges sizes vary? How do human activities affect the capacity of the environment to accommodate species? These are among the most fundamental questions about natural ecological systems. Their answers are crucial to predicting the effects of global climate change and habitat modification. ******The long-term goals of my research are: 1) to document the main patterns in the geographic distribution of biodiversity; 2) to identify predictive relationships between biodiversity and characteristics of the environment; and 3) to propose and test simple, process-based models that accurately predict those variations. My research has four main themes:******Theme I: Earlier work from my lab showed that broad-scale geographic variation in species richness is strongly correlated to contemporary climate. These correlations probably reflect a causal link, because they accurately predict variations of richness through time and in other geographic regions. We have tested and rejected several hypotheses about underlying mechanisms, but we have not yet identified the processes that produce variations of biodiversity in nature.******To identify these processes, I plan to develop and test a model of continental biogeography, inspired by MacArthur and Wilson's Equilibrium Theory of Island Biogeography (ETIB). ETIB has been extremely fruitful, both conceptually, and because of its management implications. My students and I will hypothesize analogous sets of constraints on the geographic ranges of species on continents. Using a simulation model, we will derive predicted patterns of biodiversity from these hypotheses, and will compare the predictions to observed patterns of mammal and bird diversity in the Americas. Further, we will test whether our hypothesized constraints are observed in nature. ******Theme II: We also propose to test how human activities (e.g., climate change and natural habitat removal) affect species' distributions and species richness at the landscape scale. In previous work, we found that mixtures of 50% natural forest, and 50% human-dominated land cover maximize avian biodiversity in southern Ontario. Here, we will test whether this relationship holds in other biomes, and for other taxa. ******Theme III: The studies discussed above are based on statistical descriptions of patterns in nature. However, the predictive ability of these models is rarely tested. Inferences drawn from them may be incorrect. We propose to review, and to re-evaluate the predictive accuracy of published papers in biogeography. ******Theme IV: Finally, I wish to develop a synthesis (in monograph form) of the ecological literature on the predictable patterns of ecology. What can we predict about the structure and functioning of ecological systems?