COLLABORATIVE RESEARCH: Testing predictions of the core-satellite and resource-breadth hypotheses in small mammal communities: field tests of a macroecological pattern

你有没有想过为什么有些动物（比如松鼠、浣熊和乌鸦）很常见，似乎到处都能找到，而另一些动物却很罕见，只出现在少数地方？生态学家也问过这个问题，他们研究这个谜题已经有一个多世纪了。答案可能取决于动物可以吃的食物的种类，动物长距离移动的能力，或者两者兼而有之。一方面，能够在一系列不同的食物上茁壮成长的动物，生态学家有时称之为通才，应该是普遍和广泛的，而挑食的动物应该是罕见的，只在少数地方发现。另一方面，能够迅速迁移到它们已经消失的地区的动物也应该是普遍和广泛的，而留在原地的动物应该是罕见的，只在少数地方发现。就像生态学中的许多答案一样，可能两者兼而有之。这个项目的研究人员正在努力发现饮食和运动能力是如何影响动物生活的地方，以及一个特定地区有多少动物生活。这个研究项目的结果可能有助于理解为什么有些物种（如濒危物种）是罕见的，并且在法律保护后恢复缓慢，而其他物种（如本地害虫或入侵物种）是常见的，即使面对人类的发展。通过这个项目，研究人员将培养两名研究生，一名项目经理和四名研究助理，并将利用现有的长期实验基础设施，在各自的机构中集中本科生实地课程。一个物种的丰度与其分布范围之间的正相关关系是生态学中最普遍的模式之一。两个特别引人注目的假说，Hanski的核心-卫星假说和Brown的资源宽度假说，被用来解释这种模式。核心-卫星假说认为，不同的移动速率是丰度-分布关系的基础，因此，广泛分布的物种通过从周围地区扩散来缓冲局部灭绝。相比之下，资源呼吸假说则认为物种开发一系列资源的能力存在差异：数量丰富、分布广泛的物种应该是生态通才，能够比稀有的、地理上受限制的物种（即生态专家）开发更多种类的资源。然而，对于所有这些直观的吸引力来说，支持每个假设的中心，对比预测，即一个地方的新个体应该主要来自分散（核心-卫星假设）而不是原地繁殖（资源广度假设），一直缺乏。研究人员将把消费者-资源的相互作用与草食性小型哺乳动物（啮齿动物、鼩鼱、象鼩）的分散和就地招募的估计结合起来。将在预先存在的长期实验中建立两种操作方法，即设置扩散障碍和清除资源。根据该奖项，研究人员将确定丰富的、广泛分布的物种是否通过更高的分散率、原位补充或两者兼而有之来维持其广泛的分布。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Have you ever wondered why some animals (like squirrels, raccoons, and crows) are common and seem to be found everywhere, while others are rare and occur only in a few places? Ecologists have asked this question too, and they have been working on this puzzle for over a century. The answer could depend on the variety of foods that animals can eat, the ability of animals to move long distances, or both. On the one hand, animals that can thrive on a range of different foods, what ecologists sometimes call generalists, should be common and widespread, while picky eaters should be rare and found only in a few places. On the other hand, animals that can quickly move into areas from which they have disappeared should also be common and widespread, while animals that stay put should be rare and found in only a few places. Like many answers in ecology, it's probably some of both. The researchers on this project are working to discover how diet and movement ability shape where animals live and how many individuals live in a particular area. Results of this research project could be useful in understanding why some species (like endangered species) are rare and slow to recover following legal protections, while other species (like native pests or invasive species) are common, even in the face of human development. Through this project, the researchers will train two graduate students, a project manager, and four research assistants, and will use the existing infrastructure of a long-term experiment around which to center undergraduate field courses at their respective institutions. Positive correlations between a species' abundance and its range size are among the most general patterns in ecology. Two particularly compelling hypotheses, Hanski's Core-Satellite hypothesis and Brown's Resource-Breadth hypothesis, have been proposed to explain this pattern. The Core-Satellite hypothesis posits that differential rates of movement underlie abundance-distribution relationships, such that widespread species are buffered against local extinction by dispersal from the surrounding region. In contrast, the Resource-Breath hypothesis invokes differences in the ability of species to exploit a range of resources: abundant, widespread species should be ecological generalists capable of exploiting a wider variety of resources than rare, geographically restricted species (i.e., ecological specialists). For all of their intuitive appeal, however, support for the central, contrasting predictions of each hypothesis, that new individuals at a locality should arise mostly from dispersal (Core-Satellite hypothesis) versus in situ reproduction (Resource-Breadth hypothesis), has been scant. The researchers will integrate consumer-resource interactions with estimates of dispersal and in situ recruitment in a guild of herbivorous small mammals (rodents, shrews, elephant shrews). Two manipulations, the erection of dispersal barriers and a resource removal, will be established within a pre-existing, long-term experiment. Under this award, the researchers will determine whether abundant, widespread species maintain their extensive distributions through higher rates of dispersal, in situ recruitment, or both.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.