OPUS: A general, resource-based explanation for density dependence in populations of mammalian herbivores

一种被称为密度依赖关系的关系为全世界野生和家养食草动物（例如鹿、麋鹿、牛和羊）的种群的明智管理提供了信息。在几十个栖息地的几十个物种中观察到的这种关系一致表明，随着种群中个体数量的增加，每只雌性存活后代的数量会下降。管理这些物种的收获取决于理解这种关系，因为当种群数量既不太大也不太小时，最大的收获才会持续。尽管密度依赖性对全世界的猎人、牧民和牧场主很重要，但产生这种关系的机制仍然知之甚少。该项目的目标是提高我们对草食动物种群密度依赖机制的总体理解。实现这一目标可以从根本上改变野生动物、牲畜和牧场的管理方式。通过在管理人员和决策者可获得的媒体中总结密度依赖对野生和家养食草动物收获的影响，将扩大这项工作的影响。将根据研究提出最佳做法的建议。综合三十年来对大型食草哺乳动物觅食行为和种群动态的研究，将支持开发新的、具有广泛解释性的数学和统计模型，以显示植物群落的营养特征如何产生密度依赖。这些模型将预测密度依赖性如何被动物体重、植物生物量以及植物中营养物质浓度（例如蛋白质或代谢能含量）的平均值和方差所改变。该项目将展示使用现代贝叶斯方法将这些模型拟合到数据的可行性。将评估相互竞争模型的数据证据。一个新的，理论的和经验的框架来理解植物如何调节食草动物种群的增长将产生，从而激发新的研究路线在生态学。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。

A relationship known as density dependence informs wise management of populations of wild and domestic herbivores (for example, deer, elk, cattle, and sheep) throughout the world. This relationship, observed in dozens of species in scores of habitats, consistently shows that the number of surviving offspring produced per female declines as the number of individuals in the population increases. Managing the harvest of these species depends on understanding this relationship because the largest harvests are sustained when populations are neither too big nor too small. Despite the importance of density dependence to hunters, pastoralists, and ranchers worldwide, the mechanism producing this relationship remains poorly understood. The goal of this project is to improve our general understanding of the mechanism causing density dependence in herbivore populations. Achieving this goal could fundamentally change how wildlife, livestock, and rangelands are managed. Impacts of the work will be expanded by summarizing the effects of density dependence on harvest of wild and domestic herbivores in media accessible to managers and policy makers. Recommendations for best practices will be made based on the research.A synthesis of thirty years of research on foraging behavior and population dynamics of large mammalian herbivores will support development of new, broadly explanatory mathematical and statistical models showing how nutritional characteristics of plant communities create density dependence. These models will predict how density dependence is altered by animal body mass, the biomass of plants, and the mean and variance of nutrient concentrations in plants, for example protein or metabolizable energy content. The project will demonstrate the feasibility of fitting these models to data using modern Bayesian methods. Evidence in data for competing models will be evaluated. A new, theoretical and empirical framework for understanding how plants mediate herbivore population growth will be produced, thereby motivating new lines of inquiry in ecology.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.