What Stabilizes Population Dynamics in Nature? A New Framework for Quantifying the in situ Strength and Nonlinearity of Species Interactions

生态学中的一个基本问题是物种之间的相互作用（例如捕食者-猎物）如何导致一些物种随着时间的推移表现出周期性的种群波动，而另一些物种则没有。为了预测物种及其生态系统将如何应对环境扰动，包括栖息地丧失和气候变化，了解这些机制是必要的。这个研究项目将开发新的方法和统计分析，将应用于太平洋西北地区的河流社区。研究人员将测试关于物种数量何时会大量循环的假设。目前的理论只能解释那些只捕食一种或几种猎物的专门捕食者的最简单的例子。然而，自然界中的大多数物种都是嵌入在物种相互作用的复杂网络中的通才。这一限制被广泛认为是发展资源管理和养护做法中的一个重大问题。这项工作有望推进一般生态学理论，并解决一个长期存在的难题，即自然界中捕食者-猎物相互作用的稳定性。该项目的研究结果将提高我们预测物种对环境干扰反应的能力，这对野生动物的管理和保护具有重要意义。该项目还将支持本科生和研究生的指导和研究培训，以及博士后研究员。通过与俄勒冈州立大学小学伙伴计划的广泛合作，将更广泛地参与俄勒冈州当地社区，该计划为小学生提供科学和数学丰富内容，并为他们的教师提供专业发展，以增加代表性不足和教育不足的学生的数量，这些学生将继续追求科学、数学、健康、工程和教育方面的职业。这项研究将开发一种新的观测方法，用于估计物种丰富系统中捕食者-猎物相互作用的强度。该方法在安德鲁斯实验森林长期生态研究站点的溪流群落中的观察和实验实施将用于定量比较猎物依赖、消费者依赖和适应性觅食过程对相互作用非线性的经验水平的贡献程度。经验得出的见解将被整合到抽象的数学模型中，以发展关于专业和通才消费者动态的一般理论。这项研究有望在我们对捕食者-猎物相互作用调节物种丰富群落动态的机制的概念和应用理解方面取得重大进展。在这里发展的观察方法的新颖的简单性和广泛的适用性保证了一个变革性的新方法来桥梁数学理论和经验数据。

A fundamental question in ecology is how interactions among species (e.g. predator-prey) cause some species to exhibit cyclic population fluctuations over time while for other species they do not. An understanding of these mechanisms is necessary in order to forecast how species and their ecosystems will respond to environmental perturbations, including habitat loss and climate change. This research project will develop new methods and statistical analyses that will be applied to stream communities of the Pacific Northwest. The investigators will test hypotheses regarding when species populations will cycle in abundance. Current theory can explain only the most simplistic case of specialist predator species that feed on only one or a few prey species. However, most species in nature are generalists embedded in complex networks of species interactions. This limitation is widely acknowledged as a significant problem in the development of resource management and conservation practices. This work promises to advance general ecological theory and resolve a long standing puzzle concerning stability of predator-prey interactions in nature. Results of this project will improve our ability to forecast species responses to environmental disturbances, which is important in wildlife management and conservation. This project also will support the mentoring, and research training of undergraduate and graduate students, and a postdoctoral researcher. Broader involvement with Oregon's local communities will be achieved through an extensive collaboration with Oregon State University's elementary school partnership program, which provides science and math enrichment for elementary school students and professional development for their teachers in order to increase the number of underrepresented and educationally underserved students that go on to pursue careers in science, math, health, engineering, and education.This research will develop a new class of observational methods for estimating the strength of predator-prey interactions in species-rich systems. Observational and experimental implementations of the approach in stream communities of the Andrews Experimental Forest Long Term Ecological Research site will be used to quantitatively compare the degree to which prey-dependent, consumer-dependent and adaptive-foraging processes contribute to empirical levels of interaction nonlinearity. Empirically-derived insights will be integrated into abstracted mathematical models to develop general theory regarding the dynamics of specialist and generalist consumers. This research promises significant advances in our conceptual and applied understanding of the mechanisms by which predator-prey interactions regulate the dynamics of species-rich communities. The novel simplicity and broad applicability of the observational approach to be developed here promises a transformative new way to bridge mathematical theory and empirical data.