CNH: An Ecological Trap for Parasites and Its Impacts on Human Disease Risk, Nutrition, and Income

该项目侧重于衡量各种各样的产品和服务，包括自然生态系统提供的和人类赖以生存的对人类健康的益处。对于全世界的稀树草原生态系统来说，一项重要的生态系统服务是生产供国内牲畜食用的饲料。虽然这种形式的资源开采通常被认为与野生动物的保护相冲突，但最近的证据表明，牲畜和野生动物有时可能会改善彼此的饲料质量。此外，最近的研究表明，在稀树草原生态系统中整合牲畜和野生动物可能还有一个额外的好处：控制扁虱和影响野生动物、牲畜和人类健康的扁虱传播的病原体。在肯尼亚莱基皮亚区，初步证据表明，使用杀螨剂(扁虱专用杀虫剂)处理过的牛的存在极大地减少了环境中扁虱的数量。对于畜牧场和野生动物保护者来说，这一发现提供了一种潜在的管理工具，对控制寄生虫种群具有重要意义，这些寄生虫种群可能威胁到野生动物生态旅游和畜牧业生产的经济效益。然而，在稀树草原生态系统中，影响人类福祉的众多因素中，扁虱和壁虱传播的病原体只是其中之一。尽管人们对生态系统的可持续管理非常感兴趣，但许多对农村福祉最关键的服务，例如那些促进农业和畜牧业生产的服务，在现有的生态系统服务衡量标准中是缺失的。为了了解不同的生物和社会现象如何相互作用来决定稀树大草原生态系统内的人类福祉，这一跨学科研究项目将采用综合方法，借鉴传染病生态学和生态系统服务建模方面的专门知识，以更好地了解稀树大草原生态系统产生的影响人类健康和福祉的所有生态系统服务之间的相互作用。研究人员将通过实验操纵生态陷阱(用杀螨剂处理的牛)的分布，以严格评估扁虱数量和饲料质量管理策略的后果。他们将通过一套可复制的牛和野生动物管理方法来评估牧场的扁虱丰度和饲料质量，他们将开发这个自然-人类耦合系统的简单生产函数模型，其中包括饲料-牲畜-野生动物相互作用，野生动物对旅游访问和收入的贡献，牲畜对收入和人类营养的贡献，以及野生动物-牲畜-壁虱相互作用，确定壁虱传播的疾病风险。他们还将通过情景分析使用生产函数模型来探索莱基皮亚区不同管理战略对野生动物和人类福祉的影响。该项目将整合社会和生态方法，以促进对人类健康和自然紧密相连的系统的理解。该项目将试验一种新的寄生虫控制方法，可能会产生许多意想不到的好处，它将是试图评估共同生态系统内多种不同生态系统服务价值的首批项目之一。该项目将为美国和非洲的学生和科学家提供多样化的教育机会。该项目通过描述生态系统自然和人类组成部分之间潜在双赢方案的要素，有望为社会带来显著效益，并对畜牧业、野生动物保护、牲畜和野生动物健康以及人类收入、营养和福祉产生积极影响。该项目的成果将在其他具有类似社会生态背景的地区发挥作用，可能为自然-人类耦合系统的可持续管理提供一种新的模式。该项目得到了美国自然与人类耦合系统动力学(CNH)计划的支持。

This project focuses on the measurement of the wide variety of products and services, including benefits to human health that natural ecosystems provide and on which humans depend. For savanna ecosystems worldwide, an important ecosystem service is the production of forage for consumption by domestic livestock. While this form of resource extraction often is thought to conflict with the conservation of wildlife, recent evidence suggests that livestock and wildlife may sometimes improve forage quality for one another. In addition, recent research suggests there may be an additional benefit to the integration of livestock and wildlife in savanna ecosystems: control of ticks and tick-borne pathogens that affect wildlife, livestock, and human health. In the Laikipia District of Kenya, preliminary evidence suggests that the presence of cattle treated with acaricides (tick-specific pesticides) greatly reduces the abundance of ticks in the environment. For both livestock ranches and wildlife conservancies, this finding offers a potential management tool with important implications for the control of parasite populations that may threaten economic benefits from both wildlife ecotourism and livestock production. Ticks and tick-borne pathogens are only one of many factors that influence human well-being in savanna ecosystems, however. Despite great interest in the sustainable management of ecosystems, many of the services most critical to rural well-being, such as those that contribute to agriculture and livestock production, are missing from existing measurements of ecosystem services. In order to understand how diverse biological and social phenomena interact to determine human well-being within savanna ecosystems, this interdisciplinary research project will use an integrated approach drawing from expertise in the ecology of infectious diseases and modeling of ecosystem services to better understand the interactions between all of the ecosystems services generated by savanna ecosystems that influence human health and well-being. The researchers will experimentally manipulate the distribution of an ecological trap (acaricide-treated cattle) to rigorously assess the consequences of management strategies for tick abundance and forage quality. They will evaluate tick abundance and forage quality on ranches with a suite of replicated approaches to cattle and wildlife management, and they will develop simple production function models of this coupled natural-human system that capture forage-livestock-wildlife interactions, contributions of wildlife to tourism visitation and income, contributions of livestock to income and human nutrition, and wildlife-livestock-tick interactions that determine tick-borne disease risk. They also will employ production function models through scenario analysis to explore the consequences for wildlife and human well-being of different management strategies across the Laikipia District.This project will integrate social and ecological approaches to advance understanding of systems in which the health of humans and nature are strongly interconnected. This project will experiment with a novel approach to parasite control that may yield numerous unintended benefits, and it will be among the first projects to attempt to assess the value of multiple different ecosystems services within a common ecosystem. The project will provide diverse educational opportunities for both U.S. and African students and scientists. The project holds promise for yielding significant benefits for society by characterizing the elements of potential win-win scenarios between natural and human components of an ecosystem, with positive ramifications for livestock husbandry, wildlife conservation, livestock and wildlife health, and human income, nutrition, and well-being. Project findings will have utility in other regions with similar socioecological contexts, possibly providing a new model for the sustainable management of coupled natural-human systems. This project is supported by the NSF Dynamics of Coupled Natural and Human Systems (CNH) Program.