Modeling Pastoral Dynamics

田园动态建模

• 批准号: 1946258
• 负责人: Mark Moritz
• 金额: $ 5.76万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1946258&HistoricalAwards=false
• 关键词: Modeling; Pastoral; Dynamics

Pastoralism refers to economic systems that depend on raising livestock. Anthropologists have long explained that pastoralism is a good strategy for people who live in environments inhospitable to agriculture. However, even pastoralists have to be concerned about balancing the number of animals they keep with the pasture available to feed them and the labor available to care for them. Indeed, population models show that livestock populations have the potential to grow exponentially and outstrip the carrying capacity of their environments. But empirical evidence indicates otherwise: in the real world, pastoral livestock populations are relatively stable. The question then is how is this balance achieved. Until now the most popular explanation has been that droughts, diseases, and other disasters keep livestock populations in check. But the research supported by this award will test an alternative explanation: demographic dynamics -- the natural expansion and contraction of family sizes over time -- operating at the livestock herd and household level may constrain the growth of livestock populations regionally. If this is indeed the case, as this interdisciplinary research team proposes, then it has implications for development interventions in livestock-dependent economic systems. Results will be disseminated to organizations invested in improving veterinary health and reducing drought vulnerability to improve livelihoods in livestock-dependent economies. In addition, the project trains students in sophisticated computational methods and analysis. The research team will develop an agent-based model to examine the impact of the domestic cycle of households on the demography of family herds and ultimately on regional livestock populations. Data from previous studies will be used to parameterize the agent-based model. The model will be used to simulate the domestic cycle of the household and the demographic processes of their family herds under different experimental conditions in which the size and composition of herds and households is modified and running the simulations for one or ten generations (25 or 250 years). The simulations will allow the researchers to examine how the domestic cycle affects herd demography by examining the impact of changes in age of first marriage, increasing in the number of sons, or increasing polygyny rates. In addition, the simulations will be used to examine how sensitive the growth of regional livestock populations is to changes in the herd-size threshold, i.e., whether a lower threshold leads to stronger growth of livestock populations at the regional level. Findings from this research will provide insight into livestock population dynamics in pastoral societies, in particular the question of why these populations do not seem to increase in the absence of major disasters like droughts and diseases.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.

牧民是指依赖饲养牲畜的经济体系。人类学家长期以来一直解释说，牧民是生活在农业偏僻的环境中的人们的好策略。但是，即使是牧民也必须担心将它们保留的动物与可用的牧场保持平衡，以喂养它们以及可以照顾他们的劳动。确实，人口模型表明，牲畜种群有可能成倍增长并超过其环境的承载能力。但是经验证据表明另有说明：在现实世界中，田园牲畜种群相对稳定。那么问题是如何实现这种平衡。到目前为止，最受欢迎的解释是干旱，疾病和其他灾难可以控制牲畜种群。但是，该奖项支持的研究将测试另一种解释：人口动态 - 随着时间的流逝，家庭规模的自然扩张和收缩 - 在牲畜群和家庭一级运作可能会限制牲畜种群的增长。如果确实如此，那么正如这个跨学科研究团队所提出的那样，它对依赖牲畜依赖的经济体系的发展干预具有影响。结果将传播给投资用于改善兽医健康并减少干旱脆弱性以改善依赖牲畜经济体的生计的组织。此外，该项目还通过复杂的计算方法和分析来培训学生。研究团队将开发一个基于代理的模型，以研究家庭的国内周期对家庭群人口统计以及最终对地区牲畜人口的影响。先前研究的数据将用于参数化基于代理的模型。该模型将用于模拟家庭的国内周期以及在不同的实验条件下的家人群的人口统计过程，在不同的实验条件下，将群和家庭的大小和组成修改并运行模拟一代或十代（25或250年）。这些模拟将使研究人员能够通过检查初婚年龄变化，增加儿子的数量或增加一夫多妻制的影响，从而研究国内周期如何影响群人口统计学。此外，这些模拟将用于检查区域牲畜种群的敏感性是对牛群大小阈值的变化的敏感性，即，较低的阈值是否导致区域水平的牲畜种群的增长更强。这项研究的结果将提供对牧区社会中牲畜人口动态的见解，尤其是为什么这些人群在没有干旱和疾病（例如干旱和疾病）的主要灾害中似乎不会增加的问题。该奖项反映了NSF的法定使命，并通过使用基金会的知识优点和广泛的影响来评估NSF的法定任务，并被认为是值得的。