MSA: Quantifying the drivers of mammal food web networks over space and time in Sub-Saharan Africa

生物多样性是人类健康和福祉的核心，因为它影响到使人类生活成为可能的服务。食物网和组成它们的捕食者-猎物相互作用在维持生物多样性方面发挥着关键作用。大多数食物网都是在当地研究的，这阻碍了对更大范围的概括，并阻碍了对全球环境变化影响的预测。食物网在多大程度上依赖于初级生产力的变化--植物通过光合作用将能量转化为植物材料的速度--在很大程度上仍是未知的。与其他动物相比，已发表的关于哺乳动物捕食者与猎物相互作用的研究更多，但我们对影响哺乳动物食物网的因素知之甚少。初级生产力对非洲哺乳动物生物多样性的预测比其他地区更大，这表明有可能对非洲的食物网产生重大影响。然而，随着生物圈的迅速变化，气候和土地利用的变化可以改变捕食者-猎物的相互作用，从而改变食物网。在未来几十年里，非洲哺乳动物的食物网可能比其他区域更受土地利用变化的影响，因为撒哈拉以南非洲的预计人口增长率是全球最高的之一。确定食物网在空间和时间上的生态和人为驱动因素从未像现在这样重要。这项工作支持2名博士生和3名本科生，由生物科学国际和电气和计算机工程共同指导，从而为数学、计算和环境科学的跨学科教育提供机会。为了扩大这项研究在休斯顿地区的广泛影响，两名当地的K-12教师参加了莱斯大学的R-STEM项目，该项目为教师提供基于探究的专业发展。这项研究利用了来自五个非洲保护区的标准化年度相机陷阱数据和来自撒哈拉以南非洲170个哺乳动物群落的群落组成数据，研究人员正在根据公布的数据为这些哺乳动物物种构建一个总体的食物网。到目前为止，生态网络研究的一个关键局限是启发式方法的广泛应用，缺乏强有力的理论支持。研究人员正在利用拓扑数据分析的最新发展来量化食物网络结构中的相似性。具体地说，他们正在开发快速算法实现，以衡量食物网在空间和时间上的差异。研究目标是确定：1)气候和碎片化如何影响植被生产力，2)当地食物网动态如何响应生产力和碎片化随时间的变化，以及3)食物网结构如何随区域和大陆尺度上的生产力和碎片化而变化。研究人员还提供了算法的开源实现以及它们的使用示例和教程。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Biodiversity is central to human health and well-being because it influences services that make human life possible. Food webs and the predator-prey interactions that comprise them play a critical role in maintaining biodiversity. Most food webs have been studied locally, which inhibits generalizations to larger areas and hampers predictions of the impact of global environmental changes. The extent to which food webs depend on changes in primary productivity – the rate at which plants turn energy into plant material through photosynthesis – remains largely unknown. More studies have been published describing predator-prey interactions in mammals than in other animals, but we know little about what affects mammal food webs. Primary productivity predicts mammal biodiversity in Africa more than in other regions, suggesting the potential for a strong influence on African food webs. Nevertheless, as the biosphere changes rapidly, changes in climate and land use can alter predator-prey interactions, thereby altering food webs. In the coming decades, African mammal food webs may be more intensely affected by land-use change than other regions because projected human population growth rates for sub-Saharan Africa are among the highest globally. Identifying the ecological and anthropogenic drivers of food webs over space and time has never been more important. This work supports 2 Ph.D. students and 3 undergraduate students co-advised by the PI in Biosciences and the Co-PI in Electrical and Computer Engineering, thus providing opportunities for cross-disciplinary education in mathematical, computational, and environmental sciences. To amplify the broader impacts of the research in the Houston area, two local K-12 teachers are participating in Rice University's R-STEM program, which provides inquiry-based professional development for teachers.The research leverages standardized annual camera trap data from five African protected areas and community composition data from 170 mammal communities throughout sub-Saharan Africa, and the researchers are constructing an overarching food web for the mammal species from published data. To date, a key limitation of ecological network research has been the widespread application of heuristic approaches lacking strong theoretical support. The researchers are harnessing recent developments in topological data analysis to quantify similarities in food web structures. Specifically, they are developing fast algorithmic implementations to measure differences in food webs over space and time. The research objectives are to determine: 1) how climate and fragmentation influence vegetation productivity, 2) how local food web dynamics respond to changes in productivity and fragmentation over time, and 3) how food web network structure varies as a function of productivity and fragmentation at regional and continental scales. The researchers are also providing open-source implementation of the algorithms and examples and tutorials of their use.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.