Collaborative Research: Ecological legacy effects of megacarcasses in African savanna ecosystems

合作研究：非洲稀树草原生态系统中巨型动物的生态遗产效应

• 批准号: 2128092
• 负责人: Deron Burkepile
• 金额: $ 53.65万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2128092&HistoricalAwards=false
• 关键词: Collaborative; Research; Ecological; legacy; effects

Large animals such as elephants and rhinoceros, called ‘megafauna’ for their extreme size, have outsized impacts on the ecosystems they live in. They engineer their environments by knocking down trees and grazing grasses to create large lawns, helping to form habitats that facilitate other animals. But, there is little research that addresses the impact that the carcasses of these megafauna, or ‘megacarcasses’, have on ecosystems after they die. Their carcasses represent huge sources of nutrients that have a long-lasting ecological legacy on the areas of ecosystems where their carcasses occur. For example, African elephants are the largest land animals, but almost nothing is known about how the nutrients from their massive carcasses (up to 6,000 kg) affect savanna ecosystems. This award asks the main question: How do elephant megacarcasses affect the ecology of African savannas? The work will address how these megacarcasses affect nutrient cycling in the soil by microbes, plant primary production and species diversity, and herbivory by vertebrate herbivores, such as zebra and giraffe, and invertebrate herbivores, such as grasshoppers. This research will support the mentoring of 1 postdoctoral scholar, graduate and undergraduate students in ecology as well as science communication and outreach. The main broader impact will be the production of a scientific documentary, The Legacy of Megaherbivores, which will ‘follow’ the life and death of an elephant in the African savanna, that will put the life cycle of these elephants into broader ecological context, understanding how they impact ecosystems and the current implications for ecosystems facing their disappearance. To address the overarching question, the award will use elephant carcasses of different ages (up to 15+ years old) in Kruger National Park (KNP), South Africa. Combining soil (physical, chemical and biological properties), plant (productivity and diversity), and herbivore (vertebrate and invertebrate) surveys at 50 megacarcass sites along with greenhouse experiments, the award will assess how nutrient pulses from elephant carcasses drive integrated responses of ecosystem processes. Importantly, the elephant megacarcasses are distributed across gradients of rainfall (375-700 mm) and soil fertility (less-fertile sandy, granitic soils vs. more-fertile clayey, basaltic soils) in KNP. These gradients of rainfall and soil nutrients provide a robust experimental framework for testing how the abiotic environment impacts the ecosystem-level legacy effects of terrestrial megacarcasses. Finally, by combining the data from the field on the effects of megacarcasses on ecosystem processes with a database of elephant population across KNP, the researchers will use ecological modeling to show how the distribution of megacarcasses generates variability in ecosystem processes across the savanna landscape as elephants naturally die over time. This study will represent the first examination of the ecological legacies of megacarcasses on terrestrial ecosystems.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.

大象和犀牛等大型动物的大小为“ Megafauna”，对它们所居住的生态系统产生了巨大影响。他们通过撞倒树木并磨碎树木来制定大型法律，帮助形成促进其他动物的栖息地来设计其环境。但是，几乎没有研究来解决这些巨型法（Megafauna）或“巨型质量”对生态系统死后产生的影响。它们的尸体代表了巨大的营养来源，这些营养素是在发生尸体发生的生态系统地区具有持久生态遗产的。例如，非洲大象是最大的陆生动物，但几乎一无所知。该奖项提出了一个主要问题：大象巨型巨质如何影响非洲稀树草原的生态？这项工作将解决这些巨质质量如何影响微生物，植物初级生产和物种多样性以及脊椎动物食草动物（例如斑马和长颈鹿）以及无脊椎动物的食草动物（例如蚱hoppers）如何影响土壤中的营养循环。这项研究将支持1个博士后科学，生态学研究生和本科生以及科学传播和外展的心理。主要的广泛影响将是制作一部科学纪录片《大型生物的遗产》，它将“遵循”非洲稀树草原中大象的生与死，这将使这些大象的生命周期置于更广泛的生态环境中，了解它们如何影响生态系统以及对面对他们消失的生态系统的影响。为了解决总体问题，该奖项将在南非的克鲁格国家公园（KNP）使用不同年龄（长达15岁以上）的大象尸体。该奖项结合土壤（物理，化学和生物学特性），植物（生产力和多样性）以及在50兆卡质站点进行的草食动物（脊椎动物和无脊椎动物）调查以及温室​​实验，该奖项将如何评估来自大象癌的养分脉冲如何推动生态系统过程的整体响应。重要的是，大象的巨型巨质分布在降雨（375-700毫米）和土壤生育能力（少于泥土沙质，花岗岩土壤中，而肥大的粘土质，玄武岩土壤，玄武岩土）。这些降雨和土壤养分的梯度提供了一个强大的实验框架，用于测试非生物环境如何影响陆生巨质体的生态系统级遗产效应。最后，通过将来自现场的数据结合到巨型系统过程的影响与跨KNP的大象种群的数据库，研究人员将使用生态建模来展示巨质质量的分布如何在大象自然而然地逐渐消亡的大象中的大象中的生态系统过程中如何产生可变性。这项研究将是对陆地生态系统中巨质体的生态遗产的首次检查。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为是通过评估而被视为珍贵的支持。