LTER: Manipulating drivers to assess grassland resilience

LTER：操纵驱动程序来评估草原恢复力

• 批准号: 2025849
• 负责人: Jesse Nippert
• 金额: $ 712.2万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2025849&HistoricalAwards=false
• 关键词: LTER; Manipulating; drivers; assess; grassland

Grasslands provide many benefits to society. In the eastern portion of the Central Plains, tallgrass prairie is the most common type of grassland. Tallgrass prairies once supported vast herds of bison and elk, and now support cattle ranching. Native prairie grasses are highly nutritious for cattle and can withstand frequent grazing, making tallgrass prairie the most productive rangeland in the United States. Tallgrass prairies also provide habitat for commercially important game species including deer, turkey, and waterfowl. Additionally, the prairies regulate water and nutrient cycles, and help store carbon. Remaining tallgrass prairie is threatened by invasive species, climate change, and expansion of woody plants. Sustainable management of tallgrass prairies requires a deep understanding of how these threats affect species, water, and nutrient cycling. Decades of research at the Konza Prairie Long-Term Ecological Research (LTER) site in Kansas have provided a deep understanding of how the prairie responds to environmental changes of many kinds. New research will focus on ecological resilience, identifying how plants and animals respond to natural disturbances (fire and grazing) and to the more recent challenges imposed by climate shifts and invasion of woody plants. This work will inform grassland restoration, management and conservation efforts throughout the Great Plains. Konza scientists will be active in education and outreach activities. For example, the Konza Environmental Education Program provides activities for thousands of K-12 students every year, illustrating the societal value of collecting long-term data. Konza scientists also provide community outreach and engagement for the public, land managers, conservationists, and policy-makers.Since 1980, the Konza Prairie LTER site has investigated how key drivers of grasslands globally - fire, grazing, and climatic variability - interact to influence tallgrass prairie structure and function. The conceptual framework of this renewal award builds on long-term studies, reflects the increasing complexity of research questions developed over the history of the site, and explicitly recognizes that tallgrass prairie pattern and process result from human alteration of ecological drivers at local (e.g., land use and management), regional (e.g., nutrient inputs) and global (e.g., climate change) scales. This research leverages long-term, watershed-scale manipulations of fire frequency and grazing by large ungulates, coupled with numerous plot-scale manipulations to test ecological theory and address timely questions regarding grassland responses to multiple, interacting global changes. Specifically, researchers will focus on mechanisms underlying sensitivity and resilience of ecosystem states in mesic grasslands. New research will utilize the array of ecosystem states that have emerged from previous landscape manipulations to refine the understanding of sensitivity, resilience, and ecosystem state change in tallgrass prairie. The research comprises four thematic areas: 1) continued watershed-level manipulations of historical drivers (fire and grazing), 2) experimental manipulations of global change drivers, 3) cessation or reversal of selected drivers to assess legacies, and 4) human intervention. Collectively, Konza Prairie research will advance ecological theory and improve our mechanistic understanding of ecosystem state changes by manipulating key drivers to alter ecological states while employing new analytical approaches to augment the value of Konza LTER’s long-term data sets. The research will provide new information critical for understanding, managing, and conserving grasslands globally, while concurrently addressing fundamental ecological questions to explain grassland dynamics in a changing world.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.

草原给社会带来了许多好处。在中原东部，高草草原是最常见的草原类型。高草草原曾经养育着大量的野牛和麋鹿，现在则支持着养牛业。原生草原草对牛来说营养丰富，可以承受频繁的放牧，使高草草原成为美国最具生产力的牧场。高草草原也为鹿、火鸡和水禽等重要的商业猎物提供了栖息地。此外，草原调节水和养分循环，并帮助储存碳。现存的高草草原受到入侵物种、气候变化和木本植物扩张的威胁。高草草原的可持续管理需要深入了解这些威胁如何影响物种，水和养分循环。在堪萨斯的Konza大草原长期生态研究（LTER）站点进行了数十年的研究，深入了解了大草原如何对多种环境变化做出反应。新的研究将侧重于生态恢复力，确定植物和动物如何应对自然干扰（火灾和放牧）以及气候变化和木本植物入侵带来的最新挑战。这项工作将为整个大平原的草原恢复、管理和保护工作提供信息。Konza科学家将积极参与教育和外联活动。例如，Konza环境教育计划每年为数千名K-12学生提供活动，说明收集长期数据的社会价值。自1980年以来，Konza Prairie LTER网站调查了全球草原的关键驱动因素-火灾，放牧和气候变化-如何相互作用影响高草草原的结构和功能。这个更新奖的概念框架建立在长期研究的基础上，反映了该遗址历史上发展的研究问题日益复杂，并明确承认高草草原模式和过程是人类改变当地生态驱动因素的结果（例如，土地利用和管理）、区域（例如，养分输入）和全球（例如，气候变化）尺度。这项研究利用了长期的，流域规模的操纵火灾频率和放牧的大型有蹄类动物，再加上众多的情节规模的操纵，以测试生态理论和解决及时的问题，草原响应多个，相互作用的全球变化。具体来说，研究人员将专注于机制的敏感性和恢复力的生态系统状态在梅西奇草原。新的研究将利用从以前的景观操作中出现的一系列生态系统状态，以完善对高草草原的敏感性，弹性和生态系统状态变化的理解。该研究包括四个主题领域：1）持续的流域级历史驱动因素（火灾和放牧）的操纵，2）全球变化驱动因素的实验操纵，3）停止或逆转选定的驱动因素以评估遗产，以及4）人为干预。总的来说，Konza Prairie的研究将推进生态理论，并通过操纵关键驱动因素来改变生态状态，同时采用新的分析方法来增加Konza LTER长期数据集的价值，从而提高我们对生态系统状态变化的机械理解。该研究将为全球草原的理解、管理和保护提供新的关键信息，同时解决基本的生态问题，以解释不断变化的世界中的草原动态。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Mechanisms influencing physically sequestered soil carbon in temperate restored grasslands in South Africa and North America

• DOI: 10.1007/s10533-021-00774-y
• 发表时间: 2021-03
• 期刊: Biogeochemistry
• 影响因子: 4
• 作者: D. Scott;E. Bach;C. D. du Preez;J. Six;S. Baer

Fire frequency, state change and hysteresis in tallgrass prairie

• DOI: 10.1111/ele.13676
• 发表时间: 2021-01-14
• 期刊: ECOLOGY LETTERS
• 影响因子: 8.8
• 作者: Collins, Scott L.;Nippert, Jesse B.;Ratajczak, Zak
• 通讯作者: Ratajczak, Zak

Watershed and fire severity are stronger determinants of soil chemistry and microbiomes than within-watershed woody encroachment in a tallgrass prairie system

与高草草原系统中流域内的木质侵占相比，流域和火灾严重程度是土壤化学和微生物组的更强决定因素

• DOI: 10.1093/femsec/fiab154
• 发表时间: 2021
• 期刊: FEMS Microbiology Ecology
• 影响因子: 4.2
• 作者: Mino, Laura;Kolp, Matthew R.;Fox, Sam;Reazin, Chris;Zeglin, Lydia;Jumpponen, Ari
• 通讯作者: Jumpponen, Ari

Persistent decadal differences in plant communities assembled under contrasting climate conditions

在对比气候条件下聚集的植物群落持续存在十年差异

• DOI: 10.1002/eap.2823
• 发表时间: 2023
• 期刊: Ecological Applications
• 影响因子: 5
• 作者: Eckhoff, Kathryn D.;Scott, Drew A.;Manning, George;Baer, Sara G.
• 通讯作者: Baer, Sara G.

Intermittent streamflow generation in a merokarst headwater catchment

微岩溶源头流域的间歇性水流生成

• DOI: 10.1039/d2va00191h
• 发表时间: 2023
• 期刊: Environmental Science: Advances
• 作者: Hatley, Camden M.;Armijo, Brooklyn;Andrews, Katherine;Anhold, Christa;Nippert, Jesse B.;Kirk, Matthew F.
• 通讯作者: Kirk, Matthew F.