LTREB Renewal: Long-term ecosystem responses to directional changes in precipitation amount and variability in an arid grassland

LTREB 更新：干旱草原中降水量和变异性方向变化的长期生态系统响应

• 批准号: 2326482
• 负责人: Osvaldo Sala
• 金额: $ 67万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2326482&HistoricalAwards=false
• 关键词: LTREB; Renewal; Long; term; ecosystem

Rainfall plays an important role in dryland environments. Climate is changing fast and significantly. A drier and more variable climate is expected, which could affect dryland environments. Predicting the effects of a new climate on the functioning of ecosystems is the most pressing objective of ecology. Understanding, the way ecosystems will function under these novel conditions is necessary to develop management strategies that generate optimal societal outcomes. Drylands are very important because they cover 40% of the terrestrial surface and provide invaluable goods and services. These goods and services range from forage production to recreation. This project will continue two unique long-term experiments, where researchers separately manipulated rain amount and variability in a desert grassland in New Mexico for 16 years. Results from the first 5 years of this project yielded unexpected results. Drought had indirect effects on the composition of plant species that offset the direct effects of drought. The continuation of the project will determine how these different responses occurred. Broader impacts include directly contributing to increasing participation of underrepresented groups. This project will collaborate with Asombro Institute for Science Education by building a new demonstration project at the 960-acre Chihuahuan Desert Nature Park. Asombro is a non-profit organization that provides award-winning science education to more than 22,000 children and 4,500 adults annually in southern New Mexico and western Texas.This proposal is guided by two hypotheses about dryland responses to changes in amount and variability of precipitation. (1) Endogenous Mechanisms: Biogeochemical and demographic phenomena mediate abrupt or continuous changes in populations, communities and ecosystem processes. (2) Exogenous Phenomena: El Niño events at 3-4-year periods interact with changes in low-frequency Pacific Decadal Oscillation (PDO) and Atlantic Multi-Decadal Oscillation (AMO). These climate events interact with internal mechanisms. Jointly, they affect system resistance, and lead to changes in species composition and ecosystem processes. After 16 years, the ecosystem seems to be at crossroads regarding soil organic nitrogen forms. This condition may result in a new N-water limitation. The project will continue two unique long-term precipitation-manipulation experiments that separately manipulated precipitation amount and variability in a desert grassland in New Mexico for 16 years. The long-term manipulations of precipitation amount are accomplished using rainout shelters coupled with irrigation systems. This project will directly contribute to increasing participation of underrepresented minorities with emphasis on Hispanic students. This project will collaborate with Asombro Institute for Science Education by building a new demonstration project at the 960-acre Chihuahuan Desert Nature Park. Asombro is a non-profit organization that provides award-winning science education to more than 22,000 children and 4,500 adults annually in southern New Mexico and western Texas.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.

降雨在旱地环境中起着重要作用。气候正在快速而显着变化。预计驾驶员和更可变的气候，可能会影响旱地环境。预测新气候对生态系统功能的影响是生态学的最紧迫目标。理解，生态系统在这些新颖条件下的运作方式对于制定产生最佳社会成果的管理策略所需的方式。旱地非常重要，因为它们覆盖了40％的陆地表面并提供宝贵的商品和服务。这些商品和服务范围从饲料生产到娱乐。该项目将继续进行两个独特的长期实验，研究人员分别操纵了新墨西哥州沙漠草原的降雨量和可变性16年。该项目的前5年的结果产生了意外的结果。干旱对植物物种的组成有间接影响，以抵消干旱的直接影响。项目的延续将决定这些不同的反应是如何发生的。更广泛的影响包括直接促进代表性不足的群体的参与。该项目将通过在占地960英亩的奇瓦瓦州沙漠自然公园建立一个新的示范项目与阿姆布罗科学教育研究所合作。 Asombro是一个非营利组织，每年在新墨西哥州和德克萨斯州南部为22,000多名儿童和4,500名成年人提供屡获殊荣的科学教育。该提案以两个关于旱地对降水量变化和变异性的反应的假设指导。 （1）内源性机制：生物地球化学和人口统计学现象媒体的突然或人口，社区和生态系统过程的持续变化。 （2）外源现象：3 - 4年期间的厄尔尼诺现象与低频太平洋十年振荡（PDO）和大西洋多年振荡（AMO）的变化相互作用。这些气候事件与内部机制相互作用。它们共同影响系统抗性，并导致物种组成和生态系统过程的变化。 16年后，关于土壤有机氮形式的生态系统似乎处于十字路口。这种情况可能会导致新的N水限制。该项目将继续两个独特的长期降水操作实验，这些实验分别操纵了新墨西哥州沙漠草原的降水量和可变性16年。使用Rainout避难所和灌溉系统结合了降水量的长期操纵。该项目将直接有助于增加代表性不足的少数民族的参与，重点是西班牙裔学生。该项目将通过在占地960英亩的奇瓦瓦州沙漠自然公园建立一个新的示范项目与阿姆布罗科学教育研究所合作。 Asombro是一个非营利组织，每年在新墨西哥州南部和德克萨斯州西部为22,000多名儿童和4,500名成年人提供屡获殊荣的科学教育。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来评估通过评估而被认为是珍贵的。