LTREB: Community reordering alters ecosystem processes in desert grassland

LTREB：群落重新排序改变了沙漠草原的生态系统过程

• 批准号: 1856383
• 负责人: Scott Collins
• 金额: $ 48.9万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1856383&HistoricalAwards=false
• 关键词: LTREB; Community; reordering; alters; ecosystem

Global environmental change can cause large-scale disruptions to ecosystems by gradually shifting both the presence and abundance of different plant species. Many ecosytems are characterized by a few dominant plants, but it is unclear if these species will remain dominants as environmental conditions change. The loss of dominant species may have a large impact, creating a potential cascade of effects on the overall structure and function of the ecosystem. Ongoing work at the Sevilleta National Wildlife Refuge in New Mexico indicates that a common desert grass is gradually replacing a widespread Great Plains grass. To understand how changes in rainfall amount, timing and variability affect the rate, amount and direction of reordering among the dominant grass species, this project will link the effects of species reordering to carbon cycling and net primary production. Experiments will alter water, temperature and nitrogen availability to test how grasslands respond to these environmental changes. Dryland ecosystems, which cover ~45% of global continental land area, have measurable impacts on the global carbon budget. Drylands are changing rapidly in response to droughts, air pollution, and increased rainfall variability. Community reordering may be key to advancing the understanding of different global change factors affecting dryland ecosystems in the southwestern United States and elsewhere. Grasslands cover 240 million ha (33% of land area) in the continental US, providing valuable resources for livestock, wildlife habitat, water resources, recreation, and carbon storage. Three experiments will test how environmental change alters the presence, success and contiuity of 2 important grasslands, one dominated by the Chihuahuan Desert grass, black grama, and the other by Great Plains grass, blue grama. Both are important forage grasses that respond differently to global change. One experiment will alter the severity of drought and seasonality of rainfall, while a second experiment manipulates warming, nitrogen fertilization and winter (El Nino) rainfall on plots located in the ecotone where blue and black grama co-occur. The third experiment alters the size and frequency of summer rain events in black grama grassland, which is most likely to experience future invasion by native shrubs (another kind of reordering among species). To improve understanding of the causes and consequences of community reordering among these species, measurements of important carbon processes (root production and soil respiration) along with additions of seeds and biological soil crusts will directly test for interactive effects of plant and microbe community reordering on ecosystem function.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.

全球环境变化可能会逐渐改变不同植物物种的存在和丰度，从而对生态系统造成大规模破坏。许多生态系统的特点是少数占主导地位的植物，但尚不清楚随着环境条件的变化，这些物种是否仍将保持主导地位。优势物种的丧失可能会产生巨大影响，对生态系统的整体结构和功能产生潜在的级联影响。新墨西哥州塞维利亚塔国家野生动物保护区正在进行的工作表明，常见的沙漠草正在逐渐取代广泛分布的大平原草。为了了解降雨量、时间和变异性的变化如何影响优势草种重新排序的速度、数量和方向，该项目将物种重新排序的影响与碳循环和净初级生产联系起来。实验将改变水、温度和氮的可用性，以测试草原如何应对这些环境变化。旱地生态系统覆盖全球陆地面积约 45%，对全球碳预算具有显着影响。由于干旱、空气污染和降雨量变化的增加，旱地正在迅速发生变化。群落重新排序可能是加深对影响美国西南部和其他地区旱地生态系统的不同全球变化因素的理解的关键。美国大陆草原面积达 2.4 亿公顷（占陆地面积的 33%），为牲畜、野生动物栖息地、水资源、娱乐和碳储存提供了宝贵的资源。 三项实验将测试环境变化如何改变两个重要草原的存在、成功和连续性，其中一个以奇瓦瓦沙漠草（黑格拉玛）为主，另一个以大平原草（蓝格拉玛）为主。两者都是重要的饲草，对全球变化的反应不同。其中一项实验将改变干旱的严重程度和降雨的季节性，而第二项实验则在位于蓝格拉马和黑格拉马共存的生态交错带的土地上控制变暖、氮肥和冬季（厄尔尼诺）降雨。第三个实验改变了黑格拉玛草原夏季降雨事件的规模和频率，该草原未来最有可能遭受本土灌木的入侵（物种间的另一种重新排序）。为了提高对这些物种群落重新排序的原因和后果的理解，对重要碳过程（根系生产和土壤呼吸）的测量以及种子和生物土壤结皮的添加将直接测试植物和微生物群落重新排序对生态系统的相互作用影响该奖项反映了 NSF 的法定使命，并通过使用基金会的智力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

Extreme Drought in Grassland Ecosystems (EDGE) Net Primary Production Quadrat Data at the Sevilleta National Wildlife Refuge, New Mexico

新墨西哥州塞维利亚塔国家野生动物保护区的草原生态系统极端干旱 (EDGE) 净初级生产样方数据

• DOI: 10.6073/pasta/4b6fca5328fcdfa8bc644a3d6d9727f7
• 发表时间: 2021
• 期刊: Environmental Data Initiative
• 作者: Baur, Lauren;Collins, Scott;Muldavin, Esteban;Rudgers, Jennifer A;Pockman, William T.
• 通讯作者: Pockman, William T.

Monsoon Rainfall Manipulation Experiment (MRME): Net Primary Production Quadrat Data at the Sevilleta National Wildlife Refuge, New Mexico

季风降雨操纵实验 (MRME)：新墨西哥州塞维利亚塔国家野生动物保护区的净初级生产样方数据

• DOI: 10.6073/pasta/b249097975dcd58ea2470854d5409f42
• 发表时间: 2021
• 期刊: Environmental Data Initiative
• 作者: Baur, Lauren;Collins, Scott;Muldavin, Esteban;Rudgers, Jennifer A;Pockman, William T.
• 通讯作者: Pockman, William T.

Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Soil Temperature, Moisture, and Carbon Dioxide Data from the Sevilleta National Wildlife Refuge, New Mexico

变暖厄尔尼诺氮沉积实验 (WENNDEx)：来自新墨西哥州塞维利亚塔国家野生动物保护区的土壤温度、湿度和二氧化碳数据

• DOI: 10.6073/pasta/9e9f235128c82a46bb073589d91c6989
• 发表时间: 2021
• 期刊: Environmental Data Initiative
• 作者: Collins, Scott

Belowground responses to altered precipitation regimes in two semi-arid grasslands

• DOI: 10.1016/j.soilbio.2022.108725
• 发表时间: 2022-05-30
• 期刊: SOIL BIOLOGY & BIOCHEMISTRY
• 影响因子: 9.7
• 作者: Holguin, Jennifer;Collins, Scott L.;McLaren, Jennie R.
• 通讯作者: McLaren, Jennie R.

Extreme drought has limited effects on soil seed bank composition in desert grasslands

极端干旱对荒漠草原土壤种子库组成影响有限

• DOI: 10.1111/jvs.13089
• 发表时间: 2021
• 期刊: Journal of Vegetation Science
• 影响因子: 2.8
• 作者: Loydi, Alejandro;Collins, Scott L.
• 通讯作者: Collins, Scott L.