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优势植物，但尚不清楚随着环境条件的变化，这些物种是否会保持优势地位。优势物种的丧失可能会产生很大的影响，对生态系统的整体结构和功能产生潜在的级联影响。新墨西哥州塞维莱塔国家野生动物保护区正在进行的工作表明，一种普通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之间的重新排序的速度、数量和方向，该项目将把物种重新排序的影响与碳循环和净初级生产力联系起来。实验将改变水、温度和氮素的有效性，以测试草原对这些环境变化的反应。占全球陆地面积约45%的旱地生态系统对全球碳收支有可衡量的影响。旱地正在迅速变化，以应对干旱、空气污染和更大的降雨变异性。社区重新排序可能是促进对影响美国西南部和其他地方旱地生态系统的不同全球变化因素的了解的关键。草原在美国大陆占地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。三个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，一个由奇瓦瓦沙漠草(黑色格拉玛)主导，另一个由大平原草(蓝色格拉玛)主导。两者都是重要的牧草，对全球变化的反应不同。一个实验将改变干旱的严重程度和降雨的季节性，而第二个实验将在蓝色和黑色格拉玛共同出现的交错带上操纵变暖、氮肥和冬季(厄尔尼诺)降雨。第三个实验改变了黑色格拉玛草原夏季降雨事件的大小和频率，那里最有可能经历当地灌木的未来入侵(另一种物种之间的重新排序)。为了更好地理解这些物种之间群落重新排序的原因和后果，通过测量重要的碳过程(根生产和土壤呼吸)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功能的交互影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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

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

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.

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.

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.