Predicting effects of interannual variability in climate and drought on plant community outcomes, resilience, and soil carbon using temporally replicated grassland reconstructions

使用临时复制的草地重建来预测气候和干旱的年际变化对植物群落结果、恢复力和土壤碳的影响

• 批准号: 2343738
• 负责人: Sara Baer
• 金额: $ 78.07万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2343738&HistoricalAwards=false
• 关键词: Predicting; effects; interannual; variability; climate; Predicting; effects; interannual; variability; climate

Grasslands provide services that benefit society and there is growing interest in restoring native grasslands to enhance ecosystem services in targeted areas, such as marginal agricultural land. A goal of restoring agricultural land to grassland is to promote the recovery of diverse native plant communities that can withstand and bounce back from periodic stress, and that improve the health of soil degraded from cultivation. However, the composition of plant communities that develop and rate at which soil recovers in restored grasslands is highly variable and difficult to predict. Forecasting plant community outcomes and soil recovery is further complicated by an increasingly variable climate, especially in the southern Great Plains. This research uses a series of grassland restorations established in an agricultural field every other year for twelve years, encompassing a wide range of climate conditions, to understand of the role of climate variability on plant community composition, the resilience of restored communities to drought, and the rate at which carbon accumulates in the soil. This long-term study provides new insights into the role of climate in achieving conservation goals and reduces uncertainty about the capacity for restored grasslands to sequester carbon in soil. The similarly reconstructed grasslands provide a novel framework to test the hypotheses that stochastic variation in climate has deterministic consequences for restored community states, resilience develops as communities age and interact with community state, and climate-driven differences in plant composition contribute to variation in soil carbon accrual. Previously collected and continued measurements of plant species composition are used to model the effect of planting-year climate on restored community trajectories of change. Climate-influenced community states in these grasslands vary uniquely and widely in the ratio of C4-grasses and C3-forbs. The grasses and forbs produce organic matter that varies in both substrate quality and stable carbon isotopic signatures that are measured to determine whether soil carbon accrual is influenced more by recalcitrant or high-quality inputs, respectively. The occurrence of multiple droughts over the course of establishing this long-term experiment provides a rare opportunity to evaluate whether resilience varies predictably with restoration age and whether it interacts with climate-influenced community state. Ultimately, this research helps to transition long-term studies in community ecology toward prediction, advance understanding of factors influencing resilience in ecosystems, and help resolve competing hypotheses regarding plant-based controls on soil carbon accrual.This project is jointly funded by Ecosystem Science and the Established Program to Stimulate Competitive Research (EPSCoR).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.

草原提供使社会受益的服务，并且越来越有兴趣恢复本地草原，以增强目标地区（例如边际农业用地）的生态系统服务。恢复农业土地到草原的目标是促进可以承受周期性压力并反弹的各种本地植物群落的恢复，并改善了从耕种中退化的土壤的健康。但是，在经过修复的草原中恢复土壤的植物群落的组成是高度可变且难以预测的。越来越多的气候，尤其是在大平原南部，预测植物群落的结果和土壤恢复进一步变得更加复杂。这项研究使用每隔一年在农业领域中建立的一系列草原修复体，其中包含多种气候条件，以了解气候变异性在植物社区组成上的作用，恢复的社区对干旱的弹性以及在土壤中碳积聚的速度。这项长期研究为气候在实现保护目标中的作用提供了新的见解，并降低了对恢复的草地隔离土壤中碳的能力的不确定性。类似地重建的草原提供了一个新颖的框架，以测试气候随机变化对恢复的社区国家的确定性后果，随着社区的年龄和社区状态相互作用，植物组成的植物组成差异有助于土壤碳的变化。先前收集的植物物种组成和持续测量用于建模种植年气候对恢复的变化社区轨迹的影响。这些草原中受气候影响的社区国家在C4-Grasses和C3柱的比率上差异很大。草和FORB会产生有机物，这些有机物在底物质量和稳定的同位素特征中都有不同，这些特征是确定土壤碳应计是否受到顽固或高质量输入更大的影响。在建立这项长期实验的过程中，多次干旱的发生提供了一个难得的机会，可以评估恢复能力是否随恢复时代的变化而变化，以及它是否与受气候影响的社区国家相互作用。最终，这项研究有助于将社区生态学的长期研究转变为预测，对影响生态系统的复原力的因素进行预测，并有助于解决有关基于植物基于植物的土壤碳的控制的竞争假设，该项目由生态系统科学和既定的计划（EPSCOR）促进竞争性研究（EPSCOR）的既定计划（EPSCOR）共同资助。基金会的智力优点和更广泛的影响审查标准。