Collaborative Research: MSA: The influence of temperature and resource supply on community size spectra in streams

合作研究：MSA：温度和资源供应对溪流中群落大小谱的影响

• 批准号: 2106067
• 负责人: Jeff Wesner
• 金额: $ 25.89万
• 依托单位: University of South Dakota Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2106067&HistoricalAwards=false
• 关键词: Collaborative; Research; MSA; influence; temperature

Humans rely on properly functioning freshwater ecosystems (e.g., streams, lakes, wetlands) for food, recreation, and drinking water. A major challenge in ecology is to understand how freshwater ecosystems will change in response to environmental disruptions. However, past efforts at measuring this change across large spatial scales are complicated by at least two challenges: 1) different places have different species, which makes it hard to compare across species when it comes to ecosystem function, and 2) collecting ecological information is extremely labor intensive, which makes it difficult to study ecological communities over space and time. This project solves those problems using cutting-edge ecological approaches. First, to overcome the limitations of species turnover, this project will measure ecosystem structure and function using animal body size distributions known as size-spectra (e.g., the relative abundance of large to small organisms), which are thought to be conserved across ecosystems regardless of species composition. Size spectra are an indicator of how efficiently energy is transferred from one organism to another in a food chain. Second, this project overcomes logistical limitations by using data already collected and curated from the National Ecological Observatory Network (NEON). Using NEON data, the researchers will analyze a large collection of size-spectra in streams over a wide range of environmental conditions to determine how stream temperature and nutrients influence freshwater ecosystems. This project is in the national interest because it provides a critical test of how freshwater ecosystems might respond to future temperature scenarios at macroecological scales. The researchers will also develop software that makes analysis of body size distributions freely available to the public and easier for ecologists to study in the future. Over 50 years of research reveals a common pattern across ecosystems in which abundance (N) declines with increasing body mass (M). The shape of this relationship is described by a power law, N ~ M(exp b), known as the abundance size-spectrum, and the exponent b varies in relation to changes in energy flow through the food web. The value of b is almost always negative, suggesting a remarkably consistent ecological pattern. However, climate change is expected to alter size-spectra, based in part on shifts in body size with temperature. Despite a seemingly simple relationship of body size and temperature, experimental and field studies demonstrate disparate results for size spectra-temperature relationships, finding positive, negative, and neutral shifts in size-spectra across temperature regimes. These studies largely consist of limited samples across relatively small spatial scales, making it difficult to predict how size-spectra varies with temperature at larger scales such as continents. In addition, deviations from theoretical predictions of the b-temperature relationship may be resolved by accounting for variation in resource supply, but the effect of resource supply at large scales is also unknown. This project uses statistical modeling to determine the influence of stream temperature and resource supply on stream size spectra exponents across a broad environmental gradient represented by a national monitoring network.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.

人类依靠适当运作的淡水生态系统（例如，溪流，湖泊，湿地）进行食物，娱乐和饮用水。生态学的一个主要挑战是了解淡水生态系统将如何响应环境干扰而变化。但是，过去至少有两个挑战使过去衡量大型空间尺度的这种变化的努力变得复杂：1）不同的地方具有不同的物种，这使得在生态系统功能方面很难比较各种物种，而2）收集生态信息非常密集，这使得很难在空间和时间上研究生态社区。该项目使用尖端的生态方法解决了这些问题。首先，为了克服物种营业额的局限性，该项目将使用称为大小 - 谱的动物体大小分布（例如，大到小生物的相对丰度）来衡量生态系统的结构和功能，无论物种组成如何，它们都被认为是整个生态系统的保守。尺寸光谱是指在食物链中如何有效地从一种生物传递到另一种生物的能量的指标。其次，该项目通过使用已经从国家生态观测网络（NEON）收集和策划的数据来克服后勤局限性。使用霓虹灯数据，研究人员将在各种环境条件下分析溪流中的大量尺寸，以确定流温度和养分如何影响淡水生态系统。该项目符合国家利益，因为它对淡水生态系统如何应对宏观生态量表的未来温度情景进行了批判性测试。研究人员还将开发软件，使公众可以自由地分析身体大小分布，并使生态学家将来更容易学习。 超过50年的研究揭示了整个生态系统的共同模式，其中丰度（N）随着体重的增加而下降。这种关系的形状由功率定律N〜M（EXP B）描述，称为丰度尺寸谱，指数B因通过食物网的能量流的变化而变化。 B的价值几乎总是负面的，表明生态模式非常一致。但是，预计气候变化将改变体谱，部分基于体型随温度的变化。尽管体型和温度有看似简单的关系，但实验和现场研究表明了大小光谱 - 温度关系的不同结果，在温度方案中发现了尺寸光谱的正面，阴性和中性变化。这些研究在很大程度上由相对较小的空间尺度的有限样品组成，因此很难预测大小在大尺度（例如大陆）的温度变化。此外，可以通过考虑资源供应的变化来解决与B-温度关系的理论预测的偏差，但是大规模资源供应的影响也未知。该项目使用统计建模来确定流温度和资源供应对以国家监测网络为代表的广泛环境梯度的流尺寸光谱指数的影响。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准通过评估来进行评估的。