Population and food web responses to variation in rates and timing of pulsed, cross-ecosystem resource subsidies

人口和食物网对脉冲式跨生态系统资源补贴的比率和时间变化的反应

• 批准号: RGPIN-2018-03838
• 负责人: Richardson, John
• 金额: $ 2.91万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712390
• 关键词: Population; food; web; responses; variation

Many ecological communities receive resource inputs from adjacent ecosystems, sometimes very pulsed in time, such as leaf litter or terrestrial invertebrates falling into streams and wetlands in forests. Studies have shown that these “cross-ecosystem resource subsidies”, such as leaf litter, invertebrates, salmon, sea wrack, pollen and others, contribute in a large way to the productivity of the receiving ecosystems. However, most experiments on this topic involve binary comparisons based on augmentation or exclusion of a subsidy resource compared with an ambient reference or control. We have a limited understanding of how the quantitative effects of variation along characteristics of input rates, timing, duration and resource quality affects recipient population dynamics and productivity, community processes, and stability. In our research we have used leaf litter or terrestrial invertebrate inputs to streams as models to test the effects on receiving consumers. However, questions about consequences of quantitative gradients in input characteristics still need study in terms of population and community dynamics. Some stream predators use subsidy resources directly, and we have used cutthroat trout as a model system for understanding how inputs of terrestrial invertebrates affects their growth and reproduction. However, there are few studies of the consequences for population dynamics of those predators, including invertebrates, which do not directly use subsidies themselves, i.e. effects moderated through food webs. Food-web size structure is likely important given that predators (invertebrates and vertebrates) span several orders of magnitude in mass in food webs, and yet predators are often grouped as a single functional category. Thus, we will also test questions of size-dependent responses of consumers. Further, increases in productivity of recipient consumers have rarely been followed carefully into other parts of their food webs, which we will address. We have used field-based experimental manipulations to test the effects of input rates and quality of subsidies, and have made some progress on considering how these characteristics affect recipient populations and communities. The work proposed here will expand our understanding and predictive capability of how pulsed resource subsidies affect the productivity and stability of recipient populations and communities. Moreover, this work will serve to demonstrate the importance of protecting and managing ecosystems adjacent to aquatic environments, e.g. in forestry, agricultural and urban settings, to sustain productive and healthy freshwaters.

许多生态群落的资源投入来自相邻的生态系统，有时在森林中掉进了脑部的脑部和te骨，鲑鱼，鲑鱼，花粉等。环境参考或控制，我们对跨投入率，时机和资源的变化的定量影响有限，会影响接受者人口动态和生产力，社区过程和稳定性。 在我们的研究中，我们对流的叶子或Terrestebrate输入，以测试对消费者的影响。无脊椎动物会影响R的增长和繁殖。但是，捕食者通常被分组为单个功能类别，因此我们还将测试消费者的探索者。 我们已经使用基于现场的操作来测试补贴的投入率的影响，并取得了一些进展，特征如何影响人群和社区。稳定性的稳定性在于保护和管理生态系统的重要性