Quantifying the Resilience and Functioning of Freshwater Ecosystems Across Spatial and Temporal Gradients of Environmental Stress

自然和半自然系统将如何适应极端事件，因为我们的气候变化仍然是一个紧迫的生态学问题。生态系统对多重且往往相互作用的环境压力高度敏感，如农业集约化和气候变化，这些环境压力在时空尺度上的分布和强度各不相同，并具有区域差异（如地理气候）。这可能导致影响，改变生态系统的结构和功能特性。因此，这给生态系统带来了巨大的压力，减少了生态系统的服务。生态系统应对压力的能力是有限的，因此，当系统的适应能力被超越时，预计它们会发生制度转变，尽管最近的研究表明缺乏这种转变的经验证据（Hillebrand et al. 2020）。该项目将重点关注地理系统吸收、适应和从环境压力梯度和社区恢复力的偶发性干扰中恢复的能力。该项目是与北爱尔兰农业食品和生物科学研究所（AFBI）合作的CASE学生项目，将通过实验量化和评估不同生态恢复力措施（Holling 1973）和多种生态稳定性措施（Donohue et al. 2013）的相对优点。因此，该项目为评估支撑生态稳定性变化的机制提供了机会，并将尝试以经验量化物种对多种稳定性措施的贡献，包括变异性、抗性和恢复（工程弹性）。重点将放在淡水无脊椎动物和底栖生物膜群落结构上，重点是量化物种相互作用，以及功能（如体重、营养水平和营养作用）和结构特性（如丰度和丰富度），以支持对不同稳定性概念及其在应用管理中的相关性的基本探索。

How natural and semi-natural systems will adapt to extreme events as our climate changes remains a pressing question in ecology. Ecosystems are highly sensitive to multiple, and often interacting, environmental pressures, such as agricultural intensification and climate change, which vary in distribution and intensity across spatiotemporal scales, and with regional variations (e.g. geo-climate). This can result in impacts, which alters both the structural and functional properties of the ecosystems. Consequently, this places ecosystems under significant stress, reducing ecosystem services. The capacity of an ecosystem to deal with stress is finite, and consequently they are predicted to undergo regime shifts when the adaptive capacity of the system is exceeded, although recent studies demonstrate a lack of empirical evidence for such shifts (Hillebrand et al. 2020). This project will focus on the capacity of lotic systems to absorb, adapt and recover from episodic disturbances across a gradient of environmental stress and community resilience. The project is a CASE studentship in collaboration with the Agri-Food and Biosciences Institute (AFBI) in Northern Ireland and will experimentally quantify and assess the relative merits of different measures of ecological resilience (Holling 1973) and multiple measures of ecological stability (Donohue et al. 2013). This project, therefore, offers the opportunity to evaluate the mechanisms that underpin variation in ecological stability and will attempt to quantify empirically species-specific contributions to multiple measures of stability including variability, resistance and recovery (engineering resilience). Emphasis will be placed on freshwater invertebrate and benthic biofilm community structure, with a focus on quantifying species interactions, and both functional (e.g. body mass, trophic level and trophic role) and structural properties (e.g. abundances and richness) to support a fundamental exploration of different stability concepts and their relevance in applied management.