Interactive effects of climate change and land use on food webs and energy flux across time

Abstract

Global changes, such as warming, agriculture, and deforestation, have significantly impacted the structure and functioning of communities in freshwater ecosystems. Ecological networks exhibit various characteristics that offer insights into community structure, but their dynamics are less well understood due to the difficulty in quantifying food webs at multiple time points. Detecting changes in the properties of ecological networks over time can indicate essential interruptions in the mechanisms that maintain diversity, stability, and energy flux through ecosystems. However, the effects of human-induced pressures are often investigated in isolation, with their interactive effects still poorly understood. This study aims to quantify the effects of warming and altered bottom-up and top-down control on structural (food web metrics) and functional (energy flux) properties of ecosystems. For this, we will use data from a 160-day multifactorial, orthogonal experiment conducted in freshwater mesocosms. The experiment systematically manipulated climate warming, nutrient enrichment from agricultural fertilizers, and the reduction of leaf litter through loss of riparian vegetation. We will evaluate how food web metrics and energy fluxes changed over the 160-day duration of the experiment, which is crucial for assessing how major global change drivers interact to alter the stabilizing structures and functions of freshwater ecosystems. Thus, we aim to provide a thorough understanding of the underlying causes of global changes and offer valuable insights for managing and conserving aquatic ecosystems in the face of emerging challenges.