Response of Pond Food Webs to Anthropogenic Habitat Degradation

ABSTRACT In the context of the Anthropocene, it is crucial to understand how habitat degradation and species loss alter the structure and functioning of ecological communities. Using a pondscape within the Pampas Biome as a study model, we analysed the impact of agricultural intensification on the taxonomic and trophic assemblage of pond communities. We sampled ponds in landscapes of natural grasslands, artificial grasslands, and crop fields. Using a multitrophic approach that included zooplankton, macroinvertebrates, fish, and amphibians, we evaluated taxonomic richness, assemblage abundance, and food web structure. The trophic niche structure, energy pathways, and network topology were inferred from stable isotopes and stomach content. Ponds in crop fields exhibited lower species richness, with significant decreases in the abundance of tadpoles, fish, and predatory macroinvertebrates, and increases in scrapers and filter‐feeding macroinvertebrates indicating a severe impact of agriculture. These ponds also showed more diversity in basal resources and trophic positions but reduced trophic redundancy. Although no changes in the relative importance of trophic pathways were detected, we observed fewer primary consumers subsidised by detritus in crop‐affected systems. The ponds in artificial grassland exhibited fewer alterations than those in crop fields, where environmental disruption is greater. This study shows how land use impacts aquatic ecosystems, leading to loss of biodiversity and functional disruptions, and underscores the vulnerability of certain species and interactions to agricultural intensification. We highlight the urgent need for targeted management to mitigate these consequences for ecosystem resilience and services, safeguard biodiversity, and preserve ecosystem functions in agricultural landscapes.