Work

Aquatic and terrestrial environmental DNA signals reveal decoupling of blue-green communities along an urbanization gradient

Year: 2025

Type: article

Abstract: • Aquatic and terrestrial invertebrates display highly divergent patterns of alpha and beta diversity. • Aquatic taxa respond to local habitat quality, whereas terrestrial taxa rely more on landscape habitat quantity. • Aquatic and terrestrial communities became increasingly dissimilar with increasing levels of urbanization. • Environmental DNA from aquatic and terrestrial samples provide complementary assessment of biodiversity. • Newly adapted primers showed high specificity to Metazoans with both water and soil samples. Urban blue and green spaces, like ponds and parks, can mitigate the negative effects of urbanization on biodiversity by providing diverse, connected habitats and enabling resource flows between ecosystems. While studies have evaluated these spaces for terrestrial and aquatic communities individually, few have examined shared factors influencing both communities simultaneously. Consequently, it is unclear how these spaces should be conceived and maintained to support the diversity of both aquatic and terrestrial species, as well as their interactions. Here, we use environmental DNA (eDNA) metabarcoding to identify shared drivers and assess if and how aquatic and terrestrial invertebrate communities are coupled across 54 paired aquatic and terrestrial habitats along an urbanization gradient in the city of Zurich, Switzerland. Contrary to general expectations, we find no significant correlation in aquatic and terrestrial community structure, which we attribute to distinct drivers identified for both communities. Aquatic communities were primarily influenced by local factors related to habitat quality, while terrestrial communities were associated to landscape drivers pertaining to habitat quantity, suggesting that different processes at different spatial scales need to be considered to support both communities. Furthermore, with increasing urbanization, aquatic and terrestrial communities exhibited signs of decoupling driven by the filtering of organisms straddling ecosystem boundaries. We conclude that increasing levels of urbanization weaken resource flow between aquatic and terrestrial environments. By employing eDNA across ecosystem boundaries, our study highlights the critical importance of both the quality and quantity of urban habitats in conserving aquatic and terrestrial communities, as well as their linkages.

Source: Landscape and Urban Planning

DOI: 10.1016/j.landurbplan.2025.105376

Authors: Kilian Perrelet, Lauren M. Cook, Andreas Dietzel, Florian Altermatt, Marco Moretti

Institutions: University of Zurich, Swiss Federal Institute for Forest, Snow and Landscape Research, Swiss Federal Institute of Aquatic Science and Technology

Language: English

Topic: Environmental DNA in Biodiversity Studies

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Sustainable cities and communities, Life on land, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $3,120