ENVIRONMENTAL FILTERING DOMINATES ZOOPLANKTON COMMUNITY ASSEMBLY IN PONDS

Ponds are biodiversity hotspots and ideal ecosystems for studying community assembly of different organisms due to being numerous, having small size, discrete boundaries and being in a network. Zooplankton, rapidly respond to environmental change and provide functional links within food webs. However, the drivers shaping zooplankton functional diversity in small waterbodies remain understudied. We examined zooplankton functional traits, community-weighted means, and standardized functional diversity indices across 52 ponds in Ankara, Türkiye. Using trait-based metrics and null-model standardized effect sizes, we assessed whether zooplankton communities are structured by habitat filtering or by limiting similarity. We found clear functional convergence, demonstrating strong environmental filtering. Several traits including feeding strategies, habitat preferences, and stoichiometric categories showed significant convergence relative to null expectations. In contrast; species richness, functional dispersion, and body size did not respond to single environmental variables, indicating that no single factor drives community assembly. The results point to the combined influence of multiple co-occurring stressors producing a multi-filtering scenario. Overall, zooplankton communities in these ponds are shaped by synergistic habitat filters rather than trait divergence, highlighting their vulnerability to land and water use. Understanding how multiple stressors jointly structure pond communities is essential for designing conservation strategies for these overlooked ecosystems.

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Feride Avci, Middle East Technical University (ferideavci18@gmail.com)

Authors:

Hilal Kıran Isufi, Middle East Technical University, Department of Biological Sciences  (hilalkiran16@gmail.com)

Gizem Oğuz, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences  (gizemoguz9806@gmail.com)

Sarah Hasnain, Laboratoire d'Océanographie de Villefranche, LOV, Institut de la Mer de Villefranche,  (sarah.s.hasnain@gmail.com)

Emine Büşra Mülayim, Middle East Technical University, Department of Biological Sciences  (busramulayim1792@gmail.com)

Cemreay Dede, Middle East Technical University, Department of Biological Sciences  (dedecemre@gmail.com)

Meryem Beklioğlu, Centre for Ecosystem Research and Implementation (EKOSAM), Middle East Technical University,  (meryem@metu.edu.tr)