School of Integrative Biological & Chemical Sciences Faculty Publications and Presentations

Document Type

Article

Publication Date

10-25-2025

Abstract

Invertebrate communities in the hyporheic zone are structured by metacommunity processes including environmental filtering and spatial effects (e.g., dispersal). We investigated how these processes differentially influence two functional groups: groundwater-obligate invertebrates (stygobionts) and benthic insects. We predicted that environmental filtering would dominate for insects, while spatial effects would prevail for stygobionts. We collected 76 samples from 28 hyporheic sites along 109 km of the Rio Grande, Texas, USA, enumerating 54,508 individuals across 80 taxa. Concordance analysis and RDA revealed two communities: one dominated by insects, and another by crustaceans and soft-bodied organisms, including all stygobionts. In linear models, insect richness and abundance were influenced by temperature, alkalinity, oxygen, and pH. Stygobionts were associated with higher nitrate, higher temperature, and lower specific conductance (indicating groundwater discharge in the study area). Stygobiont presence, richness, and abundance increased near springs. Stygobiont communities exhibited spatial autocorrelation while insect communities did not. Insect responses to environmental variables suggest species sorting effects, which prevail for taxa with sufficient dispersal ability. Stygobiont responses to spatial variables suggest limited dispersal from source populations in adjacent aquifers. Dispersal ability may limit stygobionts’ ability to recolonize habitats after hydrologic disturbances, especially when connection with adjacent aquifers is lost.

Comments

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Hydrobiologia

DOI

10.1007/s10750-025-06027-5

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