Combining taxonomic and functional approaches to assess land‐use impacts on macroinvertebrate assemblages and improve bioindication

PAZ, L. E.; RODRIGUEZ, M.; RODRIGUES CAPÍTULO, A.; SPACCESI, F.; ARMENDÁRIZ, L.; CORTELEZZI, A.

RIVER RESEARCH AND APPLICATIONS

JOHN WILEY & SONS LTD

Año: 2023

1535-1459

Most studies exploring land use impacts have focused on taxonomic metrics, butinterest in the functional approach has increased because it helps to understand therelationships between community structure and functioning of aquatic ecosystems.We evaluated how functional and taxonomic approaches, and the associationbetween them, contribute to assessing the effects of land use on macroinvertebrateassemblages of lowland streams. We sampled benthic macroinvertebrates in 17 siteswith different land uses (agricultural, peri-urban, and extensive livestock) in BuenosAires, Argentina. We computed the taxonomic metrics and biotic indexes as well asfunctional richness (FRic), divergence (FDiv), dispersion (FDis), and Rao diversityindexes for each site. We performed general linear mixed models to compare landuses,a redundancy analysis, and also performed correlation analysis between taxonomicand functional indexes. Taxonomic richness was significantly higher in extensivelivestock than in the other two land uses, while Shannon diversity wassignificantly different between land uses (extensive livestock > peri-urban > agriculture).FRic and FDiv were significantly lower in peri-urban land use than in agriculturaland extensive livestock sites. Only taxonomic richness showed a significant andpositive relationship with FRic, FDis, and Rao, but they fit better to a logarithmicfunction. Therefore, an increase in taxonomic richness and Shannon diversity did notnecessarily imply an increase in the functional aspects of the macroinvertebrateassemblage. Using only one of these approaches could lead to partial evaluations andloss of information. Combining them could improve bioindication and predictivepotential and help assess the effects of multiple stressors on freshwater ecosystemsto improve biomonitoring.