Lower diversity in benthic macrofaunal assemblages associated with increasing riparian deforestation in first-order lowland tropical streams

ABSTRACT

In aquatic ecosystems, benthic macroinvertebrates are strongly influenced by riparian habitat quality. We investigated associations between riparian deforestation, stream habitat variables and benthic macroinvertebrate assemblage structure, particularly sensitive taxa. We sampled macroinvertebrates and physical-chemical variables during both the dry and wet seasons at three sites, each with low, medium, and high levels of riparian deforestation, in each of three first-order streams in the lower zone of the Caeté river in eastern Amazonia, Brazil. The relationships were examined using Generalized Linear Mixed-Models (GLMM) and multivariate analysis. Macroinvertebrate families most associated with deforestation levels were determined by Indicator Species Analysis. We hypothesized that lower riparian deforestation is associated with greater diversity, especially of sensitive taxa, and lower dominance. A total of 3,427 macroinvertebrates distributed in 54 families were found, of which 25 were sensitive taxa. Sites with high deforestation, associated with Glossiphonidae, Tubificidae, and Naididae, differed from those with medium (associated with Limnephilidae) and low (associated with Polycentropodidae and Hydropsychidae) deforestation. Families and abundance of EPTC (Ephemeroptera, Plecoptera, Trichoptera, and Coleoptera) were lower at high deforestation, with significant losses of taxa compared to the whole assemblage. In Caeté headwaters, deforestation is an important factor for structuring benthic macroinvertebrate assemblages.

KEYWORDS:

• Headwaters
• aquatic biodiversity
• macroinvertebrates
• gallery forest
• Caeté river

Acknowledgments

We are grateful to the Universidade Federal do Pará for logistic support and to the residents of the riverside communities that received us on their properties during this research. We also thank the following for their support during sampling, especially Layana Cecília dos Santos Sousa, Thayara Alcântara, Erisson Duarte, Ismael Sander da Silva Nunes and Flavia Gisane Soares da Silva for help in identification, and Kelly Silva and Claudio Padilha for support in pilot collections.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data associated with this manuscript are available on Figshare (https://doi.org/10.6084/m9.figshare.22731665).

Geolocation Information

Sampling was carried out in an area of the lower Caeté river basin delimited by the following coordinates: 1°02'38.4’S 46°46'03.2’W; 1°02'38.4’S 46°43'24.4’W; 1°04'44.0’S 46°46'03.2’W; 1°04'44.0’S 46°43'24.4’W.

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/01650521.2024.2307070.