AUTHOR=Keke Unique N. , Arimoro Francis O. , Edegbene Augustine O. , Akamagwuna Frank C. , Assie Fulbert A. G. J. , Odume Oghenekaro N. 

TITLE=Biotic homogenization of stream macroinvertebrates in an Afrotropical Anthropocene: Land use and ecological correlates

JOURNAL=Frontiers in Environmental Science

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2022.1022776

DOI=10.3389/fenvs.2022.1022776

ISSN=2296-665X

ABSTRACT=Land use modification is a notable cause of biodiversity loss in streams. However, the impacts of anthropogenic forest conversion on β-diversity are difficult to forecast, especially in Afrotropical stream ecosystem, mainly because: 1) empirical research is scant, and; 2) the few available studies provide conflicting findings. In our study, we used techniques of decomposing β-diversity to evaluate the influence of land use changes on macroinvertebrates β-diversity of 66 stream sites in an Afrotropical Anthropocene. We also evaluated the potential exclusive and shared contributions of ecological drivers of community composition and β-diversity. Our total β-diversity for both forested and modified streams was driven mainly by the turnover component, while the nestedness-resultant component was negligible. The dominance of turnover in both forested and modified streams in our systems stresses the urgency to protect many sites in order to conserve γ-diversity. While β-diversity diminished in our urban+agric streams in relation to our forest streams, leading to a process of biotic homogenization, β-diversity of our forest streams was similar to that of the urban streams, implying that land use does not necessarily lead to a process of biotic homogenization. The contrasting findings about relationships between land use and β-diversity in our study showed that the effects of land use on β-diversity can be variable and context-dependent. Larger parts of variation in community composition and β-diversity were accounted for by the local environmental conditions (through environmental filtering) and land use, while geographical spatial factors (through dispersal limitation) explained little part of variation in our system – highlighting the importance of species sorting (environmental filtering) over dispersal-related processes in metacommunity organization