Land-use influence on the functional organization of Afrotropical macroinvertebrate assemblages

No Difference in Instream Decomposition Among Upland Agricultural and Forested Streams in Kenya

“…In temperate streams, shredders play a major role in leaf litter decomposition because of their higher abundance and diversity (Dobson et al, 2002;Gonçalves et al, 2006;Gessner et al, 2010;Medina-villar et al, 2015). However, a scarcity of macroinvertebrate shredders has been reported in some tropical studies (Camacho et al, 2009;Yule et al, 2009;Blanco and Gutiérrez-isaza, 2014), although in others a diverse shredder assemblage has been reported (e.g., Cheshire et al, 2005;Masese et al, 2014a;Sitati et al, 2021). The low number and abundance of shredders found in this study (only 7% of macroinvertebrates in coarse-mesh litterbags) demonstrate the potentially dominant role of microbial breakdown of leaf litter in tropical streams (Mathuriau and Chauvet, 2002;Wantzen et al, 2008;Boyero et al, 2015).…”

“…Macroinvertebrate kick sampling was conducted using a semiquantitative kick-net sampling method (Dickens and Graham, 2002). The following biotopes were delineated and sampled within each site: 1) GSM: gravel, sand and mud; 2) STONES: bedrock, boulders, cobbles, and pebbles, either under flowing or non-flowing conditions; 3) VEG: submerged and marginal vegetation (Masese et al, 2021;Sitati et al, 2021). The sampling process involved disturbing/kicking the bottom upstream of the net (500-μm mesh size), so that dislodged invertebrates are washed into the net by water currents.…”

“…Forest cover in the Afrotropical catchments has been declining over the years with potential effects for stream ecosystems (Fugère et al, 2016(Fugère et al, , 2018. Studies have reported negative effects of land-use changes from forestry to agriculture and urbanization in tropical streams, ranging from declines in water quality and quantity, loss of biodiversity, mainly the sensitive shredder taxa, and changes in ecosystem structure and functioning (Masese et al, 2014a, b;Fugère et al, 2016Fugère et al, , 2018Masese et al, 2017;Yegon et al, 2021). However, the findings of this study show that agriculture does not necessarily have negative effects on streams if riparian zones and habitat quality are well protected.…”

“…Macroinvertebrates play a major role in ecosystem-level processes and their functional composition in terms of functional feeding groups are indicators of ecosystem attributes and the health of streams and rivers (Boyero et al, 2015;Merritt et al, 2017;Sitati et al, 2021). This approach has been extended to leaf litter decomposition rates (Gessner and Chauvet, 2002;Young and Matthaei, 2008).…”

Low diversity of fishes in high elevation Afrotromontane streams renders them unsuitable for biomonitoring

“…Human population growth and the need for space for increasing food production and settlements have driven deforestation of large areas around biodiversity hotspots around the world (Fugère et al, 2016; Mapulanga & Naito, 2019; Ordway et al, 2017). At the river catchment scale, land use and land cover changes have been linked with modified flow regimes, deterioration in water and habitat quality, changes in nutrient cycling, organic matter processing and basal food resources for aquatic communities, leading to biodiversity loss and general impairment of ecological integrity of streams and rivers (Fugère, Jacobsen, et al, 2018; Kadeka et al, 2021; Mangadze et al, 2019; Masese et al, 2014a, 2014b; Masese & McClain, 2012; Sitati, Raburu, et al, 2021; Tampo et al, 2020).…”