Distance decay as a descriptor of the diatom compositional variation in tropical reservoirs

Abstract

In the present study, distance decay was used as a descriptor of the compositional variation in diatom communities’ similarity between different habitats (phytoplankton and surface sediment) and seasons (summer and winter; only for phytoplankton) along a geographical gradient of ~64km over six reservoirs located in south-east Brazil. Whether rates of decay in similarity changed with distance in tropical biological communities was tested, and the degree to which dispersal (geographic distance) and niche (habitat association) processes explain variation in the diatom communities was estimated. In addition, whether the diatom assemblage captured in the surface sediment reflected the water column assemblage events was evaluated. Distance–decay curves were estimated using linear regressions. Partial Mantel tests were performed to examine the significance of relationships among the biological, environmental and spatial datasets. Similarity decreased significantly with distance between habitats and seasons, but the results were not statistically significant for surface sediment assemblages. All diatom communities were controlled more by limited dispersal than by environmental factors, probably as a result of the water quality and scale of the study area.

Diatom assemblages (Bacillariophyta) in six tropical reservoirs from southeast Brazil: species composition and spatial and temporal variation patterns

“…variance and range of environmental conditions and their spatial autocorrelation) (Ai et al, 2013). Approaches concerning the significance of relationships among the biological, environmental and spatial datasets in the systems currently studied can be found in Marquardt et al (2017a).…”

Environmental and spatial factors drive diatom species distribution in Alpine streams: Implications for biomonitoring

“…The importance of diatom dispersal-related processes in the framework of the biological monitoring has been recently proved in lacustrine ecosystems (Vilmi et al, 2016). Although lake communities are more spatiallystructured than stream ones, due to the higher dispersal limitation characterizing the lentic species (Soininen, 2007;Marquardt et al, 2017), Bottin et al (2014) remarked the importance of the spatial component also in mountain streams, where steep slopes surrounding streams might limit organism dispersion (Dong et al, 2016). In addition, also human alterations such as stream channelization, flow regulations and the construction of reservoirs, interrupt habitat connectivity and limit dispersal of organisms.…”

177 years of diatom studies in Brazil: knowledge, gaps, and perspectives

“…He introduces periphytic diatoms flora in Sargassum (Moreira-Filho 1959) and thereafter publishes studies on diatoms in mollusk stomach content (Moreira-Filho 1960), estuarine planktonic diatom (Moreira-Filho 1961, Moreira-Filho & Kutner 1962, diatoms in sambaquis (Moreira-Filho & Mômoli 1962), and a new genus of an estuarine diatom (Moreira-Filho 1968). Over time, other Brazilian authors have published many other works on the subjects of flora (e.g., Morais et al 2019, Silva-Lehmkuhl et al 2020, new species (e.g., Tusset et al 2018, Costa et al 2019, Bertolli et al 2019, Lehmkuhl et al 2019, Morais et al 2020, Zorzal-Almeida et al 2020, Marquardt et al 2021a, ecology (e.g., Marquardt et al 2017, Zorzal-Almeida et al 2018, Medeiros et al 2020), bioindicators (e.g., Lobo et al 2015), and paleolimnological approach (e.g., Fontana et al 2014, Wengrat et al 2019. However, the evolution and current status of diatom research in Brazil have not yet been addressed.…”