Patterns in species and functional dissimilarity: insights from periphytic algae in subtropical floodplain lakes

Abstract

Understanding spatial and temporal changes in species composition has long demanded the attention of ecologists. However, only recently questions related to changes in species functional traits have been investigated. We explored patterns of species and functional dissimilarity of periphytic algae at six lakes sampled over a year across a subtropical floodplain. We evaluated the importance of turnover and nestedness components across space and time; the influence of environmental dissimilarity, spatial distance, and time on species and functional dissimilarity; and whether functional dissimilarity results from nonstochastic assembly processes. We used six functional traits to describe 155 species. Functional dissimilarity was estimated by functional dendrograms, and stochasticity was evaluated using null models. The turnover component was greater than nestedness for species and functional dissimilarity. Environmental dissimilarity, spatial distance, or time did not significantly explain species or functional dissimilarity. However, functional dissimilarity was significantly greater than expected given the observed species dissimilarity. The main finding of this study is that community assembly was deterministic with respect to traits. Further, each lake contributed similarly to the overall species and traits pool. These results highlight the importance of comparing species and functional dissimilarities to reach a better understanding of the organization of periphytic algal communities.

Influence of tributaries on the periphytic diatom community in a floodplain

“…High species turnover may be provided by environmental restrictions or spatial barriers (Villéger et al, 2013), and in our case it can be provided by the sum of all hydrographic basin downstream influence. A higher contribution of the βsim component (species turnover) in periphytic communities in this floodplain was also demonstrated by Dunck et al (2016) and for periphytic diatoms by Algarte et al (2016). Those studies suggest a great alteration occurring in these communities due to flood pulses, and that after Porto Primavera reservoir construction, the diatom community went through major changes, mainly indicating great environmental fluctuations provided by damming in a floodplain.…”

Periphytic algae in a floodplain lake and river under low water conditions

“…In floodplains, periphytic algae is responsible for part of the primary production, is the principal source of organic carbon deposition, plays an important role in mineralization and nutrient cycling, and is the base of the food web for many organisms (Stevenson 1996, Felisberto & Murakami 2013. These organisms are influenced by several factors in the floodplain, such as the water level, current flow, macro and micro nutrients, light, temperature, predation, and the substrate type (Rodrigues et al 2003, Algarte et al 2014, Dunck et al 2016. The alterations caused by drought events and changes in water level also affect these communities, particularly in the availability of substrates for adhesion, reproduction and development (Stevenson 1996).…”

Periphytic Cosmarium (Zygnematophyceae, Desmidiaceae) in lentic environments of the Upper Paraná River floodplain: Taxonomy and ecological aspects

“…Figures 16a-c Material examined: HNUP-16499, 16500, 16501, 16502. O c c u r re n c e : A l g a r t e e t a l . ( 2 0 0 6 ) ; Bichoff et al (2016); Dunck et al (2016);Train et al (2004).…”