Local environmental controls of Atlantic Forest tree community assembly on a coastal continental island in southeastern Brazil

Abstract

Tropical forests with high species diversity are commonly found in rugged montane areas. We investigated causes of local tropical forest tree community assembly on a continental island with heterogeneous terrain. We recorded tree community (absolute species abundance), topography, soil, litter and location in 40 sampling units on two opposite sides of the island with similar heterogeneous terrain. We used transformation based Redundancy Analyses and variation partitioning to determine the contribution of environment (topography, soil and litter), spatial structure (geographic location and Moran Eigenvector Maps) and the shared effects of these to explain community assembly. The environment made a significant contribution to explain tree community patterns (species composition and abundance) across all models. Conversely, spatial structure showed minor impact. Contribution of strictly environmental effects and spatially structured environmental effects varied when evaluating each site independently as well as when evaluating the combined data. Evidence suggests that local tropical tree community assembly on heterogeneous terrain may be located much closer to the niche end of the hypothetic niche-neutral continuum. Findings indicate additionally that heterogeneity of environmental factors present in dissected mountainous terrain can affect the way tropical community assembly processes are perceived.

Species representativeness of Fabaceae in restrictive soils explains the difference in structure of two types of Chaco vegetation

“…However, we did not identify significant contribution from the pure effects of the spatial structure. Since the environmental changes are in a small scale, we believe that such fact is likely related to a greater relevance of processes based on niches on the assemblage of the community (Nettesheim et al 2019). This is because edaphic factors are generally structured on locals where the distribution of some species change to keep up with this structure (Peres-Neto & Legendre 2010;Vleminckx et al 2017).…”

Environmental filters structure plant communities in the Brazilian Chaco

“…A low variation in soil fertility and elemental composition among the different types of Chaco (Morello 1967) might act as an environmental filter for woody species, driving community composition and structure at a local scale. Previous studies have considered the soil as a determinant of variation in phytophysiognomies in the Cerrado (Gottsberger & Silberbauer-Gottsberger 2006;Almeida et al 2018;Barros et al 2018), Amazonian Caatinga (Coomes & Grubb 1996), Mata Atlântica (Nettesheim et al 2019;Arruda et al 2020), Argentinean Chaco (Kunst et al 2006) and Paraguayan Chaco (Navarro et al 2006). The number of individuals of trees and shrubs in chaco forest is more than twice that of the chaco woodland.…”