Environmental Heterogeneity Caused by Anthropogenic Disturbance Drives Forest Structure and Dynamics in Brazilian Atlantic Forest

Abstract

We evaluated how tree community floristic composition, forest structure and dynamics varied over a period of 13 years across a topographic gradient of ravines created by anthropic disturbance in Brazilian Atlantic Forest. The study area is located within a fragment of Atlantic Forest (21° 09' S, 44° 54' W), in Minas Gerais state, Brazil. This work was based on data of tree diameter at 1.3 m from the soil, collected in four inventories. Each individual was recorded as being in one of three stratified topographic classes: hilltop, slope and bottom. We used direct gradient analysis to evaluate floristic compositional changes, phytosociological analysis to evaluate structural variations, and assessed demographic and biomass changes over time through analysis of rates of forest dynamics. The results did not reflect modifications in the patterns of floristic composition and species diversity along the topographic gradient, while differences in forest structural attributes and dynamics may be detected at these smaller spatial scales. Thus, the same species group may employ different strategies against different restrictive environmental factors. Finally, we suggest that floristic composition and species diversity may be less sensitive parameters for post-disturbance responses than forest dynamics and structure.

An Assessment of Human Opportunistic Pathogenic Bacteria on Daily Necessities in Nanjing City during Plum Rain Season

“…This was consistent with previous findings that drift was most important when selection was weak, α-diversity was low, and total community membership was low [ 42 ]. Notably, previous studies have revealed that anthropogenic selection pressures are similar to natural ecological selection, promoting more deterministic processes in the form of selection [ 43 , 44 ]. In this study, the electric bicycles and the washbasins were exposed to a higher frequency of human activities than the cotton and rice, which, consequently, accounted for a higher percentage of deterministic processes in the assembly of their communities than that of cotton cloth and rice.…”

The Soil Seed Bank as an Indicator of Altitudinal Gradient in a Montane Tropical Forest

“…Forest regeneration depends on mechanisms involved in the deposition of propagules in the plant community and also on disturbances that shaped patterns and processes of a given forest across time (Cirne-Silva et al 2020). In this context, the usually species-rich seed bank on the forest floor stored large quantities of dormant propagules, mainly belonging to pioneer species (Johnstone et al 2016).…”