Dinâmica de comunidade arbórea de Campinaranas da Reserva de Desenvolvimento Sustentável do Uatumã na Amazônia Central

Abstract

Amazonian white-sand ecosystems (campinaranas) are harsh environments characterized by nutrient-poor soils exposed to waterlogging and/or high water deficit, requiring specific adaptations for tree species. However, little is known about the dynamics of campinaranas tree communities in response to variations in climate, hydrology and soil along the hydro-edaphic gradient. We studied how demographic rates (increment, mortality, recruitment) and their respective changes in biomass estimates of tree communities and species groups (endemics (WSS), specialists (OHS), generalists (GEN)) responds to different hydroclimatic conditions comparing the periods 2015-2019 and 2019-2022. Therefore, a total of 1170 individuals representing 118 tree species with diameter at breast height ≥ 10 cm were monitored in seven 2500 m² plots in the Uatumã Sustainable Development Reserve (USDR) in central Amazonia considering a hydroclimatic gradient from permanent dry to permanent waterlogged soils. The dynamic of the campinaranas’ tree species community is mainly influenced by water deficit and some physio-chemical soil parameters, mainly driving the dynamics of GEN presenting a higher sensibility to environmental changes than the other species groups. OHS and WSS do not respond to changing environmental conditions, probably due to sophisticated adaptations to these harsh environmental conditions. We discuss the findings for conservation in the background of the ongoing climate change.