Global climate change in the Amazon tropical forest assessed by dendrocronological multi-proxy

Abstract

The increment of atmospheric CO2 concentrations and changes in land use are triggering extreme events relevant to the global climate. Thus understanding the response of tropical forest species to this global climate change is critical. The best way to estimate how these changes can affect forests is through the indirect records achieved with dendrochronological analyzes. It presents as an alternative to scarce observational data and enables the climatic and environmental reconstruction of forest ecosystems. Although in the Neotropical region different species have been signaled as potentials for dendrochronological studies, there are still few sites with sufficiently long series that have been used to interpret climatic variations. Therefore, this project aimed to study the ecological dynamics of species with dendrochronological potential occurring in the Jamari National Forest in the state of Rondônia in response to regional and global climatic variation. To reach this objective, four chapters are developed: (i) The tree-ring formation and ring width and density series synchronization. (ii) Intrinsic efficiency of tree water use by the 13 C and 18 O isotope variation. (iii) Tree-ring elements concentration and the nutrient cycle interpretation. (iv) Tree-ring chronologies and their relation with regional and global climatic variables. As one of its most important results, the project will provide a multi-indicator model of the effect of climate change on the dynamics of growth, carbon-biomass cycles, water and nutrients of Amazonian species.