Mudanças climáticas e a resiliência da floresta amazônica ao longo do tempo e espaço

Abstract

The climate is changing fast, and we still do not know for sure what the consequences will be and the magnitude of the changes in the Earth's most biodiverse terrestrial ecosystem, the Amazon rainforest. To overcome such a scientific limitation, here we conceive and execute a four-fold innovative methodological structure, with the necessary interdisciplinary theoretical robustness. Such methods are capable of (1) measuring, and mapping ecosystem resilience at large scales; (2) assess the intrinsic vulnerability of ecosystems to climate change; (3) predict catastrophic transition events between the Amazon rainforest and savannas; and (4) to analyze the effects of past climate change in a quantitative and qualitative way on the ecosystems of the Amazon Basin. Our results show that forest is intrinsically more vulnerable to climate change in the near future than other terrestrial ecosystems. Also, there is highly probable chance that ongoing climate changes will suddenly trigger catastrophic transitional events to other stable states with lower plant cover density. Our findings indicate that such transitional regimes were frequent due to the climatic oscillations of the past over the last 22,000 years. Indeed, these paleobiogeographic events contributed to the ecological and evolutionary structuring of the Amazonian biota as we know it today. However, today's anthropogenic forcing, characterized by large-scale and high rates of transformations, has a disproportionate weight in the historical balance and may lead, in the near future, to an event of massive extinction of Amazonian biodiversity.