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Abstract In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics. 

The Brazilian Cerrado, one of the most threatened biomes of our planet, illustrates the challenges and opportunities of reconciling economic development with conservation of land and water ecosystems. Here, we assess the state of the art of and present new information on the impacts of agricultural expansion, dams, and water use, and make recommendations for basin management, conservation, and restoration of water‐related Cerrado ecosystems and rivers. The conservation of the Cerrado requires not only the preservation of remnants of its vegetation but also the ability to keep the hydro‐geomorphological and ecological functionality of its rivers, particularly the Araguaia River, the last large well preserved and unregulated system. If business as usual continues, the Cerrado riverine ecosystems may never rebound.