The Maximum Entropy Formalism of statistical mechanics in a biological application: a quantitative analysis of tropical forest ecology

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 almost ten times more of local relative abundances then constraints based on either directional or stabilizing 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.

Energy and nutrients

This chapter deals with the ecology of Tropical East Asia from the perspective of water, energy, and matter flows through ecosystems, particularly forests. Data from the network of eddy flux covariance towers is revealing general patterns in gross primary production, ecosystem respiration, and net ecosystem production, and exchange. There is also new information on the patterns of net primary production and biomass within the region. In contrast, our understanding of the role of soil nutrients in tropical forest ecology still relies mostly on work done in the Neotropics, with just enough data from Asia to suggest that the major patterns may be pantropical. Nitrogen and phosphorus have received most attention regionally, followed by calcium, potassium, and magnesium, and there has been very little study of the role of micronutrients and potentially toxic concentrations of aluminium, manganese, and hydrogen ions. Animal nutrition has also been neglected.

Decomposition as Life Politics: Soils, Selva, and Small Farmers under the Gun of the U.S.–Colombia War on Drugs

How is life in a criminalized ecology in the Andean-Amazonian foothills of southwestern Colombia? In what way does antinarcotics policy that aims to eradicate la mata que mata (the plant that kills) pursue peace through poison? Relatedly, how do people keep on cultivating a garden, caring for forest, or growing food when at any moment a crop-duster plane may pass overhead, indiscriminately spraying herbicides over entire landscapes? Since 2000, the U.S.–Colombian War on Drugs has relied on the militarized aerial fumigation of coca plants, coupled with alternative development interventions that aim to forcibly eradicate illicit livelihoods. Through ethnographic engagement with small farmers in the frontier department of Putumayo, the gateway to the country’s Amazon and a region that has been the focus of counternarcotic operations, this article explores the different possibilities and foreclosures for life and death that emerge in a tropical forest ecology under military duress. By following farmers, their material practices, and their life philosophies, I trace the ways in which human-soil relations come to potentiate forms of resistance to the violence and criminalization produced by militarized, growth-oriented development. Rather than productivity—one of the central elements of modern capitalist growth—the regenerative capacity of these ecologies relies on organic decay, impermanence, decomposition, and even fragility that complicates modernist bifurcations of living and dying, allowing, I argue, for ecological imaginaries and life processes that do not rely on productivity or growth to strive into existence.