ECOSySTEM SCIENCE: A NEw AppROACH IN THE ANALySIS OF FUNCTIONAL pROCESSES IN NATURAL AND HUMAN TRANSFORMED TERRESTRIAL ECOSySTEMS

Although Tansley originally proposed the ecosystem concept in 1935, ecosystem science underwent significant development in the last 20 years, as in this period it has been consolidated with concepts and methods arisen in convergent disciplines, such as ecosystem genetics, ecological stoichiometry, global ecology, and ecosystem services. The objective of this paper is to review new concepts and methods of water, energy, and nutrient dynamics research in terrestrial ecosystems to contribute to generate a new theoretical framework in the field of ecosystem science. From this review, a new conceptual definition of ecosystem is required based on three key issues: (a) the integration of functional processes at different spatial and temporal scales to understand the ecosystem dynamics in its environmental context; (b) the concept of resource (i.e., water or nutrients) use efficiency as a key metric for ecosystem function; and (c) the role of biological species in ecosystem functioning, using the genetic framework. These new concepts and methods are necessary to advance in the research on ecosystem functioning and resilience in the context of the current environmental crisis that includes processes such as ecosystem degradation, biodiversity loss, and global climate change. Finally, this new conceptual definition must be linked to evolutionary theory and global ecology research.