Reciprocal adjustments between landforms and living organisms: Extended geomorphic evolutionary insights

Whilst biological organisms adapt to the environment, earth surface processes and landforms evolve as a result of physicochemical processes, and as the result of the activity of certain living organisms defined as 'ecosystem engineers. The importance of long- and short-term impacts on geomorphic structures and processes by ecosystem engineers appears to be underestimated. Recent recognition of complex abiotic-biotic feedbacks in nature has resulted in a convergence of approaches in ecology and geomorphology. Present biogeomorphic knowledge supports the hypothesis that abiotic-biotic feedbacks create characteristic modulated patterns of earth surface landforms, adjusting according to biological evolution in the long term and to ecological succession in the short term. In this context, natural selection of organisms and ecological successions are considered to have the potential, in some cases, for extension to the physical world, including earth surface landforms. This perspective aims to contribute to the disruption of the 'classical' dichotomy between abiotic-biotic compartments because it emphasizes reciprocal adjustments (i.e., feedback mechanisms) between living organisms and abiotic environment dynamics. The extended evolutionary perspective, that is intended to feed back to ecology and evolutionary biology, indicates the potential for change in our deep understanding of geomorphology to reflect evolutionary and ecological succession theories. (C) 2007 Elsevier B.V. All rights reserved.