Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 2, 2004
Publication Date: December 2, 2004
Citation: Peters, D.C., Pielke, R.A., Sr., Bestelmeyer, B.T., Allen, C.D. 2004. Spatial nonlinearities and cascading effects across landscapes in the Earth system [abstract]. LAND Open Science Conference, December 2-5, 2004, Morelia, Mexico. p. 50. Technical Abstract: Our objective was to develop and apply a conceptual framework to examine the importance and generality of spatial nonlinearities in the dynamics of the Earth system. Atmosphere-biosphere interactions are increasingly recognized as important to local ecosystem dynamics as well as to the global carbon cycle. However, the multi-scale nature of these interactions and their feedbacks are less well-known and poorly understood. This lack of understanding leads to ecological 'surprises' associated with nonlinear ecosystem responses to broad-scale forcing functions and feedbacks to the atmosphere. Our lack of understanding about these nonlinear dynamics cascading spatially across landscapes (i.e., spatial nonlinearities) severely limits our ability to identify the conditions leading to catastrophic events, as well as the impacts of these events on local and regional economies, conservation of species, ecosystem services, and balances in atmospheric gases. We examine these spatial nonlinearities in the dynamics of the Earth system in the context of interactions and feedbacks between atmospheric processes and ecosystem structure and dynamics across a range of spatial and temporal scales. We surmise that changes in spatial pattern of ecosystems over time, especially at the landscape scale, due to local ecological processes mediate the influence of atmospheric processes operating at broader scales. Rapid shifts in rates of atmospheric processes across values of spatial metrics create thresholds in time and feedbacks to spatial structure of the landscape with subsequent feedbacks to the atmosphere. Thus, small changes in spatial pattern can determine if a forcing function is amplified or attenuated across a landscape. It is only by accounting for these complex, multi-scale feedbacks between local ecological processes, landscape structure, and the atmosphere that can we begin to understand extreme events and to reduce the probability that we will be surprised. We first develop a theoretical framework to describe these complex interactions that builds on ideas from a number of disciplines, in particular, ecology and atmospheric sciences; then, we present several key examples from different systems to illustrate emerging patterns and concepts, as well as insights to improving management.