Surface analysis as a method to reconstruct past and recent dynamics of forest ecosystems.

The most direct way of deciphering the dynamics of an ecosystem is to examine its biotic and abiotic components based on analysis of living and dead organisms distributed above ground. The surface analysis method presented here provides a centennial to millennial stand-scale composition and disturbance history and is applicable in any wood-dominated ecosystem. A meticulous analysis of living and dead trees, and macroremains (charcoal, leaves and insect) laying above mineral soil was performed in a virgin and an anthropic sugar maple ( Acer saccharum ) forests. Sugar maple ecosystems provide an appropriate setting for testing this method as they are impacted by several natural and human disturbances. The living and dead components in both sites indicate an increase of the species abundance independent of human interventions, although accelerated by logging in the anthropic forest. The stands were affected by recent insect outbreaks and by fire over the last 2000 years. Charcoal remains indicate that a mixed forest occupied both sites with sugar maple as companion species for more than 1000 years. Surface analysis is a direct method for improving our understanding of current, past and future forest dynamics in natural and anthropic conditions, in this case highlighting how a structuring species of eastern North America thrives in different successional states and disturbance regimes. Novel tools that give insight into pre-colonial ecosystems are greatly needed as a proper understanding of species current distributions and behavior relative to allogenic disturbances is of crucial importance for restoration purposes and accurate prediction of future changes. [ABSTRACT FROM AUTHOR]