Emergence and Evolution of Anthropogenic Landscapes in the Western Mediterranean and Adjacent Atlantic Regions

Virginia Iglesias,Isabelle Jouffroy-Bapicot,Boris Vannière

doi:10.3390/fire2040053

Abstract

Socio-ecological systems are complex, dynamic structures driven by cross-scale interactions between climate, disturbance and subsistence strategies. We synthetize paleoecological data to explore the emergence and evolution of anthropogenic landscapes in southwestern Europe and northern Africa. Specifically, we estimate trends in vegetation and fire, and assess how changes in climate and resource exploitation altered ecosystem dynamics over the last 10,000 years. Pollen data reveal that a complex vegetation mosaic resulted from the conversion of forests into areas suitable for crops, especially after 7000 cal yr BP. Cross-scale analysis shows a progressive decoupling of climate and ecosystem trajectories, which displayed an overall south-to-north time-transgressive pattern consistent with models of population expansion. As human impact increased, so did the use of fire, and after 4000 cal yr BP, levels of biomass burning became homogeneous across the region. This region-wide rise in burning suggests that land-management overrode the effects of climate, fuel and topography. Thus, while increasing the returns and predictability of resources, rapidly-growing communities created a new form of frequent and extensive disturbance that led to profound and persistent changes in the landscape, including shrub encroachment, increased erosion and soil impoverishment.

Highlights

Throughout the geological history of Earth, climate has been a key driver of biophysical processes at a variety of scales, from landform transformation and biological evolution, to biome reorganization and geochemical cycles
The Western Mediterranean and Adjacent Atlantic Regions has been continuously inhabited since the beginning of the Holocene
Paleoenvironmental data reveal a sustained increase in anthropogenic impact during this period, as indicated by pronounced non-climate-driven deforestation after ca

Summary

Introduction

Throughout the geological history of Earth, climate has been a key driver of biophysical processes at a variety of scales, from landform transformation and biological evolution, to biome reorganization and geochemical cycles. The emergence of agriculture and the changes in land-cover associated with its spread may have altered, the local distribution of vegetation, and greenhouse-gas concentrations and global climate [2]. Pollen- and charcoal-based reconstructions show coeval deforestation that resulted in the loss of up to 60% of Early Holocene European forests (10,000–8000 cal yr BP) by preindustrial times [4], as well as altered fire regimes [5]. This association suggests that, rather than pristine landscapes, anthropic ecosystems have dominated the continent for thousands of years

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Conclusion