Mediterranean forests, land use and climate change: a social-ecological perspective

Abstract

Mediterranean forests are found in the Mediterranean basin, California, the South African Cape Province, South and southwestern Australia and parts of Central Chile. They represent 1.8 % of the world forest areas of which the vast majority is found in the Mediterranean basin, where historical and paleogeographic episodes, long-term human influence and geographical and climatic contrasts have created ecosystemic diversity and heterogeneity. Even if evergreen is dominant, deciduous trees are also represented, with different forest types including dense stands with a closed canopy (forests sensu stricto) and pre-forestal or pre-steppic structures with lower trees density and height. The Mediterranean basin is also a hot spot of forest species and genetic diversity, with 290 woody species versus only 135 for non-Mediterranean Europe. However, the characteristics of the Mediterranean area (long-standing anthropogenic pressure, significant current human activity and broad biodiversity) make it one of the world’s regions most threatened by current changes. Four examples of Mediterranean forest types, present in south and north of the Mediterranean basin and more or less threatened, are developed in order to show that linking “hard sciences” and humanities and social sciences is necessary to understand these complex ecosystems. We show also that these forests, in spite of specific climatic constraints, can also be healthy and productive and play a major ecological and social role. Furthermore, even if the current human activity and global change constitute a risk for these exceptional ecosystems, Mediterranean forests represent a great asset and opportunities for the future of the Mediterranean basin

Forest Adaptation to Climate Change along Steep Ecological Gradients: The Case of the Mediterranean-Temperate Transition in South-Western Europe

“…The functional features of Mediterranean systems can vary widely, but they typically include open vegetation, a low accumulation of biomass because of grazing, and recurrent low-to medium-intensity fires during the summer dry period when little plant growth occurs [27]. Evergreen, fire-resistant, and slow-growing trees (e.g., Quercus suber, Quercus ilex) are typically the keystone tree species.…”

“…Indeed, extensification through agroforestry such as in montado and dehesa savanna-type areas in Portugal and Spain (Figures 2 and 5), integration of animal production, cork/firewood harvesting, and cereal cultivation are often presented as solutions to decreasing populations and managing fire risks in these regions [11,13,23,24,27], a system type present in all Mediterranean countries. Maintaining open spaces in the landscape mosaic by keeping domestic herbivores, having low but sufficient tree density, and/or performing controlled burning allow agroforestry systems to contribute to the avoidance of massive fires that can accelerate rural abandonment.…”

Efficiency of species survey networks can be improved by integrating different monitoring approaches in a spatial prioritization design

“…Forest immaturity threatens forest-dependent species that require a given stand structure to find feeding and nesting resources (e.g., closer canopies, larger tree diameters). Old-growth and mature forests are an exception across the long heavily managed Mediterranean basin (Gauquelin et al, 2018). F I G U R E 1 Mean achievement of monitoring targets across the 671 monitoring features, for the optimal solution under each scenario, at different target levels (x-axis), with and without connectivity penalty (a and b, respectively).…”

The use of scenarios and models to evaluate the future of nature values and ecosystem services in Mediterranean forests

“…Mediterranean forests are a good example of such systems, because they represent semi natural systems subjected to a long history of use and transformation (Nocentini and Coll 2013). They are biodiversity-rich, complex socio-ecological systems that have been continuously adapting to use and exploitation throughout many centuries, while providing important services and goods to society (Myers et al 2000;Gauquelin et al 2016). Currently, they cover approximately 25 % of the Mediterranean region (Malek and Verburg 2017).…”