Local policies and actions have a important role to play in addressing climate change in Mediterranean ecosystems, where rural abandonment, increasing wildland-urban interface and coastal degradation are key processes

This is the main conclusion of a work recently published in the BioScience journal, which has had the participation of the prestigious scientists, Juli G. Pauses of the Desertification Research Centre (CIDE) and Millán Millán Muñoz, director emeritus of The Mediterranean Center for Environmental Studies (CEAM).

The work focuses on the Mediterranean Basin (southern Europe and northern Africa). This is a hotspot of biodiversity, a hotspot of climate change (warming of the region is above global average) and a hotspot of human population (a highly populated area and a leading tourist and retirement destination). In addition, the Mediterranean Sea is the world’s largest inland sea, and, therefore, environmental changes and disruptions of the water cycling have consequences affecting a large human population.

Three main local processes, often overlooked in global climate predicitve models, are highlighted: a) Rural abandonment in an environment depauperate of native herbivores; this increases wildlands (greening) but also the abundance and continuity of fuels that feed wildfires; b) Increasing the wildland-urban interface; this increases biodiversity degradation (e.g., alien species), fire ignitions, and the vulnerability of the society to fires; and, c) Coastal degradation enhances drought (browning) through negative feedback processes; that is, the desiccation of coastal marshes, the deforestation for agriculture, and more recently, the explosive coastal urbanization, have drastically reduced the original ecosystems and thus the water available for the sea breeze that was once feeding the rain in the upper part of the mountains.

Mechanisms acting at a fine scale, together with global drivers interact and drive current vegetation changes in Mediterranean landscapes. Its incorporation into climate models would allow to increase the spatial resolution of future climate scenarios and better understand and predict their impact on Mediterranean ecosystems.

The importance of of small-scale drivers suggests that local policies and actions can make a difference in reducing overall impact on the landscape and society.

Reference:

Pausas J.G. & Millán M.M. 2019. Greening and browning in a climate change hotspot: the Mediterranean Basin. BioScience 69: 143-151