Global Change and Forest Disturbances in the Mediterranean Basin: Breakthroughs, Knowledge Gaps, and Recommendations

Abstract

Forest ecosystems in the Mediterranean Basin are mostly situated in the north of the Basin (mesic). In the most southern and dry areas, the forest can only exist where topography and/or altitude favor a sufficient availability of water to sustain forest biomass. We have conducted a thorough review of recent literature (2000–2021) that clearly indicates large direct and indirect impacts of increasing drought conditions on the forests of the Mediterranean Basin, their changes in surface and distribution areas, and the main impacts they have suffered. We have focused on the main trends that emerge from the current literature and have highlighted the main threatens and management solution for the maintenance of these forests. The results clearly indicate large direct and indirect impacts of increasing drought conditions on the forests of the Mediterranean Basin. These increasing drought conditions together with over-exploitation, pest expansion, fire and soil degradation, are synergistically driving to forest regression and dieback in several areas of this Mediterranean Basin. These environmental changes have triggered responses in tree morphology, physiology, growth, reproduction, and mortality. We identified at least seven causes of the changes in the last three decades that have led to the current situation and that can provide clues for projecting the future of these forests: (i) The direct effect of increased aridity due to more frequent and prolonged droughts, which has driven Mediterranean forest communities to the limit of their capacity to respond to drought and escape to wetter sites, (ii) the indirect effects of drought, mainly by the spread of pests and fires, (iii) the direct and indirect effects of anthropogenic activity associated with general environmental degradation, including soil degradation and the impacts of fire, species invasion and pollution, (iv) human pressure and intense management of water resources, (v) agricultural land abandonment in the northern Mediterranean Basin without adequate management of new forests, (vi) very high pressure on forested areas of northern Africa coupled with the demographic enhancement, the expansion of crops and higher livestock pressure, and the more intense and overexploitation of water resources uses on the remaining forested areas, and (vii) scarcity and inequality of human management and policies, depending on the national and/or regional governments and agencies, being unable to counteract the previous changes. We identified appropriate measures of management intervention, using the most adequate techniques and processes to counteract these impacts and thus to conserve the health, service capacity, and biodiversity of Mediterranean forests. Future policies should, moreover, promote research to improve our knowledge of the mechanisms of, and the effects on, nutrient and carbon plant-soil status concurrent with the impacts of aridity and leaching due to the effects of current changes. Finally, we acknowledge the difficulty to obtain an accurate quantification of the impacts of increasing aridity rise that warrants an urgent investment in more focused research to further develop future tools in order to counteract the negative effects of climate change on Mediterranean forests.

Application of Arbuscular Mycorrhizal Fungi Isolates from Semi-arid Mediterranean Ecosystems as Biofertilizers in Argan Tree Development

“…The Mediterranean region is considered one of the most original and richest regions in terms of biodiversity on the planet (Blondel et al 2010;Peñuelas 2021) due to its diverse biogeographic specificities (climate, soils, landscapes) (Cuttelod et al 2008). This area is also considered as one of the most fragile eco-regions (Egidi et al 2021).…”

“…In these regions, plants are confronted to several challenging situations such as stresses and overexploitation of natural resources, thereby leading to soil fragility and impoverishment. The development and the production of plants in arid and semi-arid zones is thus limited, causing the disappearance of the most exposed tree species (Peñuelas 2021;Zaimeche and Sutton 1997). In Morocco, the Argan tree is an important essence of the southwestern region.…”

Conservancy of forest shelter belts in Russia and the Rostov region as one of the factors of transition to a green economy

“…Desert advancing leads to the degradation of droughtafflicted, semi-drought-afflicted and dry sub-humid land because of different factors, including change of climate and human activities. Besides, it is hard to come by an accurate quantitative estimate of the consequences of increasing aridity, which requires urgent investment in more targeted research to further develop future instruments to counter the negative effects of climate change [1].…”

A Synoptic Review of Forestry and Forest Products Trade and Production in Africa- The Case of Wood and Non-Wood Forest Products in West Africa

“…Forest harvesting, unsustainable resource activities (e.g., removals or cocoa cultivation), wildfires, mining activities, and political upheaval have all contributed to a major reduction in the nature reserve. Forest destruction continues, resulting in biodiversity degradation for morphological and anatomical as well as floristic features, reducing vegetation and society -having to respond to worldwide forces of change; species diversity has amplified desertification, resulting in deteriorated farm yields and, as a result, deterioration of sparsely populated community livelihoods [5,6]. If the woods are not removed and converted to other land uses, the plant cover will be damaged or destroyed [7].…”