The Threat of Desertification in the Island of Crete: Current Status, Future Trends and Management Practices

摘要

This work provides a brief description of the factors favoring desertification in the island of Crete including climate, hydrology, geomorphology and agricultural practices. Particular emphasis is given on the role of olive trees. The reason is twofold; firstly to investigate the impacts of olive tree cultivation, which is the dominant crop in the area, on desertification and secondly to investigate the potential of restoration disturbed areas by using olive trees as well as other native species. Population increase, bare lands, overgrazing, occurrence of fires, and the elevated concentration in salts of water resources, especially at the eastern part of the island were identified as the causes of desertification. With regard to adopted agricultural practices and especially those applied in olive oil trees, environmental compacts can be either positive or negative, depending on the prevailing climatic conditions, soil properties and the used cultivating practices. Restoration of vegetation is considered one of the most effective ways to control desertification. Native plant species suitable for such use include Olea europea, Ceratonia siliqua, and Pistacia lentiscus which are adapted to environmental conditions prevailing in Crete. Additionally, research studies reveal an important role of arbuscular mycorrhiza on vegetation establishment in degraded soils. Understanding the interrelationships between vegetation and microbes is expected to contribute in the successful re-establishment of native vegetation in the degraded soils in Crete and their rehabilitation.