Renewable Energy Sources

Factors, both human and physical, including climatic conditions, hydrology, geomorphology and cropping practices are evaluated in terms of their contribution in desertification development. Particular emphasis is given on the effects of cultivation practices and the animal husbandry. The relation between local plants and desertification is also studied, emphasizing the role of the olive tree which is the dominant crop in the area. The main causes which are found to favor the occurrence of desertification include population increase, the extent of areas with low or without plant coverage, overgrazing combined or with the occurrence of fires, and the increased content in salts of water resources, especially at the eastern part of the island. With regard to agricultural practices and especially these applied for olive oil trees environmental compacts are either positive or negative depending on the physical circumstances and the used cultivating practices. What is important is the way weeds are combated, the type of the soil, irrigation applied and the conservation of plant cover. Vegetation restoration is considered one of the most effective ways to combat desertification. Native plant species suitable for such use include Ceratonia siliqua, Olea europea subsp.sylvestri and Pistacia lentiscus which are adapted to environmental conditions prevailing in the island of Crete. Additionally, findings from the international literature reveal an important role of AM fungi on the establishment of vegetation in degraded soils. Understanding the interrelationships between vegetation and soil microfauna is expected to contribute in the successful reestablishment of native shrub species in the degraded soils in Crete. Brief Biography of the Speaker: Vassilis Gekas son of Christos and Dimitra was born in Gallini of Larissa the year 1948. His studies were as follows: elementary school in the Gallini village (1954-1960) , secondary school in Larissa και(1960-1966). Chemical Engineering School in the National Technical University of Athens, (1966-1971). Military Service 1971-1973. In the Greek Industry worked as a Chemical Engineer (1973-1983) Ph D studies in the Technical Institute of Lund (1983-1987). Post doc studies on an ELF AQUITAINE sponsorship in the PAUL SABATIER University in Toulouse of France. Coming back to Sweden he obtained the degree of DOCENT (Asssociate Professor) in 1992. He taught in Lund and HELSINGBORG of Sweden, Oporto Portugal, Bahia Blanca and Rio Cuarto og Argentina, Celaya and Mexico City of Mexico and also he gave lectures in France, Italy, Spain and Germany. He speaks english, french, german, spanish, italian, portuguese and swedish. Since 1998 Professor of Transport Phenomana & Thermodynamics at the Environmental Department of the Technical University of Crete, Chania. He was the first Chairman of the Department (2000-2004). Author of several books and of chapters of books, in english and in greek. Author of >50 publications in cited journals with a Citation Index of approx. 1000. Know how in Membrane Technology, Food Engineering, Stirling cycles and active heliothermic systems. Current research topics: Desertification, Geometry & transport phenomena of biological structures such as the bronchic tree, sun-driven cars, BOLTZMANN equation. He participates in the Summer school of Delfi teaching on the connection between the modern knowledge with the Ancient Greek wisdom. 2nd WSEAS/IASME International Conference on RENEWABLE ENERGY SOURCES (RES'08) Corfu, Greece, October 26-28, 2008 ISSN: 1790-5095 11 ISBN: 978-960-474-015-4