Changes in farming techniques and management of underground water resources are needed to help reduce the future risk of desertification in parts of southern Greece, experts said yesterday. At a conference in Thessaloniki, experts said environmental changes and a lack of strategic planning will lead to large areas becoming arid land. «A slight increase in temperature can cause the oxidization of organic materials, a reduction in humidity and an increase in fire risk,» said Thessaloniki University professor Nikolaos Sillaios. «A fire is in turn a factor that leads to desertification as the blaze is followed by erosion and floods,» he added. The mountainous areas of Kilkis, near the border with Bulgaria, are also high-risk regions due to the lack of diversification in crop cultivation, experts said after inspecting areas of Argos in the Peloponnese and the islands of Naxos and Mytilene. Temperatures across Greece may rise by up to 4 to 5 degrees in coming years if current pollution levels are maintained.