1. School of Agricultural Development, Faculty of Agricultural and Forestry Sciences, Democritus University of Thrace, GR-68200 Orestiada, Greece
2. School of Forestry and Management of the Environment and Natural Resources, Faculty of Agricultural and Forestry Sciences, Democritus University of Thrace, GR-68200 Orestiada, Greece
3. School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece