Productivity of grazed and restored Mediterranean rangelands of Lagadas County in northern Greece

Livestock grazing is an old practice in the Mediterranean Basin, while continuous overgrazing increases the risk to land degradation. Several management actions are applied in the Mediterranean rangelands in order to reduce this risk. Five such actions were evaluated in Lagadas County (Northern Greece), for their impact on primary standing productivity. They involved overgrazed, moderately grazed and control areas, as well as partially and fully reforested areas with rangeland pines. Measurements included soil characteristics and plant biomass. Samples were taken from areas where each action was implemented in order to estimate soil texture and organic matter content. For plant biomass (herbs and shrubs), three transects of 50m each were established in each of the five actions and 10 quadrats were taken in each transect. The double sampling technique of visual weight estimation calibrated by harvesting was applied. For the tree biomass, two representative plots, (0.1 ha each), were selected in the three actions that had trees, i.e. the control area, and the partial and full reforestation areas. Allometric equations related to the diameter at breast height, the average tree height and the form factor were applied for the tree biomass estimation. The results showed that actions promoting grazing tended to result in shallower soil and less organic matter content than the other. Shrub biomass was highest in the overgrazed area, while herbaceous biomass was highest in the moderately grazed area. The reforestation actions resulted in the highest pine biomass, while the highest oak biomass was recorded in the control area.