Correlation of productivity and nutritive value of the herbaceous vegetation with the tree cover of oak and beech trees in Lagadas county of Thessaloniki

Silvopastoral systems are complex systems that produce in the same area forest products and feed for livestock. In this paper the effect of low cover of oak and beech trees (10-35%) was studied on forage production and nutritive value of the understory herbaceous vegetation. The research was conducted in silvopastoral systems of Lagadas county of Thessaloniki, in spring of 2003. The tree cover, the annual production of the herbaceous species were measured in the field while the nutritive value of the production was estimated with laboratory techniques. Regression models were generated that correlates the tree cover with the annual herbage production, ground litter and the nutritive value. The annual herbage production was relatively high (210 kg/0.1ha) and correlated positively with the tree cover but there was no significant correlation between tree cover and the parameters of nutritive value. The relative high herbaceous production and its satisfied nutritive value suggest that the oak and beech silvopastoral systems are important forage resources for meeting the demands of livestock in the county of Lagadas of  Thessaloniki.