Relationships between woody and herbaceous plants in silvopastoral systems

Agroforestry and especially silvopastolisιn is an old land use which recently came into scene for ecological and economic reasons. Studies have shown its beneficial ecological role for stabilisation and improvement of degraded pastures through the biodiversity and ιnicroclimatic conditions that are created. The function of these systems is affected by the intereelations and competition between woody and herbaceous plants ιnainly for light, water and nutrients. Herbaceous plants seem to suppress tree seedlings, especially in extreme conditions. Woody plants however result in the reduction of herbage production as they ιnature due to lack of light, favour the shade tolerant species and affect seed production. On the other hand, herbage production seems to be higher and of better quality under shade than in open pastures. Competition for nutrients is significant at the seedlings stage but it is reduced Jater on as roots grow in different soil layers as well as with fertilisation. Finally, forest floor suppresses herbaceous species but this depends on the leaf size and their decomposition rate.