Perevolotsky, A., Department of Natural Resources, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, Israel
Haimov, Y., Department of Natural Resources, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, Israel

The structural development of a Mediterranean woodland dominated by Quercus calliprinos and Phillyrea latifolia was studied after extensive shrub removal, thinning and pruning of the woody vegetation followed by continuous goat grazing. Four management combinations were monitored: thinning only, grazing only, thinning plus grazing, and an undisturbed control. The study was begun 4 years after a single massive habitat manipulation and initiation of grazing, and was continued for 2 years. Grazing increased non-woody cover (the open space) to 32% from 23% in the undisturbed control. Thinning alone increased the open space to 38%, while the combination of thinning and grazing increased it to 45%. Most of the reduction of woody cover was due to the tree thinning. Shrub cover that was drastically reduced by removal, recovered to 80-90% of the cover in the undisturbed control, which may represent the cover before the treatment application. Quercus calliprinos responded to thinning and pruning with an increase of 25% in height and of 40% in trunk diameter, while P. latifolia shrubs and trees did not respond at all. The combined effect of thinning and subsequent goat browsing caused an additional increase of 10% in the height of Quercus and of 25% in the height and trunk diameter of P. latifolia. The effect of treatments and grazing on shoot regrowth, number of trunks and canopy growth is also presented. The implications of these results for the management of complex woody Mediterranean ecosystems are discussed and an evolutionary-ecological interpretation is suggested. © 1992.