Growth of Halimium halimifolium under simulated and natural browsing in the Donana National Park (SW Spain)

The annual cycle of vegetative growth in the Mediterranean shrub Halimium halimifolium (Cistaceae) subjected to simulated and natural browsing on the stabilized sands of Donana National Park (SW Spain) is described. In a drier area without herbivory (Monte Intermedio) plants were subjected to different intensities of clipping. In a more humid area with high herbivory pressure (Monte Negro) plants were isolated by cages. Plants were monitored monthly from February to November 1994. Vegetative growth starts in March and ends in June or July, according to temperature and water availability. Plants intensely clipped and plants subjected to natural browsing responded maximally regarding shoot length, and number of leaves on main shoots and branches. Clipped plants, however, did not reach the height and cover of controls.