EFFECTS OF ROSMARINUS-OFFICINALIS NEIGHBORS ON RESPROUTING OF ERICA-MULTIFLORA INDIVIDUALS

To study the effects of competition in Mediterranean shrubland regener ation following disturbance, we used a neighborhood approach to assess the influence of mature Rosmarinus officinalis neighbors on the respr outing of Erica multiflora individuals after clipping. Sprout biomass of target plants 2 years after clipping was regressed against various measures of neighbor abundance within a 2 m radius around target E. mu ltiflora individuals in which all vegetation except R. officinalis had been removed. The largest single influence on the biomass of sprouts produced was the previous biomass of the resprouting plant. The abunda nce of R. officinalis neighbors had a weak but detectable effect on re sprouting of E. multiflora. Abundance of neighbors within 60 cm from t arget plants was the best predictor of regrowth. At this distance, two simple measures of neighbor abundance within the neighborhood, the nu mber of neighbors and the sum of their heights, were significant in ac counting for variation in resprouted biomass. None of the combinations of neighbor variables performed significantly better than single vari ables. The best models accounted for around 24 percent of the variatio n in resprout biomass. As in other studies, angular dispersion of neig hbors never had a significant effect on performance of target plants. The weak but significant response of resprouting to variation in R. of ficinalis abundance suggests that the intensity of competition in the experiment was low because of the removal of other species.