Demographic variation in a desert shrub, Larrea tridentata, in response toa thinning treatment

We performed a perturbation experiment to determine the relative importance of intra-specific competition on the demographic performance of a populati on of creosotebush, Larrea tridentata. From 1992 to 1995, we followed 1000 individuals, half of which were in plots subjected to a thinning treatment, and the other half were in unmanipulated plots. We found no significant re sponse to the thinning treatment for any of the traits studied. The strict interpretation of these results is that intra-specific competition is not i mportant in this Larrea population. (C) 2000 Academic Press.