Competition, differential mortality, and their effect on the spatial pattern of a desert perennial, Eriogonum inflatum Torr and Frem (Polygonaceae).

Eriogonum inflatum Torr and Frém. (Polygonaceae) experiences unusually high population turnover for a desert perennial. For example, 20% of the individuals in the study population were dead but still rooted. Pairs of nearest neighbors which included one dead individual tended to be closer to one another than pairs of live nearest neighbors. Thus, deaths are nonrandom. Individuals which are too close to one another are most vulnerable. Nevertheless, the deaths of 20% of the individuals had no effect on the intensity of the spatial pattern of the population; survivors were just as highly aggregated as survivors and dead individuals together. I conclude that competitor-induced mortality will not have predictable effects on the spatial pattern of plant populations which consist of a mosaic of individuals of different ages and sizes.