Hobbs, R.J. and Mooney, H.A. (1985) Community and population dynamics of serpentine grassland annuals in relation to gopher disturbance. Oecologia 67: 342-351.
This study examines the effects of soil disturbance by gophers on patterns of species abundance in an annual grassland community on serpentine soil. The authors assessed production, dispersal and storage of seed, germination, survivorship and growth of the most abundant species in undisturbed vegetation and on gopher mounds. Fewer seeds of the dominant species were dispersed onto gopher mounds due to the limited movement of seeds from within the closed vegetation. Species with taller flowering stalks were more likely to colonise gopher mounds. The timing of gopher disturbance in relation to the timing of seed fall determined which species could colonise mounds. Lower numbers of seeds falling onto gopher mounds resulted in lower seedling densities of several species compared with undisturbed areas. Survivorship of the commonest species differed between undisturbed areas and gopher mounds formed at different times of year. The authors suggest that continued gopher disturbance is a factor allowing several species, including perennial grasses, to persist in this community.