Neighbour relationships in grass–legume communities. II. Temporal stability and community evolution

Abstract

Surveys of three old pastures near London, Ontario, over a period of 2 years revealed three categories of plant associations important in community evolution: stable, seasonal, and temporary. These are considered as counterparts to stabilizing, directional, and disruptive selection pressures in species evolution. Trifolium repens is proposed as a major "driving force" in directing community evolution. It is suggested that seral stages in secondary grassland succession are manifested through seasonal and random associations, whereas stable associations characterize the approach to subclimax.