Studies in the Dynamics of Plant Populations: I. The Fate of Seed and Transplants Introduced into Various Habitats

Abstract

Seeds and transplants of Rumex crispus, R. obtusifolius and R. crispus var. littoreus were introduced into a wlde variety of habitats. Seeds germinated freely in most habitats giving spring and autumn flushes of seedlings. Most of these survived only 2-3 months in closed grassland communities, but survival was up to 2 years in a woodland site. The maritime variety of R. crispus germinated particularly freely in all sites and survivedTor 2 years on a single site. The habitat specificities of the taxa are apparently determined not so much by specialized germination requirements but by differential seedling survival. Transplants of the 3 taxa persisted longer man seedlings but in most habitats had lost weight at the end of the experiments. The significance of the ability of seedlings of a certain age to resist inanition is discussed. The fact that habitats in which 1 or more of the 3 Rumex taxa were abundant did not permit further recruitment from seed or transplants suggests that the existing populations represented a relic from an earlier condition of the habitat when the environment was favorable for establishment. Alternatively, most of the habitats chosen may already have reached saturation densities of Rumex spp. The most successful establishment from seed and phytometers was in the uncolonized habitat of new shingle.