Plant distribution patterns during early succession on an artificial protosoil

Abstract. Plant succession has been studied since 1977 in permanent plots on a calcareous protosoil in the northern outskirts of Göttingen (Central Germany). At the beginning the substrate was extremely poor in organic carbon and nitrogen. On 128 plots of 100 m², the temporal and spatial distribution of the most conspicuous plant species showed remarkable changes and correlations to soil site factors. While presenting data on Melilotus alba, Medicago lupulina, Agropyron repens, Arrhenatherum elatius, Dactylis glomerata, and Picris hieracioides the mechanisms of successional changes on nutrient-poor soils are discussed. It is demonstrated that a high cover of legumes favours the accumulation of soil nitrogen. Grassland species were more abundant in areas with low humus content whereas ruderal plant species preferred those parts of the area which contained more humus in the substrate. Life-form, colonization and population strategies play an important role in the described successional processes, in addition to resource competition. Finally, some methodological conclusions for permanent plot studies are presented.