Morphometric parameters: an approach for the indication of environmental conditions on calcareous grassland

Morphological traits of plants often vary considerably in response to different environmental conditions, which may render them suitable as sensible indicators for conservation purpose. To compare the plasticity of morphological traits of species of calcareous grassland under different environmental conditions (stands of different structure with respect to litter and vegetation height), morphometric investigations were carried out on calcareous grasslands differing in grazing regime. Populations of the calcareous grassland species Plantago media and Scabiosa columbaria subject to different grazing regimes showed considerable plasticity. There were, e.g. relationships between shoot height, biomass, and fertility of individuals. Shoot height and the number of diaspores per inflorescence increased significantly with increasing cover of litter. Simultaneously there were considerable changes in the reproductive mode, from generative only to a combination of generative and vegetative reproduction. The analysis of morphological plasticity showed that different environmental conditions could accurately and easily be monitored through the species-specific growth response. Especially shoot height appears to play a central role, since the study species can vary this growth parameter to escape light deficiency of tall stands rich in litter. Due to its large variability, shoot height can be used as an indicator of growth conditions of the studied populations that are closely linked to land use and conservation management.