Population dynamics of Cardamine amara L. (Brassicaceae): Evidence from the soil seed bank and aboveground populations

Abstract

KOCH, M., HUTHMANN, M. & BERNHARDT, K.-G.: Population dynamics of Cardamine amara L. (Brassicaceae): Evidence from the soil seed bank and aboveground populations. — Bot. Jahrb. Syst. 125: 405–429. 2004. — ISSN 0006-8152. In a recently presented paper we investigated the spatial distribution of genetic diversity in a strictly outcrossing cruciferous plant species, Cardamine amara, comparing surface population with subpopulations stored as seeds in the soil seed bank using isozyme analysis. Genetically, thirty-six populations from an area of approximately 900 square kilometres were investigated in a geographically well-defined region in Northwestern Germany. For ten out of these 36 populations, detailed soil seed bank analyses have been performed. Comparisons of soil seed bank composition and aboveground vegetation have been tested to serve as indicator of the environmental dynamics influencing floristic composition of the total habitat. Herein we are presenting the original and complete soil seed bank data of the different Cardamine amara habitats and comparing them to the actual vegetation cover. In total, we recovered 142 plant species (including 3 Equisetum species and Athyrium filix-femina from the pteridophytes), of which 78 were found also in the soil seed bank (including Athyrium filix-femina). These plant species have been characterized within seven groups depending on their occurrence in the soil seed bank and/or actual vegetation. Because particular attention has been paid on environmental dynamics, we fractionated the soil samples according to their depth (0–10 and 10–20 cm) and provided the according information about seed distribution. However, in four species only seeds occurred with a significantly higher frequency in the lower soil fraction than in the upper soil layer.