Growth of the alpine herb Rumex alpinus over two decades: effect of climate fluctuations and local conditions

Abstract

Plants in arctic and alpine habitats could potentially escape the effects of climatic fluctuations by surviving in suitable microsites. We tested this hypothesis by conducting a herb-chronological analysis of the morphological growth markers retained on the rhizomes of the clonal herb Rumex alpinus—a common plant with a broad ecological amplitude found in the alpine zone of the Low Tatra Mts., Western Carpathians, Slovakia. We asked whether aspects of plant growth were related to the climatic conditions measured at a local weather station over two approximately decade-long study periods (1977–1988 and 2001–2010) on both snowbed and non-snowbed sites. Although the latter period had average summer temperatures that were about 2 °C warmer than the first, both had the same average growing season length and average total monthly precipitation. Snow accumulation and other climatic events shortened the growing seasons for the plants in the first period, thus reducing vegetative growth. On the other hand, climatic events prolonging the growing seasons supported plant growth and flowering in the snowbed site. In the second, warmer period, growing season lengths were not related to plant performance but August temperatures had a positive effect on plant growth in both the snowbed and non-snowbed sites. Our results imply that mesoclimatic factors substantially affect plant growth, although their relative importance might change with climate fluctuations altering their influence in sites of differing snow accumulation.