Small-scale vegetation pattern related to the growth of Lycopodium annotinum and variations in its micro-environment

Small-scale variations in topography, soil depth and species occurrence were studied in a sub-arctic/sub-alpine brich forest in Swedish Lapland in order to evaluate the effects of various micro-habitats on the growth and distribution of Lycopodium annotinum. Micro-topographical variation in the study plot (280 by 420 cm) reached 100 cm, while soil depth varied from 0 to more than 50 cm over small distances of 10's of centimetres. Nineteen species were recorded in the plot and dwarf shrubs and L. annotinum were the most frequent. A micro-scale vegetation pattern was detected by a polythetic agglomerative cluster analysis and also by the divisive TWINSPAN analysis. The distribution patterns of the species appeared to be associated with variation in moisture regimes, which in turn were associated with variations in micro-topography. Lycopodium annotinum performed best when growing on the sides of valleys with deciduous dwarf shrubs and Deschampsia flexuosa, and when evergreen dwarf shrubs were absent.