Aspects of the Ecological Amplitude of Two Woodland Herbs, Oxalis Acetosella L. and Galeobdolon Luteum Huds

Abstract

Ecological amplitudes of plant species can be compared using polythetic divisive methods, which frequently produce stand groupings possessing characteristic differences in soil pH and species density. In a comparison of the ecological amplitude of O. acetosella and G. luteum, records of floristic composition and of several environmental factors relating to the Wyre Forest, to Coal Measure woodlands near Sheffield and to scree and grassland on the Carboniferous limestone near Sheffield [England] were analyzed. The 1st axis of the species ordination of the Seckley Ravine, Wyre Forest, is a strong floristic one with G. luteum close to the damp deciduous woodland end and O. acetosella further towards the heathland end. A similar distribution was obtained for stands from a number of other Coal Measure woodlands from the Sheffield area. In both these instances the greater ecological amplitude of Oxalis was shown by plotting symbols indicating the presence of one, both or neither of these species in each quadrat on the stand ordination. Boundaries of the main groups obtained by indicator species analysis were plotted on the stand ordinations. In both, all quadrats containing Galeobdolon passes to Group O (containing species of damp deciduous woodland) at the 1st dichotomy; Oxalis was present in Group 1 (containing plants with heathland affinities) also. Reciprocal averaging applied to 70 quadrats from Carboniferous Limestone scree and grassland yielded stand and species ordinations in which a strong floristic 1st axis is correlated with succession. Oxalis occurs quite early in the succession, but is confined to N-facing slopes.