Respiratory processes and growth rates of alpine and lowland species of three genera (Ranunculus, Plantago and Luzula) were compared. Relative growth rates were determined for the first 14 weeks of growth at two temperatures (7-10°C and 12-15°C). Generally, the relative growth rates of the alpine species were lower than those of their lowland relatives. Whole-plant respiration rates were measured and leaf slices from each species were used for a detailed analysis of respiratory pathways. Major differences were found between genera, particularly in their alternative oxidase activity, but respiratory patterns (both whole-plant respiration rates and the relative rates of cytochrome and alternative pathways in leaf slices) were maintained within a given genus, independent of the environmental or geographical origin of each species from that genus. The lack of correlation between growth rates and respiration rates suggests that the alpine plants used their respiratory products less efficiently than did the lowland species.

We studied soil and vegetation patterns of two late snow areas in the Kosciusko alpine region of New South Wales, Australia. Marked floristic differences were found between the lower, central and upper regions of each area. The distributions of six selected species, and the spatial variation in total vegetation cover, were related to the spatial variation in total and exchangeable soil nitrogen concentrations. To test whether variations in soil nitrogen were controlling the spatial separation of late snow area plant species six selected species were subsequently grown at 12-15°C, over a range of increasing nitrogen concentrations. Five of the six selected species (Luzula oldfieldii subsp. dura, Epilobium tasmanicum, Plantago glacialis, Luzula acutifolia subsp. nana and Ranunculus niphophilus) showed similar responses to increasing nitrogen levels, both in terms of relative dry weight production and shoot nitrogen concentrations. Only in one species (Colobanthus nivicola) did responses suggest that it may have been more suited to growth on nitrogen-deficient soils. We concluded, however, that variations in nitrogen availability alone are not responsible for the floristic variation in late snow areas. Possible factors responsible for the variation in floristic composition of the late snow areas are discussed.