The effects of aerial microclimate and edaphic conditions on the growth of young vegetative tillers of Phleum alpinum L. from contrasting habitats on South Georgia have been investigated using growth analysis concepts. Relative growth rate (Rw) was found to be negatively correlated with habitat severity, there being a strong relationship between Rw and the amount of lateral production per tiller. Unit leaf rate (EA) was depressed at the highest altitude. Specific leaf area increased with habitat favourability but no simple relationship was apparent between leaf area ratio (FA) and site conditions. Native soils were shown to be severely limiting, although there was considerable variation in edaphic conditions between the various sites.
There was striking uniformity in Rw values between plants from different populations when grown under similar conditions, this stabilization effect being produced by compensatory mechanisms involving the contributory growth parameters, EA and FA the specific leaf areas of the different populations when grown at one site were also very similar.