The relationship between Calluna vulgaris seedbank density and climate was investigated using regression analysis and two related techniques (factor-ceiling analysis). The seedbank data originated from published and unpublished studies. Low seedbank densities were associated with sites in the relatively dry, sunny and warm south and east of Great Britain. However, as the climatic variables used in the study were highly intercorrelated, it was not possible to determine which climatic variable had the greatest influence on seedbank density. A hypothesis is described suggesting that the limits of seedbank density can be described for single environmental factors. The operation of other environmental and management factors may reduce the seedbank density to less than this maximum. This is illustrated for a range of climatic variables using factor-ceiling analysis. The processes following seed deposition and the longevity of seeds in the soil are highlighted as possible factors controlled by climate which determine seedbank density.
