The Structure of Some Upland Plant Communities in Caernarvonshire: II. The Pattern Shown by Vaccinium Myrtillus and Calluna Vulgaris

Abstract

A description is given of the pattern of these two species in several communities, and evidence is presented which indicates the importance of soil aeration as a factor controlling the distribution and performance of Vaccinium myrtillus. Further evidence relates the present heterogeneity in soil aeration to agricultural management 150 years ago. A field experiment designed to test the relation between treading and grazing on the yield and stem/leaf ratio in Vaccinium myrtillus is described. The need for knowledge of ''normal'' morphological pattern as a guide to species performance under different ecological conditions is emphasised.