Pollen-vegetation relationships in non-arboreal moorland taxa

Pollen assemblages from moss polsters from northwest Scotland are compared with the vegetation composition around the sampling points. Presence-absence data are used to calculate association, over- and under-representation indices for the relationship between plants and the pollen assemblages, and results are found to be broadly comparable with published results from Norway. Relevant pollen source areas for individual taxa are estimated using least-squares linear regression analysis of pollen percentage against distance-weighted plant abundance. The extended R-value model is applied to estimate the relevant pollen source area for the pollen assemblages. The results indicate relevant pollen source areas on the order of 2 m or less for Calluna vulgaris, Vaccinium type, Myrica gale, Cyperaceae, Poaceae, Potentilla type and Succisa pratensis. Changes in non-arboreal components of pollen assemblages from mire communities therefore appear to reflect predominantly local patch dynamics rather than wider landscape changes. (C) 2003 Elsevier Science B.V. All rights reserved.