Studies in the Vegetational History of S. W. Spain. I. Modern Pollen Rain in the Donana National Park, Huelva

Abstract

Modern pollen analyses have been conducted in the Doniana National Park, Huelva, S.W. Spain. The main vegetation types are described and pollen diagrams of their respective pollen spectra presented. Data analysis, involving classification and ordination procedures, has thrown some interesting features of the data to light. The results demonstrate that: (i) Some of the major forest and shrub communities can be distinguished on the basis of their associated pollen rain: e.g. Erica scoparia shrub, Olea forest, Quercus forest,Juniperus forest. (ii) Variable pollen representation of the dominant canopy-forming taxa was found to be extremely common in Fraxinus and Pistacia forests and to a limited extent Juniperus forests. (iii) Dioecy in Pistacia is thought to be the cause of the very variable represen- tation found throughout the analysis. (iv) Pine plantations from inland locations cannot, on the whole, be distin- guished from the natural populations of the dune slacks. (v) The importance of an open vegetation structure in allowing increased levels of non-local pollen to enter the local pollen spectrum is illustrated. This