Biogeographical classification of some plant-parasitic nematode species groups in Spain

Abstract

Distribution data for the Criconematid and Longidorid nematofauna in Spain were analysed to identify both species groups with similar distribution patterns and areas typified by a distinct fauna. Nematode presence/absence data in 100 km squares of the Universal Transverse Mercator (UTM) grid were usefully grouped into areas by Information Analysis whilst the faunistic elements were best differentiated by Cluster analysis of the mean co-ordinate position of all records for each species within 10 km UTM squares. Eight main faunistic groups were distinguished: north-eastern, north-western, southern, south-eastern and four central groups; and five areal groupings which were related to altitude within Spain. The varying frequency of nematodes from the different faunistic groups within areal groupings was used to define four distinct distribution patterns in which (i) northern species were predominant, (ii) southern species were predominant, (iii) mediterranean and central-European species were predominant and (iv) areas of high faunistic diversity, characterised by a wide range of environmental factors.