A preliminary study of biodiversity hotspots for odonates in Galicia, NW Spain

Abstract

The analysis of distribution data of odon. in NW Spain indicates the presence of 49 spp. Macromia splendens, Oxygastra curtisii, Gomphus graslini and Coenagrion mercuriale are protected under the European Habitats Directive and Spanish Law. Localities of specimens collected between 1978 and 2004 were situated in UTM squares of 10 × 10 km to produce a map of species richness for the region. Additionally, all localities (UTM 1 × 1 km) where protected and rare spp. were found are introduced in a GIS system, on a map of the Natura 2000 network of the region. The results indicate that O. curtisii and C. mercuriale are common in NW Spain. As local rare taxa are identified Brachytron pratense, Aeshna affinis and Erythromma viridulum, because they were found in less than 10 squares, and are also relatively rare in the Iberian peninsula. As areas of special interest are selected those that include all known populations of M. splendens, G. graslini, and B. pratense, all localities with at least 2 of the 4 protected spp., and areas with more than 20 spp. This gives a list of 24 hotspots, most of them (15) at least partially included in the Natura 2000 network. Unfortunately the analysis also reveals that the knowledge of this group is clearly fragmentary, with most records concentrated on the coastal region, and very few squares sampled more than 20 times, the minimum to obtain reliable data. Therefore a systematic sampling of the region is needed to properly identify areas with high species richness.