Temporary and permanent ponds: An assessment of the effects of drying out on the conservation value of aquatic macroinvertebrate communities

This study was designed to investigate whether temporary ponds were markedly different from more permanent ponds in terms of their species richness, species rarity and community type. Macroinvertebrates were recorded from six temporary ponds in Oxfordshire, and the resulting data were compared with species data from 33 Oxfordshire ponds of a more permanent character. Classification and ordination using TWINSPAN and DECORANA suggest that there were marked differences in the macroinvertebrate assemblages of temporary and permanent ponds. Overall, temporary ponds had similar rarity indices to permanent ponds. However, four of the five highest rarity index values were from temporary or semi-permanent sites. The number of aquatic species was significantly lower in the temporary ponds.