County Wildife Site Criteria for Cornwall Appendices

LOWLAND DRY ACID GRASSLAND: CommentsData SourcesPhase 1County Wildlife Site (CWS)surveysThe DefinitionPoor-GoodReliability of PHTInterpretationGoodOverall AssessmentPoorCommentThere is insufficient detail contained within these sources.CommentThe definition of Lowland Dry Acid Grassland (LDAG) is clearlydefined by both NVC communities and in the introductorygeneral description. Accordingly, given detailed surveyinformation, there should be little problem in identifying thoseareas which qualified. However, we believe that the definition isinadequate, for while it is precise, it is clearly biased againstselection of the habitat. Moreover, it is incompatible with theLowland Heathland definition, a habitat with which LDAG formsmosaics.ExplanationWe believe that nearly all the areas where the NVCcommunities U1-4 and U20a are found in Cornwall are abovethe level of functional enclosure. Accordingly, there are only arelatively few small areas that may qualify and the majority ofthose will be found as mosaics of LDAG and Lowland Heathland(LH).However, there is a problem in those areas where the LH formsa mosaic with LDAG. We have not been able to clearlydistinguish those areas from the information that we hold and sothis PHT probably contains some areas that might be bestrepresented as the LDAG PHT rather than as a heathland.Nevertheless, the best approach would probably be to includesuch areas as both LH and as LDAG.CommentsThe distribution of LDAG in Cornwall is not well-known andthere are difficulties of interpretation in some areas, which aredescribed above. We believe that there are some areas ofLDAG in Cornwall, but at present they fall within some areasmapped as LH. We have not been able to distinguish them in areliable way.Appendix 4 - Information Relating to Priority Habitat TypesCounty Wildlife Sites Criteria