County Wildife Site Criteria for Cornwall Appendices

LOCAL FLOODPLAIN GRASSLANDS: CommentsData SourcesPhase 1County Wildlife Site (CWS)surveysNational Trust (NT) surveysVarious NVC surveysCommentPhase 1 maps were produced in 1983 and the results aresomewhat inconsistent, but their accuracy is sufficient to accorda grassland to this LHT with low probability.The CWS surveys mainly date from 1980-1987. They givesome additional useful information relating to this PHT.The NT and other NVC surveys often produce useful insightsinto small areas, particularly on the coast.The DefinitionGoodReliability of PHTInterpretationAverageCommentAny NVC surveys produce clear and unequivocal results andPhase 1 surveys too should produce sufficient information,especially if accompanied by target notes.ExplanationThere are two methods that may be reliably used to identifythis LHT: Phase 1 habitat maps and NVC communities. ThePhase 1 results are somewhat inconsistent, but their accuracy isusually sufficient to accord a grassland to this PHT with lowprobability. Unfortunately, the age of the Phase 1 maps and thefact that they are of uncertain accuracy (there is no way ofseparating MG1 from MG5 for example), eventually led us toabandon the use of Phase 1 maps by themselves.Where we did have access to NVC data then there was noproblem. However, there are relatively few grasslands thathave been assigned to an NVC community and it is extremelytime consuming to try to derive one from what are usuallylimited species lists.Overall AssessmentPoorThe CWS surveys did have useful information because dryherb-rich neutral grasslands usually only are MG5 in this county,so there is little doubt over their identity. Nevertheless, theage of this source made it rather irrelevant.CommentsWe believe that there are a relatively large number ofmesotrophic grasslands grasslands in the county that have eithernot been surveyed, or where the results are not publiclyavailable. Some of them may be above the minimum mappableunit (MMU).We have insufficient information to map this PHT. Three areashave long been known and they have been mapped, but thereare certainly more. At least 22 ha of MG5 grasslands on theCaradon coast have not been mapped and there areunquestionably other coastal areas in the county which alsohold MG5 grasslands. We do not know the number and extentof those additional sites and considerable fieldwork would beneeded to complete the inventory.Appendix 5 - Information Relating to Local Habitat Types.County Wildlife Sites Criteria