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Abstract: Butterfly decline in Northern Europe is a cause of concern and it has been hypothesised that this is due to nitrogen deposition inducing excess early growth of plants. It has also been changing the quality of the food available to larvae. We tested these hypotheses by linking butterfly biodiversity quality indices (species richness, population, biomass, conservation value, evenness (Simpson's Index) and modelled species richness (Chao 1 and 2)) with nitrogen Critical Load Exceedence (nCLE) data. An index of butterfly sensitivity to nitrogen was also created (Species Nitrogen Value Index (SNVI)). Using PCA, datasets were tested for associations and relationships. The results included multiple biodiversity quality indices based on 17 years of data (aggregated into three periods of six, six and five years to give 287 datasets) in four habitat types (grassland, heathland, woodland and farmland). With the exception of heathland the analysis showed that nitrogen deposition and all other indices (except SNVI) were in decline. For heathland the last 11 years did not show any significant decline. Heathland also showed an anomalous biodiversity quality profile for these last 11 years, suggesting that the sensitivity of heathland to nitrogen deposition will require further considerable efforts to achieve a nitrogen deposition that is not in exceedence of the critical load. Habitat restoration will take time due to the multiple hindrances to colonisation, which in the case of heathland might prevent successful butterfly colonisation for the foreseeable future. These results indicate the efficacy of butterfly biodiversity quality and nCLE as indicators for the SEBI 2020 process (Streamlining European Biodiversity Indicators) by showing the relationship between them. [Copyright &y& Elsevier]

Abstract: [1.] Recent political agreements mandate that the current rate of biodiversity loss is reduced by 2010 (the 2010 target). In Europe one of the 26 indicators given for this assessment is butterfly biodiversity which therefore requires butterfly biodiversity to be measured. advocates that this can be done using the concept of “Biodiversity Quality”. [2.] “Biodiversity Quality” measurement requires data analysis based on a series of indices examined both independently and jointly, rather than the use of a single measure such as species richness or a single composite index. We show that, where the theoretical base of sampling is sound, data collected with a simple analytical procedure in mind, can generate far more information than envisaged initially. An example of the compilation of “Biodiversity Quality” indicators is given for a site in the Dutch butterfly monitoring scheme (de Vlinderstichting) and two sites are compared for difference. [3.] A scheme showing how changes in the different indices might be interpreted to show change in biodiversity quality is given. [4.] These butterfly data are important from the perspective of the 2010 targets because: [(i)] they represent invertebrates, which comprise over half of all terrestrial species; [(ii)] they are based on relatively long time series; and [(iii)] they provide a model against which similar programmes can be designed for other taxonomic groups. [ABSTRACT FROM AUTHOR]