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No. 297: Biodiversity indicators for an effect-based nature supplementation scheme

Fløjgaard, C., Nielsen, S.S., Nygaard, B. & Ejrnæs, R. 2018. Biodiversitetsindikatorer til en effektbaseret naturtilskudsordning. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 68 s. - Videnskabelig rapport nr. 297.  http://dce2.au.dk/pub/SR297.pdf

Summary

This report was commissioned to DCE – Danish Centre of Environment, Aarhus University, by the Danish Agricultural Agency and identifies different potential indicators of biodiversity to be tested in a pilot project and possibly subsequently implemented in a result-based agro-environmental programme. Our basis was the characteristics of habitat types with favourable conservation status and with high biodiversity. We considered the natural processes creating resources and niches for biodiversity and contemplated biodiversity in an ecosystem context with emphasis on the importance of large connected nature areas. The indicators include indicator plant species, red listed species, niches, natural processes, management history, size and heterogeneity of the area under consideration as well as indicators of negative impacts of eutrophication and draining. Among the indicators are a number of well-known characteristics from an existing system for evaluating conservation status, such as bare soil, exposed rock, ant hills etc. We have supplemented these with new indicators, such as dung, bites on woody vegetation and bark stripping, with focus on grazing as a natural process creating niches for biodiversity. We developed a set of indicator plants suggesting favourable conservation status. Based on data from the Nationwide Monitoring and Assessment Programme for the Aquatic and Terrestrial Environments (NOVANA) and other plant inventories of nature areas (§3), we analysed the plant species frequency in bogs, meadows, grasslands, heathlands and salt meadows based on the plant species in 5 m circles. We selected indicator species that are relatively common in nature areas in a good state. We evaluated the set of indicator plants and found that the number of indicator plants correlated positively with both total number of plants and with “artsscore” (~species score), an indicator of conservation value. The relationship becomes more pronounced, the higher number of indicator species recorded. We recommend a combination of indicators so as to encompass species, conservation status and effects of grazing. The exact selection and combination of indicators will be decided in an upcoming process led by The Danish Agricultural Agency and will involve stakeholders and DCE, Aarhus University. Technical reports and guidelines for registration of indicators are not included in this report.