Habitats in good conservation status support European biodiversity and ecosystem services

In the European Union (EU) efforts to conserve biodiversity have been consistently directed towards the protection of habitats and species through the designation of protected areas under the Habitats Directive. Stepping up the efforts to achieve favourable conservation status of threatened habitats and species by completing the Natura 2000 network and by ensuring good management practises in the included protected areas is the first and foremost target of the new EU Biodiversity Strategy to 2020. The second target of the Strategy uses the argument of ecosystem services to maintain and restore ecosystems through the deployment of a green infrastructure. It is argued that failure to incorporate the values of ecosystem services and biodiversity into economic decision-making has resulted in investments and activities that degrade natural capital.

The concept of ecosystem services is said to have great potential in adding value to current conservation approaches, in particular for local and regional planning; however, this potential remains poorly explored across Europe. Our study reports on a spatial assessment of the relationships between biodiversity, ecosystem services, and conservation status of protected habitats at European scale. The hypothesis is that habitats in a favourable conservation status provide higher levels across multiple ecosystem services and host a richer biodiversity than habitats in unfavourable conservation status. Using spatial datasets of habitat conservation status, ecosystem service supply, and biodiversity covering the EU, we present two lines of evidence that support this hypothesis.

Firstly, we assessed the spatial concordance between multiple ecosystem services and biodiversity across Europe. We mapped spatially explicit indicators for biodiversity (Mean Species Abundance, forest tree species diversity and the relative area of Natura 2000 sites) and ecosystem services (four provisioning services, five regulating services and one cultural service) at EU scale (Figure 1). Indicators for biodiversity and aggregated ecosystem service supply were positively related but this relationship was influenced by the spatial trade-offs among ecosystem services, in particular between crop production and regulating ecosystem services. The trade-offs among ecosystem services resulted in weak or non-linear relationships between biodiversity and aggregated ecosystem service supply. Our analysis showed that the provision of forest ecosystem services increased with biodiversity while the share of land under crop production is characterized by decreasing biodiversity. The analysis also showed that some services are provided at constant rates, irrespective of the value of biodiversity as estimated by the indicators of this study. The result was an overall increasing, albeit asymptotic, relationship between aggregated ecosystem service supply and biodiversity.

Figure 1. Biodiversity and ecosystem services maps. Top left: Aggregated ecosystem service supply (TESV) calculated as the sum of standardized values of 10 ecosystem service indicators. Top right: Mean Species Abundance. Bottom left: The proportion of protected areas which are part of the Natura 2000 network. Bottom right: The forest tree species diversity measured using the average Shannon Wiener Diversity Index calculated from a 1 km resolution grid. This figure is modified from Maes et al. (2012).

Secondly, we analysed the relationship between habitat conservation status, ecosystem services, and biodiversity. The data on the conservation status of habitats were taken from an EU wide habitat assessment. The legal basis for this assessment is Article 17 of the Habitats Directive which requires that Member States evaluate every six years the conservation status of habitats and species that are listed in the annexes of the directive. Habitat status was not assessed at local scale but across an entire bio-geographical region within each Member State. The assessment assigned favourable, unfavourable-inadequate or unfavourable-bad conservation status to 216 different habitats across 25 Member States. We demonstrated that habitats in a favourable conservation status provided more biodiversity and had a higher potential to supply, in particular, regulating and cultural ecosystem services than habitats in an unfavourable conservation status (Figure 2).

Figure 2. Probability of habitat conservation status (favourable status, unfavourable-inadequate status, unfavourable-bad status) as a function of biodiversity proxies and aggregated (or total) ecosystem service supply (TESV). This figure is modified from Maes et al. (2012).

Bridging the gap between different approaches of nature conservation and adaptive management of ecosystems to enhance their service provision is key to new global and regional biodiversity policies. Both the Strategic Plan 2011-2010 of the Convention of Biological Diversity as well as the EU Biodiversity Strategy to 2020 bring together targets for nature conservation, ecosystem restoration, and increased socio-economic benefits derived from biodiversity. Ecosystem services, although appealing to decision makers, are not yet anchored in environmental legislation. The conclusions of our work suggest that actions which target the restoration of ecosystems, and the maintenance of the services they provide, are likely to have positive effects on habitat and species conservation status. This information is of utmost importance in identifying regions in which measures are likely to result in cost-effective progress towards both target 1 (nature conservation) and target 2 (restoring ecosystems and maintaining ecosystem services) of the Biodiversity Strategy.

Reference:

Maes J, Paracchini ML, Zulian G, Dunbar MB, Alkemade R (2012) Synergies and trade-offs between ecosystem service supply, biodiversity, and habitat conservation status in Europe. Biological Conservation 155, 1-12.

Joachim Maes, Maria Luisa Paracchini, Grazia Zulian, Martha Bonnet Dunbar - Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, 21027 Ispra (VA), Italy

Rob Alkemade - PBL Netherlands Environmental Assessment Agency, P.O. Box 303, 3720 AH Bilthoven, The Netherlands and Environmental Systems Analysis Group, Wageningen University, P.O. Box 47, 6700AA Wageningen, The Netherlands

E-mail address (JM): joachim.maes@jrc.ec.europa.eu