Natura 2000 sites. blue: Habitat Directive sites; red: Birds Directive sites. Source: http://natura2000.eea.europa.eu
Despite successful establishment of the Natura 2000 network, maintenance of these sites remains challenging. One important consideration is that management authorities have been established for only a limited number of sites, and thus not all sites of the network can be equally protected. Associated with that, prioritisation is not only an issue of management, but also of money allocation. Member states have actually established sub-networks within their national N2000 network that are under specific management protocols, making organisation and logistics even more complicated.
Another important issue is that mainly prominent species are monitored. However, data are scarce for smaller and less "charismatic" species and evidently outdated for some others. Hence, the coverage of the network for those groups is difficult to determine. Insufficient or outdated data is a huge problem that appeared during site selection as well as ongoing management and needs to be solved.
Case study: Recommendations for the improvement of species coverage and data update on Natura 2000 sites
Recent criticism of Europe's Natura 2000 network relates to the fact that these sites were not established based on a true "network" plan, but rather as a set of separate, often disconnected, sites. An important question is, therefore, to what degree these sites are interlinked. Namely, are movements between fragmented sites possible? This is of particular importance for low migrating species. Additionally, low migrating species are more often found on fragmented sites than on non-fragmented ones. Thus, additional to the structural connectivity of these fragmented sites of the network, it should be taken into account that species that are actually present and documented on them lead to different functional connectivity per species. Hence, designation of these sites is unsuitable for the conservation purposes they should serve
Case study: Connectivity inside fragmented sites of Natura 2000 in Poland
Apart from the status quo of species conservation, drivers that change species viability were disregarded during the design of the N2000 network. Even under the assumption that current networks of protected areas would adequately conserve natural habitats, climate change and associated land-use changes are anticipated to alter a range of habitat landscapes in the near future. As a consequence, neighboring sites (i.e. falling within the dispersal distance of a given species) that currently protect a sufficient area of suitable habitat to support viable populations of species might no longer contribute to overall network connectivity if climate change eliminates habitat from one or both sites, or landscape resistance between them inhibits movements. Likewise, new sites may facilitate connectivity in the future if land-use changes enable expanding into, or through, such favorable habitats. Previous studies have already shown that climate change and land use changes could significantly alter the effectiveness of conservation networks. These studies have attempted to quantify these sources of threat by providing evidence on the number of sites becoming unfavorable for species persistence. However, the efficiency of the Natura 2000 network to mitigate the detrimental effects of land use and climate change still remains an open research question.
Natural and semi-natural habitats outside protected sites can serve as important buffers supporting the populations of species and the movements among them - thus facilitating both connectivity and the overall viability of metapopulations and species in fragmented landscapes. However, interactions with agriculture are of high importance in times of agricultural intensification and land abandonment.
Case study: The Importance of Connectivity for Agri-Environment Schemes
In summary, while the initiation of a broad-scale ecological network was a big step forward, large potential for improvements exists regarding the design and management of the Natura 2000 network. This includes the harmonization of policies between member states and the intensification of monitoring schemes towards a systematic coverage of taxa (beyond charismatic species). Additionally, thorough long-term planning has to be conducted to adapt the network to future climate and land-use changes. In this regard, much more emphasis should be given to the spatial arrangement of reserve sites and especially to the non-protected area in between, which should be managed as an integrative part of the network.
