EU Level 1
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Poland 1
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The goal of our study was to analyse small scale structural connectivity of the Polish Natura 2000 network based on a species traits database.
We have concentrated our analysis on fragmented sites (156 sites) of the network (Fig. 1). Next we identified, based on available Standard Data Format (SDF) data, the low-migrating species present on these sites. We used the available information from the trait database or, when information was lacking, we have estimated it using available literature for other closely related species. Minimum distance between all fragments of given multi-fragmented sites was measured for each site based on the available Google Earth maps attached to SDF data. This method allowed us to characterize each site using one distance, and then compare this distance to the maximal dispersal distances of the species present on these sites. This coarse comparison allowed us to describe the structural connectivity of fragmented sites of the network taking into account species that are actually present and documented on them.
The Polish Natura 2000 network, though it was created according to the principal of "...design(ing) large-area Natura 2000 sites, while limiting their number as much as possible", actually consists of 17% of sites which are fragmented, though described as one in the SDFs. Our analysis showed that the chosen low-migrating species present on these sites may lack connectivity between fragments (Fig. 2.). Additionally, low migrating species are more often found on fragmented sites than on non-fragmented ones. We are aware that our results show only a coarse structural connectivity of these sites and do not describe the real functional linkage. In spite of these shortcomings, our conclusion is that the designation of these sites is unsuitable for the conservation purposes they should serve. Steps should be taken to increase connectivity and/or correct monitoring plans to take into account fragmentation inside sites.
Figure 1. Google Earth projection of a fragmented Polish Natura 2000 site PLH120082 "Łąki Koło Kasiny Wielkiej"
Figure 2. Fragmented Natura 2000 sites in Poland with possible linkage or isolation for a chosen species present in these sites. Numbers on the columns show the percentage of fragmented sites not allowing dispersal between fragments.
