Primary succession on re-created coastal wetland leads to successful restoration of coastal halophyte vegetation

Abstract

Understanding the causes of patterns in plant distribution is especially important when we want to create new terrain for vegetation development for conservation purposes. In Škocjan Inlet Nature Reserve it was carefully planned for new mudflats and islets to be created along a microaltitudinal gradient, aiming to achieve the spontaneous development of at least three target habitat types (mudflats not covered by seawater at low tide, Mediterranean glasswort swards and Mediterranean saltmarsh scrubs, including the transitional forms between them) through the primary succession pathways. Thus, this study was actually projected as a field experiment, on the one hand, and as a practical conservation measure, to recover a degraded area, on another. Vegetation cover on the newly constructed mudflats changed by 92% over 6 years of succession. In general, un-vegetated mudflats decreased from 71% to 26%. In contrast to this, Mediterranean glasswort swards increased from 6.5% to 28.2%, whereas saltmarsh scrub had the longest positive trend, constantly gaining area from 2008 (0.6%) to 2012 (28.9%). Detailed mapping showed rather deterministic successional pathways, which make restoration plans for halophyte communities more predictable. The study shows that this “ecological experiment” might have concrete implications for the restoration or re-creation of halophyte plant communities along sedimentary seacoasts—in general, all priority habitats in the European Union. The approach of creating artificial terrain within coastal protected areas is especially important in the light of the climate change-driven rise in sea level, often in conjunction with the “coastal squeeze” phenomenon.