Logo EUCC
Deutsch English

Kuijper, D.P.J., Bakker, J.P.: Large-scale effects of a small herbivore on salt-marsh vegetation succession – A comparative study on three Wadden Sea islands. Journal of Coastal Conservation, 9: 179-188, 2003.

Zusammenfassung:

Abstract. Grazing by livestock is used as a management tool to prevent the dominance of a single tall-growing species during succession on European salt marshes. The effects of natural small herbivores are often neglected by managers. Long-term exclosure experiments on the island of Schiermonnikoog show that hares retard vegetation succession at the early stages of salt-marsh development. In the present study we test whether we can scale-up these exclosure studies to a whole salt-marsh system. We compared 30 years of undisturbed vegetation succession at the Wadden Sea islands of Schiermonnikoog, Rottumerplaat (both The Netherlands) and Mellum (Germany). Salt-marsh development started at all sites in the early 1970s. Hares have been present only on Schiermonnikoog. At each site an area was selected covering a gradient from high to low salt marsh. Surface elevation and clay thickness were measured and a vegetation map was made on the three islands. The areas showed similar clay thickness at low surface elevation, indicating similar sedimentation rates and hence nitrogen inputs. Rottumerplaat and Mellum showed a higher dominance of the late successional species Atriplex portulacoides in the low marsh and Elymus athericus in the high marsh compared to Schiermonnikoog. Typical mid-successional, important food plant species for hares and geese had a higher abundance at Schiermonnikoog. Patterns of vegetation development in the absence of hares followed the observed patterns in the smallscale exclosure experiments at Schiermonnikoog. Without hare grazing, vegetation succession proceeds more rapidly and leads to the dominance of tall-growing species in earlier stages of succession. The present study shows that next to large herbivores, small herbivores potentially have largescale effects on salt-marsh vegetation succession during the early successional stages.

PDF: C9.179-188.pdf (545.111 Bytes)
(Seite in 0,00 Sekunden erzeugt.)