Past and future of the EU-habitat directive species Liparis loeselii in relation to landscape and habitat dynamics in SW-Texel, the Netherlands.
Dune slacks are important habitats, with many endangered plant species. A series of eleven dune slacks of 1-42years old was studied in SW-Texel, the Netherlands, with the EU-habitat directive species Liparis loeselii present in all except the youngest and oldest. Analysis of aerial photographs revealed that new slacks are currently formed every 4-5years. In each slack, topsoil and vegetation data were collected in 2010 and 2014-2015. During succession, vegetation changed from brackish pioneer stages to dune slacks with L. loeselii and Parnassia palustris and ultimately grassland species. Differences between dune slacks and sampling periods were mostly significant. Herb cover and soil C increased with slack age, and over the five year study period, while bare sand, bulk density and pH decreased. The annual pH-decrease was 0.055 and 0.075 for pH-H2O and pH-KCl respectively, and annual C-increase 0.16% and 35gm(-2). Liparis loeselii was only present between pHH2O 5.8-7.5 and pHKCl 5.6-7.6, and only occurred at C-content below 4.3%. In lime-poor dunes, environmental conditions thus become unsuitable approximately 34years after the start of succession. In the dune slacks, Liparis loeselii established within 6years, showed peak values after 11-16years, and declined until conditions became unsuitable. Rejuvenation may occur after large storms with fresh sand deposits. However, even with further succession, the present populations are not endangered and probably last until 2040. With new dune slacks every 5years, L. loeselii occurs in approximately eight different dune slacks at the same time, ensuring viable populations also in the future. This shows that adverse effects of succession can be counteracted by dynamics on local and landscape scale.
Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park, PO box 94062, 1090 GB Amsterdam, The Netherlands. Electronic address: a.m.kooijman@uva.nl.
A M
AM
Kooijman
State Forestry Service Texel, The Netherlands.
C J W
CJW
Bruin
Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park, PO box 94062, 1090 GB Amsterdam, The Netherlands.
A
A
van de Craats
Centre for Energy and Environmental Studies (IVEM), University of Groningen, The Netherlands, 9747 AG Groningen, The Netherlands; Institute for Wetland and Water research, Radboud University of Nijmegen, The Netherlands.
A P
AP
Grootjans
Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park, PO box 94062, 1090 GB Amsterdam, The Netherlands.
J G B
JGB
Oostermeijer
Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park, PO box 94062, 1090 GB Amsterdam, The Netherlands.
R
R
Scholten
Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park, PO box 94062, 1090 GB Amsterdam, The Netherlands; Centre for Energy and Environmental Studies (IVEM), University of Groningen, The Netherlands, 9747 AG Groningen, The Netherlands; School of Marine and Environmental Sciences, University of Terengganu, Malaysia.
R
R
Sharudin
D003247:Conservation of Natural Resources; D017753:Ecosystem; D009426:Netherlands; D029595:Orchidaceae / Q000502:physiology*; D063148:Plant Dispersal
Carbon; Natural dynamics; Nature conservation; Orchid; pH