Effect van overstuiving op korstmosrijke duinen op Terschelling

De botanische verscheidenheid in kalkarme droge duinen wordt o.a. door korstmossen gevormd. Sinds de jaren 80 van de vorige eeuw zijn deze duinen in het Waddendistrict sterk veranderd door vergrassing met Helm en Zandzegge en vermossing met Grijs kronkelsteeltje. Kan overstuiving met vers zand deze uniformiteit doorbreken? Jarenlange monitoring van de vegetatie op Terschelling geeft hier het antwoord op

Effectgerichte maatregelen voor het herstel en beheer van stuifzanden

Onderzoek naar het functioneren van stuifzanden onder gewijzigde abiotische condities en naar beheer en herstel van klein- en grootschalige stuifzandlandschappen. Waarin bijdragen: Bosschap, Stichting Bargerveen, Radboud Universiteit, Universiteit Amsterdam, SOVON, Vlinderstichting, Alterra en Stichting Geomofologie en Landschap. Het is een vervolg op Preadvies stuifzanden (Bakker, 2003)

Branden als beheersmaatregel voor vermoste stuifzandvegetatie?

De stuifzanden worden de laatste decennia bedreigd door vermossin

Vegetation change in a lichen-rich inland drift sand area in the Netherlands

In this paper we compare the cryptogam vegetation in the Spergulo-Corynephoretum and Genisto-Callunetum in an inland drift-sand area in three periods (1968, 1993 and 2004). In the early period the lichen diversity in these plant communities appeared to be very high. The aspect was formed by Corynephorus canescens and Polytrichum piliferum. The highest numbers of lichen species are found in the S.-C. cladonietosum, irrespective of the period. In all years, variants of this subassociation are found, with many lichen species. In time pH decreases and organic matter, % total N and % total P increase by humus production. Cover sands having relatively high content of cations form a suitable substrate for lichens. Since the 1970s the neophytic moss Campylopus introflexus, a species adapted to acidic, nutrient-poor sand, has invaded the sand dunes. These changes have been attributed to the high aerial deposition of N in this central part of the Netherlands. In the more recent periods the actual lichen diversity did not really diminish, but the cover of lichen-rich plant communities was clearly reduced when encroaching mosses outgrew the lichens in all succession stages. However, when C. introflexus is less vital because of ageing, desiccation or burial under wind-blown sand, common humicole, aero-hygrophytic and even pioneer lichen species may locally establish on or between the moss cushions. The former succession series starting with P. piliferum and ending with lichen-rich Calluna heath (1968) has been partly replaced by one including C. introflexus (1993 and 2004). Process management is necessary to keep the sand blowing and hereby reduce the colonization by C. introflexus. Habitat restoration by small-scale management consisting of cutting down self-sown trees and removing the top soil has positively influenced lichen diversity and needs to be continued