Enkele opmerkingen over de verarming van de duinflora bij Wijk aan Zee

The naturally large annual fluctuation in the number of flowering individuals of Anacamptis pyramidalis in the water catchment- and conservation area the „Noordhollands Duinreservaat” tends to obscure the alternative possibility that this species, which was formerly locally very abundant, is at present severely threatened by drought, and now is almost extinct. The author argues that this, as well as the depauperation of the whole dune flora, is caused directly and indirectly by the excessive withdrawal of the groundwater.