Notes on Dutch Lichens

In Madroño (1936) Herre has lamented the disappearance of lichen species through the disastrous interference of man. Unavoidably, the advance of civilised modern life is linked with destruction of the vegetation. This applies all the more as the endangered area is more densely populated and it certainly applies most alarmingly to the lichen flora of the Netherlands. Here, every way-side tree felled is an irreparable loss to the epiphytic lichen communities, every acre of heath burnt or turned into arable land is a blow to our stock of terrestrial lichen species, whereas the use of dry fertilisers and the spraying of orchards are very effective in killing any lichen in the neighbourhood that otherwise might have survived. A comparison of the material preserved in the older collections with what can be found nowadays, clearly shows what has gone lost. It is sad to think that an ever increasing number of species are on their way to total extermination. However, from a thorough investigation of the epiphytic communities of cryptogams latterly started by Mr J. J. Barkman, it becomes apparent that at least to some extent the losses may be compensated by the discovery of species hitherto overlooked or not recognised. It is on such and other finds that I intend to report from time to time.