Laurens Sparrius
André Aptroot
Objectives
In the Netherlands, a country devoid of natural rock outcrops,
many saxicolous and terricolous lichens are endangered. Unlike epiphytical lichens, no extensive monitoring research has been
done on these groups.
As a part of the Network Ecological Monitoring (NEM), a project
financed by the Dutch government, the Dutch Bryological and
Lichenological Society (BLWG) set up a long-term monitoring
project for the non-epiphytical, red listed lichens.
The habitats with saxicolous species include megalithic monuments,
sea dykes and semi natural calcareous rock outcrops. Church walls
are being monitored as well, but have not been included in the
project, because of the many different, non-governmental
proprietors.
Methods
For this monitoring project we use permanent plots, which will be
revisited every five years. For each type of habitat, a different
plot size is used, up to 14,000 m2. Vegetation and substrates in
the plots are often heterogeneous. The abundance scale is the same for all habitats.
For several of the rarest red listed species, all known
populations are being monitored. For inland dunes, a random
selection of hot spots was made, using a database with known
localities of red listed species occurring in this type of
habitat.
The project started in 1999 and is carried out by trained
lichenologists, often during regular excursions of the BLWG.
Statistics Netherlands (CBS) processes the monitoring data, using
it for determining the 'state of nature' together with data from
other species monitoring projects.
Read more about specific habitats
Megalithic
monuments
Sea
dykes
Inland
dunes
Semi natural
limestone outcrops
Zinc-polluted
soil
Medieval
church walls
* This text was presented as a poster at the LIMON Nato Advanced Research Workshop, Pembroke, Wales, August 2000, organised by the British Lichen Society.