This 1 November 2016 Dutch video from Gelderland province ia about Thijs van Trigt who tries to save rare lichens on the dike south of the lake separating Gelderland province from Flevoland province.
Translated from Dutch Vroege Vogels radio, 4 January 2019:
It is quite a job that Thijs van Trigt has started: cleaning a piece of dike between Nijkerk and Putten. And all to preserve the rare lichens that grow on the stones.
The lichens are now overgrown by plants and mosses. And that while some types of lichens only occur in Nijkerk, such as Xanthoparmelia protomatrae and Brianaria lutulata, Pertusaria lactea, Anaptychia runcinata and Pertusaria aspergilla are also extremely rare and have been found on the dikes near Nijkerk.
Thijs van Trigt has been visiting Nijkerk regularly since the discovery of the lichens on the dike in 2015 to clean a piece of dike. But getting rid of the vegetation is a big job. The cleaning action must actually have a periodical character if the effect is to be permanent.
It is therefore the wish of Thijs van Trigt to design parts of the dike as a lichen reserve, with a permanent information sign with explanations for the interested passers-by. By making a reservation, Thijs van Trigt hopes for a better protection of the lichens.