Inland dune ecosystems are rich in terricolous lichen species. However, these communities are sensitive to human activities, both locally and globally. Since terricolous lichens have a dominant role in semi-arid sandy grasslands, it is important to explore the composition of their communities and the environmental factors affecting them. We studied the structure of the terricolous lichen assemblages of calcareous grassland in an inland duneland ecosystem by comparing the lichen communities of arid and humid dune sides on two sites with different disturbance histories. Microcoenological data were collected according to the Braun-Blanquet method. Environmental variables include the cover of bare soil, moss, litter, herb cover and height of herbs. We investigated the relationship of these variables and the presence and absence data of terricolous lichen species to sites and dune side. We found that the site had a significant effect on species richness that might reflect the different types and severity of previous disturbance events at the studied sites. On a smaller, ‘dune’ scale, in general lower herb cover and height and a higher moss cover were characteristic of arid dune sides. Most of the frequent species were negatively affected by higher moss cover. Some lichen species were more abundant (e.g. Cladonia furcata) or found only (e.g. Xanthoparmelia subdiffluens, Gyalolechia fulgens) on arid dune sides, while others preferred (e.g. C. pyxidata) or occurred only on (e.g. Peltigera species, C. rei) humid sides. It was observed that the impact of the dune side on several variables differed between sites. The diverse microhabitat types, microclimate and landscape structure, results in species-rich and valuable terricolous lichen communities forming in inland dune ecosystems.

Dry, oligotrophic ecosystems are highly threatened in Europe due to massive changes in land use and eutrophication. The conservation of these xeric habitats has received much attention, whereas the ecotones between xeric habitats and other habitat types are often disregarded. One species which mainly inhabits the transition zone between pine forests and adjacent xeric habitats is the heath grasshopper, Chorthippus vagans. This species is endangered in large parts of Europe. One of the largest populations in northern Germany is found on a degraded inland dune near Hanover. This population is threatened by dense growth of deciduous trees and litter accumulation. We analyzed changes in the distribution of this population after the implementation of conservation measures (thinning out the forest and removal of leaf litter). Moreover, we examined dispersal distances of the species in order to assess its colonization potential. We also studied the microhabitat preferences of C. vagans to assess key factors influencing its local distribution. Our data show a substantial growth in population size, which might be a consequence of the conservation measures. New patches on the dune were colonized, promoting dispersal between the subpopulations. We propose that restoration of forest-dune ecotones should be considered more often in landscape planning and conservation management.