6a, g). Bryophytes (mainly mosses) dominate at the Gössenheim, Öland and Tabernas sites, with Gössenheim having the highest moss coverage of more than 40 % (Fig. 3a). At these three

sites, cyanolichen coverage is well below 5 % and the amount of the bare soil fraction is highest at the Swedish Öland site, followed XMU-MP-1 by the Tabernas site (Fig. 6a). Fig. 3 a Coverage of the different crust types and other vegetation at all sites; b chlorophyll content (a and a + b; lines in bars show standard deviation) at all sites C59 wnt manufacturer Biological soil crust chlorophyll a and chlorophyll a + b content reached values around 200 mg chlorophyll a + b per m2 at

all sites with slightly higher values at the human influenced sites Öland and Gössenheim (Fig. 3b). This places the four SCIN-BSC sites at the lower end of the soil crust chlorophyll a + b content scale, ranging from 980 mg/m2 in the local steppe formation near Würzburg, Germany to 500 mg/m2 in the Namib Desert, Namibia and down to 380 mg/m2 in Utah, USA (Lange 2003). However, the SCIN-BSC values are comparable to those of the BSCs found along the BIOTA-South transect in South Africa and Namibia (Büdel et al. 2009). Soil properties and structure Soil types at the Öland site are skeletal and Rendzic Leptosols with a depth of less than 20 cm and Ai, (B), BC, and C horizons. The bedrock is find more an Ordovician limestone with “alvarmo layers” (cromic, relic?). Soil pH is 7.35 ± 0.05 (n = 40), while the pH of the BSC

is 7.3 ± 0.06 (n = 40). At the Gössenheim site, soil types are skeletal, Rendzic Leptosols with a depth of less than 10 cm and AC and C horizons. The bedrock is a Triassic shell limestone (Muschelkalk) with characteristic top soil removal. Soil pH is 7.37 ± 0.06 (n = 40), while the pH of the BSC is 7.33 ± 0.07 (n = 40). Soil types at the Hochtor site are calcareous Regosols and Rendzic Leptosols with a depth of 15–30 (>50) cm and A1, A2, C1, and C2 horizons, with a buried iron-humus layer. The bedrock is Triassic Seidlwinkl and Rauwacke. Soil pH is 7.43 ± 0.09 (n = 40), while Pyruvate dehydrogenase the pH of the BSC is 7.34 ± 0.05 (n = 40). Soil types at the Tabernas site are Haplic Calcisols with a depth of less than 100 cm and A, AC, Ck1, Ck2, and C3 horizons, originating from Miocene sediments (gypsum-calcitic mudstone and sandstones) with a surface accumulation of gypsum. Soil pH is 7.4 ± 0.06 (n = 40), while the pH of the BSC is 7.03 ± 0.1 (n = 40). Soil compaction was highest (3.84 ± 0.1 kg/cm2) and clay content lowest (<3 %) at the Hochtor site (Fig. 4a–b) which also had the highest water holding capacity, 48.1 ± 5.