Ongoing succession of biological soil crusts increases water repellency — a case study on Arenosols in Sekule, Slovakia

Abstract

After soil surface disturbances biological soil crusts (BSC) cover rapidly the topmost soil millimeters. Depending on BSC age, development of soil water repellency, water infiltration and soil surface stability are influenced by this thin surface sealing. Within this study disturbed, early-mid-and late successional stages of BSC development were examined along a recovery transect. The results show an increase in water repellency and a decrease in water sorptivity and conductivity with ongoing BSC succession. Penetration resistance data shows very stable thin surface protection by cyanobacteria in early successional BSC that is non-repellent. Later successional stages show increased water repellency and lower water conductivity. We conclude that BSC development induces changes in surface structure and wettability. The soil surface wettability is strongly linked to the BSC community composition.

Biological soil crusts cause subcritical water repellency in a sand dune ecosystem located along a rainfall gradient in the NW Negev desert, Israel

“…This agrees with Eldridge et al (2010), Maestre et al (2011) andRodríguez-Caballero et al (2013) describing lichens as runoff promoters and mosses as infiltration promoters for arid ecosystems, but may contradict results of Drahorad et al (2013b) describing a negative relation of infiltration rate and a positive relation of WR with successional stages of moss dominated BSCs under humid climate conditions. Here, vegetation (coniferous trees) plays an important role in the development of WR (Lichner et al, 2007), but this can be ruled out in the Negev desert since there is no sufficient plant cover present that may contribute significantly to WR development.…”

“…Compared to other values of RI measurements from BSCs around the world, ranging from a RI of 4.4 to 210 (cf. Drahorad et al, 2013b;Fischer et al, 2010;Lichner et al, 2013Lichner et al, , 2007) the values measured for the crust in the NW Negev are located in the lower RI range with the highest RI values on wet crust in N84 of 5.70 (see Table 2). The comparison of the RIs between the three sites showed that WR is significantly higher in N84 compared to NS and N69 (p < 0.05).…”

“…This suggests that other factors contribute to the development of WR. Some studies showed that development stages of BSCs are responsible for strongly varying hydrological behavior (Drahorad et al, 2013b;Rodríguez-Caballero et al, 2012;Yair et al, 2011;Zaady et al, 2014). Lichner et al (2013) showed that species composition had a strong effect on the development of WR.…”

“…The modifications in hydrological surface properties are due to a multitude of factors associated with the BSCs, including texture (Fischer et al, 2013), surface roughness (Rodríguez-Caballero et al, 2012), vesicular porosity and capillary barriers , pore clogging and swelling of organic crust components (Fischer et al, 2010;Kidron et al, 1999) as well as water repellency (WR) (Drahorad et al, 2013b;Fischer et al, 2010). Recently the importance of the single factors have not been characterized systematically, as the complex interactions between them make it difficult to state general claims on their importance.…”

“…Lichner et al (2007) showed that the RI method is well suited for a wide range of hydrophobic soils. The RI method was successfully used in several ecosystems to investigate WR on BSCs in a range of studies (Drahorad et al, 2013b;Fischer et al, 2010;Lichner et al, 2013). In the sand dune ecosystems of the NW Negev the content of SOM within the BSC is higher compared to the topsoil (Drahorad et al, 2013a;Yair et al, 2011).…”