The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8 degrees in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micropatterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes.
ecological restoration actions through creation of biological soil crusts (soil surface covers planted with moss and lichen) [note this is a field experiment w/ small experimental plots, different plots have different arrangements of the moss/lichen such as either full coverage of plot with biocrust or patchy coverage but these different configurations are not delineated as separate interventions]
|Climate change impacts||Effect of Nbs on CCI||Effect measures|
|Soil erosion||Positive||soil stability (rate of soil loss), cumulative soil loss|
|Reduced water availability||Positive||Soil hydrologic characteristics: SBD—soil buck density, HWC—highest water holding capacity, CWC—soil capillary water holding capacity, LWC- lowest water holding capacity, TSP— total soil porosity, CSP—soil capillary porosity, and NCP—non-capillary porosity Water loss from runoff|
Anjiapo catchment (35°33'–35° 35'N, 104°38'–104°41'E), a loess hilly region in Dingxi of Gansu province