Does biocrust successional stage determine the degradation of vascular vegetation via alterations in its hydrological roles in semi‐arid ecosystem?. Issue 3 (7th February 2019)

• Record Type: Journal Article
• Authors: Guan, Hongjie; Liu, Xinyu
• Is Part Of: Ecohydrology. Volume 12:Issue 3(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-02-07
• Subjects: patchy vegetation -- soil evaporation -- soil infiltrability -- soil moisture -- soil water holding capacity; Ecohydrology -- Periodicals; Hydrology -- Periodicals; Water -- Environmental aspects -- Periodicals; 577.6
• DOI: 10.1002/eco.2075
• Languages: English
• ISSNs: 1936-0584

Abstract

Abstract: Biocrusts may influence soil moisture by changing soil hydrological properties and thus affect the growth of vascular vegetation. However, their effects on soil moisture and vascular vegetation have not been sufficiently evaluated. In this study, five treatments, including bare land with sporadic cyanobacterial biocrusts (BL), lichen‐dominated biocrusts, Artemisia ordosica (AO), A. ordosica with moss biocrusts, and old‐aged A. ordosica with moss biocrusts (OAMB), were established to evaluate the effects of biocrusts on soil hydrological properties and shrub growth. Our results showed that the field capacity ( θ f ) and saturated soil moisture ( θ s ) for the OAMB treatment was higher than that for the BL treatment, although the difference between the five treatments was insignificant. The OAMB treatment deceased soil moisture 8.7% on average due to their significant lower saturated hydraulic conductivity ( K s ) (82.9%), compared with the BL treatment. The OAMB treatment protected against soil water loss during the beginning stages of evaporation and facilitated soil evaporation during the late stages. Interestingly, the soil water condition underneath the OAMB treatment was not improved after the degradation of AO. The A. ordosica with moss biocrusts treatment had 12.7% lower aboveground biomass and 46.0% lower twig biomass than that for the AO treatment, suggesting the negative effects of biocrusts on the growth of artificially planted shrubs. The findings have important implications for the competitive relationships between biocrusts and vascular vegetation and managing artificial planted shrubs.