Impacts of soil crusts on soil physicochemical characteristics in different rainfall zones of the arid and semi-arid desert regions of northern China

Abstract

Soil crusts commonly form in arid and semi-arid desert regions once shifting sand dunes stabilize. The crusts affect soil properties such as texture and fertility. However, the role of crusts depends on the species composition, their physiological activity, and their stage of evolution, and varies with precipitation and season. In this study, the soil properties of physical and biological crusts in different rainfall zones of the arid and semi-arid desert regions of northern China were analyzed. More developed crusts had finer soil texture. The impact on chemical properties was greater in areas with higher precipitation. Contents of soil organic carbon (SOC), total nutrients, available N, and exchangeable ions did not vary among crust types in a hyperarid region. SOC, total N and P, and available N increased with crust development at 150-400 mm rainfall. Soil crusts increased available P during the initial stage of development. Crust development increased available K at 300-400 mm precipitation, but not at B250 mm precipitation. CaCO 3 changes were related to windblown dust and soil moisture in the crust. Electrical conductivity and total salinity varied in response to variation of soil nutrients and aeolian salt accumulation. The pH did not vary greatly between crust types and sites. Crust development was accompanied by soil alkalization. Ca 2? was more abundant than other cations. Crust development did not influence Cl -, but increased HCO 3 -and Na ? . During crust development, SO 4 2-and K ? contents decreased, and Mg 2? increased, in regions with B250 mm precipitation. The opposite changes occurred at 300-400 mm precipitation.

Relationships between Soil Crust Development and Soil Properties in the Desert Region of North China

“…The structure of small aggregates can be easily broken up, and the organic carbon content is low (approx. 6 mg/kg) (Chen and Duan, 2015). In this study, the establishment and development of soil crust reduced the bulk density and micro-aggregate content.…”

“…Physical and biological soil crusts have been formed between the bare sand dune and vegetation. Chen and Duan (2015) has recently reported that the local biological soil crusts include algal crust, lichen crust, algal-lichen mixed crust and moss crust. The dominant species composing the local biological soil crusts are Microcoleus vaginatus, Collema tenax and Byum argenteum.…”

Relationships between Soil Crust Development and Soil Properties in the Desert Region of North China

“…The structure of small aggregates can be easily broken up, and the organic carbon content is low (∼6 mg/kg) [22]. In this study, the establishment and development of soil crust reduced the bulk density and micro-aggregate content.…”

“…Physical and biological soil crusts have been formed between the bare sand dune and vegetation. Chen and Duan [22] have recently reported that the local biological soil crusts include algal crust, lichen crust, algal-lichen mixed crust, and moss crust. The dominant species composing the local biological soil crusts are Microcoleus vaginatus, Collema tenax, and Byum argenteum.…”

The effect of biological soil crusts on soil moisture dynamics under different rainfall conditions in the Tengger Desert, China

“…Biological soil crusts (BSCs), composed of associations of cyanobacteria, microfungi, lichens and mosses with soil particles, cover the first millimetres of topsoil (Lichner et al, ) and are ubiquitous cover types in desert ecosystems (Aguilar, Huber‐Sannwald, Belnap, Smart, & Moreno, ). The existence of BSCs significantly change the surface soil characteristics, such as increasing C and N stocks, changing soil texture and aggregate stability, which contribute to enhancement in soil stability and improvement in soil fertility (Chamizo, Cantón, Lázaro, Solé‐Benet, & Domingo, ; Chamizo, Rodríguez‐Caballero, Román, & Cantón, ; X. Chen & Duan, ; Felde et al, ; Gao et al, ; Johnson et al, ; Maestre et al, ; Wu et al, ). Consequently, the BSCs will affect the degree to which rainfall will infiltrate to a limited depth (Loik et al, ; H. Zhu, Shi, et al, ).…”