Elsevier

Journal of Arid Environments

Volume 144, September 2017, Pages 201-211
Journal of Arid Environments

Effect of biological soil crusts on microbial activity in soils of the Tengger Desert (China)

https://doi.org/10.1016/j.jaridenv.2017.04.003Get rights and content

Highlights

  • Biocrusts significantly increased soil microbial activity parameters.

  • Severe trampling of biocrusts markedly affected soil microbial activity parameters.

  • Moss crusts increased soil microbial activity more than cyanobacteria-lichen crusts.

  • The sand dune restoration age was correlated with soil microbial activities.

  • Soil microbial activity parameters beneath biocrusts varied with soil depth and season.

Abstract

Soil microbes, as an important biological component of soils, have a function in the formation of soils and soil-remediation processes. This paper aims to analyze effects of biocrusts on soil microbial activities in desert ecosystems. Two sets of samples were collected under biocrusts in April, July, October, 2013, and January, 2014, in natural and revegetated areas of the Tengger Desert. The results showed that biocrusts significantly improved soil physicochemical properties, basal respiration and the quantity of soil alkaline phosphatase, protease, and cellulose, and decreased qCO2 in vegetated areas. Impact of biocrusts on soil microbial activities also varied, depending on the successional stage of crusts and the restoration age. Soil basal respiration and enzyme activity were obviously higher, but qCO2 were significantly lower in moss-dominated crusts than those dominated by cyanobacteria-lichen. Soil basal respiration and enzyme activity positively correlated with the restoration age, but qCO2 negatively correlated with the restoration age. Soil basal respiration and enzyme activity were the highest in summer, followed by autumn, and the lowest in spring and winter; whereas, qCO2 displayed an opposite trend. The study suggests that biocrusts have the ability to improve soil quality and promote soil recovery in vegetated areas of the Tengger Desert.

Introduction

Arid and semiarid lands account for as much as 33–40% of Earth's terrestrial surface, and are expanding rapidly (Billings et al., 2003). Vegetation cover in these areas is patchy and discontinuous due to combined impacts of harsh environmental factors such as prolonged drought, high temperatures and high soil erosion rates. Nevertheless, biocrusts are able to adapt successfully to these adverse environments, colonize the bare disaggregated geological substrate (Li, 2012) and cover as much as 70% of the interspaces between the sparse vegetation in these areas (Steven et al., 2014). Numerous studies have examined the ecosystem functions of biocrusts in desert ecosystems, such as fixing of C and N, improving soil structure, enhancing soil stability, modifying soil temperature, moisture and local hydrology, reinforcing plant colonization and promoting soil invertebrate and microbial diversity (Belnap and Lange, 2003, Bowker et al., 2013, Darby et al., 2010, Liu et al., 2013, Neher et al., 2009).

Soil microbes, as an important biological component of soils, have a function in soil formation and soil remediation processes, through the decomposition of organic matter, formation of humus, and nutrient cycling. Soil basal respiration is mostly associated with activity of microbes, therefore it indicates the potential mineralization rate of soil organic matter by soil microbes from a desert ecosystem (Pell et al., 2006). The ratio of basal respiration to microbial biomass carbon (metabolic quotient: qCO2), provides a method to relate both the amount and activity of soil microbes (Anderson and Domsch, 1990). Soil basal respiration, qCO2 and enzyme activity provide a measure of microbial activity, which is a sensitive indicator of soil quality changes in response to environmental changes (Creamer et al., 2014, Raiesi and Beheshti, 2015, Wardle and Ghani, 1995). Recent studies have examined the relationship between biocrusts and soil microbial activity. For example, Bastida et al. (2014) found that the values of soil basal respiration and enzyme activities were higher in biocrusts than in soil beneath biocrusts in south-east Spain. Miralles et al., 2012a, Miralles et al., 2012b found that the values of soil basal respiration and the activities of arylsulphatase, β-glucosidase, casein-protease, cellulase and phosphomonoesterase were higher in soil beneath biocrusts than in bare substrate of the Tabernas Desert. Yu and Steinberger (2012) reported that the values of soil basal respiration were two-fold higher in biocrusts-covered interdune than in playa in the western Negev Desert. Studies by Zhang et al. (2012) and Liu et al. (2014) showed that soil catalase, urease, dehydrogenase and sucrase activities were high beneath biocrusts compared with bare soil without crust. It is also suggested that the successional stages of crusts could influence soil basal respiration and enzyme activities such as catalase, urease, dehydrogenases, sucrase and nitrogenase (Liu et al., 2014, Miralles et al., 2012b, Wu et al., 2009).

Although the influence of biocrusts on soil basal respiration, qCO2 and enzyme activity has been studied, few studies have specifically examined how the soil microbial activity parameters respond to differences in successional stages of crusts, such as those in restored sand dunes in the Tengger Desert. Moreover, less is known about the effects of biocrusts on qCO2 and enzyme activity at different soil depths and in different seasons. The present study aims to clarify functions of biocrusts in soil processes based on soil basal respiration, qCO2 and enzymatic activities. Firstly, we determined the impacts of biocrusts on soil basal respiration, qCO2 and enzyme activities in the study area and secondly, showed how these parameters varied with successional stages of crusts. Thirdly, we examined how these parameters changed after trampling disturbance. Finally, we studied the spatial and temporal variations of soil basal respiration, qCO2 and enzyme activities under biocrusts in the study area.

Section snippets

Study area

The field sites (i.e., revegetated and natural vegetated) were located in the desert steppe region at the Shapotou Desert Research and Experiment Station, bordering the Tengger Desert, northern China (37°32′N, 105°02′E) at an elevation of 1300 m a.s.l. The sites are representative of the transition zone between desertified steppe and sand dunes. The climate is tropical dry with an average precipitation and potential evaporation of approximately 186 and 3000 mm yr−1, respectively. Average annual

Effects of biocrusts on soil physicochemical properties

Both cyanobacteria–lichen and moss crusts affected soil texture, resulting in an increase in the content of soil clay and silt and reduction in the content of sand in 0–30 cm soil in comparison with bare soil (Table 1). Soil organic C, total N, available N, total P, available P and pH were higher beneath biocrusts than in bare soil at the depth of 0–30 cm (Table 1). These soil physicochemical properties markedly varied with the successional stage of crusts, the restoration age and soil depth (

Effects of biocrusts on soil basal respiration, qCO2 and enzyme activities

The biocrusts in vegetated areas enhanced soil physicochemical properties, basal respiration and the activity of soil alkaline phosphatase, protease and cellulase, and reduced qCO2. These results are similar to the findings of Miralles et al., 2012a, Miralles et al., 2012b and Bastida et al. (2014), who found that soil basal respiration and several hydrolase enzyme activities were higher in biocrusts than in bare substrata in south-east Spain. High soil basal respiration under biocrusts

Conclusions

Biocrusts strongly increased soil basal respiration and activities of soil alkaline phosphatase, protease and cellulase, and reduced qCO2 in vegetated areas of the Tengger Desert. Severe trampling of biocrusts markedly reduced soil basal respiration and activities of soil alkaline phosphatase, protease and cellulase, and enhanced qCO2 in 0–15 cm soil layer in the study areas. The successional stage of crusts and the restoration age also highly affected soil basal respiration, qCO2 and enzyme

Acknowledgements

This research was funded by China National Funds for Regional Science (grant No. 41261014) and the China National Funds for Young Scientists (grant No. 41401341).

References (50)

  • D.J. Eldridge et al.

    Soil disturbance by native animals along grazing gradients in an arid grassland

    J. Arid. Environ.

    (2009)
  • E. Enowashu et al.

    Microbial biomass and enzyme activities under reduced nitrogen deposition in a spruce forest soil

    Appl. Soil Ecol.

    (2009)
  • J. Frouz et al.

    Development of soil microbial properties in topsoil layer during spontaneous succession in heaps after brown coal mining in relation to humus microstructure development

    Geoderma

    (2005)
  • S.T. Hamman et al.

    Relationships between microbial community structure and soil environmental conditions in a recently burned system

    Soil Biol. Biochem.

    (2007)
  • S. Heinze et al.

    Small scale stratification of microbial activity parameters in Mediterranean soils under freshwater and treated wastewater Irrigation

    Soil Biol. Biochem.

    (2014)
  • R.L. Jia et al.

    Responses of biological soil crusts to sand burial in a revegetated area of the Tengger Desert, Northern China

    Soil Biol. Biochem.

    (2008)
  • X.R. Li et al.

    Association of ant nests with successional stages of biological soil crusts in the Tengger Desert

    North. China. Appl. Soil Ecol.

    (2011)
  • X.R. Li et al.

    Carbon fixation by biological soil crusts following revegetation of sand dunes in arid desert regions of China: a four-year field study

    Catena

    (2012)
  • Y.M. Liu et al.

    Responses of soil microbial biomass and community composition to biological soil crusts in the revegetated areas of the Tengger Desert

    Appl. Soil Ecol.

    (2013)
  • Y.M. Liu et al.

    Effects of biological soil crusts on soil enzyme activities in revegetated areas of the Tengger Desert, China

    Appl. Soil Ecol.

    (2014)
  • I. Miralles et al.

    Hydrolase enzyme activities in a successional gradient of biological soil crusts in arid and semi-arid zones

    Soil Biol. Biochem.

    (2012)
  • I. Miralles et al.

    Biological and microbial activity in biological soil crusts from the Tabernas desert, a sub-arid zone in SE Spain

    Soil Biol. Biochem.

    (2012)
  • D.A. Neher et al.

    Microarthropod communities associated with biological soil crusts in the Colorado Plateau and Chihuahuan deserts

    J. Arid. Environ.

    (2009)
  • F. Raiesi et al.

    Microbiological indicators of soil quality and degradation following conversion of native forests to continuous croplands

    Ecolo. Indic.

    (2015)
  • B. Steven et al.

    Common and distinguishing features of the bacterial and fungal communities in biological soil crusts and shrub root zone soils

    Soil Biol. Biochem.

    (2014)
  • Cited by (31)

    • Soil nutrients, enzyme activities, and microbial communities differ among biocrust types and soil layers in a degraded karst ecosystem

      2022, Catena
      Citation Excerpt :

      As a complex community of cyanobacteria, lichens, mosses, fungi, and algae on the soil surface (Belnap, 2003), BSCs are crucial engineers regulating ecosystem functions (Eldridge et al., 2020). These functions include regulating carbon and nitrogen cycles (Büdel et al., 2018; Torres-Cruz et al., 2018), conservation of soil and water (Gao et al., 2020), impact on soil microbial communities and functions (Liu et al., 2017; Su et al., 2020), regulation of soil hydrology (Belnap et al., 2013), etc. BSCs have become a new and vital research hotspot in recent decades because of their irreplaceable roles of the restoration and reconstruction in many degraded ecosystems in arid and semi-arid areas (Belnap, 2003; Bowker et al., 2018; Zhao et al., 2020).

    • Exposure of cyanobacterium Nostoc sp. to the Mars-like stratosphere environment

      2021, Journal of Photochemistry and Photobiology B: Biology
      Citation Excerpt :

      In addition, they developed several mechanisms that enable them to tolerate desiccation, and survive acute water deficiency and significant salt stress; these include decreased photosynthesis levels [19–20], the ability of vegetative cells to enter a dormant state [21], biodegradation of rocks to enrich and inoculate soil [22], and synthesis of extracellular polymeric substances (EPS) to improve salt tolerance [23–24]. Desert cyanobacteria in microbiotic crust can even collect a great amount of dew [25–26] in desert regions with low precipitation, and play an important role in soil quality improvement, soil recovery promotion in vegetated areas [27], evaporation retardation and dune fixation [28–30]. These capabilities make cyanobacteria from microbiotic crusts the most promising candidate for remediation of Mars-like desert soil and terraforming of Mars for the future establishment of human settlement bases [31–35].

    View all citing articles on Scopus
    View full text