Inhibiting Desertification Using Aquatic Cyanobacteria Assisted by a Nanocomposite

Abstract

Desertification and water body eutrophication are two severe environmental problems worldwide. To alleviate these two problems simultaneously, a new idea, introducing aquatic cyanobacteria (AC) from Lake Chaohu to the surface of the Tengger Desert to encourage the growth of biological soil crusts, was proposed. A networkstructured nanocomposite (SXA) consisting of sodium polyacrylate (SP), xanthan gum (XG), and attapulgite (ATP) was also fabricated. The SXA showed high water-retention ability, viscosity, and biosafety and could provide a suitable microenvironment for AC and desert cyanobacteria (DC) growth. It was found that the combination of AC and SXA effectively increased sand nutrient levels, facilitating the growth of DC and biological soil crusts. Importantly, the resultant biological soil crusts maintained stability for at least 210 days and played a key role in stabilizing the sand surface. Therefore, this work provides a novel technology not only for desert immobilization but also for the utilization of aquatic blooms.

Artificial biocrust establishment on materials of potash tailings piles along a salinity gradient

“…The application of sodium alginate as a surface stabilizer in combination with BC plus as a nutrient source significantly increased the biocrusts Chl a content on the NE, WS, NaCl, and NoSalt substrates (Table 3). Therefore, we confirm statements on beneficial effects of surface stabilizers on artificial biocrust formation (Peng et al 2017;Chi et al 2020). Sodium alginate increases the compressive strength of the soil by forming a film on the surface, which supported the induction of cyanobacterial biocrusts on sand (Peng et al 2017).…”

“…Besides the restoration of disturbed biocrusts, artificial biocrust development can be actively initiated in areas without previous natural biocrust cover, in order to prevent or reverse soil degradation (Chen et al 2006;Rossi et al 2017;Chi et al 2020;Li et al 2021) or to stabilize sand and other surfaces, such as artificial water-body margins (Cruz de Carvalho et al 2018). So far, research on artificial biocrusts is restricted to dryland areas, while such studies are absent from Central Europe.…”

Combination of Chemical and Cyanobacterial Inoculation Promotes Biocrust Development: A Novel Perspective for Combating Desertification

“…Biocrusts are associations of phototrophic and heterotrophic communities, which dwell within the uppermost millimeters of soil surfaces. , They are ecosystem engineers involved in surface stabilization and nutrient cycling, and therefore are regarded as important agents for combating desertification . In a recent published article on ACS Sustainable Chemistry & Engineering , Chi et al proposed a new idea to promote biocrust development and increase soil nutrient levels by inoculating cyanobacteria and nanosand-stabilizers to dryland surfaces . They corroborated the feasibility of this approach by a 10-month field experiment (1 m × 1 m).…”

“…Conversely, cyanobacteria are easy to cultivate and harvest to achieve large amount of biomass, , which is required for large-scale biocrust engineering. In the research of Chi et al, they even introduced water-bloom (aquatic) cyanobacteria to promote biocrust development, an approach which has been proved highly effective for dryland ecological restoration, as well as for alleviating water eutrophication . Furthermore, large-scale inoculation with biocrust-dwelling cyanobacteria Microcoleus vaginatus and Scytonema javanicum has been carried out over more than 40 km 2 in Inner Mongolia, China, to induce biocrust development for combating desertification .…”

“…Furthermore, large-scale inoculation with biocrust-dwelling cyanobacteria Microcoleus vaginatus and Scytonema javanicum has been carried out over more than 40 km 2 in Inner Mongolia, China, to induce biocrust development for combating desertification . Therefore, on the basis of the researches of Chi et al and others, ,, artificially induced biocrusts through cyanobacterial inoculation technology may be one of the most promising approaches for large-scale and sustainable restoration of degraded dryland soils.…”