Search

This article is an editorial that discusses the development and ecological functions of biological soil crusts (biocrusts). Biocrusts are composed of microorganisms and play important roles in soil stabilization, microbial diversity, and ecosystem development. The editorial emphasizes the need for further research on biocrust communities and their impact on landscape-scale outcomes. It also highlights the ecological functions of biocrusts, such as reducing erosion and influencing biogeochemical cycles. The article concludes by discussing the importance of understanding biocrusts for ecological restoration and land management strategies. Another document provides a list of references for articles related to biological soil crusts, covering topics such as land degradation neutrality, ecological restoration, and the impact of biocrusts on microbial communities. The articles also explore the composition and response of biocrusts to climate change and physical disturbance, as well as their effects on soil properties and metabolic response to hydration. [Extracted from the article]

Summary: Biocrusts provide numerous ecological functions in drylands. Recovering biocrusts via cyanobacterial inoculation recently gathered interest for ecological restoration, yet it still lacks long‐term experiments to unravel biocrust community dynamics. To examine how cyanobacterial inoculants influenced local microbial community and biocrust development, we observed a 2 km2 (Qubqi Desert, China) inoculation experiment after 10 and 15 years, following biocrust formation. Our results revealed that biocrust development was in line with ecological regime shift, providing evidence for biocrust community succession, from cyanobacteria‐ to moss‐dominated types. Associated with biocrust development, microbial communities differed significantly with less specialists compared to shifting sands. Cyanobacterial community analysis showed that Microcoleus vaginatus and Scytonema javanicum are an ideal inoculating model, as they were still dominating the community after 15 years since inoculation, while other nitrogen‐fixing cyanobacteria occurred profusely with biocrust development. Biocrust community composition combined with thickness, Chl‐a and exopolysaccharide measurements revealed the large variation of cyanobacterial ecological functions along biocrust development, suggesting a main function shift: from carbon fixation associated with exopolysaccharide secretion in bare sandy soils to nitrogen fixation in developed biocrusts. This large‐scale field study verifies that cyanobacterial inoculation accelerates biocrust development and forwards succession, shaping the biocrust community composition over a long time. [ABSTRACT FROM AUTHOR]

Abstract: Lichen soil crusts (LSCs) are an important stage during the development of biological soil crusts (BSCs). The photosynthetic characteristics of this stage are determined by both of the symbiotic and free-living cyanobacteria and algae in the crusts. In this study, the recovery rate, extent, pattern of chlorophyll fluorescence and CO2 exchange in LSCs were detected after rehydration under different water contents (5%, 20% and 40%). The results showed that original fluorescence (Fo) of each group increased dramatically after rehydration and then reached a plateau to steady state; however both maximum quantum efficiency of PS II photochemistry (Fv/Fm) and the ratio of variable fluorescence at different recovery time to the maximal value during the recovery period (Fv/FvMax) showed a similar and corresponding “three steps” recovery pattern. At the end of experiment, Fv/Fm of 20% water content group recovered to the highest level (0.45), although no obvious difference in the Fv/Fm was found among the three water content groups within the first 4 h. Additionally, after the rehydration CO2 release from LSCs (under the light) gradually decreased, and the organic carbon accumulation first occurred in 40% water content group, in which a higher CO2 assimilation rate was also observed. The obvious inconsistency between chlorophyll fluorescence detection and CO2 exchange analysis is considered to be the result of the special structure and photosynthetic characteristics of LSCs. [Copyright &y& Elsevier]

Realizing the reasonable allocation of resources is possible to solve the dual problems of resources and environment. Therefore, in this study desert cyanobacterium Scytonema javanicum was cultivated in artificial synthetic wastewater to explore the feasibility of nutrient transferring from wastewater to desert. After inoculation, S. javanicum grew well in the wastewater; nitrogen and phosphorus were gradually removed from the wastewater. In general, cyanobacterial biomass, exopolysaccharide content, COD, nitrogen and phosphorus contents were all significantly affected by the cultivation time, wastewater dilution treatment and their interaction ( P < 0.001). Comprehensively considering the producing period, biomass accumulation and nutrient removal efficiency, cultivation time of cyanobacterium S. javanicum in the synthetic wastewater should be controlled around 20 days, with wastewater dilution ratio at 1:1. Conclusively, desert cyanobacterium S. javanicum is a promising species for nutrient transferring from wastewater to desert, and its maximum biomass yield could reach 3.91 mg Chl- a L −1 in the synthetic wastewater. [ABSTRACT FROM AUTHOR]