scholarly journals A New Strain of Bacillus tequilensis CGMCC 17603 Isolated from Biological Soil Crusts: A Promising Sand-Fixation Agent for Desertification Control

2019 ◽  
Vol 11 (22) ◽  
pp. 6501 ◽  
Author(s):  
Zhao ◽  
Li ◽  
Wang ◽  
Qi ◽  
Zhang ◽  
...  
Keyword(s):  
Field Experiments ◽  
Biological Soil Crusts ◽  
Culture Conditions ◽  
High Density ◽  
Desert Ecosystems ◽  
High Density Culture ◽  
High Productivity ◽  
Soil Crusts ◽  
Bacillus Tequilensis ◽  
Semi Arid

In arid and semi-arid desert ecosystems, physical, chemical, and vegetative measures were used to prevent wind erosion. However, studies on the utilization of microbial resources for sand fixation are still limited. To fill this gap, a new strain of Bacillus tequilensis CGMCC 17603 with high productivity of exopolysaccharide (EPS) was isolated from biological soil crusts, and its high-density culture technology and sand-fixing ability were studied. The one-factor-at-a-time approach (OFAT) and Box–Behnken design of CGMCC 17603 showed that the optimum culture conditions were pH 8.5, temperature 31 °C, agitation speed 230 rpm, and inoculation quantity 3%, and the optimum medium was 27.25 g/L glucose, 15.90 g/L yeast extract, and 5.61 g/L MgSO4•7H2O. High-density culture showed that the biomass and EPS yield of CGMCC 17603 increased from 9.62 × 107 to 2.33 × 109 CFU/mL, and from 8.01 to 15.61 g/L, respectively. The field experiments showed that CGMCC 17603 could effectively improve the ability of sand fixation and wind prevention. These results indicated that B. tequilensis, first isolated from cyanobacterial crusts, can be considered as an ideal soil-fixing agent to combat desertification in arid and semi-arid areas.

scholarly journals A New Application of Random Forest Algorithm to Estimate Coverage of Moss-Dominated Biological Soil Crusts in Semi-Arid Mu Us Sandy Land, China

2019 ◽  
Vol 11 (11) ◽  
pp. 1286 ◽  
Author(s):  
Xiang Chen ◽  
Tao Wang ◽  
Shulin Liu ◽  
Fei Peng ◽  
Atsushi Tsunekawa ◽  
...  
Keyword(s):  
Random Forest ◽  
Biological Soil Crusts ◽  
Data Availability ◽  
Sandy Land ◽  
Desert Ecosystems ◽  
Mu Us Sandy Land ◽  
Soil Crusts ◽  
Band Combinations ◽  
Semi Arid ◽  
Sentinel 2

Biological soil crusts (BSCs) play an essential role in desert ecosystems. Knowledge of the distribution and disappearance of BSCs is vital for the management of ecosystems and for desertification researches. However, the major remote sensing approaches used to extract BSCs are multispectral indices, which lack accuracy, and hyperspectral indices, which have lower data availability and require a higher computational effort. This study employs random forest (RF) models to optimize the extraction of BSCs using band combinations similar to the two multispectral BSC indices (Crust Index-CI; Biological Soil Crust Index-BSCI), but covering all possible band combinations. Simulated multispectral datasets resampled from in-situ hyperspectral data were used to extract BSC information. Multispectral datasets (Landsat-8 and Sentinel-2 datasets) were then used to detect BSC coverage in Mu Us Sandy Land, located in northern China, where BSCs dominated by moss are widely distributed. The results show that (i) the spectral curves of moss-dominated BSCs are different from those of other typical land surfaces, (ii) the BSC coverage can be predicted using the simulated multispectral data (mean square error (MSE) < 0.01), (iii) Sentinel-2 satellite datasets with CI-based band combinations provided a reliable RF model for detecting moss-dominated BSCs (10-fold validation, R2 = 0.947; ground validation, R2 = 0.906). In conclusion, application of the RF algorithm to the Sentinel-2 dataset can precisely and effectively map BSCs dominated by moss. This new application can be used as a theoretical basis for detecting BSCs in other arid and semi-arid lands within desert ecosystems.

Biological soil crusts modulate nitrogen availability in semi-arid ecosystems: insights from a Mediterranean grassland

2010 ◽  
Vol 333 (1-2) ◽  
pp. 21-34 ◽  
Author(s):  
Andrea P. Castillo-Monroy ◽  
Fernando T. Maestre ◽  
Manuel Delgado-Baquerizo ◽  
Antonio Gallardo
Keyword(s):  
Nitrogen Availability ◽  
Biological Soil Crusts ◽  
Arid Ecosystems ◽  
Soil Crusts ◽  
Semi Arid

Disturbance of the biological soil crusts and performance of Stipa tenacissima in a semi-arid Mediterranean steppe

2010 ◽  
Vol 334 (1-2) ◽  
pp. 311-322 ◽  
Author(s):  
Jordi Cortina ◽  
Noelia Martín ◽  
Fernando T. Maestre ◽  
Susana Bautista
Keyword(s):  
Biological Soil Crusts ◽  
Stipa Tenacissima ◽  
Soil Crusts ◽  
And Performance ◽  
Semi Arid

Variation of albedo to soil moisture for sand dunes and biological soil crusts in arid desert ecosystems

2013 ◽  
Vol 71 (3) ◽  
pp. 1281-1288 ◽  
Author(s):  
Ya-feng Zhang ◽  
Xin-ping Wang ◽  
Rui Hu ◽  
Yan-xia Pan ◽  
Hao Zhang
Keyword(s):  
Soil Moisture ◽  
Sand Dunes ◽  
Biological Soil Crusts ◽  
Desert Ecosystems ◽  
Soil Crusts ◽  
Arid Desert

scholarly journals Warming reduces the growth and diversity of biological soil crusts in a semi-arid environment: implications for ecosystem structure and functioning

2012 ◽  
Vol 367 (1606) ◽  
pp. 3087-3099 ◽  
Author(s):  
Cristina Escolar ◽  
Isabel Martínez ◽  
Matthew A. Bowker ◽  
Fernando T. Maestre
Keyword(s):  
Climate Change ◽  
Soil Stabilization ◽  
Arid Environment ◽  
Biological Soil Crusts ◽  
Water Dynamics ◽  
Annual Rainfall ◽  
Ecosystem Structure ◽  
Positive Effects ◽  
Soil Crusts ◽  
Semi Arid

Biological soil crusts (BSCs) are key biotic components of dryland ecosystems worldwide that control many functional processes, including carbon and nitrogen cycling, soil stabilization and infiltration. Regardless of their ecological importance and prevalence in drylands, very few studies have explicitly evaluated how climate change will affect the structure and composition of BSCs, and the functioning of their constituents. Using a manipulative experiment conducted over 3 years in a semi-arid site from central Spain, we evaluated how the composition, structure and performance of lichen-dominated BSCs respond to a 2.4°C increase in temperature, and to an approximately 30 per cent reduction of total annual rainfall. In areas with well-developed BSCs, warming promoted a significant decrease in the richness and diversity of the whole BSC community. This was accompanied by important compositional changes, as the cover of lichens suffered a substantial decrease with warming (from 70 to 40% on average), while that of mosses increased slightly (from 0.3 to 7% on average). The physiological performance of the BSC community, evaluated using chlorophyll fluorescence, increased with warming during the first year of the experiment, but did not respond to rainfall reduction. Our results indicate that ongoing climate change will strongly affect the diversity and composition of BSC communities, as well as their recovery after disturbances. The expected changes in richness and composition under warming could reduce or even reverse the positive effects of BSCs on important soil processes. Thus, these changes are likely to promote an overall reduction in ecosystem processes that sustain and control nutrient cycling, soil stabilization and water dynamics.

scholarly journals A rainfall enrichment system suitable for open field experiments in arid and semi-arid ecosystems

Lilloa ◽  
2020 ◽  
pp. 54-71
Author(s):  
Zhiming Xin ◽  
Jianqiang Qian ◽  
Carlos A. Busso ◽  
Bo Wu ◽  
Yajuan Zhu ◽  
...  
Keyword(s):  
Open Field ◽  
Field Experiments ◽  
Experimental Studies ◽  
Terrestrial Ecosystems ◽  
Arid Ecosystems ◽  
Hydraulic Pressure ◽  
Desert Ecosystems ◽  
Rainfall Events ◽  
Arid Desert ◽  
Semi Arid

The predicted changes in precipitation patterns because of global change have profound effects on terrestrial ecosystems. In the present study, the principle and design details of a rainfall enrichment system (RAINES) for open field experiments in semi-arid and arid ecosystems are shown. The rainfall intensity, validity and uniformity of this experimental facility were also tested. During the period from 2008 to 2010, our data showed that the RAINES was able to simulate rainfall events with different rainfall sizes, frequencies and timing. The greatest advantage of the RAINES was its high uniformity in rainfall distribution over a relatively large experimental surface area (>90 m2), which was important for experimental studies of semi-arid and arid ecosystems where vegetation distribution is sparse. The rainfall validity of RAINES was steadily at 66% or higher as long as the hydraulic pressure exceeded 1.4 KPa and the wind speed was below 2.5 m s-1. Since the RAINES is light-weight, inexpensive and versatile enough to be used to simulate various rainfall events with needed properties in remote fields, it is able to provide reliable simulated rainfall in the field for studying possible responses of soil and vegetation processes to rainfall change in arid and semi-arid ecosystems. The application of the RAINES will improve our understanding on the relationship between water availability and ecosystem processes in arid and semi-arid ecosystems, which will provide useful knowledge for the protection, restoration and sustainable management of semi-arid and arid desert ecosystems world.

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