Small-scale patterns of abundance of mosses and lichens forming biological soil crusts in two semi-arid gypsum environments

2006 ◽  
Vol 54 (4) ◽  
pp. 339 ◽  
Author(s):  
I. Martínez ◽  
A. Escudero ◽  
F. T. Maestre ◽  
A. de la Cruz ◽  
C. Guerrero ◽  
...  
Keyword(s):  
Biological Soil Crust ◽  
Aggregate Stability ◽  
Bare Soil ◽  
Biological Soil Crusts ◽  
Small Scale ◽  
Arid Environments ◽  
Soil Variables ◽  
Constrained Ordination ◽  
Soil Crusts ◽  
Semi Arid

Despite important advances in the understanding of biological soil crusts and their key role in ecosystem processes in arid and semi-arid environments, little is known about those factors driving the small-scale patterns of abundance and distribution of crust-forming lichens and mosses. We used constrained ordination techniques (RDAs) to test the hypothesis that the spatial patterning of lichens and mosses is related to surface and subsurface soil variables in two semi-arid gypsum environments of Spain. Our results show that the abundance of mosses and lichens forming biological soil crusts was related to a limited set of variables (cover of bare soil and litter, soil respiration, potassium content and aggregate stability). Moreover, they provide some insights into the importance of these variables as drivers of biological soil-crust composition and abundance in semi-arid gypsum environments.

scholarly journals Emission of nitrous acid from soil and biological soil crusts represents an important source of HONO in the remote atmosphere in Cyprus

2018 ◽  
Vol 18 (2) ◽  
pp. 799-813 ◽  
Author(s):  
Hannah Meusel ◽  
Alexandra Tamm ◽  
Uwe Kuhn ◽  
Dianming Wu ◽  
Anna Lena Leifke ◽  
...  
Keyword(s):  
Nitrous Acid ◽  
Biological Soil Crust ◽  
Ground Surface ◽  
Field Studies ◽  
Bare Soil ◽  
Biological Soil Crusts ◽  
Soil Crusts ◽  
Wide Range ◽  
Mediterranean Island ◽  
Water Holding

Abstract. Soil and biological soil crusts can emit nitrous acid (HONO) and nitric oxide (NO). The terrestrial ground surface in arid and semiarid regions is anticipated to play an important role in the local atmospheric HONO budget, deemed to represent one of the unaccounted-for HONO sources frequently observed in field studies. In this study HONO and NO emissions from a representative variety of soil and biological soil crust samples from the Mediterranean island Cyprus were investigated under controlled laboratory conditions. A wide range of fluxes was observed, ranging from 0.6 to 264 ng m−2 s−1 HONO-N at optimal soil water content (20–30 % of water holding capacity, WHC). Maximum NO-N fluxes at this WHC were lower (0.8–121 ng m−2 s−1). The highest emissions of both reactive nitrogen species were found from bare soil, followed by light and dark cyanobacteria-dominated biological soil crusts (biocrusts), correlating well with the sample nutrient levels (nitrite and nitrate). Extrapolations of lab-based HONO emission studies agree well with the unaccounted-for HONO source derived previously for the extensive CYPHEX field campaign, i.e., emissions from soil and biocrusts may essentially close the Cyprus HONO budget.

scholarly journals Emission of nitrous acid from soil and biological soil crusts represents a dominant source of HONO in the remote atmosphere in Cyprus

2017 ◽  
Author(s):  
Hannah Meusel ◽  
Alexandra Tamm ◽  
Uwe Kuhn ◽  
Dianming Wu ◽  
Anna Lena Leifke ◽  
...  
Keyword(s):  
Nitrous Acid ◽  
Biological Soil Crust ◽  
Ground Surface ◽  
Field Studies ◽  
Bare Soil ◽  
Biological Soil Crusts ◽  
Soil Crusts ◽  
Wide Range ◽  
Mediterranean Island ◽  
Water Holding

Abstract. Soil and biological soil crusts can emit nitrous acid (HONO) and nitric oxide (NO). The terrestrial ground surface in arid and semi-arid regions is anticipated to play an important role in the local atmospheric HONO budget, deemed to represent one of the unaccounted HONO sources frequently observed in field studies. In this study HONO and NO emissions from a representative variety of soil and biological soil crust samples from the Mediterranean island Cyprus were investigated under controlled laboratory conditions. A wide range of fluxes was observed, ranging from 0.6 to 264 ng m−2 s−1 HONO-N at optimal soil water content (20–30 % of water holding capacity, WHC). Maximum NO-N at this WHC fluxes were lower (0.8–121 ng m−2 s−1). Highest emissions of both reactive nitrogen species were found from bare soil, followed by light and dark cyanobacteria-dominated biological soil crusts (biocrusts), correlating well with the sample nutrient levels (nitrite and nitrate). Extrapolations of lab-based HONO emission studies agree well with the unaccounted HONO source derived previously for the extensive CYPHEX field campaign, i.e., emissions from soil and biocrusts may essentially close the Cyprus HONO budget.

Distribution and Floristics of Bryophytes in Soil Crusts in Semi-Arid and Arid Eastern Australia

1996 ◽  
Vol 44 (2) ◽  
pp. 223 ◽  
Author(s):  
DJ Eldridge ◽  
ME Tozer
Keyword(s):  
Condition Assessment ◽  
Biological Soil Crusts ◽  
Arid Environments ◽  
Survey Area ◽  
Soil Crusts ◽  
Unpublished Studies ◽  
Eastern Australia ◽  
The Mean ◽  
Landscape Types ◽  
Semi Arid

A total of 56 bryophyte taxa associated with biological soil crusts was collected from 282 sites in semi-arid and arid eastern Australia. The 41 moss taxa and 15 liverwort taxa found were dominated by the families Pottiaceae and Ricciaceae respectively. Bryophytes were present at 224 of the 282 sites, and their distribution varied widely according to different landscapes. The mean number of taxa per site ranged from 8.9 on plains with red earths to 2.1 on active floodplains. The most common bryophytes found in the survey area were Bryum pachytheca, Didymodon torquatus, Gigaspermum repens, Goniomitrium enerve, Desmatodon convolutus, Stonea oleaginosa, Crossidium davidai, Riccia limbata and Riccia lamellosa. In this paper, the distribution of bryophytes in relation to landscape types, and some strategies for surviving in arid environments and their roles in biodiversity and rangeland condition assessment are discussed. Their distribution is compared with other published and unpublished studies from similar areas of Australia.

Biological soil crusts greatly contribute to small-scale soil heterogeneity along a grazing gradient

2013 ◽  
Vol 64 ◽  
pp. 28-36 ◽  
Author(s):  
L. Concostrina-Zubiri ◽  
E. Huber-Sannwald ◽  
I. Martínez ◽  
J.L. Flores Flores ◽  
A. Escudero
Keyword(s):  
Soil Heterogeneity ◽  
Biological Soil Crusts ◽  
Small Scale ◽  
Soil Crusts ◽  
Small Scale Soil

scholarly journals Quantifying Mechanistic Detachment Parameters Due to Humic Acids in Biological Soil Crusts

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1180
Author(s):  
Atheer A. Abbood ◽  
Abdul-Sahib T. Al-Madhhachi
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Humic Acid ◽  
Biological Soil Crusts ◽  
Exchange Capacity ◽  
Scale Model ◽  
Small Scale ◽  
Soil Erodibility ◽  
Soil Crusts ◽  
Detachment Rate

Humic acid (HA) is a material that could be used to decrease erosion and improve soil structure. It is also known that biological soil crusts (biocrusts) have a major role in soil stabilization, but the mechanism is not well understood in the presence of HA, especially with mechanistic soil detachment rate parameters (b0 and b1) of the Wilson model, where b0 is the dimensional soil detachment parameter and b1 is the dimensional soil threshold parameter. Therefore, this study intends to (1) investigate the effect of different humic acid (HA) concentrations (0%, 4%, and 8%) on mechanistic soil detachment rate parameters (b0 and b1,) in the Tigris Riversides of the Gheraiat region, Baghdad City, Iraq, of the crusted versus uncrusted soils using a small scale model of the jet erosion tests (mini-JET) at different curing periods (1 week, 2 weeks, and 3 weeks), and (2) examine the impact of HA on b0 and b1 parameters versus some soil characteristics, such as electrical conductivity, cation exchange capacity, and soil organic matter for uncrusted and crusted soils. Thirty-six undisturbed soil specimens (18 for crusted soils and 18 for uncrusted soils) were acquired from the Tigris Riverbank. On these specimens, the mini-JET was used to determine the mechanistic cohesive soil erodibility parameters b0 and b1. The results showed that the value of b0 decreased up to 60% with an increase in curing times for crusted soils until they reached their optimum values at 2 weeks. There was no consistent pattern for b1 at different curing times. As the concentration of HA increased, the value of b0 decreased up to 86% and 99% for crusted and uncrusted soils, respectively. HA significantly improved electrical conductivity, exchange capacity, and organic matter in the soil and reduced soil erodibility. This study provides the benefits of adding HA to the soils as a soil stabilizer using a low-cost technique, which is the JET instrument.

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.

scholarly journals Flux balance modeling to predict bacterial survival during pulsed-activity events

2018 ◽  
Vol 15 (7) ◽  
pp. 2219-2229 ◽  
Author(s):  
Nicholas A. Jose ◽  
Rebecca Lau ◽  
Tami L. Swenson ◽  
Niels Klitgord ◽  
Ferran Garcia-Pichel ◽  
...  
Keyword(s):  
Mass Spectroscopy ◽  
Compatible Solutes ◽  
Soil Microbial Communities ◽  
Metabolic Model ◽  
Biological Soil Crusts ◽  
Arid Environments ◽  
Bacterial Survival ◽  
Flux Balance ◽  
Soil Crusts ◽  
Microcoleus Vaginatus

Abstract. Desert biological soil crusts (BSCs) are cyanobacteria-dominated surface soil microbial communities common to plant interspaces in arid environments. The capability to significantly dampen their metabolism allows them to exist for extended periods in a desiccated dormant state that is highly robust to environmental stresses. However, within minutes of wetting, metabolic functions reboot, maximizing activity during infrequent permissive periods. Microcoleus vaginatus, a primary producer within the crust ecosystem and an early colonizer, initiates crust formation by binding particles in the upper layer of soil via exopolysaccharides, making microbial dominated biological soil crusts highly dependent on the viability of this organism. Previous studies have suggested that biopolymers play a central role in the survival of this organism by powering resuscitation, rapidly forming compatible solutes, and fueling metabolic activity in dark, hydrated conditions. To elucidate the mechanism of this phenomenon and provide a basis for future modeling of BSCs, we developed a manually curated, genome-scale metabolic model of Microcoleus vaginatus (iNJ1153). To validate this model, gas chromatography–mass spectroscopy (GC–MS) and liquid chromatography–mass spectroscopy (LC–MS) were used to characterize the rate of biopolymer accumulation and depletion in in hydrated Microcoleus vaginatus under light and dark conditions. Constraint-based flux balance analysis showed agreement between model predictions and experimental reaction fluxes. A significant amount of consumed carbon and light energy is invested into storage molecules glycogen and polyphosphate, while β-polyhydroxybutyrate may function as a secondary resource. Pseudo-steady-state modeling suggests that glycogen, the primary carbon source with the fastest depletion rate, will be exhausted if M. vaginatus experiences dark wetting events 4 times longer than light wetting events.

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