Small-Scale Vertical Distribution of Bacterial Biomass and Diversity in Biological Soil Crusts from Arid Lands in the Colorado Plateau

2003 ◽  
Vol 46 (3) ◽  
pp. 312-321 ◽  
Author(s):  
F. Garcia-Pichel ◽  
S. L. Johnson ◽  
D. Youngkin ◽  
J. Belnap
Keyword(s):  
Vertical Distribution ◽  
Colorado Plateau ◽  
Bacterial Biomass ◽  
Biological Soil Crusts ◽  
Arid Lands ◽  
Small Scale ◽  
Soil Crusts

Small-Scale Vertical Distribution of Algae and Structure of Lichen Soil Crusts

2011 ◽  
Vol 62 (3) ◽  
pp. 715-724 ◽  
Author(s):  
Li Wu ◽  
Shubin Lan ◽  
Delu Zhang ◽  
Chunxiang Hu
Keyword(s):  
Vertical Distribution ◽  
Small Scale ◽  
Soil Crusts

scholarly journals Diazotrophic Community Structure and Function in Two Successional Stages of Biological Soil Crusts from the Colorado Plateau and Chihuahuan Desert

2004 ◽  
Vol 70 (2) ◽  
pp. 973-983 ◽  
Author(s):  
Chris M. Yeager ◽  
Jennifer L. Kornosky ◽  
David C. Housman ◽  
Edmund E. Grote ◽  
Jayne Belnap ◽  
...  
Keyword(s):  
Community Structure ◽  
Chihuahuan Desert ◽  
Nitrogenase Activity ◽  
Colorado Plateau ◽  
Biological Soil Crusts ◽  
Rrna Gene ◽  
Soil Crusts ◽  
Clone Sequencing ◽  
Microcoleus Vaginatus ◽  
Diazotrophic Community

ABSTRACT The objective of this study was to characterize the community structure and activity of N2-fixing microorganisms in mature and poorly developed biological soil crusts from both the Colorado Plateau and Chihuahuan Desert. Nitrogenase activity was approximately 10 and 2.5 times higher in mature crusts than in poorly developed crusts at the Colorado Plateau site and Chihuahuan Desert site, respectively. Analysis of nifH sequences by clone sequencing and the terminal restriction fragment length polymorphism technique indicated that the crust diazotrophic community was 80 to 90% heterocystous cyanobacteria most closely related to Nostoc spp. and that the composition of N2-fixing species did not vary significantly between the poorly developed and mature crusts at either site. In contrast, the abundance of nifH sequences was approximately 7.5 times greater (per microgram of total DNA) in mature crusts than in poorly developed crusts at a given site as measured by quantitative PCR. 16S rRNA gene clone sequencing and microscopic analysis of the cyanobacterial community within both crust types demonstrated a transition from a Microcoleus vaginatus-dominated, poorly developed crust to mature crusts harboring a greater percentage of Nostoc and Scytonema spp. We hypothesize that ecological factors, such as soil instability and water stress, may constrain the growth of N2-fixing microorganisms at our study sites and that the transition to a mature, nitrogen-producing crust initially requires bioengineering of the surface microenvironment by Microcoleus vaginatus.

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.

Ecophysiological traits of various genotypes of a green key alga in biological soil crusts from the semi-arid Colorado Plateau, USA

2017 ◽  
Vol 29 (6) ◽  
pp. 2911-2923 ◽  
Author(s):  
Antje Donner ◽  
David Ryšánek ◽  
Tatiana Mikhailyuk ◽  
Ulf Karsten
Keyword(s):  
Colorado Plateau ◽  
Biological Soil Crusts ◽  
Ecophysiological Traits ◽  
Soil Crusts ◽  
Semi Arid

Archaeal populations in biological soil crusts from arid lands in North America

2009 ◽  
Vol 41 (10) ◽  
pp. 2069-2074 ◽  
Author(s):  
Tanya Soule ◽  
Ian J. Anderson ◽  
Shannon L. Johnson ◽  
Scott T. Bates ◽  
Ferran Garcia-Pichel
Keyword(s):  
North America ◽  
Biological Soil Crusts ◽  
Arid Lands ◽  
Soil Crusts

Soil Erosion in Mesic Forests: How do Biological Soil Crusts affect sediment transport and surface runoff?

2020 ◽  
Author(s):  
Corinna Gall ◽  
Martin Nebel ◽  
Dietmar Quandt ◽  
Michael Sauer ◽  
Thomas Scholten ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Surface Runoff ◽  
Dna Analysis ◽  
Soil Layer ◽  
Soil Surface ◽  
Biological Soil Crusts ◽  
Small Scale ◽  
Sediment Discharge ◽  
Soil Crusts ◽  
Disturbed Areas

<p>Soil erosion under forests occurs if forest layers get disturbed. Disturbances may arise from treefall, forest road works, skid trails or deforestation. In these disturbed areas, both an intact canopy and forest floor cover are missing, so that forest soils lack protection against water erosion. To counteract these negative effects a quick restoration of soil surface covers by vegetation is important. In particular, biological soil crusts (biocrusts) are able to quickly colonize gaps in higher vegetation and they are known to reduce soil erodibility. So far, the focus of biocrust research has been in drylands, whereas biocrusts have proven to be an important factor in mesic environments, especially as a pioneer vegetation in disturbed areas.</p><p>In this study, the natural succession of biocrusts in skid trails was observed on four different underlying substrates in a temperate European forest ecosystem (Schönbuch Nature Park in the state of Baden-Württemberg, Germany) and their influence on surface runoff, sediment discharge and nutrient relocation was investigated. Therefore, 144 micro-scale runoff plots (ROPs, 40 x 40 cm) were established with four replicates in the wheel tracks as well as in the center tracks and two replicates on undisturbed forest soil. In order to initiate splash and interrill erosion, four rainfall simulations were carried out from spring to winter with a constant intensity of 45 mm h<sup>-1</sup>. With the purpose to compare these small-scale erosion rates with a larger scale, additional turbidity sensors were installed in the catchment area. The biocrust succession was determined by regular vegetation surveys with a classification of mainly mosses and liverworts up to the species level. Additionally, DNA samples of the upper soil layer were collected to conduct DNA extractions specify other potential biocrust organisms such as lichens, cyanobacteria, fungi and algae.</p><p>First results show that surface runoff and sediment discharge are higher in the wheel track than in the center track and that both parameters are reduced with a higher developmental stage of soil surface cover. The vegetation survey demonstrates a quick development of moss-dominated biocrusts from April to October with up to ten different species in one ROP. Depending on the location of the skid trail, a quick development of the higher vegetation was observed as well. Lab work on nutrient relocation and DNA analysis is still in progress and further results will be presented at the EGU 2020.</p>

Export of nitrogenous compounds due to incomplete cycling within biological soil crusts of arid lands

2007 ◽  
Vol 9 (3) ◽  
pp. 680-689 ◽  
Author(s):  
Shannon L. Johnson ◽  
Susanne Neuer ◽  
Ferran Garcia-Pichel
Keyword(s):  
Biological Soil Crusts ◽  
Arid Lands ◽  
Nitrogenous Compounds ◽  
Soil Crusts
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