The role of cyanobacteria in stabilization of sand dunes in Southern Israel

Danin, Avinoam; Bar-Or, Y.; Dor, Inka; Yisraeli, T.

doi:10.3406/ecmed.1989.1633

Cited by 117 publications

(31 citation statements)

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“…90 mm, with annual fluctuations of 47-13 1 mm during the years 1989-1994. The rainy season is limited to [4][5].…”

Section: Regional Climatic Conditionsmentioning

confidence: 99%

“…Microbial crust samples of each type were collected from several locations within the dune area. Each location with a different crust type was sampled several times (4)(5) during the summer and assayed for chlorophyll a, polysaccharides and protein. Standard deviation for each parameter within each group was f 50%.…”

Section: Optimization Of Growth and Polysaccharide Excretionmentioning

confidence: 99%

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The role of cyanobacterial exopolysaccharides in structuring desert microbial crusts

Mazor

1996

FEMS Microbiology Ecology

132

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Microbialcrusts are present on surfaces of soils throughout the world. A key feature of these crusts in arid zones is the abundance of filamentous sheath-forming and polysaccharide-excreting cyanobacteria. Several isolates of cyanobacteria were prepared from crust samples (Nizzana sand dunes, north-western Negev Desert, Israel). Optimal growth conditions for two such isolates of Microcoleus sp. were defined, and the role of the excreted polysaccharides in affecting the hydrological properties of crust-covered sand dunes was studied. Experiments with the native crust microbial population demonstrated the possibility of net primary productivity at both high relative air humidities and low moisture content.

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“…90 mm, with annual fluctuations of 47-13 1 mm during the years 1989-1994. The rainy season is limited to [4][5].…”

Section: Regional Climatic Conditionsmentioning

confidence: 99%

Section: Optimization Of Growth and Polysaccharide Excretionmentioning

confidence: 99%

The role of cyanobacterial exopolysaccharides in structuring desert microbial crusts

Mazor

1996

FEMS Microbiology Ecology

132

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“…Sand dunes cover vast areas in arid and coastal regions (∼ 10% of Earth's terrestrial surface [Pye, 1982;Pye and Tsoar, 1990;Thomas and Wiggs, 2008]) and, therefore, are considered to be an important component of ecosystems [Tsoar, 2008;Veste et al, 2001;Shanas et al, 2006] and climate [Thomas et al, 2005;Ashkenazy et al, 2012;Otterman, 1974;Charney et al, 1975] dynamics. Dunes may be stabilized by vegetation and/or biogenic soil crust (BSC) [Danin et al, 1989]; since vegetation can only exist above a certain precipitation threshold (typically ∼ 50 mm/year [Tsoar, 2005]), sand dune dynamics and activity in arid regions are affected by the precipitation rate.…”

Section: Introductionmentioning

confidence: 99%

The effects of psammophilous plants on sand dune dynamics

Bel

Ashkenazy

2014

JGR Earth Surface

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Mathematical models of sand dune dynamics have considered different types of sand dune cover. However, despite the important role of psammophilous plants (plants that flourish in moving-sand environments) in dune dynamics, the incorporation of their effects into mathematical models of sand dunes remains a challenging task. Here we propose a nonlinear physical model for the role of psammophilous plants in the stabilization and destabilization of sand dunes. There are two main mechanisms by which the wind affects these plants: (i) sand drift results in the burial and exposure of plants, a process that is known to result in an enhanced growth rate, and (ii) strong winds remove shoots and rhizomes and seed them in nearby locations, enhancing their growth rate. Our model describes the temporal evolution of the fractions of surface cover of regular vegetation, biogenic soil crust, and psammophilous plants. The latter reach their optimal growth under either (i) specific sand drift or (ii) specific wind power. The model exhibits complex bifurcation diagrams and dynamics, which explain observed phenomena, and it predicts new dune stabilization scenarios. Depending on the climatological conditions, it is possible to obtain one, two, or, predicted here for the first time, three stable dune states. Our model shows that the development of the different cover types depends on the precipitation rate and the wind power and that the psammophilous plants are not always the first to grow and stabilize the dunes.

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“…The microphytic patches of the northern Negev possess a well-developed soil crust typical of loessial soils. These patches differ from microphytic soil crusts on sand dunes (Danin et al 1990) in that the loessial crusts are thicker, generate more runoff, and are more resistant to disturbance than are crusts on sand dunes in Israel (Yair et al 1995) or most crusts in the western United States (Harper and Marble 1988).…”

Section: Introductionmentioning

confidence: 99%

Atmospheric Deposition to a Desert Ecosystem and Its Implications for Management

Shachak¹,

Lovett²

1998

Ecological Applications

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The Negev Desert in Israel is a mosaic of macrophytic patches, consisting of shrubs and annual plants growing in a soil mound, and microphytic patches, consisting of algae, cyanobacteria, bacteria, mosses, and lichens growing on a soil crust. Accumulation of soil is often a limiting resource in this ecosystem, so the loose soil mound in the macrophytic patch permits relatively high production of annual plants. To determine whether atmospheric deposition was responsible for soil mound formation, we measured particle deposition in macrophytic and microphytic patches. Our results show that fine particles, consisting mostly of mineral dust, are deposited at similar rates in macrophytic and microphytic patches. However, coarse particles, which are primarily composed of organic material from plant detritus, are deposited at greater rates in macrophytic compared to microphytic patches. The coarse particles have higher concentrations of carbon and nitrogen than the fine particles. Further experimentation showed that much of the runoff water generated from microphytic patches is captured by macrophytic patches downslope. Calculations based on the measured deposition rates suggest that a typical soil mound would require at least 180-290 yr to develop. Since the presence of the soil mound is crucial for annual plant germination and growth, and since annual plants are the major source of productivity in the system, these results imply that the system will be slow to recover from disturbances that reduce the abundance of macrophytic patches, such as livestock grazing and firewood cutting.

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The role of cyanobacteria in stabilization of sand dunes in Southern Israel

Cited by 117 publications

References 0 publications

The role of cyanobacterial exopolysaccharides in structuring desert microbial crusts

The role of cyanobacterial exopolysaccharides in structuring desert microbial crusts

The effects of psammophilous plants on sand dune dynamics

Atmospheric Deposition to a Desert Ecosystem and Its Implications for Management

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