Effect of topography and protecting barriers on revegetation of sandy land, Southern Tibetan Plateau

Background. Sahara is one of the largest deserts in the world. The hard conditions especially high temperature and aridity lead to unique adaptation of organisms that could be a potential source of new metabolites. In this respect, two Saharan soils from El Oued Souf and Beni Abbes in Algeria were collected. The bacterial isolates were selected by screening the antibacterial, antifungal, and enzymatic activities. The whole genomes of the two native Saharan strains were sequenced to study the desert Streptomyces microbiology and ecology from genomic perspective. Results. The strains Babs14 (from Beni Abbes, Algeria) and Osf17 (from El Oued Souf, Algeria) were initially identified by 16S rRNA sequence as belonging to the Streptomyces genus. The whole genome sequencing of the two strains was performed by using Pacific Biosciences Sequel II technology (PacBio) and it showed that Babs14 and Osf17 have a linear chromosome of 8.00 Mb and 7.97 Mb, respectively. The number of identified proteins is 6910 in Babs14 and 6894 in Osf17. No plasmids were found in Babs14, whereas three plasmids were detected in Osf17 and no genome duplications were detected in the two strains. Although the strains have different phenotypes and are from different regions, they are slightly different from each other in protein sequence level but, differ more from their earlier published relatives. 29 biosynthetic gene clusters (BGCs) coding for secondary metabolites were predicted in each strain indicating antifungal, antibiotic, and other activities of Babs14 and Osf17. Moreover, many other BGCs were related to biosynthesis of factors needed in response to environmental stress in temperature, UV light and osmolarity. Conclusion. The genome sequencing of Saharan Streptomyces strains revealed factors that are related to their adaptation to an extreme environment and stress conditions. The genome information gives tools to study the ecological adaptation in desert environment and to explore the bioactive compounds of these microorganisms. The two whole genome sequences are among the first ones for the Streptomyces genus of Algerian Sahara. The present research was undertaken as a first step to explore more profoundly the desert microbiome.

show abstract

“…Sand dune habitats are changing by many factors e.g. dune encroachment, sand accumulation, and wind erosion [53].…”

Section: Discussionmentioning

confidence: 99%

Whole-genome Sequencing of Two Streptomyces Strains Isolated From Sand Dunes of Sahara

Zerouki

Bensalah

Kuittinen

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Natural restoration is an ecosystem management approach to reduce the adverse effects of unreasonable human activities, such as overgrazing, extensive land reclamation, and excessive firewood collection , Peng et al 2019. Artificial restoration mainly includes afforestation and revegetation of a seriously degraded land (Kang et al 2018, Liao et al 2019). Many scholars have initiated studies on ecological restoration to control the spread of aeolian desertification and restore degraded grasslands.…”

Section: Introductionmentioning

confidence: 99%

“…These studies have explored the artificial restoration of ecosystems , screening of suitable plant species (Li et al 2019a), the effects of fencing enclosures on soil seed banks (Shang et al 2013), and the effects of micro-topography on revegetation (Li et al 2019a). Previous studies have shown that Artemisia sphaerocephala, Artemisia younghusbandii, and Heteropappus gouldii are suitable as the pioneer species for revegetation of a sandy land (Li et al 2019a, Liao et al 2019. Previous studies have shown that Artemisia sphaerocephala, Artemisia younghusbandii, and Heteropappus gouldii are suitable as the pioneer species for revegetation of a sandy land (Li et al 2019a, Liao et al 2019.…”

Section: Introductionmentioning

confidence: 99%

“…Types of ecological restoration include artificial and natural restoration, which are considered as two effective measures for the management of degraded ecosystems (Jin et al 2014, Liao et al 2019. In 2015, the General Office of State Council of China promulgated "the opinions on accelerating the construction of an ecological civilization," proposing that natural restoration is the main measure in the process of ecological restoration and should be combined with artificial recovery; both these measures have been used to control desertification in the Tibetan Plateau (Li et al 2019a).…”

Section: Introductionmentioning

confidence: 99%

“…Li et al (2013) investigated the spatiotemporal variability of soil moisture in an aeolian riparian ecotone in an extremely dry year and found that the soil moisture content showed great spatial and temporal variability, and had a great effect on artificial restoration of the sandy land. Previous studies have shown that Artemisia sphaerocephala, Artemisia younghusbandii, and Heteropappus gouldii are suitable as the pioneer species for revegetation of a sandy land (Li et al 2019a, Liao et al 2019. However, few studies have been conducted to investigate the effect of ecological restoration on soil properties of sandy land, as well as the relationships between soil and plants in a phase of vegetation recovery, in the middle reaches of the Yarlung Zangbo River basin.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of ecological restoration on soil properties of the aeolian sandy land around Lhasa, southern Tibetan Plateau

Liao

et al. 2020

Ecosphere

Self Cite

View full text Add to dashboard Cite

2020. Effects of ecological restoration on soil properties of the aeolian sandy land around Lhasa, southern Tibetan Plateau. Ecosphere 11(1):e03009.Abstract. The ecological restoration of aeolian sandy land has not only improved the function of ecosystem services, such as wind prevention and sand fixation, but has also indirectly reduced the regional economic losses caused by sandstorms. However, the interaction between vegetation and soil properties after natural and artificial restoration of the sandy land in southern Tibetan Plateau has not been sufficiently studied. In the present study, we selected four vegetation types, including artificial forest (A), revegetated shrub (B), natural shrub (C), and natural grassland (D), in the sandy land in the middle reaches of the Yarlung Zangbo River basin, Tibet, China, and investigated the changes in soil particle size and nutrients at depths of 0-20 cm and 20-40 cm, finally examining the potential relationships between soil properties and leaf nutrients. Our results indicated that in the topsoil (0-20 cm), the natural shrub (C) and natural grassland (D) have greater silt content, recorded as 50.77% and 62.16%, respectively, compared to the artificial forest (A) and revegetated shrub (B). Natural grassland (D) had the highest silt content and the lowest soil bulk density (SBD) among the four vegetation types. There was no significant difference in the soil organic matter (SOM) in the topsoil of the different vegetation types. However, at the depth of 20-40 cm, the SOM content of the different vegetation types was in the following order: natural grassland (D) (23.37 g/ kg) > natural shrub (C) (17.42 g/kg) > revegetated shrub (B) (14.85 g/kg) > artificial forest (A) (8.43 g/kg). The ammonium nitrogen content in the revegetated shrub (B) was higher compared to the other vegetation types. The SOM content was significantly correlated with the total phosphorus (TP) and available phosphorus (AP) of the sandy land. The leaf total carbon, nitrogen, and phosphorus exhibited a positive correlation with SBD, AP, and available potassium. These findings can provide useful information to optimize the patterns of natural and artificial restoration for controlling desertification in similar eco-regions.

show abstract

Large‐scale modelling of highly braided and laterally confined reach of a sand‐bed river

Han

Sun

Lin

et al. 2023

Earth Surf Processes Landf

View full text Add to dashboard Cite

Morphological processes in sand‐bed braided rivers are highly complicated and dynamic, and it is challenging to fully comprehend and predict them quantitatively or even qualitatively. In this paper, we report the application of a physics‐based model with a single sediment fraction (D50 = 0.23 mm), based on field data, to simulate the morphodynamic processes of a large‐scale braided system in a wide valley of the middle Yarlung Tsangpo River in China. The model is capable of reproducing the evolution of large braided patterns at both microscopic and macroscopic scales, and simulating the formation of a high‐intensity braided reach from an initial lateral flat bed under lateral valley confinement. A narrow strip zone of braided corridor presents long‐term concentrated anabranches in the wide valley reach. Moreover, sensitivity analyses suggest that physics‐based modelling can simulate the multi‐thread river pattern even with relatively coarse grids and a large morphological acceleration factor. The model results show that active riverbed movement occurs and additional chutes are encouraged during flooding, while rising water level makes subchannels merge so that the statistical braiding index decreases. Conversely, only about 40% of the total channels are active in transporting sediment at low‐discharge stages, resulting in a local and slow bed scouring. The planimetric confinement of width variations and valley curvatures acts as a primary control on the local braided corridor and the forced bar assemblages. Width variations restrict the section‐average stream power for a given discharge event, while valley curvatures regulate velocity distribution through several control points. Moreover, the activities of riparian vegetation and sandstorm can interfere with the ability of rivers to braid in the corridor area, which requires much more attention in the follow‐up research.

show abstract

Effect of topography and protecting barriers on revegetation of sandy land, Southern Tibetan Plateau

Cited by 23 publications

References 41 publications

Whole-genome Sequencing of Two Streptomyces Strains Isolated From Sand Dunes of Sahara

Whole-genome Sequencing of Two Streptomyces Strains Isolated From Sand Dunes of Sahara

Effects of ecological restoration on soil properties of the aeolian sandy land around Lhasa, southern Tibetan Plateau

Large‐scale modelling of highly braided and laterally confined reach of a sand‐bed river

Contact Info

Product

Resources

About