 |
| Titel |
Identifying key soil cyanobacteria easy to isolate and culture for arid soil restoration |
| VerfasserIn |
Beatriz Roncero-Ramos, M. Ángeles Muñoz-Martín, Sonia Chamizo, Raúl Román, Emilio Rodriguez-Caballero, Pilar Mateo, Yolanda Cantón |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138067
|
| Publikation (Nr.) |
 EGU/EGU2017-976.pdf |
|
|
|
|
|
| Zusammenfassung |
| Drylands represent an important fraction of the Earth land’s surface. Low cover of vascular
plants characterizes these regions, and the large open areas among plants are often colonized
by cyanobacteria, mosses, lichens, algae, bryophytes, bacteria and fungi, known as biocrusts.
Because these communities are on or within the soil surface, they contribute to
improve physicochemical properties of the uppermost soil layers and have important
effects on soil fertility and stability, so they could play an important role on soil
restoration. Cyanobacteria appear to be a cross component of biocrusts and they have
been demonstrated to enhance water availability, soil fertility (fixing atmospheric
C and N), and soil aggregation (thanks to their filamentous morphology and the
exopolysaccharides they excrete), and significantly reduce water and wind erosion. Besides,
they are able to tolerate high temperatures and UV radiation. All these features
convert cyanobacteria in pioneer organisms capable of colonizing degraded soils and
may be crucial in facilitating the succession of more developed organisms such as
vascular plants. Therefore, the use of native cyanobacteria, already adapted to site
environmental conditions, could guarantee a successful restoration approach of
degraded soils. However, previous to their application for soil restoration, the most
representative species inhabiting these soils should be identified. The objective of this
study was to identify (morphologically and genetically) and isolate representative
native cyanobacteria species from arid soils in SE Spain, characterized for being
easily isolated and cultured with the aim of using them to inoculate degraded arid
soil.
We selected two study areas in Almería, SE Spain, where biocrust cover most of the open
spaces between plants: El Cautivo experimental site located in the Tabernas desert and a
limestone quarry located at the southeastern edge of the Gádor massif. The first site is
characterized by scarcely developed soils with low thickness, poor structure and low organic
matter content, while soils in the second site present high degradation due to human
activities. Cyanobacterial biocrust at different developmental stages were collected and
maintained in the laboratory under dry and dark conditions until they were processed.
Different culture media, with and without N, were used to isolate single trichomes, in order to
have representatives of N fixing and non-fixing cyanobacteria. The isolated strains were
morphological and genetically characterized by sequencing the 16S rRNA gene and
phylogenetic analyses.
Results from cultures of several soil samples with different media show that the most
representative soil cyanobacteria genera in these areas and easiest to maintain under
laboratory conditions were: Scytonema, Tolypothrix, Leptolyngbya and Trichocoleus from the
El Cautivo experimental site; and Nostoc, Tolypothrix and Leptolyngbya from the limestone
quarry.
In this study, we present a description of some of the cyanobacteria colonizing biocrust in
these area, which are easy to be isolated and cultured under laboratory conditions, as a
previous step to design a restoration method for their inoculation on degraded soils. |
|
|
|
|
|
|