Search results for "desert"
showing 10 items of 149 documents
Olive Yield and Future Climate Forcings
2013
Abstract The rainfall reduction and the temperature increase forecasted for Mediterranean regions would likely increase the vegetation water stress and decrease productivity in rainfed agriculture. Olive trees, which have traditionally been grown under rainfed conditions, are one of the most characteristic tree crops from the Mediterranean not only for economical importance but also for minimizing erosion and desertification and for improving the carbon balance of these areas. In order to simulate how climatic change could alter soil moisture dynamics, biomass growth and fruit productivity, a water driven crop model is used in this study. The model quantitatively links olive yield to climat…
Soil degradation and its impact on desertification: A research design for Mediterranean environments
1988
Summary Much is said but little is known of the processes and linkages of soil degradation with desertification. With particular emphasis on South-East Spain, a research design is proposed to characterize the processes, their dynamics and effect on productivity. Through detailed monitoring of plot experiments at three slope positions, changes in soil physical and chemical parameters and analyses of runoff and eroded sediments will be related to induced destruction of the vegetation. Knowing the cause and process will lead to the identification of management techniques that may protect vulnerable Mediterranean environments.
LAND USE CHANGE DETECTION AS A BASIS FOR ANALYSING DESERTIFICATION PROCESSES: A CASE STUDY IN TABERNAS (ALMERIA, SPAIN)
2006
12 paginas, 5 figuras, 1 tabla. Proceedings of the NATO Mediterranean Dialogue Workshop on Desertification in the Mediterranean Region. A Security Issue -- Part III. Assessing land use change relative to anthropogenic and natural cause. Valencia, Spain 2-5 December 2003
Impact of Rocky Desertification Control on Soil Bacterial Community in Karst Graben Basin, Southwestern China
2021
Microorganisms play critical roles in belowground ecosystems, and karst rocky desertification (KRD) control affects edaphic properties and vegetation coverage. However, the relationship between KRD control and soil bacterial communities remains unclear. 16S rRNA gene next-generation sequencing was used to investigate soil bacterial community structure, composition, diversity, and co-occurrence network from five ecological types in KRD control area. Moreover, soil physical-chemical properties and soil stoichiometry characteristics of carbon, nitrogen and phosphorus were analyzed. Soil N and P co-limitation decreased in the contribution of the promotion of KRD control on edaphic properties. T…
A round trip to the desert: In situ nanopore sequencing informs targeted bioprospecting
2021
Bioprospecting expeditions are often performed in remote locations, in order to access previously unexplored samples. Nevertheless, the actual potential of those samples is only assessed once scientists are back in the laboratory, where a time-consuming screening must take place. This work evaluates the suitability of using Nanopore sequencing during a journey to the Tabernas Desert (Spain) for forecasting the potential of specific samples in terms of bacterial diversity and prevalence of radiation- and desiccation-resistant taxa, which were the target of the bioprospecting activities. Samples collected during the first day were analyzed through 16S rRNA gene sequencing using a mobile labor…
Spatial segregation of the biological soil crust microbiome around its foundational cyanobacterium, Microcoleus vaginatus, and the formation of a nit…
2019
12 pages; International audience; Background Biological soil crusts (biocrusts) are a key component of arid land ecosystems, where they render critical services such as soil surface stabilization and nutrient fertilization. The bundle-forming, filamentous, non-nitrogen-fixing cyanobacterium Microcoleus vaginatus is a pioneer primary producer, often the dominant member of the biocrust microbiome, and the main source of leaked organic carbon. We hypothesized that, by analogy to the rhizosphere of plant roots, M. vaginatus may shape the microbial populations of heterotrophs around it, forming a specialized cyanosphere. Results By physically isolating bundles of M. vaginatus from biocrusts, we …
High Culturable Bacterial Diversity From a European Desert: The Tabernas Desert.
2020
One of the most diverse ecological niches for microbial bioprospecting is soil, including that of drylands. Drylands are one of the most abundant biomes on Earth, but extreme cases, such as deserts, are considered very rare in Europe. The so-called Tabernas Desert is one of the few examples of a desert area in continental Europe, and although some microbial studies have been performed on this region, a comprehensive strategy to maximize the isolation of environmental bacteria has not been conducted to date. We report here a culturomics approach to study the bacterial diversity of this dryland by using a simple strategy consisting of combining different media, using serial dilutions of the n…
Does fragmentation of wetlands affect gene flow in sympatric Acrocephalus warblers with different migration strategies?
2015
Wetlands are naturally patchy habitats, but patchiness has been accentuated by the extensive wetlands loss due to human activities. In such a fragmented habitat, dispersal ability is especially important to maintain gene flow between populations. Here we studied population structure, genetic diversity and demographic history of Iberian and North African populations of two wetland passerines, the Eurasian reed warbler Acrocephalus scirpaceus and the moustached warbler Acrocephalus melanopogon. These species are closely related and sympatric in our study sites, but the reed warbler is a long-distance migrant and widespread bird while the moustached warbler is resident or migrates over short d…
Short note of field workshop on Neoproterozoic ophiolites, ophiolitic mélanges and other rock units in the Eastern Desert of Egypt and comparison wit…
2016
The Neoproterozoic Arabian–Nubian Shield (ANS) and the latest Mesoproterozoic to late Palaeozoic Central Asian Orogenic Belt (CAOB) are two large and long-lived accretionary orogens. Both are mostl...
NDVI seasonal amplitude and its variability
2008
NDVI (Normalized Difference Vegetation Index) is a remotely sensed index of vegetation greenness. Its yearly cycle gives information on vegetation type or health, and monitoring its temporal evolut...