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At least 19 recordsLinked to original sources
PubMed2026

Restoration contexts shape the bacterial and fungal soil communities in desertification hotspots in the Brazilian semiarid region.

Desertification in the Brazilian semiarid has compromised ecosystem functionality, impacting soil microbial biodiversity. Thus, restoration strategies have been implemented, aiming to mitigate the negative impacts. However, little is known about their effects on soil microbial communities. In this study, we hypothesized that the two restoration contexts would promote distinct trajectories of soil microbial community recovery. We evaluated 36 soil samples collected from two desertification hotspots in the Brazilian semiarid, representing active (Gilbués) and passive (Irauçuba) restoration contexts. Soil DNA was extracted and subjected to 16S and ITS amplicon sequencing to characterize bacterial and fungal communities, respectively. Community differences were assessed using alpha-diversity metrics, redundancy analysis (RDA), and PERMANOVA. The results showed that within Gilbués (active restoration), bacterial and fungal community composition differed among soils under desertification and restoration. In Irauçuba (passive restoration), only native soils differed from both soils under desertification and restoration. Proteobacteria, Actinobacteriota, and Firmicutes (bacteria), and Ascomycota and Basidiomycota (fungi), were the dominant phyla in both hotspots. Bacterial and fungal communities showed distinct taxonomic patterns among native, degraded, and restored soils within each restoration context. Niche occupancy patterns also differed between restoration contexts. In conclusion, the two hotspots followed contrasting microbial recovery trajectories, demonstrating that restoration responses are context-dependent and vary according to the microbial groups, rather than supporting the universal superiority of one restoration strategy over the other.

Soil Microbiology↗
PubMed2002

[Prospect of the study on desertification and its restoration of Keerqin sandy land].

In this paper, the study on desertification and its restoration of the Keerqin sandy land was briefly reviewed. With reference to the trends in related scientific fields and pressing demand in restoring existing desertified lands, several key aspects, including vegetation processes, eco-hydrological processes, landscape processes, and assessment of regional environmental state, prediction of desertification trends and exploration of restoration measures for the whole Keerqin sandy land, aimed to discover mechanisms leading to desertification and to restore desertified lands, were raised.

Agriculture↗
PubMed1991

[Desertification and animal health in the Sahel].

This article reviews the causes of desertification proposed by various authors. For a long time, overgrazing of pastures in the Sahel was considered responsible for rapid degradation of the soil. Consequently, the owners of livestock have been accused of enlarging their flocks, and animal husbandry services of involuntary complicity, since their action has reduced the occurrence of epizootics which used to decimate the flocks. The underlying causes of overstocking of pastures and of desertification are in fact multiple and intertwined: population pressure, drought, changes in land ownership systems, social changes. For this reason, the problems of animal production cannot be treated in isolation, and strategies devised by numerous organisations for combating desertification are taking into account the different causes of a situation which can be described, without exaggeration, as a catastrophe. So far there has been no consensus on a given strategy, and results seem to be disappointing, perhaps because the resources have been inadequate, and the schemes have not been supported by the populations involved. Moreover, projects conceived on a global and theoretical basis may not cater for the diversity of actual situations. In contrast, animal health actions, by their concrete nature, directly involve nomadic and sedentary owners of animals and motivate the populations. They remain an indispensable factor in the development of livestock husbandry and its necessary integration with agriculture where both activities can coexist. They are also a preliminary step to intensification in pastoral zones, which makes better management of forage resources possible.

Animal Husbandry↗
PubMed1989

Ecological upheavals with special reference to desertification and predicting health impact.

This paper begins with an introduction that touches on the ecological upheavals of earthquakes, floods, as well as other upheavals that result from sudden huge crowding of people in one place such as in refugee situations and situations of a famine disaster. The point is made that for sudden emergencies the health impact will very much depend on the nature of traumatic physical damage on the people's bodies and property as well as the capacity with which response is organised for assessment of damage and medical management. A number of texts are mentioned with respect to management in emergencies, including health, feeding and water and the point made that familiarity with these texts provides a starting point in responding to emergencies. These have put together information on how one goes about organising the response to save lives. Also mentioned are the consequences of the approach taken to providing food in these situations; whether it is through distribution of dry ration to be taken home, or whether one is dealing with shelter situations. In this introduction, land degradation/desertification is mentioned as being the largest and possibly the most devastating ecological upheaval. The rest of the paper goes on to address this ecological upheaval of land degradation/desertification. The magnitude of this upheaval is presented. The contribution of overcultivation, overgrazing, deforestation and irrigation to desertification are discussed. The health consequence of this process is then presented and finally, there is a discussion on the challenges that social scientists and health professionals could help to address in order to bring about some appropriate interventions that would contribute to arresting and possibly reversing the desertification process.

Africa↗
PubMed2000

[Ecological study on relationship between desertification process and vegetation dynamics in west of northeast China: vegetation classification].

Based on the data obtained from 72 plant community plots and 276 plant species in Hulunbeier Sandy Land and Kerqin Sandy Land in the northeast desertification region of China, TWINSPAN analysis was carried out. Meanwhile the practical classification result was obtained by Detrended correspondence Analysis (DCA). Under the vegetation classification principles of China, the vegetation classification system of the desertification regions in northeast China was preliminarily established, which includes 6 vegetation types, 11 subtypes, 40 formations, and 55 associations.

China↗
PubMed2002

[Correlation between desertification and variations of soil and surface vegetation in agriculture-pasture ecotone--a case study in Kangbao County, northern Hebei Province].

In the agriculture-pasture ecotone, due to its specific natural condition, the natural system is unstable, the self-regulation capability is weak, the equilibrium is easily broken, and hence the habitat is fairly vulnerable. During last 20 years, the increasing population and livestock, over-reclamation, over-grazing, over-deforesting, and other intensified negative human activities in this area resulted in surface soil coarsening, organic matter content in soil decreasing, vegetation coverage decreasing, community structure varying and degrading, and hence desertification of the land was aggravated. The results also proved that there was close correlation between desertification and the variations of soil and surface vegetation.

Agriculture↗
PubMed2002

Onset of Asian desertification by 22 Myr ago inferred from loess deposits in China.

The initial desertification in the Asian interior is thought to be one of the most prominent climate changes in the Northern Hemisphere during the Cenozoic era. But the dating of this transition is uncertain, partly because desert sediments are usually scattered, discontinuous and difficult to date. Here we report nearly continuous aeolian deposits covering the interval from 22 to 6.2 million years ago, on the basis of palaeomagnetic measurements and fossil evidence. A total of 231 visually definable aeolian layers occur as brownish loesses interbedded with reddish soils. This new evidence indicates that large source areas of aeolian dust and energetic winter monsoon winds to transport the material must have existed in the interior of Asia by the early Miocene epoch, at least 14 million years earlier than previously thought. Regional tectonic changes and ongoing global cooling are probable causes of these changes in aridity and circulation in Asia.

Journal Article↗
PubMed2003

Recent trends of plutonium fallout observed in Japan: plutonium as a proxy for desertification.

Plutonium in monthly deposition samples collected in Tsukuba (the Meteorological Research Institute), Japan from 1990 to end of 2001 is reported, together with monthly plutonium deposition in Nagasaki and Yonaguni in 2000. The annual deposition of (239,240)Pu during the period from 1990 to 2001 shows no systematic interannual variation. However, monthly (239,240)Pu depositions show a typical seasonal variation with a maximum in spring season (March to April), which corresponds to seasonal cycle of soil dusts originating from the East Asian arid area. Plutonium isotopic ratios in the deposition samples suggest that significant amounts of the recent (239,240)Pu deposition observed in Japan are attributed to the resuspension of plutonium-bearing surface soil particles; resuspended plutonium originates from the East Asian arid areas. The recent increased tendency of (239,240)Pu content in residues in deposition samples may reflect desertification in the East Asian continent.

Asia↗
PubMed2001

Desert dust suppressing precipitation: a possible desertification feedback loop.

The effect of desert dust on cloud properties and precipitation has so far been studied solely by using theoretical models, which predict that rainfall would be enhanced. Here we present observations showing the contrary; the effect of dust on cloud properties is to inhibit precipitation. Using satellite and aircraft observations we show that clouds forming within desert dust contain small droplets and produce little precipitation by drop coalescence. Measurement of the size distribution and the chemical analysis of individual Saharan dust particles collected in such a dust storm suggest a possible mechanism for the diminished rainfall. The detrimental impact of dust on rainfall is smaller than that caused by smoke from biomass burning or anthropogenic air pollution, but the large abundance of desert dust in the atmosphere renders it important. The reduction of precipitation from clouds affected by desert dust can cause drier soil, which in turn raises more dust, thus providing a possible feedback loop to further decrease precipitation. Furthermore, anthropogenic changes of land use exposing the topsoil can initiate such a desertification feedback process.

Journal Article↗
PubMed2001

Diversity of vegetation patterns and desertification.

A new model for vegetation patterns is introduced. The model reproduces a wide range of patterns observed in water-limited regions, including drifting bands, spots, and labyrinths. It predicts transitions from bare soil at low precipitation to homogeneous vegetation at high precipitation, through intermediate states of spot, stripe, and hole patterns. It also predicts wide precipitation ranges where different stable states coexist. Using these predictions we propose a novel explanation of desertification phenomena and a new approach to classifying aridity.

Desert Climate↗
PubMed1990

Urban desertification, public health and public order: 'planned shrinkage', violent death, substance abuse and AIDS in the Bronx.

Techniques and approaches from population and community ecology, along with theoretical viewpoints from criminology and the 'social support hypothesis' of health maintenance, are used to examine recent patterns of rising homicide and suicide, intensified substance abuse, low birth weight and AIDS deaths in the Bronx section of New York City. Empirical and theoretical analyses strongly imply present sharply rising levels of violent death, intensification of deviant behaviors implicated in the spread of AIDS, and the pattern of the AIDS outbreak itself, have been gravely affected, and even strongly determined, by the outcomes of a program of 'planned shrinkage' directed against African-American and Hispanic communities, and implemented through systematic and continuing denial of municipal services--particularly fire extinguishment resources--essential for maintaining urban levels of population density and ensuring community stability. This work complements a recent study by McCord and Freeman [1. New Engl. J. Med. 332, 173, 1990] on Harlem, and suggests the present overburdening of New York's criminal justice system arises from almost exactly the same causes as its accelerating inability to meet demands for acute medical service, so-called 'medical gridlock', in that both are expressions of the increasing social disorganization of poor communities initiated and continued in considerable part by government policy. The critical role played by improper policy in triggering the syndrome suggests ecologically informed interventions, particularly essential service restoration, may hold the potential for great positive impact.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Desertification: measuring population decline in rural Ireland.

"This paper addresses the issue of rural population decline in the Republic of Ireland during the past two decades having regard to size of place and estimated net migration for key age groups. The analysis is pursued at the level of some 160 Rural Districts. The results of the analysis confirm expected relationships between peripheral locations, small population size and a depletion of the young working age groups. The method used, however, permits the links between size of place, population change and the composition of that change to be identified with some precision."

Age Factors↗