Photo credit: Desert Restoration Hub
Overgrazing, as seen in Botswana, can also leave the soil exposed and easily eroded, and is therefore an indicator of land degradation. Compare the vegetation on the grazed and ungrazed sides of the fence (picture M.Reed)
A Drylands and Desert Restoration Hub
There is great need to restore existing despoiled drylands and to combat increasing desertification. Restoring habitats improves biodiversity, increases carbon sequestration, enhancing the quality of life for people. An essential measure is the planting of and reestablishment of vegetation. The successful establishment of vegetation in arid areas is complex requiring the multi-disciplinary skills of arid land experts with various capabilities, in soils, hydrology, ecology, agronomy, land management etc. However, vegetation restoration techniques in arid areas require review and development. Information on restoration is highly dispersed and often difficult to obtain.
The creation of the ‘Drylands and Desert Restoration Hub’ is thus aimed to bring together the expertise, knowledge and information on vegetation establishment and management that exists in the EU and around the world. The drylands and desert restoration hub provides a focus for information for all stakeholders.
The Action is devised to provide the science and practical guidance for dryland restoration and combat of desertification through coordinated data-collection with an integrated database within a harmonized information hub of current and new methods and techniques of restoration, trials and field studies, assessment indicators, academic and practical publications, and tools to identify and support practical restoration projects and decision makers in planning and restoring drylands and the combat of desertification. The Action promotes open knowledge, innovation in procedures and methods for improved restoration in dry lands.
Read the full article: Desert Restoration Hub
Photo credit: GFCS
Implementation of Drought Early-warning System over IRAN (DESIR)
Iran’s precipitation is approximately one third of global average and distribution of the monthly rainfall has been changed in recent years. Water scarcity has many environmental and socio-economical impacts over Iran. Unlike to the floods that have limited coverage areas, water scarcity impacts cover vast regions. By increasing global mean temperature, drought and population, water and its consumption has become important. This may even become more significant in those countries where the volume of rainfall is limited. Occurrence of drought is one of the main reasons of the water crisis. Implementation of a drought early warning system is the most important priority for I. R. of Iran Meteorological Organization (IRIMO).
Read the full article: Global Framework Climate Services
Photo credit: Pixabay
Is drought-induced forest dieback globally increasing?
by Jörg Steinkamp and Thomas Hickler
Journal of Ecology – , Issue 1, p. 31–43
- Recently, it has been suggested that forest mortality has been generally increasing because of increasing drought and heat stress. But it is unclear if the observations at the investigated forest sites and regions are representative of forests globally and it has not been tested whether forest models are capable of reproducing these observations. We analysed historical climate data and used a dynamic global vegetation model (LPJ-GUESS) to assess (i) Which forests globally might have been affected by drought, (ii) If the field observations are representative for all forests and (iii) If the model can reproduce the reported mortality events.
- Using two climate data sets and three drought indices, we identified no general global drying trend across all forests, but a large spatial variability. We neither detected a general increase in extreme drought events. A weak drying trend and an increase in extreme drought events were only apparent for forests in already dry climates and the locations or regions for which drought-induced mortality trends have been reported are predominantly in these dry climates.
- LPJ-GUESS reproduced 66% of the reported mortality events and in 49% of the reported drought-induced mortality events drought was apparent in any of the climatologically derived drought indices. However, only in 30% of the cases simulated increased mortality coincided with drought events.
- Synthesis. Our results indeed suggest that dry forests have been experiencing increasing drought-induced mortality. However, this does not apply to forests in general and the spatial variability has been large. The poor correspondence between the simulated and reported mortality events indicates that models like LPJ-GUESS driven by standard climatologies, and soil input data do not represent drought-induced mortality well. But the poor detection of the reported drought events in our climate indices also suggests that drought stress might not be the main driver of all the reported drought-mortality events.
Photo credit: Pixabay
Monitoring land-cover changes in semi-arid regions: remote sensing data and field observations in the Ferlo, Senegal
by A. Diouf and E.F. Lambin
Dryland degradation rarely translates into linear, declining trends in vegetation cover due to interannual climatic variability. Appropriate indicators of land-cover modifications need to be defined for semi-arid regions.
Our hypothesis is that degradation can be measured by:
- (1) a decrease in the resilience of vegetation to droughts;
- (2) a decrease in rain-use efficiency; and
- (3) a modification of floristic composition.
The objective of this paper is to test the relationships between a remotely sensed indicator of vegetation, rainfall data and field measurements of biomass and floristic composition.
The study was based on field measurements of vegetation conditions covering a period of 10 years, in the semi-arid region of the Ferlo in Senegal.
Our results indicate that land-cover modifications in the Ferlo are best measured by changes in rain-use efficiency. No consistent trend in the relative abundance of grass species was visible at the scale of the decade, even on the two sites affected by degradation. Just after a drought, a given increase in rainfall results in less biomass production than is the case for normal years.
Read the full article: Science Direct
Read at : Google Alerts – desertification
Evaluation and Selection of Indicators for Land Degradation and Desertification Monitoring: Types of Degradation, Causes, and Implications for Management.
, Kosmas C
, Karavitis C
, Ritsema C
, Salvati L
, Acikalin S
, Alcalá M
, Alfama P
, Atlhopheng J
, Barrera J
, Belgacem A
, Solé-Benet A
, Brito J
, Chaker M
, Chanda R
, Coelho C
, Darkoh M
, Diamantis I
, Ermolaeva O
, Fassouli V
, Fei W
, Feng J
, Fernandez F
, Ferreira A
, Gokceoglu C
, Gonzalez D
, Gungor H
, Hessel R
, Juying J
, Khatteli H
, Khitrov N
, Kounalaki A
, Laouina A
, Lollino P
, Lopes M
, Magole L
, Medina L
, Mendoza M
, Morais P
, Mulale K
, Ocakoglu F
, Ouessar M
, Ovalle C
, Perez C
, Perkins J
, Pliakas F
, Polemio M
, Pozo A
, Prat C
, Qinke Y
, Ramos A
, Ramos J
, Riquelme J
, Romanenkov V
, Rui L
, Santaloia F
, Sebego R
, Sghaier M
, Silva N
, Sizemskaya M
, Soares J
, Sonmez H
, Taamallah H
, Tezcan L
, Torri D
, Ungaro F
, Valente S
, de Vente J
, Zagal E
, Zeiliguer A
, Zhonging W
, Ziogas A
Laboratory of Soils, Agricultural University of Athens
Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17 study sites around the world using a wide set of biophysical and socioeconomic indicators.
The database described earlier in this issue by Kosmas and others (Environ Manage, 2013) for defining desertification risk was further analyzed to define the most important indicators related to the following degradation processes: water erosion in various land uses, tillage erosion, soil salinization, water stress, forest fires, and overgrazing. A correlation analysis was applied to the selected indicators in order to identify the most important variables contributing to each land degradation process.
The analysis indicates that the most important indicators are: (i) rain seasonality affecting water erosion, water stress, and forest fires, (ii) slope gradient affecting water erosion, tillage erosion and water stress, and (iii) water scarcity soil salinization, water stress, and forest fires. Implementation of existing regulations or policies concerned with resources development and environmental sustainability was identified as the most important indicator of land protection.
Read at :
UNCCD Expert Group on Impact Indicators Discusses Outputs
The Secretariat of the UN Convention to Combat Desertification (UNCCD) has posted the report from the second meeting of the Ad Hoc Advisory Group of Technical Experts (AGTE) for Impact Indicator Refinement.
This Group was tasked by the tenth meeting of the Conference of the Parties (COP 10) to address four issues: identify the best scientific approach to operationally delineate affected areas; develop a mechanism that encourages country Parties to identify nationally and locally relevant impact indicators and integrate them in their contribution to the global impact assessment effort; further refine the set of the provisionally adopted impact indicators; and develop a scientifically-based approach for integrating, analyzing and interpreting impact-indicator information.
Read at : Google Alerts – desertification
A spatial desertification indicator for Mediterranean arid rangelands: a case study in Algeria
by Slim Saïdi and Gustave Gintzburger
Sheep and goat production is the main and sometimes only agricultural activity available to populations living on rangelands in the arid regions around the Mediterranean. Desertification threatens large areas of Mediterranean arid rangelands but remains difficult to describe, quantify and accurately locate for management purposes. A methodology is described which estimates a Spatial Rain-Use Efficiency Index (SRUEI) and its potential use to evaluate rangeland condition at a large scale. It is based on an Aboveground Net Primary Production (AGNPP) map generated from field herbage mass measurements and a rainfall spatial distribution map derived from local elevation–rainfall gradients with the whole resulting from satellite imagery processing and GIS technology. The area of the case study was in the Nâama–Mecheria region located on the High Plateau south of Oran (Algeria). It covers ~215 000 ha, receiving ~200 mm year–1 of winter and spring precipitation.
The Nâama–Mecheria SRUEI-derived map clearly shows the degradation gradient declining away from the settlements. The Mecheria AGNPP 2007 map and associated grazing rings indicate that the Mecheria cooperative flocks may ingest 48–57% (Range Use Factor) of the rangeland’s seasonal plant production, which is barely compatible with sustainable rangeland use. When adding the effect of fuel wood collection by local residents and rain-fed arable cropping, the Nâama–Mecheria region is undoubtedly heading towards a slow but certain desertification of its fragile arid rangelands unless correcting measures are implemented. The SRUEI and associated results are powerful tools that allow rangeland conditions to be mapped, and which can be employed in planning and pursuing sustainable management of rangelands in such arid areas.
Read at :
A test of critical thresholds and their indicators in a desertification-prone ecosystem: more resilience than we thought
submitted by tozzaka
Theoretical models predict that drylands can cross critical thresholds, but experimental manipulations to evaluate them are non-existent. We used a long-term (13-year) pulse-perturbation experiment featuring heavy grazing and shrub removal to determine if critical thresholds and their determinants can be demonstrated in Chihuahuan Desert grasslands. We asked if cover values or patch-size metrics could predict vegetation recovery, supporting their use as early-warning indicators. We found that season of grazing, but not the presence of competing shrubs, mediated the severity of grazing impacts on dominant grasses.
Appreciating very much your past commitment to the process of refinement of the UNCCD impact indicators, I would like to draw your attention to the fact that the UNCCD secretariat has launched a call for inviting applications from experts to act as members of the ad hoc Advisory Group of Technical Experts for Impact Indicator Refinement. The call starts on 1st March 2012 and ends on 31 2012 24:00 GMT.
I would kindly invite you to submit your application form with a copy of your curriculum vitae to email@example.com
Details can be found here:
Read at : DNI News
The UNCCD secretariat has launched a call for inviting applications from experts to act as members of the ad hoc Advisory Group of Technical Experts for Impact Indicator Refinement.
The call starts on 1st March 2012 and ends on 31 2012 24:00 GMT.
Details can be found here: http://www.unccd.int/science/announce/agte.php <http://www.unccd.int/science/announce/agte.php>
Victor M. Castillo
Programme Officer- KMST Unit
Read at : DesertNet News UNCCD
Dear members of DNI,
UNEP-WCMC has asked DNI to forward the following message to its members (see below).
UNEP-WCMC has been contracted by UNCCD to provide technical support to countries piloting the UNCCD Impact Indicators. In this respect, we are working to compile a list of experts available to provide advice on Impact Indicators during and after the UNCCD Pilot Tracking Exercise.
We designed a very brief online survey (<2mins) to gain an overview of the level of expertise available.
To complete the survey please visit: http://www.surveymonkey.com/s/2QJWPR3
Thank you for your cooperation.
A message from DesertNet International
“On behalf of the UNEP World Conservation Monitoring Centre, we are herewith providing you with the final report of the UNCCD Pilot Impact Indicator Tracking Exercise Inception Workshop held in Mexico in July 2011.”
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