The Maghreb (North Africa) rangelands evolution over forty years: re-greening or degradation

cg.contacta.belgacem@cgiar.orgen_US
cg.contributor.centerInternational Center for Agricultural Research in the Dry Areas - ICARDAen_US
cg.contributor.centerArid Regions Institute - IRAen_US
cg.contributor.centerSudan Academy of Sciences, Kharthoum - SASen_US
cg.contributor.centerUniversity of science and Technology Houari Boumediene, Faculty of Biological Sciences - USTHB - FBIOLen_US
cg.contributor.centerRegional Center for Remote Sensing of North Africa States - CRTEANen_US
cg.contributor.centerUniversity of Algiersen_US
cg.contributor.centerScientific and Technical Research Center on Arid Regions - CRSTRAen_US
cg.contributor.centerSahara and Sahel Observatory - OSSen_US
cg.contributor.funderArab Fund for Economic and Social Development - AFESDen_US
cg.contributor.projectEnhancing Agricultural Production Systems and Conserving Natural Resources in the Countries of the Arabian Peninsula (V Phase)en_US
cg.contributor.project-lead-instituteInternational Center for Agricultural Research in the Dry Areas - ICARDAen_US
cg.coverage.countryDZen_US
cg.coverage.regionNorthern Africaen_US
cg.creator.idOuled Belgacem, Azaiez: 0000-0002-5946-7540en_US
cg.date.embargo-end-dateTimelessen_US
cg.isbn978-1-53614-212-9en_US
cg.subject.agrovocbiodiversityen_US
cg.subject.agrovocdegradationen_US
cg.subject.agrovocdesertificationen_US
cg.subject.agrovocsoilen_US
cg.subject.agrovocremote sensingen_US
cg.subject.agrovocsahelen_US
cg.subject.agrovocnorth africaen_US
dc.contributorSalamani, Mostefaen_US
dc.contributorTarhouni, Mohameden_US
dc.contributorNedjraoui, Dalilaen_US
dc.contributorEl Hag, Mustaphaen_US
dc.contributorGashut, El Hadien_US
dc.contributorAbdelmadjid, Boughanien_US
dc.contributorAdi, Naceren_US
dc.contributorHourizi, Ratibaen_US
dc.contributorOuled Belgacem, Azaiezen_US
dc.contributorGrandi, Mohameden_US
dc.contributorBen Khetra, Nabilen_US
dc.contributorBrik, Mouraden_US
dc.contributorAmrani, Saiden_US
dc.creatorHirche, Azizen_US
dc.date.accessioned2019-03-13T08:52:08Z
dc.date.available2019-03-13T08:52:08Z
dc.description.abstractThe Sahel region is subject of several controversies over the current trends of its ecosystems. Some consider that despite the rain recovery, this region remains in a regressive dynamics, while others consider that they are in re-greening, according to the studies using remote sensing. However, in North Africa, and more specifically in the Maghreb countries, despite numerous studies, this controversy is rarely discussed. The question asked here is whether this region which include most of the North African arid steppes and the largest desert of the world (the Sahara), is in regressive or progressive dynamics . In 1975, three Maghreb countries, Algeria, Tunisia, and Morocco, have launched national programs for monitoring and assessing ecosystems dynamics through the establishement of several observatories becoming fully operational in 1978. Afterwards, they had joined the international ROSELT network (Long Term Ecological Monitoring Observatories Network) implemented and coordinated by the OSS (Observatory of the Sahara and the Sahel) created in 1992. It relies on national studies, at regional or local level (observation stations) and standardize their monitoring methodologies to obtain comparable data. The results showed that this area has undergone profound changes of both physical and biological components. The parameters considered include vegetation, and soil surface properties. In particular, the results show that land degradation, especially from 1980 onwards, is the main feature of this evolution due to the combination of an outsized livestock and the occurrence of repeated and exceptional drought. The former vegetation communities dominated by Stipa tenacissima, Lygeum spartum and Artemisia herba alba have been mostly disappeared. New species, like Atractyis serratuloides, Salsola vermiculata, Hammada scoparia, and Noaea mucronata, which were rare in 1978, became dominant, in relation to degradation. The largest decline was observed for Stipa tenacissima vegetation units constituting 33% of the landscape in 1978 and occupying just 2% in 2011. The total vegetation cover has also significantly declined from more 34% in 1978 to less than 20 % in 2011. They also been subject to significant biodiversity loss and reduced richness. The number of species inventoried were 234, 134 and only 91 respectively in 1978 , 2005 and 2011. Since 2007, precipitation has been considerably improved but this was not accompanied with significant increase of vegetation cover and biodiversity even if the sandy fractions become less represented in the soil surface. Remote sensing, however, showed that the trend, as in the Sahel, is moving towards either towards a regreening or a stationary state. There is therefore an apparent contradiction between the “remote sensing” and the field data. It is considered that the soil moisture, the soil surface and the roughness, have probably much more influence on the spectral response than chlorophyll in vegetation, causing confusion in the data interpretation. This emphasizes the limits of the use of NDVI in arid zones, especially in North Africa.en_US
dc.formatPDFen_US
dc.identifierhttps://mel.cgiar.org/dspace/limiteden_US
dc.identifierhttps://novapublishers.com/shop/desertification-past-current-and-future-trends/en_US
dc.identifier.citationAziz Hirche, Mostefa Salamani, Mohamed Tarhouni, Dalila Nedjraoui, Mustapha El Hag, El Hadi Gashut, Boughani Abdelmadjid, Nacer Adi, Ratiba Hourizi, Azaiez Ouled Belgacem, Mohamed Grandi, Nabil Ben Khetra, Mourad Brik, Said Amrani. (31/12/2018). The Maghreb (North Africa) rangelands evolution over forty years: re-greening or degradation, in "Desertification: Past, Current and Future Trends". New York, United States of America: Nova Science Publishers.en_US
dc.identifier.statusTimeless limited accessen_US
dc.identifier.urihttps://hdl.handle.net/20.500.11766/9658
dc.languageenen_US
dc.publisherNova Science Publishersen_US
dc.subjectregreeningen_US
dc.subjectsteppeen_US
dc.subjectalfaen_US
dc.subjectnvdien_US
dc.titleThe Maghreb (North Africa) rangelands evolution over forty years: re-greening or degradationen_US
dc.typeBook Chapteren_US
dcterms.available2018-12-31en_US
mel.project.openhttps://mel.cgiar.org/projects/748en_US

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