{{Short description|Water-scarce areas}} {{for|other uses of "drylands" and "dryland"|dryland (disambiguation)}} [[File:Cueva de los casares 07.JPG|thumb|Dryland farms and the {{ill|Linares River|es|Río Linares (afluente del Ablanquejo)}} in the Castilla–La Mancha region of Spain]]

'''Drylands''' are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by evapotranspiration by plants.<ref>Middleton and Thomas, 1997. "The World Atlas of Desertification Millennium Ecosystem Assessment (2005a). Climate Change". Chapter 13 in: ''Ecosystems and Human Wellbeing: Current State and Trends'', Volume 1. Island Press.</ref> The United Nations Environment Program defines drylands as tropical and temperate areas with an aridity index of less than 0.65.<ref name="Millennium Ecosystem Assessment">"Millennium Ecosystem Assessment, 2005. Drylands Systems". Chapter 22 in: ''Ecosystems and Human Wellbeing: Current State and Trends'', Volume 1. Island Press.</ref> Drylands can be classified into four sub-types:

* Dry sub-humid lands * Semi-arid lands * Arid lands * Hyper-arid lands

Some authorities regard hyper-arid lands as deserts (United Nations Convention to Combat Desertification) although a number of the world's deserts include both hyper-arid and arid climate zones. The UNCCD excludes hyper-arid zones from its definition of drylands.

Drylands cover 41.3% of the Earth's land surface, including 15% of Latin America, 66% of Africa, 40% of Asia, and 24% of Europe. There is a significantly greater proportion of drylands in developing countries (72%), and the proportion increases with aridity: almost 100% of all hyper-arid lands are in the developing world. Nevertheless, the United States, Australia, and several countries in Southern Europe also contain significant dryland areas.<ref name="Millennium Ecosystem Assessment"/> Drylands are home to more than 2 billion people.<ref name="cc">{{Cite web |title=Drylands and climate change |url=https://iucn.org/resources/issues-brief/drylands-and-climate-change |website=iucn.org |language=en |access-date=2026-02-02}}</ref>

Drylands are complex ecosystems, whose characteristics and dynamic properties depend on many interrelated interactions between climate, soil, and vegetation.<ref> Rodríguez-Iturbe, I. and A. Porporato 2004. ''Ecohydrology of Water-Controlled Ecosystems: Soil Moisture and Plant Dynamics''. Cambridge University Press.</ref> Drylands are highly vulnerable to climate change due to changing rainfall patterns and land degradation.<ref name="cc"/>

== Importance == The livelihoods of millions of people in developing countries depend highly on dryland ecosystems to ensure their food security and their well-being. Drylands, unlike more humid biomes, rely mostly on above ground water runoff for redistribution of water.<ref>{{Cite journal|last=Puigdefabregas|first=J|date=October 1999|title=Scales and processes of water and sediment redistribution in drylands: results from the Rambla Honda field site in Southeast Spain|journal=Earth-Science Reviews|volume=48|issue=1–2|pages=39–70|doi=10.1016/S0012-8252(99)00046-X|bibcode=1999ESRv...48...39P|hdl=10261/358465|hdl-access=free}}</ref> Dryland inhabitants' lifestyle provides global environmental benefits such as contribute to halting climate change through carbon sequestration and species conservation. Dryland biodiversity is equally important to ensuring sustainable development, along with providing significant global economic value through the provision of ecosystem services and biodiversity conservation. The UN Conference on Sustainable Development, Rio+20 held in Brazil in June 2012, stressed the intrinsic value of biodiversity and recognized the severity of global biodiversity loss and degradation of ecosystems.<ref>{{cite web|url=http://www.iucn.org/fr/propos/union/commissions/wcpa/?10867/Conserving-Drylands-Biodiversity|title=Conserving Drylands Biodiversity|date=9 September 2012}}</ref>

== Climate change == [[File:Fig 1.3.11 Schematic showing key feedbacks that could lead to dryland tipping..png|thumb|Key feedbacks that could lead to dryland ecosystems crossing tipping points. SOC stands for soil organic carbon. White arrows represent positive effects and red arrows are negative effects.]] Climate change and human activities are causing land degradation in drylands. These factors have led to increasing droughts, desertification and soil erosion, which decreases biodiversity, soil fertility and carbon sequestration in these regions. This has negative impacts on local agriculture and food security.<ref>{{Cite journal |last=Yao |first=Jingyu |last2=Liu |first2=Heping |last3=Huang |first3=Jianping |last4=Gao |first4=Zhongming |last5=Wang |first5=Guoyin |last6=Li |first6=Dan |last7=Yu |first7=Haipeng |last8=Chen |first8=Xingyuan |date=2020-04-03 |title=Accelerated dryland expansion regulates future variability in dryland gross primary production |url=https://www.nature.com/articles/s41467-020-15515-2 |journal=Nature Communications |language=en |volume=11 |issue=1 |page=1665 |doi=10.1038/s41467-020-15515-2 |issn=2041-1723|pmc=7125214 }}</ref><ref>{{Cite web |last= |date=2017-04-25 |title=Dryland expansion to hit food crops as planet warms |url=https://www.climatechangenews.com/2017/04/25/dryland-expansion-hit-food-crops-planet-warms/ |access-date=2025-03-13 |website=Climate Home News |language=en-GB}}</ref> Drylands ecosystems also feature climate tipping points.<ref>T. M. Lenton, D.I. Armstrong McKay, S. Loriani, J.F. Abrams, S.J. Lade, J.F. Donges, M. Milkoreit, T. Powell, S.R. Smith, C. Zimm, J.E. Buxton, E. Bailey, L. Laybourn, A. Ghadiali, J.G. Dyke (eds), 2023, [https://report-2023.global-tipping-points.org/ The Global Tipping Points Report 2023]. University of Exeter, Exeter, UK.</ref>

From 1982 to 2015, 12.6% of the world's drylands have degraded due to anthropogenic climate change.<ref name="ap">{{Cite journal |last=Burrell |first=A. L. |last2=Evans |first2=J. P. |last3=De Kauwe |first3=M. G. |date=2020-07-31 |title=Anthropogenic climate change has driven over 5 million km2 of drylands towards desertification |url=https://www.nature.com/articles/s41467-020-17710-7 |journal=Nature Communications |language=en |volume=11 |issue=1 |doi=10.1038/s41467-020-17710-7 |issn=2041-1723 |pmc=7395722 |pmid=32737311}}</ref> Drylands' vulnerability to land degradation and desertification is affecting 213 million people of which the vast majority live in the Global South.<ref name="ap" /> In recent decades, about 7.6% of global land (an area larger than Canada) has transitioned into drier conditions, either becoming more arid or shifting from non-drylands to drylands. An area half the size of Australia has transformed from once-humid landscapes into drylands.<ref>{{Cite web |date=2024-12-09 |title=The global threat of drying lands: Regional and global aridity trends and future projections |url=https://www.unccd.int/resources/reports/global-threat-drying-lands-regional-and-global-aridity-trends-and-future |access-date=2025-03-13 |website=UNCCD |language=en}}</ref>

Sustainable land management practices (such as mobile pastoralism), restoring degraded lands, and climate-smart agriculture can mitigate these impacts.<ref name="cc"/> Addressing urban expansion's indirect impacts, such as water use, on dryland habitats is also important for preserving biodiversity.<ref>{{Cite journal |last=Ren |first=Qiang |last2=He |first2=Chunyang |last3=Huang |first3=Qingxu |last4=Shi |first4=Peijun |last5=Zhang |first5=Da |last6=Güneralp |first6=Burak |date=25 July 2022 |title=Impacts of urban expansion on natural habitats in global drylands |url=https://www.nature.com/articles/s41893-022-00930-8 |journal=Nature Sustainability |language=en |volume=5 |issue=10 |pages=869–878 |doi=10.1038/s41893-022-00930-8 |issn=2398-9629 |url-access=subscription}}</ref>

=== Drylands in East Africa === The East African drylands cover of the land areas and are home to more than 60 million people.<ref name="dd">{{Cite web |title=Drylands Development, Pastoralism and Biodiversity Conservation in Eastern Africa |url=https://iucn.org/sites/default/files/import/downloads/policy_brief__drylands_development__pastoralism_and_biodiversity_conservation_in_east.pdf}}</ref> Pastoralists who rely on cattle for both economic and cultural well-being constitute the majority of rural inhabitants in the drylands. Pastoralists use strategic movement to gain access to pasture during the dry season, using the available resources effectively. However, this is facing challenges due to demographics and climate change.<ref>{{Cite journal |last1=Turner |first1=Matthew D. |last2=Schlecht |first2=Eva |date=2019-08-26 |title=Livestock mobility in sub-Saharan Africa: A critical review |journal=Pastoralism |volume=9 |issue=1 |page=13 |doi=10.1186/s13570-019-0150-z |s2cid=201642982 |issn=2041-7136|doi-access=free |bibcode=2019Pasto...9...13T }}</ref> The greatest issue in drylands, is land degradation which poses a huge danger to food security.<ref>{{Cite web |last1=Bekele |first1=Adugna Eneyew |last2=Drabik |first2=Dusan |last3=Dries |first3=Liesbeth |last4=Heijman |first4=Wim |date=September 2020 |title=Large scale land investments, household displacement and the effect on land degradation in semiarid agro-pastoral areas of Ethiopia |url=https://www.researchgate.net/publication/344142265 |website=Research Gate}}</ref> Drylands occupy around 2 million km<sup>2</sup> and 90% of Kenya,<ref>{{Cite journal |date=2022-09-21 |title=Updated Link and Survey Tool Added to Supplement |journal=JAMA Dermatology |volume=158 |issue=11 |page=1333 |doi=10.1001/jamadermatol.2022.4185 |pmid=36129697 |pmc=9494260 |issn=2168-6068|doi-access=free}}</ref> 75% of Tanzania,<ref>{{Cite journal |date=2022-09-21 |title=Updated Link and Survey Tool Added to Supplement |journal=JAMA Dermatology |volume=158 |issue=11 |page=1333 |doi=10.1001/jamadermatol.2022.4185 |issn=2168-6068 |pmc=9494260 |pmid=36129697 |doi-access=free}}</ref> and 67% of Ethiopia. The low level of precipitation and the high degree of variability in the climatic conditions limit the possibilities for rainfed crop production in these areas.<ref name="dd"/>

== Four sub-types == === Dry and sub-humid lands === thumb|Spiny forest, Madagascar Countries like Burkina Faso, Botswana, Iraq, Kazakhstan, Turkmenistan and the Republic of Moldova, are 99% covered in areas of dry and sub-humid lands.<ref>{{Cite web|url=https://www.cbd.int/drylands/what.shtml|title=What is Dry and Sub-humid Lands Biodiversity?|website=cbd.int|access-date=2019-04-11|date=2007-05-16}}</ref> The biodiversity of dry and sub-humid lands allows them to adapt to the unpredictable rainfall patterns that lead to both floods and droughts.<ref>{{Cite web|url=https://www.cbd.int/undb/media/factsheets/undb-factsheet-drylands-en.pdf|title=Dry and Sub-humid lands|website=cbd.int/drylands}}</ref> These areas produce a large amount the world's crops and livestock. Even further than producing the vast majority of crops in the world, it is also significant because it includes many different biomes such as the following:

* Grassland * Savannahs * Mediterranean climate

=== Semi-arid lands=== Semi-arid lands can be found in several regions of the world. For instance in places such as Europe, Mexico, Southwestern parts of the U.S., Countries in Africa that are just above the equator, and several Southern countries in Asia.<ref>{{Cite web |title=What Is a Semi-Arid Climate? |url=https://sciencing.com/semiarid-climate-10009421.html |access-date=2022-06-18 |website=Sciencing |language=en}}</ref>thumb|Brazilian semi-arid region|alt=

[[File:Inda Abba Hadera forest.jpg|thumb|Gestet forest in north Ethiopia]]'''Definition of semi-arid lands'''

Arid and semi-arid lands are defined based on the characteristics of the climate. One measure based on precipitation considers semi-arid lands as places where the annual rainfall ranges between 500 and 800mm.<ref>{{Cite web |last=Kabote |first=Samwel J. |title=Impact of Climate Variability and Change on Rain-Fed Farming System in Selected Semi-Arid Areas of Tanzania |url=https://www.academia.edu/28549467}}</ref> Other sources insist that the concept of aridity should be included in the definition.<ref>{{Cite book|url=https://www.espa.ac.uk/files/espa/Final%20Report%20Africa.pdf|title=Situation Analysis of Ecosystem Services and Poverty Alleviation in arid and semi-arid Africa|last=Fabricius|first=Christo|publisher=Consortium for Ecosystem Services and Poverty Alleviation in arid and semi-arid Africa (CEPSA)|year=2008}}</ref>

====Manifestations of climate change in semi-arid lands====

Based on the consequences caused by the variability of climate change, dryland populations appear to be more vulnerable than others. As much of the rainfall occurs in variable extreme events that are hard to predict. The manifestation of climate change on the development of socioeconomic activities in semi-arid lands are:<ref>{{Cite book |last1=Wade |first1=Cheikh Tidiane |url=http://www.iedafrique.org/IMG/pdf/Revue_Thematique_2015.pdf |title=Gestion des risques climatiques |last2=Touré |first2=Oussouby |last3=Diop |first3=Mamadou |publisher=IED Afrique |year=2015 |location=Dakar}}</ref>

* Increased variability of precipitations and their characteristics (number of rainfall days, start of rainy season, length of the season) that can be translated to an abrupt alternative between dry and humid years * a shorter rainy season correlated to its late start * an increase in the occurrence of dry sequences that occur randomly and are hard to forecast * a tendency of maximal rains concentrated in fewer consecutive days, thus causing damage * dry and violent winds associated with very scarce rainfall that prevent the building of soil moisture * increased temperatures causing thermal stress that may seriously handicap human, animal, and plant life

====Adaptation and resilience====

In semi-arid lands where pastoralism is the principal activity, the main adaptation measures are an earlier movement of herds, the reduction of the size of the herd, a change in the management of water, and diversification of paths of transhumance.<ref name="lc">{{Cite web|url=https://www.pasto-secu-ndjamena.org/classified/J2-2-1-B-Guibert-trajectoires_pasteurs.pdf|title=La contribution de l'elevage pastoral a la securite et au developpement des espaces saharo-saheliens, analyses de trajectoires de familles de pasteurs en lien avec les crises pastorales|last1=Bonnet|first1=Bernard|last2=Guibert|first2=Bertrand|year=2013|publisher=colloque regional de N'djamena, 27-29 mai|access-date=2019-08-08|archive-date=2019-08-08|archive-url=https://web.archive.org/web/20190808144709/https://www.pasto-secu-ndjamena.org/classified/J2-2-1-B-Guibert-trajectoires_pasteurs.pdf}}</ref> This allows breeders to safeguard their livestock and prevent huge losses as was the case in the drought of the seventies. Other adaptations include becoming proactive (engage in trade, real estate, guarding, transport) this is taking place in certain countries like Burkina Faso, Senegal, Mali, and Kenya.<ref name="lc"/><ref>{{Cite news|title=Essai d'évaluation des stratégies d'adaptation face aux risques climatiques sur la chaine de valeur bovine: cas du Ferlo|last1=DIOP|first1=Waoundé|last2=Beye|first2=Assane|year=2017|publisher=communication au colloque le pastoralisme dans le courant des changements globaux: defis, enjeux et perspectives|last3=Dia|first3=Néné}}</ref> These adaptation strategies allow them to be more resilient to climate change.

=== Arid lands === thumb|Arid chaco

'''Arid lands''' make up about 10% of the world's land and are home to 20% of the world's people.<ref name="si">{{Cite web |title=Soil improvement in arid and semiarid regions for sustainable development |date=2022-01-01 |work=Natural Resources Conservation and Advances for Sustainability |pages=73–90 |url=https://www.sciencedirect.com/science/chapter/edited-volume/abs/pii/B9780128229767000260 |access-date=2026-02-02 |publisher=Elsevier |language=en-US |doi=10.1016/B978-0-12-822976-7.00026-0}}</ref> The UNCCD defined them as having an aridity index between ~0.05-0.20.

=== Hyper-arid lands === These lands cover ~8% of the world and consist of areas of little to no vegetation. They receive irregular rainfall that barely surpasses 100&nbsp;mm, and in some cases, they may not receive rainfall for several years.<ref name="si" /><br/>thumb|Dry land|alt=|left

== Dryland restoration == Restoration is defined by IPBES as 'any intentional activities that initiates or accelerates the recovery of an ecosystem from a degraded state.'<ref>{{Cite web |title=restoration {{!}} IPBES secretariat |url=https://www.ipbes.net/glossary-tag/restoration |archive-url=http://web.archive.org/web/20260113111042/https://www.ipbes.net/glossary-tag/restoration |archive-date=2026-01-13 |access-date=2026-02-02 |website=IPBES secretariat |language=en}}</ref> It is one of the three pillars of nature-based solutions defined by the IUCN as "actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits".<ref name="nb">IUCN (2020). Guidance for using the IUCN Global Standard for Nature-based Solutions. A user-friendly framework for the verification, design and scaling up of Nature-based Solutions. First edition. Gland, Switzerland: IUCN.</ref> Ecosystem restoration in general is also emphasized as a tool for climate mitigation and adaptation by IUCN and IPCC.<ref name="nb"/><ref>IPCC, 2023: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, 184 pp., doi: 10.59327/IPCC/AR6-9789291691647.</ref>

Dryland restoration is often understood in two ways; either to restore a dryland to its previous functionality or to avoid further degradation. The first perspective is based on the restoration of the degraded dryland areas themselves. Restoration of a degraded dryland to its previous functionality and ecosystem state can have benefits for both humans and nature when done correctly.<ref>{{Cite journal |last=Alikhanova |first=Shahzoda |last2=Bull |first2=Joseph William |date=2023-09-01 |title=Review of Nature-based Solutions in Dryland Ecosystems: the Aral Sea Case Study |journal=Environmental Management |language=en |volume=72 |issue=3 |pages=457–472 |doi=10.1007/s00267-023-01822-z |issn=1432-1009 |pmc=10372098 |pmid=37115238}}</ref> The second emphasises preventative and adaptive land management to support ecosystem services and functionalities. This is the presumed logic behind the extensive project in the Sahel region named the Great Green Wall supported by UNCCD (see: case studies).<ref>{{Cite web |title=Great Green Wall Initiative |url=https://www.unccd.int/our-work/ggwi |access-date=2026-02-02 |website=UNCCD |language=en}}</ref>

FAO provides 10 practice principles to guide ecosystem restoration.<ref>Nelson, C.R., Hallett, J.G., Romero Montoya, A.E., Andrade, A., Besacier, C., Boerger, V., Bouazza, K., Chazdon, R., Cohen-Shacham, E., Danano, D., Diederichsen, A., Fernandez, Y., Gann, G.D., Gonzales, E.K., Gruca, M., Guariguata, M.R., Gutierrez, V., Hancock, B., Innecken, P., Katz, S.M., McCormick, R., Moraes, L.F.D., Murcia, C., Nagabhatla, N., Pouaty Nzembialela, D., Rosado-May, F.J., Shaw, K., Swiderska, K., Vasseur, L., Venkataraman, R., Walder, B., Wang, Z., & Weidlich, E.W.A. 2024. Standards of practice to guide ecosystem restoration – A contribution to the United Nations Decade on Ecosystem Restoration 2021-2030. Rome, FAO, Washington, DC, SER & Gland, Switzerland, IUCN CEM. <nowiki>https://doi.org/10.4060/cc9106en</nowiki></ref> The principles include the selection and management of restoration activities at project sites, prevention of misuse of resources and unintended consequences, enabling conditions for restoration, and assessing and applying lessons learned.

=== Desertification distribution === UNCCD works actively against desertification and land degradation to sustain humans and biodiversity under a changing climate. Their aim is to foster solutions with synergies between climate mitigation and adaptation, biodiversity, and human well-being targets.<ref>Rackelmann, F., Sparkes, E., Sabino Siemons, A-S., Hashweh, D., Pineda Fernandez, D. M., Werners, S., Orr, B. J., Andreeva, O. and Walz, Y. (2024). Promoting synergies between land degradation neutrality and climate change adaptation. A supplement to the National Adaptation Plan technical guidelines. UNCCD and UNU-EHS. Bonn, Germany</ref> Desertification is a major problem threatening ecosystems and human lives with the most affected regions being Western Asia and South America.<ref name="ap"/> However, some researchers raise criticism against the dominant desertification narrative. The Sahel region is often falsely perceived as drying at a higher rate than other places. Critics argue that desertification in the Sahel region originates from a colonial understanding of the land use/land cover. In reality, the region has experienced a greening during the last decades.<ref>{{Cite book |last=Benjaminsen |first=Tor A. |url=https://www.elgaronline.com/view/book/9781035325184/9781035325184.xml |title=Climate Security and Climate Justice: Recognizing Context in the Sahel |date=2024-09-17 |publisher=Edward Elgar Publishing |isbn=978-1-0353-2518-4 |doi=10.4337/9781035325184}}</ref>

=== Sustainable rangeland management === Rangelands cover about 25% of drylands globally.<ref name="ae">{{Cite journal |last=Teku |first=Degfie |last2=Mengesha |first2=Yeshifana Alemneh |last3=Kesete |first3=Nega |date=2025-06-04 |title=Review of area exclosure practices for sustainable land management and erosion control in Ethiopia: objectives and PRISMA review |url=https://www.frontiersin.org/articles/10.3389/fcosc.2025.1568725/full |journal=Frontiers in Conservation Science |volume=6 |doi=10.3389/fcosc.2025.1568725 |issn=2673-611X|doi-access=free }}</ref> With its carbon sequestration potential, rangeland restoration is considered a climate mitigation option.<ref>{{Cite journal |last=Yao |first=Ying |last2=Fu |first2=Bojie |last3=Liu |first3=Yanxu |last4=Wang |first4=Yijia |last5=Song |first5=Shuang |date=2021 |title=The contribution of ecosystem restoration to sustainable development goals in Asian drylands: A literature review |url=https://onlinelibrary.wiley.com/doi/10.1002/ldr.4065 |journal=Land Degradation & Development |language=en |volume=32 |issue=16 |pages=4472–4483 |doi=10.1002/ldr.4065 |issn=1085-3278|url-access=subscription }}</ref> Rangeland restoration can also improve livelihood opportunities for local pastoralists and can help combat desertification.<ref>{{Citation |last=Toderich |first=K. N. |title=Integrating Agroforestry and Pastures for Soil Salinity Management in Dryland Ecosystems in Aral Sea Basin |date=2013 |work=Developments in Soil Salinity Assessment and Reclamation: Innovative Thinking and Use of Marginal Soil and Water Resources in Irrigated Agriculture |pages=579–602 |editor-last=Shahid |editor-first=Shabbir A. |place=Dordrecht |publisher=Springer Netherlands |language=en |doi=10.1007/978-94-007-5684-7_38 |isbn=978-94-007-5684-7 |last2=Shuyskaya |first2=E. V. |last3=Taha |first3=Faisal K. |last4=Matsuo |first4=Naoko |last5=Ismail |first5=Shoaib |last6=Aralova |first6=D. B. |last7=Radjabov |first7=T. F. |editor2-last=Abdelfattah |editor2-first=Mahmoud A. |editor3-last=Taha |editor3-first=Faisal K.}}</ref>

Ecological, economic, political, institutional and socio-cultural factors can support or limit the adaptation of restoration practices. Global dynamics and external shocks such as drought, pests, diseases, and conflict have an effect at the local level. The adoption of a sustainable rangeland practice is highly context specific and cannot be generalized. For example, the same law on rangeland use could support the implementation of a specific restoration practice, but the same law might hinder another restoration practice.<ref>{{Cite book |last=Liniger |first=Hanspeter |url=https://wocat.net/documents/913/E_online_Wocat_Rangeland_April25.pdf |title=Sustainable rangeland management in Sub-Saharan Africa – Guidelines to good practice. |last2=Mekdaschi Studer |first2=Rima |publisher=TerrAfrica; World Bank, Washington D.C.; World Overview of Conservation Approaches and Technologies (WOCAT); World Bank Group (WBG), Washington DC, USA and Centre for Development and Environment (CDE), University of Bern, Switzerland |year=2019 |pages=57–58}}</ref>

=== Restoration techniques === Restoration efforts in dryland areas are particularly challenging because of rare and variable precipitation, high temperatures, low soil fertility, and invasive species.<ref>{{Cite journal |last=Shackelford |first=Nancy |last2=Paterno |first2=Gustavo B. |last3=Winkler |first3=Daniel E. |last4=Erickson |first4=Todd E. |last5=Leger |first5=Elizabeth A. |last6=Svejcar |first6=Lauren N. |last7=Breed |first7=Martin F. |last8=Faist |first8=Akasha M. |last9=Harrison |first9=Peter A. |last10=Curran |first10=Michael F. |last11=Guo |first11=Qinfeng |last12=Kirmer |first12=Anita |last13=Law |first13=Darin J. |last14=Mganga |first14=Kevin Z. |last15=Munson |first15=Seth M. |date=2021 |title=Drivers of seedling establishment success in dryland restoration efforts |url=https://www.nature.com/articles/s41559-021-01510-3 |journal=Nature Ecology & Evolution |language=en |volume=5 |issue=9 |pages=1283–1290 |doi=10.1038/s41559-021-01510-3 |issn=2397-334X|url-access=subscription }}</ref> A defining feature of dryland ecosystems is the patchiness of its vegetation, where isolated vegetated patches are scattered within largely bare areas.<ref>{{Cite journal |last=El‐Bana |first=Magdy I. |last2=Nijs |first2=Ivan |last3=Khedr |first3=Abdel‐Hamid A. |date=2003 |title=The Importance of Phytogenic Mounds (Nebkhas) for Restoration of Arid Degraded Rangelands in Northern Sinai |url=https://onlinelibrary.wiley.com/doi/10.1046/j.1526-100X.2003.00222.x |journal=Restoration Ecology |language=en |volume=11 |issue=3 |pages=317–324 |doi=10.1046/j.1526-100X.2003.00222.x |issn=1061-2971}}</ref> Restoration techniques addressing this patchiness are restoration islands (also known as assisted nucleation or nucleation plantings), the use of soil fauna, as well as techniques such as afforestation, exclosures, and silvopastoralism.<ref name="Berrahmouni 2015">{{Cite book |last=Berrahmouni |first=Nora |title=Global guidelines for the restoration of degraded forests and landscapes in drylands: building resilience and benefiting livelihoods |last2=Regato |first2=Pedro |last3=Parfondry |first3=Marc |date=2015 |publisher=FAO |isbn=978-92-5-108912-5 |series=FAO forestry paper |location=Rome}}</ref> Smaller scale techniques such as semicircular bunds have also shown promising results.

====Restoration islands====

Restoration islands use small, strategically located plantings (islands) to make use of limited resources. Once established, the island plantations proliferate (nucleate) into neighboring areas. This strategy is best suited to address the patchiness of dryland vegetation, because restoration islands can be placed in the most promising locations and are less resource-intensive than large-scale plantations. Other benefits include reduced fire risk, lower soil erosion, weed control, seed sources for long-term restoration, and habitat for wildlife. However, the harsh conditions in dryland ecosystems limit the use of restoration islands. Compared to humid ecosystems, vegetation patches in drylands take more time to nucleate as extensively.<ref>{{Cite journal |last=Hulvey |first=Kristin B. |last2=Leger |first2=Elizabeth A. |last3=Porensky |first3=Lauren M. |last4=Roche |first4=Leslie M. |last5=Veblen |first5=Kari E. |last6=Fund |first6=Adam |last7=Shaw |first7=Julea |last8=Gornish |first8=Elise S. |date=2017 |title=Restoration islands: a tool for efficiently restoring dryland ecosystems? |url=https://onlinelibrary.wiley.com/doi/10.1111/rec.12614 |journal=Restoration Ecology |language=en |volume=25 |issue=S2 |doi=10.1111/rec.12614 |issn=1061-2971}}</ref>

====Use of soil fauna====

Soil fauna improve the physical, chemical, and biological properties of the soil. They contribute to seed dispersal, pest control, nutrient cycling, water infiltration, and soil structure, thus increasing vegetation productivity. However, aridity and high temperatures in drylands put soil fauna under pressure. Supporting measures include using endemic species, restoration islands as nucleation sites, and mulching to increase soil moisture.<ref>{{Cite journal |last=Morales‐Márquez |first=Jimmy |last2=Meloni |first2=Fernando |date=2022 |title=Soil fauna and its potential use in the ecological restoration of dryland ecosystems |url=https://onlinelibrary.wiley.com/doi/10.1111/rec.13686 |journal=Restoration Ecology |language=en |volume=30 |issue=6 |doi=10.1111/rec.13686 |issn=1061-2971}}</ref>

===Indigenous knowledge and community engagement=== alt="Restoration outcomes are the product of many diverse, interconnected factors. The black textboxes in this illustration highlight key factors that directly and indirectly affect restoration success. The panels represent examples of a degraded dryland on the Colorado Plateau (left panel) and a restoration goal for that landscape (right panel). We suggest that by expanding research efforts to encompass as many of these other key factors as possible, we can promote restoration success. Speci cally, we present four research directions to achieve this goal (blue textbox). The numbers in the black textboxes correspond to the factors associated with each of the research directions highlighted here." (Young et al. 2023)|thumb|Inputs for successful dryland restoration research and including local knowledge|339x339px

Indigenous or local knowledge plays an important role in protecting and restoring drylands. Several case studies have found that the inclusion of indigenous knowledge and local communities has increased restoration success.<ref name="ae"/> Local knowledge tends to be hyper localized and is important for adaptation to climate change,<ref>{{Cite journal |last=Makondo |first=Cuthbert Casey |last2=Thomas |first2=David S. G. |date=2018-10-01 |title=Climate change adaptation: Linking indigenous knowledge with western science for effective adaptation |url=https://www.sciencedirect.com/science/article/pii/S1462901118300418 |journal=Environmental Science & Policy |volume=88 |pages=83–91 |doi=10.1016/j.envsci.2018.06.014 |issn=1462-9011|url-access=subscription }}</ref><ref>{{Cite journal |last=Hopping |first=Kelly |last2=Yangzong |first2=Ciren |last3=Klein |first3=Julia |date=2016-02-18 |title=Local knowledge production, transmission, and the importance of village leaders in a network of Tibetan pastoralists coping with environmental change |url=https://www.ecologyandsociety.org/vol21/iss1/art25/ |journal=Ecology and Society |language=en |volume=21 |issue=1 |doi=10.5751/ES-08009-210125 |issn=1708-3087|doi-access=free }}</ref> this is especially relevant for dryland areas as the ecosystems themselves tend to have high heterogeneity.<ref>{{Cite journal |last=Young |first=Kristina E. |last2=Osborne |first2=Brooke B. |last3=Phillips |first3=Michala |last4=Winkler |first4=Daniel E. |year=2023 |title=Restoration research actions to address rapid change in drylands: insights from the Colorado Plateau |url=https://onlinelibrary.wiley.com/doi/10.1111/rec.13855 |journal=Restoration Ecology |language=en |volume=31 |issue=4 |doi=10.1111/rec.13855 |issn=1061-2971|url-access=subscription }}</ref> Approaches such as silvopastoralism/agroforestry have been applied for centuries in dryland communities with great success.<ref name="gw">{{Cite book|title=Grazing with trees|url=https://openknowledge.fao.org/handle/20.500.14283/cc2903en|publisher=FAO|date=2022|isbn=978-92-5-137188-6|doi=10.4060/cc2903en|language=English|last=FAO}}</ref> These practices can also have positive outcomes for community members not engaged in pastoralism as the forest can provide important resources for building constructions and woodfuel for homes.<ref name="Berrahmouni 2015"/> One technique that studies have shown to be successful is the use of indigenous fire ecology to lower the fuel load in ecosystems and help prevent the large devastating fires.<ref>{{Cite journal |last=Bliege Bird |first=Rebecca |last2=Codding |first2=Brian F. |last3=Kauhanen |first3=Peter G. |last4=Bird |first4=Douglas W. |date=2012-06-26 |title=Aboriginal hunting buffers climate-driven fire-size variability in Australia's spinifex grasslands |url=https://www.pnas.org/doi/full/10.1073/pnas.1204585109 |journal=Proceedings of the National Academy of Sciences |volume=109 |issue=26 |pages=10287–10292 |doi=10.1073/pnas.1204585109 |pmc=3387077 |pmid=22689979}}</ref> This is especially relevant now as in North and South America over 25% of the population lives in drylands.<ref name="od">{{Cite journal |last=Abril |first=A. |last2=Barttfeld |first2=P. |last3=Bucher |first3=E. H. |date=2005-02-15 |title=The effect of fire and overgrazing disturbes on soil carbon balance in the Dry Chaco forest |url=https://www.sciencedirect.com/science/article/pii/S0378112704008199 |journal=Forest Ecology and Management |volume=206 |issue=1 |pages=399–405 |doi=10.1016/j.foreco.2004.11.014 |issn=0378-1127|url-access=subscription }}</ref> Places like California have already seen increased ecological and societal impacts from fires in recent decades.<ref name="od"/> Community engagement has also been shown to be a crucial part of successful restoration plans and efforts towards decolonization,<ref>{{Cite journal|title=Kōkua aku, Kōkua mai: An Indigenous Consensus-driven and Place-based Approach to Community Led Dryland Restoration and Stewardship|url=https://www.sciencedirect.com/science/article/pii/S0378112721010422|journal=Forest Ecology and Management|date=2022-02-15|issn=0378-1127|article-number=119949|volume=506|doi=10.1016/j.foreco.2021.119949|first=Katie L.|last=Kamelamela|first2=Hannah Kihalani|last2=Springer|first3=Roberta|last3=Ku'ulei Keakealani|first4=Moana Ulu|last4=Ching|first5=Tamara|last5=Ticktin|first6=Rebekah Dickens|last6=Ohara|first7=Elliott W.|last7=Parsons|first8=Edith D.|last8=Adkins|first9=Kainana S.|last9=Francisco|first10=Christian|last10=Giardina|doi-access=free}}</ref> as centering the local community in land decisions can help repair their right to self-determination thus improving restoration outcomes. This is especially relevant for drylands as many of worlds dryland areas are located in historically colonized regions.<ref name="gw"/>

=== Case Studies ===

==== Regenerative Agriculture in Woodend, Victoria ==== In the Woodend region of Central Victoria, integrated farm management practices have been implemented to mitigate land degradation in an area vulnerable to desertification. These systems integrate diverse livestock, vegetable, and fruit production, guided by the principles of regenerative agriculture and keyline design. To optimize water efficiency, keyline irrigation is synchronized with poultry grazing to leverage natural fertilization. By applying water during low-evaporation periods, these practices promote greater root depth and biomass production, which are instrumental in enhancing soil carbon sequestration and strengthening the landscape's climate resilience.<ref>{{Cite book |url=https://linkinghub.elsevier.com/retrieve/pii/C20130187119 |title=Land Restoration |date=2016 |publisher=Elsevier |isbn=978-0-12-801231-4 |language=en |doi=10.1016/c2013-0-18711-9}}</ref>

====The Great Green Wall====

The Great Green Wall is an African Union initiative to restore 100 million hectares of degraded land in the Sahel region through afforestation, especially across areas involved with pastoralism.<ref name="cb">{{Cite journal |last=Delay |first=Etienne |last2=Ka |first2=Abdou |last3=Niang |first3=Khoudia |last4=Touré |first4=Ibra |last5=Goffner |first5=Deborah |date=2022-04-01 |title=Coming back to a Commons approach to construct the Great Green Wall in Senegal |url=https://www.sciencedirect.com/science/article/pii/S0264837722000278 |journal=Land Use Policy |volume=115 |article-number=106000 |doi=10.1016/j.landusepol.2022.106000 |issn=0264-8377|url-access=subscription }}</ref> Initially, it aimed to plant a continuous band of trees from Senegal to Djibouti, but has since evolved into a broader restoration effort.<ref name="gg">{{Cite journal |last=Turner |first=Matthew D. |last2=Davis |first2=Diana K. |last3=Yeh |first3=Emily T. |last4=Hiernaux |first4=Pierre |last5=Loizeaux |first5=Emma R. |last6=Fornof |first6=Emily M. |last7=Rice |first7=Anika M. |last8=Suiter |first8=Aaron K. |date=2023-11-13 |title=Great Green Walls: Hype, Myth, and Science |url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-111102 |journal=Annual Review of Environment and Resources |language=en |volume=48 |issue= |pages=263–287 |doi=10.1146/annurev-environ-112321-111102 |issn=1543-5938|doi-access=free }}</ref> It aims to establish climate resilience and carbon sequestration as well as supporting local livelihoods through improved food security, economic stability and biodiversity. As of 2022, over 56 000 ha of degraded lands have been restored with almost 90 000 people involved.<ref>{{Cite web |title=Sage Journals: Discover world-class research |url=https://journals.sagepub.com/action/cookieAbsent |access-date=2026-02-02 |website=Sage Journals |language=en |doi=10.1177/03795721231190779}}</ref>

Despite these positive outcomes, the Great Green Wall project has been criticised for limited implementation,<ref name="ag"/> governance challenges<ref name="cb"/> and insufficient local participation.<ref name="gg"/> Although the project is African led, most funding and design is international.<ref name="ag">{{Cite journal |last=Zhu |first=Annah Lake |last2=Ndiaye |first2=Amadou |last3=Dahm |first3=Ruben |last4=Mauclaire |first4=Margaux |last5=Boas |first5=Ingrid |date=2025-10-01 |title=Africa's Great Green Mirage? Assessing the disconnect between global finance and local implementation in Africa's Great Green Wall|url=https://www.sciencedirect.com/science/article/pii/S0264837725002042 |journal=Land Use Policy |volume=157 |pages= |doi=10.1016/j.landusepol.2025.107670 |issn=0264-8377}}</ref> The Great Green Wall is a top-down project with the state implementing changes to the local populations' lives,<ref name="gg"/> which can lead to conflict over land access or land use changes, particularly where it affects pastoral mobility.<ref name="cb"/> Concerns have been raised that restoration efforts could reinforce marginalisation if land boundaries,<ref name="gg"/> control of resources<ref name="cb"/> and structure of authority<ref name="cb"/> are reorganised, especially if the local population is not included in the restoration efforts.<ref name="gg"/> Furthermore, the unequal distribution of economical benefits generated by the project, such as permission to harvest (food or timber)<ref name="cb"/> or new job opportunities have led to tensions among locals and with project managers.<ref name="gg"/>

Furthermore, afforestation efforts have been stifled by choosing trees that are ill-suited for arid areas and the establishment of monocultures, which reduces survival and increase vulnerability to disease.<ref name="gg"/> Trade offs between water for tree planting and locals' needs have raised concerns, with water scarcity reported in the Ferlo region of Senegal.<ref name="gg"/>

== See also == * Desert * Dryland farming

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== References == {{Reflist}}

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Category:Biomes