Restoration is defined by
IPBES as 'any intentional activities that initiates or accelerates the recovery of an ecosystem from a degraded state.' 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".
Ecosystem restoration in general is also emphasized as a tool for
climate mitigation and
adaptation by IUCN and
IPCC. 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. 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).
FAO provides 10 practice principles to guide ecosystem restoration. 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. Desertification is a major problem threatening ecosystems and human lives with the most affected regions being Western Asia and South America.
Sustainable rangeland management Rangelands cover about 25% of drylands globally. With its
carbon sequestration potential, rangeland restoration is considered a climate mitigation option. Rangeland restoration can also improve livelihood opportunities for local pastoralists and can help combat desertification. 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.
Restoration techniques Restoration efforts in dryland areas are particularly challenging because of rare and variable precipitation, high temperatures, low
soil fertility, and
invasive species. A defining feature of dryland ecosystems is the patchiness of its
vegetation, where isolated vegetated patches are scattered within largely bare areas. 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. 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.
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.
Indigenous knowledge and community engagement 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. this is especially relevant for dryland areas as the ecosystems themselves tend to have high heterogeneity. Approaches such as
silvopastoralism/
agroforestry have been applied for centuries in dryland communities with great success. 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. This is especially relevant now as in North and South America over 25% of the population lives in drylands. Places like California have already seen increased ecological and societal impacts from fires in recent decades. 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.
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. Initially, it aimed to plant a continuous band of trees from Senegal to Djibouti, but has since evolved into a broader restoration effort. 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. Despite these positive outcomes, the Great Green Wall project has been criticised for limited implementation, The Great Green Wall is a top-down project with the state implementing changes to the local populations' lives, which can lead to conflict over land access or land use changes, particularly where it affects pastoral mobility. Concerns have been raised that restoration efforts could reinforce marginalisation if land boundaries, control of resources and structure of authority are reorganised, especially if the local population is not included in the restoration efforts. Furthermore, the unequal distribution of economical benefits generated by the project, such as permission to harvest (food or timber) or new job opportunities have led to tensions among locals and with project managers. 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. Trade offs between water for tree planting and locals' needs have raised concerns, with water scarcity reported in the Ferlo region of Senegal. == See also ==