May 23, 2019 Soil Degradation Written by Sara Slavikova
Prevention of desertification
As other natural ecosystems,

deserts have their own dynamics independent of human activities. Throughout the history, sand dunes have always been retreating or slowly expanding into adjacent areas when given the chance. But processes that happen during desertification are different. They do not follow natural patterns. They are more unpredictable and dangerous. They can happen much quicker…

Lands that were once covered with a carpet of perennial grasses, woody shrubs and in some parts dense forests have reportedly turn to barren grounds where only wind sweeps dust around and rain water flushes down muddy sediments whenever it rains. These are lands that were green just a decade ago or so. And local residents still remember when their livestock had grass to graze, their fathers grew crops and their mothers warned them of not playing in the forests because they could get lost.

It doesn’t matter who shares these memories and from which country that person is, their story is the same. Their homes are being swallowed up by dust and sand as desertification creeps closer. Their pastures and crops have disappeared, and water sources became scarce. Their situation feels hopeless and most of these people do not know how their closest future will look like.  

Will they still be there? Living among the dust with diminishing resources? Will they leave? Or can desertification be stopped?  

 

How Does Desertification Happen?

Desertification is not natural expansion of deserts. In fact, natural deserts do not even have to be close to areas where desertification happens. Desertification is a form of land degradation caused by poor land management of drylands rather than spreading of already existing deserts.

This means that the degradation is mainly caused by our land use activity, when we alter natural ecosystems and, consequently, rain cycles in arid and semi-arid areas.

Lands vulnerable to desertification transform into deserts because their soil becomes progressively drier, poor and unable to support plant growth. Once desertification occurs, the most productive soil layer, known as topsoil, gets blown away by wind or washed off by rain rather quickly because there is no vegetation that would protect it. With topsoil gone, important soil nutrients with organic material are lost.

Affected soil then loses its structure and the ability to nourish plants and soil fauna. It dries out and hardens, making it increasingly difficult for any following rainfall to penetrate below the surface. When rain cannot infiltrate into deeper soil layers, it runs off instead of keeping soils moist and replenishing groundwater reservoirs.

As you can imagine, this continually makes the whole area drier. The conditions are gradually getting worse and even the most drought resistant plants eventually die, leaving the barren land exposed to complete degradation.

What Is the Difference between Drought and Desertification?

Generally used definition of drought says that it is a period of unusually low precipitation that is long enough to cause water scarcity and deplete soil moisture to the point where vegetation (including crops) dwindles [1].

Drylands, areas that are the most susceptible to desertification, are characterized by periods of droughts that lead to water scarcity and drying vegetation, but then when rains come, they re-green again and vegetation, animals and people prosper.

These cycles are characteristic to drylands and life has adapted around them. They also change according to changing climate and other complex factors influencing local water cycle, with some periods lasting longer than usual, even years, some lasting shorter. But they have always been there. Periods of abundancy and periods of decline.

Area stricken by desertification might look the same at the first look as an area affected by drought, but there is one big difference, and that is what happens when the rain comes.

Land affected by desertification

Despite of looking horribly dry and damaged, natural drylands will turn green and lush again; soils will mend; water creeks will start flowing and wells will refill with water. While lands degraded to the point of desertification will remain lifeless. The only effect rainwater will have on them will be erosion and flooding.

This does not depict only the difference between desertification and drought, this also depicts the difference between self-supporting ecosystem and an area where ecosystem collapsed and doesn’t perform any life-promoting services.  

Now, the question that might come to your mind instantly is: how is drought and desertification related? Doesn’t drought actually cause desertification?

It does. Drought can lead to desertification. But it will happen on severely damaged lands which are already so exhausted that any remaining plant life will not survive a dry spell or repetitive series of dry spells caused lately by human-induced climate change.

The process goes even the other way around, desertification exacerbates regional droughts and heat because of reducing water absorption by soils and barren land surface reflecting more sun’s heat [2].

Why Is Desertification Such a Problem?

According to Luc Gnacadja, former executive secretary of UN’s Convention to Combat Desertification (UNCCD), desertification is one of the major threats to global wellbeing [3]. This statement is in no case exaggerated.

As human population keeps increasing, so does the pressure on earth’s land surface to provide resources and nutrients. But as the pressure grows, some areas fail because resources get depleted and lands are drained of their last bits of fertility.

This pattern keeps repeating faster and faster–failing areas keep getting larger, our population too, but the land we have available on this planet remains the same.

That doesn’t sound right, does it?  

According to the World Economic Forum, land degradation could reduce global food production by 12 percent in the upcoming years, which would lead to the increase in food prices by up to 30 percent. 

Desertification is a problem because 40 percent of the earth’s surface is susceptible to this form of land degradation. The form of land degradation that makes land dead: unable to sequester carbon from the atmosphere; unable to regulate water cycle; unable to withstand erratic weather; unable to feed us; unable to protect us and provide home for us or other life forms.

This means that desertification could destroy everything we need for our health and survival, everything that brings us joy as well. It is in our own interest to take action to stop desertification, especially when considering that it is unsustainable land management that has led to this problem in the first place.  

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How Can We Prevent Desertification?

The good news is that desertification can be prevented. And even better news is that the same strategy that could help prevent desertification is also effective in addressing problems caused by drought and other forms of land degradation. Even more importantly, this strategy promotes our ability to mitigate climate change and enhances our adaptability to it as well.

Doesn’t that sound like a great solution?

Well, it is, but the widespread implementation of this strategy will demand transboundary cooperation and long-term engagement of land owners, policy makers, entrepreneurs and scientists. And as you know, to achieve synchronization at this level is a difficult task.

Farming in a desert

Additional difficulty arises from the diversity of the causes that lead to land degradation in affected areas. This means that each location needs customized measures to prevent desertification effectively. It makes sense. There is a difference between the reasons why desertification happens in the Sahel or in Canadian Prairies. So, the concept requires careful assessment of local conditions and adjustments according to local climate, water availability and prevalent land use in the area.

But before we doubt its effectivity, let’s learn how this strategy works and what benefits it brings.

The Concept of Sustainable Land Management in Fighting Desertification

The UNCCD defines Sustainable Land Management as “a holistic approach to preserve ecosystem services in long-term productive ecosystems by integrating biophysical, socio-cultural and economic needs and values.”

Land management practices leading to this outcome are rounded around four guiding principles [4]:

 
    • 1. Maintenance of soil health and fertility

This involves agricultural practices that are focused on better management of water and nutrients in soils while improving the soil structure.

Farmers also focus on prevention of common problems of agricultural lands in dry areas–erosion and salinization. Some effective methods to achieve this are no-till farming, cover cropping, improved residue management, application of compost and precision agriculture [6]. These techniques also help building up organic matter in soils, thus maintaining their long-term productivity.

To retain water for longer periods of time, farmers are encouraged to build terraces or stone walls to stop runoff, leave soils covered by mulch to decrease water evaporation from soil surface, and create swales or check dams to harvest rainwater for later use.   

 
    • 2. Promotion of resistance in lands used for livestock grazing

The key to ensuring long-term productivity of grazing lands is to protect diversity of native plant species that are well-adapted to local conditions.

This means that farmers have to manage animals in such a way that soils and grasses do not get damaged beyond the point of repair. Methods that help to achieve this long-term sustainability involve rotational grazing when land is given enough time to recover, reduction in numbers of animals per area, proper animal waste management and replanting of native grass species with deep root systems.

Further measures like planting of perennial legumes on grazed lands enrich soils of nitrogen and provide additional nutrients for animals. For example, Food and Agriculture Organization (FAO) recommends planting Mesquite trees on grazed lands, which is a leguminous plant that provides pods rich in protein.

Pods can be fed to livestock in times of drought, and the tree itself provides shade for animals during hot days and stabilizes soils against erosion [7]. The tree is also known for being extremely resistant, able to withstand drought and grow even on lands with increased salinity.

 
    • 3. Increase in biodiversity on cultivated lands

Drylands are vulnerable areas that require sensitive management when cultivated. Planting trees on crop boundaries, maintaining hedgerows or practicing agroforestry has proven to be very beneficial for the land.

Trees protect soils from wind; slow down water runoff; shield soils from the sun’s heat so it retains moisture longer; and even prevent damage to crops during storms.

Livestock can benefit from grazing among trees as well. This practice is known as silvopasture, and when done correctly, trees promote regeneration of grazed soils, while at the same time, create cooler climate for animals and people in the area. Additionally, farmers benefit not only from animal products, but they also harvest wood from these plots.

Another popular approach to diversifying farm production is intercropping–when farmers plant two or more crops in one plot. A common example of crops that complement each other is maize and beans.

But it doesn’t have to be only conventional crops that ensure success of this method, focus on diversity of local seeds and crop varieties can deliver great yields because these plants have evolved and adapted to the climate in the area, which gives them extra resilience to local challenges right from the beginning.

 
    • 4. Protection of native forests and tree planting

The role of trees in protecting soils from erosion, supplying moisture and cooling down the surrounding area is irreplaceable. We cannot substitute these functions by any technique we master. That’s the reason why forests and free-standing trees need to be protected in order to prevent spreading of desertification.

In places, where deforestation has already happened, it is recommended to replant native trees and let them grow naturally in hopes of restoring original ecosystem. The same technique can be used even on plots that were once cultivated for crops but got depleted.

Suitable tree species could restart biological activity in soils and increase land resiliency to degradation. Native species of trees should be prioritized because they have special adaptations to local climate and will sustain other native species.

 

The final effects of these principles overlap on many levels, but their efficiency in tackling desertification consists of:

  • Improved water management
  • Minimization of erosion
  • Better nutrient cycling (including enhanced carbon sequestration by soils)
  • Increase in biodiversity
  • Efficient management of available resources
  • Healthy resilience to withstand extremes [5]

 

The concept of the Sustainable Land Management combines multiple different approaches that can be combined together in order to achieve the same goal – promotion of soil health and prevention of land degradation. Maintaining healthy soils is in the best interest of farmers and land owners because it will enable them to sustain livelihoods from their land for generations.

What’s more, healthier land with richer diversity is more resistant, so it will protect local communities better in periods of weather fluctuations. And this is what brings us to the next important step in prevention of desertification – communities working together.  

Communication, Cooperation and Gender Equality Can Stop Desertification

Many stories were written about human suffering caused by desertification. Ranging from having to leave home, losing animals, not having enough food, water and money, to being terrorized by radical groups, or losing family members in wars for resources. These stories are sad reminders of how destructive for communities is the loss of their ability to grow food.   

That is why native communities also play the key role in helping to tackle the issue of desertification.

It is the people who have direct bonds with the land that may provide the missing insight on what solutions will work in their region. It is them who will carry out the challenge of implementing new land management practices, while encouraging other members of their community to adopt these techniques as well. And it is them who care the most about saving their area from destruction.

Mongolian boy herds sheep

To be even more specific, in many cases, it is women who perform these tasks. The division of labor in developing countries is such that women’s role relates to taking care of households and communities, cultivating soils, planting seeds, preserving traditional agricultural knowledge as well as managing natural resources such as firewood and water. Women are also more caring about wellbeing of their community, have more patience, are willing to share and are sensitive to learning new ways of land management.

Thus, educating local communities about the principles of the Sustainable Land Management and empowering women can go long way in helping to stop land degradation by desertification.

In connection with transition to the Sustainable Land Management is also the need to provide an opportunity to these communities to sell their products and services by developing local economy.

Local markets support local livelihoods. They enable rural people to benefit from sustainable management of their lands, rather than forcing them to look into destructive overexploitation in desperate attempts to sell cash crops quickly because of not having any other choice, and eventually having to abandon their depleted lands for the life in the city. Local markets also very often encourage exchange of various seeds and different crop varieties, which helps increase crop diversity on farms and improves their resilience. 

But local communities alone cannot halt such a large-scale problem like desertification. As the UNCCD states, partnerships and cooperation at all levels are needed at this moment. This means that not only local and national governments and stakeholders have to be involved in implementing these solutions, but even international involvement is necessary, where developed countries aid affected developing countries. For example, by introducing modern technology like highly accurate weather forecast systems to help farmers determine when is the best time to sow their crops.

Similarly, sharing of the newest findings and data from scientific research should be done on a global scale because it is in the interest of all of us to prevent further losses of inhabitable land [8].

Ambitious Projects to Save the World’s Drylands: The Great Green Walls

What do some communities in China and in Sub-Saharan Africa have in common? Desertification? Yes. That’s the problem they are facing, but they also have the same ambitious plan how to ward off encroaching sand. And they want to do it by planting a great wall of drought resistant trees.

The Great Green Wall of Africa is a large-scale tree planting project that takes place on the southern edge of the Sahara Desert. The plan is to plant about 4,350 miles (8,000 kilometers) long and 10 miles (15 kilometers) wide stripe of trees that should act as a buffer between the Sahara Desert and neighboring lands in the south. The purpose of the trees is to stop desertification and protect vulnerable soils across the entire width of the African continent.

According to the project’s official website, about 15 percent of the designated area has been already re-greened by trees – mainly Acacia trees—since the launch of the project in 2007. Around 12 million trees were planted in Senegal alone and positive effects on soils are already visible in Nigeria, Ethiopia, Niger and Burkina Faso [8]. The planting efforts are set to continue, and the next goal of this initiative is truly ambitious, planning to restore 100 million hectares of degraded land until 2030 [9].

Savannah shrubs

The Great Green Wall of China (also called Three-North Shelterbelt Project) is perhaps less known but older version of the Africa’s tree planting initiative. It has been launched in 1978 by the government of China with the aim of planting trees along the edge of the Gobi Desert in northern China. The tree belt should span across approximately 2,800 miles (4,500 kilometers).

Until this day, 66 billion trees have been planted and the project is set to continue until 2050. According to the data collected by the China’s forestry administration office, that has been monitoring land cover changes in the country, between 1999 and 2014, areas covered in deserts have decreased [10]. This suggests that the initiative has been successful so far. But is it really so?

The results from both of these grand projects seem wonderful, but in both cases appears also criticism and doubts about the data consistency and possible consequences of such a large-scale ‘artificial’ transformation of the landscape.

For example, scientists have already noticed that trees from the Green Wall in China caused water level decline in the Yellow River—the most important source of water for farmers and communities along its long channel. It’s because trees overall need more water than grasses, and if they do not have enough water for longer periods of time, especially at the beginning of their growth, they do not grow well.

According to some scientists this is problematic in already dried out and damaged regions like these, because if there are too many trees out of sudden, they draw too much water from the ground and actually exacerbate soil dryness, stealing remaining soil moisture from crops and other vegetation [10,11].

According to experts, restoration of grasslands with fewer trees to imitate natural Savannahs would be a better option in terms of water preservation in some of these arid areas [10,11,12].

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Can Desertification Be Reversed and Ecosystems Restored?

Let’s start with a little story…

The Syrian steppe, which covers approximately 10 million hectares of the Syria’s territory, has been home to nomadic Bedouins and their herds of goats and camels for centuries. But after years of exceptional droughts and unrestricted grazing due to changes in the political system in 1958, the fragile lands of the steppe became severely degraded, turning the steppe into a desert.

Herd of camels in the steppe

Luckily, the story doesn’t end buried in sand. Thanks to the cooperation of the International Fund for Agricultural Development with the Bedouin herders, 930 thousand hectares of the steppe have been regenerated and another 320 thousand are in the process of restoration [8].

Through the implementation of the Bedouins’ ancient knowledge about the grazing land maintenance and animal herding combined with principles of the sustainable land management, rehabilitation plans were put together. These plans include methods of rotational grazing, when certain areas are left to rest for up to two years, with replanting of native plants and shrubs where needed. Grazing animals then help to disseminate seeds and keep shrubs at check.

This way the livestock aids in bringing back original ecosystem, with some parts of the steppe already hosting diversity of native birds and insects.

As life slowly returns to parts of the Syrian steppe that were once barren, so does even in other parts of the world. Fortunately, this is not the only success story when common efforts of the community and traditional knowledge about the management of local resources reverted desertification.    

Ancient Farming Technique Re-Greens the Sahel

What has been nearly an impossible dream of one man has grown into his life-long mission and changed lives of many communities in Burkina Faso and Niger. Yacouba Sawadogo, a farmer from Burkina Faso, became increasingly concerned about desertification in his region, and after seeing that actions taken by the authorities to address the issue failed, he decided to stand up to the desert on his own.

Sawadogo has revived two traditional farming methods, Zai and cordons pierreux. Methods, that had been once forgotten, have actually proven to work amazingly well in restoring degraded lands of the Sahel. Both methods work on the principle of maximizing water infiltration and retention on hardened, impenetrable soils.

Zai involves digging up a hole of two to five inches deep (5 to 15 centimeters) for each plant. This measure helps to catch and store rainwater directly where it is needed–in the soil by the plant’s roots. The soil surrounding plants can be also easily enriched by compost to provide additional nutrients.

Cordons pierreux aims at slowing down runoff by building little stone barriers across each plot. This gives water more time to enter the ground [13].

According to the Right Livelihood Award Foundation, by employing these methods, Sawadogo has planted 40 hectares of forest, creating a self-sustainable ecosystem on previously barren land. He has been also actively teaching both farming techniques.

Sawadogo’s training has helped to revitalize tens of thousands of hectares of degraded lands, sustaining livelihoods of 3 million farmers and their families across two countries [12,14].

For his lifelong effort, Sawadogo was among the winners of the Sweden’s Alternative Nobel prize last year and his story has been featured in a documentary called “The Man Who Stopped the Desert.”

Video credit: Vimeo / 1080 Film & TV

Allan Savory’s Holistic Planned Grazing

Allan Savory’s name is often spelled in connection with reversing desertification and regenerating grasslands through livestock grazing. Savory has developed a system called Holistic Planned Grazing, which is based on managing livestock in a way that mimics natural behavior of wild herbivores.

Large herds of wild herbivores have always been grazing on prairies, steppes, savannahs, naturally maintaining and rejuvenating world’s grasslands for thousands of years. Characteristic behavior patterns of these animals have had positive influence on the health of soils and promotion of healthy growth of native vegetation.

Animals have benefitted from the pasture and grassland ecosystems have benefitted from their presence. Naturally, herbivores cover long distances during the day, grazing along the way, trampling vegetation, spreading seeds, maintaining diversity of plants and fertilizing soil with their dung.  

Even though, vegetation trampling may seem like an unwanted effect in drylands, Savory explains that it actually promotes its regreening because animals remove dry parts of plants, allowing for plants to start growing abundantly when the rain comes again. Furthermore, dead plant material also covers soils and protects them from drying out, while at the same time supplies soils with organic material and nutrients released during its decomposition [15].

By observing these natural dynamics between wild animals and Africa’s drylands, Savory realized that holistically managed herds of livestock could reproduce these positive results and restore areas affected by desertification.

On contrary to other grazing methods, holistic planned grazing is based on the principle of rational grazing, which focuses on carefully planned exposure of plants to grazing rather than limiting the number of animals. According to Savory, larger herds replicate the results better but they need to be herded and not spend too much time in one place [15].

On the official website of the Savory’s Institute is written that currently 9 million hectares of degraded grasslands are regenerating thanks to the implementation of this approach. It also states that his method has helped numerous farming communities in increasing productivity of their lands and maintaining their livelihoods.

But before getting all too excited, it is also necessary to mention that numerous scientists and experts from the field have criticized the efficiency of this method, claiming that there is a lack of scientific evidence to confirm positive results of this specific grazing management [16]. Some ecologists even directly state that this method yields rather negative results in extremely dry environments because livestock disturbs last remaining vegetation [17].

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Final Words

The controversy around the holistic management of grasslands and negative effects of planting too many trees in efforts to stop desertification, which have been described earlier in this article, only confirm how complex natural ecosystems are and rises a question whether it is in our power to restore them once they have faded away. From above mentioned examples, we can also tell that there isn’t one universal solution that will work in all affected areas. Instead there are many different ways we can combine in order to achieve the best results to get as close to balanced environment as possible.

One thing that is clear by now, though, is that the prevention of desertification is crucial and urgent.

With more people exerting pressure on natural resources, it’s time to turn the odds around. Rather than witnessing the degradation, it’s time to take advantage of our ancestral skills in land management and apply them for the benefit of both – people and the environment. Because the solution to stopping desertification that will work depends on local conditions, on experience of local people and socio-economic opportunities that are given to them.   

 
 

References

[1] https://www.livescience.com/21469-drought-definition.html
[2] http://www.fao.org/3/x5317e/x5317e01.htm
[3] https://www.theguardian.com/environment/2010/dec/16/desertification-climate-change
[4] https://www.unccd.int/sites/default/files/documents/2017-09/UNCCD_Report_SLM_web_v2.pdf
[5] http://www.droughtmanagement.info/literature/UNCCD_desertification_visual_synthesis_2012.pdf
[6] https://modernag.org/soil-health/the-benefits-of-fertile-soil/
[7] https://www.developmenteducation.ie/media/documents/Desertification.pdf
[8] http://www.droughtmanagement.info/literature/UNCCD_desertification_visual_synthesis_2012.pdf
[9] https://www.greatgreenwall.org/results
[10] https://news.nationalgeographic.com/2017/04/china-great-green-wall-gobi-tengger-desertification/
[11] http://theconversation.com/chinas-fight-against-desertification-should-not-be-done-at-the-cost-of-water-security-83678
[12] https://www.smithsonianmag.com/science-nature/great-green-wall-stop-desertification-not-so-much-180960171/
[13] https://www.ancient-origins.net/history-ancient-traditions/man-who-stopped-desert-using-ancient-farming-009493
[14] https://www.rightlivelihoodaward.org/2018-announcement/yacouba-sawadogo/
[15] https://ourworld.unu.edu/en/reversing-desertification-with-livestock
[16] https://www.slu.se/globalassets/ew/org/centrb/epok/dokument/holisticmanagement_review.pdf
[17] https://www.sierraclub.org/sierra/2017-2-march-april/feature/allan-savory-says-more-cows-land-will-reverse-climate-change