Samarkand State University
If you look at Uzbekistan from space, you will see that most of the country’s surface is occupied by deserts. About 80% of its surface can be considered arid and semi-arid lands.
Main agricultural production is being carried out in the river valleys or where irrigation infrastructure has been developed. Human settlements are concentrated in these areas. Arid lands are left for grazing and wood cutting, since these lands were once rich in timber resources. Unfortunately, people are used to associating arid lands with something bad and unproductive. But that is not accurate. Healthy arid lands can be covered with a variety of grasses, shrubs and trees. Healthy desert is a complex ecosystem with its own laws and associated biodiversity. It produces multiple products and services like any other ecosystem if people use it wisely and in a sustainable way. Here are just a few services and products of healthy arid lands that are most visible and tangible for humans:
1. Protection of infrastructure
Healthy arid land is covered with vegetation that protects habitats and infrastructure from sand accumulation. The state spends a lot of money to clean up transport infrastructure (roads and railways) from the sand, but presence of vegetation cover can significantly reduce or eliminate these costs.
2. Fodder for cattle
Arid lands are very fragile systems surviving in harsh conditions. Therefore, any injudicious intervention can seriously harm the health of drylands. This also applies to the use of the dryland for pasture. This ecosystem requires animal grazing to function properly. Desert steppes, for instance, need ungulates to help break the crust on the soil surface to stimulate the germination of dryland plants. They eat off the plant but they leave as much as is needed for further growth of the plant. Animals help spread plant seeds over vast dryland areas. Desert steppes were mostly inhabited by saiga antelope and gazelle that helped the plants spread over vast areas. But people have almost destroyed their populations, and most arid lands were left without much needed ungulates.
People have replaced ungulates with livestock. But there is a big difference between what nature does, and what a person does. Nature regulated ungulate populations in arid lands according to its carrying capacity. Animal population size formed according to the available plant food. In good years, more animals were born compared to the bad years. So desert regions have always had as many animals as they needed. Animals roamed across arid lands feeding on dryland plants and reviving them again, giving them a chance to recover. Unfortunately, people ignore these "limitations" of arid lands. People have as many animals grazing as they need and it often does not match up to the capabilities of the desert. In addition to population size, the cycle of pasture use is often not being adhered to. It makes it impossible for this land to recover.
Today, non-systematic use of pastures and overgrazing have significantly damaged the health of arid lands. Thus, arid land produces less vegetation compared to the potential productivity when it is being used in a sustainable way.
If one would try to use the resources of arid lands according to their capacity and follow the natural vegetation growth cycles as well as invest in dryland recovery, one could grow more fodder in a long term.
3. Arid resources as a source of fuel
Many elements are important for health of arid lands. One of them is dryland trees and shrubs that form the centers of plant communities. If this “center” is used wisely and in a sustainable way, it would provide firewood for local populations for a long time. If one would practice clear cutting without taking into consideration natural regrowth processes in arid lands, a bare dryland surface would thrive instead. This dryland won’t produce at all. Unfortunately, this process is taking place in many areas at the moment.
It is important for the health of arid lands, as any other land, that its surface is covered with vegetation. In reality, however, vegetation cover in drylands across the country is rather uniform. Due to improper use of pastures, overgrazing, forest cutting and use of shrubs for firewood vegetation cover is severely degraded. This kind of arid land cannot be considered healthy and it does not produce the amount of products and services that it would otherwise.
OUR APPROACH and PROJECT MODEL
We would like to convey the following with our project:
I. Arid lands should be protected as natural capital and as any other element of nature. To receive profit from arid land, one should invest in it. Investing in nature would enable one to receive “dividends” in the long term.
II. Cattle should be grazing in arid lands. Without livestock or wild ungulates desert will degrade. But cattle populations should be managed wisely and not exceed the carrying capacity of the system. If the carrying capacity of the land is exceeded, arid land will be degrading faster and in each subsequent year it will produce less forage.
III. One can and should collect firewood in arid lands. It should be done wisely too. Firewood can be collected from dry shrubs. But if the trees are to be cut down, no more firewood would be available.
In our project, we tried to explore what would happen if people would try to use arid lands in an unconventional way. The project was performed in Dzharkurgan district of Surkhandarya region.
This area is dominated by a sandy type of arid pasture which is mainly used for grazing. This type of pasture under overgrazing conditions is more prone to rapid change in properties of its native vegetation and soil cover compared to other types of pasture. Under non-regulated and prolonged use of sandy pasture for grazing, destruction of soil cover and then a fundamental change in natural vegetation structure can be observed. A lot of soil surface becomes broken under animal trampling and sands become mobile. They can move further to areas inhabited by humans. A significant damage to infrastructure can be caused by this process.
In addition, people living nearby cut down almost all the trees and shrubs they can find. Elders remember that when they were young, the area was covered by dry woodlands. Now one would hardly find roots of trees.
Fig. 1. Detail of degraded pasture land prior to the phytomelioration measures. April 2010
The process of sandy pasture degradation can be currently observed over large areas and is still continuing at an accelerated pace in Dzharkurgan area. Similar situations can be observed in other regions of the country.
To stop this process, a complex of phytomelioration measures (variating the types of species grown on land in order to maintain its fertility) that would restore degraded dryland land is needed. It is necessary to sow and replant native species in drought-prone areas.
The main objective of the project is to create a model that will restore the health of arid land so that it could turn into a lasting source of fodder for sustainable development of dryland pasture, support livestock husbandry and serve as a stable source of firewood for local population.
The area chosen for the project is characterized by typical degraded sandy arid land. Under the influence of excessive grazing and shrub cutting, indigenous species of local flora were on the verge of extinction. Vegetation cover is represented mainly by plant species of low palatability and plants with low forage values indicating typical degradation of pasture vegetation. In terms of basic nutritional value of present plant species, this pasture was no longer able to provide fodder and was impractical for pasture use. Sands at the site were of mobile and partly mobile character (Fig. 1).
During the project execution, seeding and planting of seedlings of drought-resistant forage species of local flora were performed. Field work was conducted in the winter of 2009 and 2010 in the project area of 60 hectares in total. The following plant species were used to restore and reclaim degraded pastures: Black saxaul (Haloxylon aphyllum), a salt-resistant shrub species Salsola richteri, in small quantities perennial grass species Aristida karelinii, and a shrub species Calligonum microcarpum.
The plots were observed and controlled during 5 years after planting. Animal grazing and cutting for firewood was limited. This work shows the results obtained five years after adoption of phytomelioration measures. A study was conducted to assess the results of the recovery process and the current state of the site. Field observations were carried out in the beginning of June 2015.
The results of the study showed that the recovered desert land has high fodder and wood supplies. After the successful adoption of phytoreclamation measures three different types of plant communities dominated by Calligonum microcarpum, Salsola richteri and Black saxaul species (Haloxylon aphyllum) and in small amounts Aristida karelinii have established. The average size of the area covered by vegetation reached 37.6% which is respectively higher than in sandy pasture lands under similar conditions. A more detailed assessment of botanical and economic characteristics of each pasture type can be found in a separate article on the GEF SGP website. Here we present only several pasture types.
Currently, vegetation at the project site is showing important signs (plant species as phytoindicators) of pastures in the process of restoration. Before introduction of the measures, the project area was represented by two main plant communities which had very low forage values. After the adoption of phytomelioration measures, which were running for five years, these plant associations naturally gave way to other characteristic plant species. They formed a healthy pasture with more characteristic sandy dryland vegetation communities with high economic value. Restoration and development of different plant communities (Astragalus, Aristida species, etc.) contributed to consolidation of sand and thus formed the necessary conditions for development of other annual and perennial plant species (Fig. 3).
Fig. 2. Self-regeneration of Bindweed species (Convolvulus divaricatus)
Fig. 3. Stabilizing the sands by Aristida karelinii species
Fig. 4. General view of Callygonum microcarpum dominated vegetation type
POTENTIAL FOR FORAGE PRODUCTION
Forage potential was evaluated for the plant species in the project area. Sections with different dominant species can vary in their fodder values. Calligonum-dominated plant community type had a total of 18 centner/ha productivity of perennial and annual plants. Total productivity of Salsola richteri is 25.3 centner/ha. The highest increase in productivity was found in Black saxaul dominated plant community where the annual growth of vegetation was 57.5 centner/ha.
Fig. 5. General view of Salsola richteri dominated vegetation type
Fig. 6. General view of Black saxaul dominated vegetation type
The project area was grazed by cattle owned by one family throughout the study period. Accurate livestock population data could not be obtained. Field observations showed that lack of grazing on pastures of the project area during five years started to affect the occurrence of some important plant species. It is another piece of evidence for the important presence of grazing animals. Lack of grazing in rangeland areas contributes to accumulation of dead plant matter. In the long term it worsens the condition of vegetation that eventually leads to pasture degradation. Balanced pasture use is essential for keeping the desert in its healthiest state. The rate of grazing in arid areas is 0,2-0,3 small cattle heads per 1 hectare.
According to obtained results, we can say that following the reclamation, this area can produce 33 kg / ha of fodder per year on average. At a daily rate of fodder needed for one sheep being 2.5 kg dry matter the land can produce enough feed for 2 small cattle heads per hectare without compromising the long-term condition of dryland vegetation.
Thus, forage from three different types of pasture in the project area has high fodder quality values. Under natural conditions, plant species that are typical for sandy pasture, would not have such a high productivity. Once sown in the project area, however, their productivity increased compared to performance in other conditions.
It should be noted that most of the forage consisted of a single plant species. Thus, in the Saxaul and Salsola dominated plant communities main fodder component (90%) accounted for such species as Black saxaul and Salsola species. Extremely high accumulation of annual growth in the project area was primarily associated with high plant density, which does not always have positive consequences. The number of Black saxaul plant individuals in Saxaul dominated plant communities was characterized by high numbers of dominant species occurrence which reached up to 2235 individuals per hectare. However, the optimal plant density of Black saxaul should be within the range of 800-1000 individuals per hectare (Shamsutdinov, 1975). In fact, the natural rate was doubled in this case. It shows that black Saxaul can also be used sustainably for firewood. This indicator in the project area is much higher than the recommended standard rate.
An identical situation with high feed stocks was observed in Salsola richteri vegetation community where 94% of the annual increase was accounted for by Salsola richteri species. Dominance of one plant species in this case (despite success in species productivity) does not provide enough diversity in animal forage. From this perspective, emergence and spread of other shrub and semi-shrub plant species in vegetation composition can be a criteria for increasing the economic value of arid land in the project area.
Fig. 7. Successful development of Salsola richteri plant on previously degraded pastures. Plant height is about 3.5 meters.
According to our calculations, Salsola richteri species formed 14.6 tons of dry wood mass per hectare in sandy pasture of the project area.
Fig. 8. The diameter of Salsola richteri trunk can reach up to 13.4 cm
Study findings have shown that restored areas have high volume of timber stock. The main species in each grazing area are represented by dominant species: Salsola richteri, Saxaul and Calligonum microcarpum. Calligonum microcarpum dominated plant communities have relatively low contribution to the overall timber stock.
Salsola richteri dominated communities. Studies have shown that Salsola richteri dominated vegetation types performed best on sandy soils after five vegetation seasons following the phytomelioration measures. In addition to accumulation of large fodder supplies, this species also had a high stock of timber. Average number of Salsola richteri individuals per hectare was 502 plants. Due to favorable soil conditions average Salsola richteri species height was 3.6-3.8 m, and the diameter of its crown ranged from 4.0-4.5 m (Fig. 7).
Haloxylon aphyllum (Black saxaul) dominated communities. A peculiar feature of Black saxaul grove is a high rate of the plant density per unit area. The average height of the plant varies between 2.5-3.0 m and 2.0-2.5 m in crown diameter. Black saxaul vegetation communities formed a dense thicket during the five years after the phytomelioration measures, which led to a significant accumulation of wood stock. According to our estimates, the average number of Black saxaul individuals is 2235 plants per hectare. It generated 14.1 tons of Black saxaul dry wood mass. 82% wood stock of Haloxylon aphyllum had on average a stem diameter of 3 to 8 cm. The remainder of the timber stock consists of secondary shoots. Their thickness is less than 3 cm.
Calligolum microcarpum dominated communities. Calligonum microcarpum dominated communities have a relatively low potential in forming the wood stock compared to Salsola richteri and Saxaul species. This is due to the smaller size of the crown of the plant and particularly intense branching of secondary shoots. Average height of the crown is about 1.3-1.5 m with an average diameter of the crown 1.7-1.9 m. The exception were the bushes. Their height exceeded 3.0 m. (Fig. 9).
Fig. 9. Height of a large Calligolum sp. individual reaches 3 m on fixed sands
Average number of Calligonum microcarpum species per hectare was about 1400 plant individuals. Despite the high number of Calligonum microcarpum individuals, it formed about 1.5 tons of air-dry timber per hectare.
Thus, remedial measures in degraded areas contributed to a significant accumulation of timber stock in the pasture area. On average, three pasture areas produced 10.1 tons of dry mass wood stock per hectare. As previously indicated, Black saxaul and Salsola richteri species were characterized by high rates of wood stock produced. It is therefore necessary to reduce the numbers of Calligonum microcarpum plant species to improve sustainability of pasture ecosystems. That is why planned phytosanitary logging in these areas is a necessary control measure.
Average volume of wood cutting can reach up to 1-3 tons/hectare per year on average after phytomelioration measures to manage the desert in a sustainable way without adverse effects on human health or health of the ecosystem.
Unfortunately, to date, we were unable to conduct a full economic analysis for calculating the effects of drylands recovery. But simple calculations can be done for each farmer or residents of desert lands who own degraded areas.
The cost of dryland restoration can be reduced to several components:
1. Work and time necessary to collect seeds. All seeds of the plants to be seeded in the area to be recovered area can be collected manually. For optimal plant mixture to be used for dryland restoration 3 to 5 kg of seeds are sufficient. One person can collect this amount of seeds in few hours.
2. Sowing seeds. Sowing seeds can be performed in several ways. a) Manual sowing is the cheapest but most time-consuming method. One hectare of the area can be planted by one person in 2 to 3 hours. b) Sowing using machinery such as simple tractor with harrow. Costs of this method depend on the type of machinery used, its rental value and the cost of fuel used in the process of seeding. c) Using cattle in the process of sowing is the most effective method. The area of planned reclamation is to be walked over by a flock of sheep, then manually sowed with seeds, after which the sheep flock is to be walked over the area again. Thus, the hooves of sheep will contribute to establishing of seeds in the soil.
Figure 10. Seeding of Black saxaul plant seeds using a mini tractor at Djeiran Ecocenter.
3. The costs of protection of the land from the potential damage. It is probably the most important task to prevent the restored area from premature and excessive use. It is necessary to "give rest" to the recovered area for 2 to 3 years and prevent grazing and cutting of vegetation in these areas. In our project, protection of restored area was made possible by the family of Namoz Dzhumaev.
Figure 11. The project owns its success to the dedication of Dzhumaev family
As a reward for restoration of the dryland area the owner receives up to 2-3 tons/hectare of firewood per year and the possibility of using the area for pasture with 2-3 heads of small ruminant cattle. Taking into account the average cost of Black saxaul and Salsola richteri wood of 0.2-0.3 USD per 1 kg and the average cost of small ruminant cattle heads of 150 USD, 1 ha of dryland can bring the owner on average annual income of 300-500 USD. Based on this estimated value recovered arid area of 60 hectares generates 18000-30000 USD income in a year. At the same time, direct investment costs can be difficult to calculate. But according to rough estimates, primary reclamation costs account for about 3000-4000 USD. Subsequent costs are equal to the costs of protecting the area and sustainable management of arid land (costs of grazing and sanitary cutting).
The wholesale price of Black saxaul wood in Kazakhstan and Russia is 160-180 dollars per ton. In fact, establishment of commercial Saxaul plantations with a sustainable method of dead wood collection and sanitary wood trimming can also serve as a good example of a business model. It can at the same time become a solution for a global problem of restoration of desert lands in Uzbekistan.
The obtained results and their analysis are the basis for our conclusion that this model of degraded sandy drylands, as in the Dzharkurgan area, has a high potential for widespread use in other degraded deserts in Uzbekistan. We have a lot of desert lands, particularly degraded dry pastures, which can and should be restored. People living in these areas could then receive a stable income. Several simple things have to be done to achieve this:
take the above steps to restore the desert land;
manage arid ecosystems wisely through limiting current resource use so that in the future desert could recover on its own;
observe nature and try to "copy" the natural processes.
Based on the experience gained in Surkhandarya region we can give some practical recommendations for the continuation of this experience:
Those who want to restore the desert to generate income, need to sow a mixture of dryland plant species, diversify fodder plant species and various semi-shrub species, especially Black saxaul and Salsola richteri. This will help create a multi-season pasture.
Grazing in arid lands is recommended in early spring and late autumn and winter. Animals would feed on perennial semi-shrub and shrub species. In summer grazing is not recommended, as sandy rangelands are prone to rapid destruction of the structure of sands under animal hooves. It is important to adhere to the recommended rates of grazing.
It is necessary to carry out a systematic and rational phytosanitary trimming of Black saxaul and Salsola richteri plant species.
GEF SGP is ready to continue work on restoration of desert land and is waiting for proposals from interested parties.
Guidelines for geobotanical survey of natural grasslands of Uzbekistan. - Tashkent: Fan, 1980. - 170 pp.
Shamsutdinov Z.Sh. Creating long-term pastures in the arid zone of Central Asia. - Tashkent: Fan, 1975. - 175 pp.