(Xinjiang Institute of Biology, Pedology and Desert Research, CAS,
Urumqi 810075, Xinjiang, China)
1.1 Location and Size
The project was being carried out in three counties of Haitian Prefecture, south to Atrium Basin, one county of Kashi Prefecture west to Atrium Basin. In Haitian the three counties are Cele, 95 km east of Yutian, 173 km east of Mingfen and 315 km east of Haitian town, and in Kashi the one county is Jiashi, 78 km east of Kashi town．
Up to 1996, the project has been extended 6,350 ha in Cele County, 6,400 ha in Yutian County, and 12,400 ha in Mingfen County, and moreover, most of them in the above three counties were revegetated in shifting sandy lands, and 20,000 ha revegetated on heavy alkaline soil in Jiashi County．
The revegetation in Jiashi is mainly distributed in 76° 20¢ 78² E, and 39° 16¢ 40² N, the elevation is 1,209 m a. s. l..
1.2 Precipitation and
runoff
The physical conditions are similar to each other among the three counties of Haitian Prefecture and the annual average precipitation of the three counties is 36.2mm. Jiashi County is more in the west and the annual rainfall is nearly 54 mm.
It is estimated that the runoffs are respectively 58 millions cubic meters in Cele, 900 millions cubic meters in Yutian, 500millions cubic meters in Mingfen, and 860 millions cubic meters in Jiashi. In addition, there are about 120 millions cubic meters of extra summer floods.
1.3 Temperature
In Cele County, the accumulated temperature ≥10℃ is 4,200 to 4,300℃; the total annual sunshine hours are 2,687.2 hours; the percentage of sunny days is 61%, the annual evaporation rate is 2,595.3 mm; the summer monthly average temperature is 23 to 25℃; the extremely maximum temperature is 41.9℃; the days of high temperature ≥35℃ are 23.7 days; the winter temperature is 0 to 6℃ below zero; and the extremely minimum temperature is 23.9℃ below zero. As for the aspects mentioned above, there are basically no differences among Cele, Yutian and Mingfen Counties.
In Jiashi County, the annual average temperature is 11.7℃; the minimum monthly average temperature is 6.6℃ below zero in January; the maximum monthly average temperature is 26.0℃ in July.
|
Month |
Jan. |
Feb. |
March |
April |
May |
June |
July |
Aug. |
Sept. |
Oct. |
Nov. |
Dec. |
|
(℃) |
-6.6 |
-1.4 |
8.0 |
15.8 |
20.1 |
23.9 |
26.0 |
24.5 |
19.5 |
12.0 |
3.0 |
-4.8 |
The extremely maximum temperature is 41.2℃ in July, and the extremely minimum temperature is -22.5℃ in January. The days of high temperature （≥35℃）are about 20 days.
1.4 Soil types and land
capability
The areas that the project was conducted in Cele, Yutian and Mingfen are mostly dominated by blown sandy soil, and it is commonly named as “shifting sandy land” or “sandy land”. The blown sandy soil mainly composed of fine silt is a kind of no structure soil and has very poor fertility. The areas in Jiashi are mostly dominated by meadow salty soil unable to be cultivated or typical salty soil without vegetation coverage. The above mentioned two types of sandy and salty soils are characterized by poor fertility and low land capability．
1.5 Land use and tenure
During the implementation of these projects of revegetation, all lands used for the project, which are not suitable for agriculture and animal husbandry, are public lands owned by the state. The activities for cultivating Tamarix shrub woodlands under the application of this project were collectively organized, in this case there are no questions about land tenure. The woodlands planted by collective group are owned by village collective system.
1.6 Agricultural,
pastoral, fuelwood and fodder productions
After revegetation of Tamarix shrub woodlands on shifting sandy lands and in areas of heavy salty or alkaline soils by use of floods, except for a fewer parts of these lands being reclaimed into cropping fields, most parts of them are being taken for grazing lands, so that the fodder production has been increased and capacity of rangeland has been promoted, and meanwhile, it also solves the problem of fuelwood energy demand for local people’s daily cooking and heating in a great extent.
Before the implementation of the projects, most areas of shifting sandy lands and heavy salty or alkaline soils have less vegetative coverage on surface, and therefore, there is nothing to say about the land productivity. All these kinds of lands are basically recognized as unsuitable lands for crop farming. And after the implementation of the projects for 3 to 5 years, these lands have been transformed into rangeland with a relatively high productivity, and there is a significant improvement in comparison with the situation at the beginning of implementation of the projects. For instance, up to now the capacity of rangeland has been increased by more than 100 thousands livestock in the artificial plantation of Tamarix shrub woodlands revegetated in recent years in the following four counties of Cele, Yutian, Mingfen and Jiashi, and meanwhile, it has suffered the inadequate supply of fuelwood, and promoted crop farming to further develop.
Table 2. Human and livestock populations (after implementation of
the projects)
|
Counties |
Human Population |
Livestock population |
Livestock/person |
|
Jiashi |
230 000 |
400 000 |
2 |
|
Cele |
110 000 |
350 000 |
3 |
|
Yutian |
160 000 |
400 000 |
2.5 |
|
Mingfen |
40 000 |
350 000 |
9 |
2.1 Land degradation
caused by sand encroachment and dune movement
Before the implementation of the projects, the Tamarix vegetation on sandy lands and alkaline soil at the periphery of oasis has been strongly destructed by human economic activities, which has resulted in acceleration of wind erosion and quick growth of dune, and further caused serious threat to crop farming field inside the existing oasis. As it has been observed in a duration of nearly 20 years in the past, woodlands at the periphery of oasis have been occupied by semi-mobile and mobile dunes, and movement rate of new developed barchan dunes is very high. For example, if the strong wind at grade 9 blows continuously for 13 hr., barchan dunes in a height of one metre will be formed and moved 9 metres, that in a height of 2 m will be moved 6 metres, and high dunes may be moved 20 metres annually. The development of dunes at the periphery of oasis may result in an acceleration of wind erosion and encroachment of sand dunes and even the consequences of spread of desertification.
2.2 Changes of
productivity
The revegetation of Tamarix shrubs on large scale on the untamable sandy lands and saline-alkaline soils at the periphery of oasis or around crop farming fields, does not only can turn the woodlands into pastoral forests/rangelands, but also may play an important role in preventing wind disasters, in stabilizing dunes, and reducing water table level to improve alkaline soil, and meanwhile, preventing crop farming fields from damages and achieving high-yield harvests of forages and fodder production. Up to now, the extension of the project to revegetate Tamarix shrub by use of floods has been conducted for 8 years in the above-mentioned four counties, cereal yield has been increased year by year continuously. It can be seen that if the extension of the project can be further accelerated, the benefit of the sustainable agricultural development will be produced.
2.3 Variation of
vegetation
Revegetation is a sound protective solution to stop soil erosion. Tamarix is one of native pioneer species with long life period of 50 to 100 years. It is estimated according to the survey made in 1950’s that there were 10,000 ha of Tamarix distributed in Jiashi County. The concentratedly distributed Tamarix was threatened by the pressure of the increasing demands of fuel consumption and the population growth, and natural vegetation was destroyed, which brought about desertification and salinization, and turned the lands into unproductive lands. After implementing the project through the efforts made by researchers and local people for recent years, 20,000 ha of Tamarix revegetation were established, which turned the eco-environment into a better condition, and the rangeland has been enlarged, and agriculture development activities have been strengthened. The efforts of revegetation of Tamarix will be beneficial to the sustainable agriculture development as long as the revegetation coverage is well protected.
2.4 Causes of soil
degradation
The human activities are the main causes of soil degradation. The arid zone is characterized by droughts, hot summer, scarcity of rainfall, and rare vegetative coverage, and fragile ecosystem. Under such conditions, the ecosystem is consequently threatened by soil degradation. Because of short supply of fuelwoods along with population growth, the local people deforested natural vegetation at the periphery of oasis without limitation, which results in destruction of vegetation, and as a result, wind erosion, land desertification and development of new sand dunes were accelerated.
2.5 Previous efforts on
studies of desertification rehabilitation
The following topics have been conducted during last more than 30 years: Study on the collection of Tamarix gene in Xinjiang; revegetation of native Tamarix species in Xinjiang; studies on rehabilitation and cultivation of Tamarix shrubs by floods irrigation; studies on species suitable for shifting sand lands and heavy saline-alkaline soils and on artificial afforestation.
3.1 Measures
The main idea is to bring the extra floods for agriculture use on sandy lands and areas of heavy salty soil where plantation is designed. The specific measure adopted is to build channels, and then dam or ditch to bring floods for restoring Tamarix with careful protection. When floods was infiltrated into sand surface, Tamarix seeds contained in floods will be generated itself with sufficient moisture in sand soil. The most important thing that have to concern for generating Tamarix woodlands is to enclose and fence the vegetated area to avoid the people interrupts and animals grazing for at least three years, and it is also important to hire a few man labors to monitor the protection. The Tamarix can grow 2 or 3 meters high after three years, and then the shrub communities can be grazed as the fodder sources.
3.2 Local social
participation and broad Involvement
The project was implemented through contract signed between forestry sectors and residents. Based on the contract, the forestry sectors implement the project through people’s involvement and, in collaboration with local communities.
3.3 Approval of the plan
The project plan was submitted and approved by Xinjiang Uygur Autonomous Region Government in 1986. The statistics of assignments completed by every village in Jiashi County showed that the contract signed between Xinjiang Institute of Biology, Pedology and Desert Research and Forestry Sector of Jiashi County for implementing the revegetating project was successful and significant result has been gained through three-year efforts.
3.4 Changes of proposed
plan
At early stage of the project, it was believed that the project would be recognized and supported by local government and people, because it is based on pre-investigation and develops direct benefits to local people. After the project was executed, the local government and people showed a great enthusiasm. In less than three years the targets were achieved. With such great achievements, another 1,300 ha have been revegetated and the final result was satisfied with smooth implementation as designed in the project document.
3.5 Species List
The revegetation is composed of following 16 species: Populous euphoritica, P. pruinosa, Tamarix Laxa, T. elongate, T. ramosissima, T. hohenackeri,T. arceuthoides, T. leptostachys, T. karelinii, T. hispida, Halostachys caspica, Poacynum hendersonii, Alhagi speudalhagi, Inula ammophylla, Scorzonera divaricata, and Phragmites commuris. All species listed above are indigenous．
3.6 Propagation of
planting materials
The measures adopted in the process of extension services are adaptable. The important steps that have to be done is to bring the extra summer floods to sandy lands and areas of heavy saline-alkaline soil in planed and suitable way, and finally the purpose of establishment of shrub communities will be reached. After several year studies on Tamarix, it has been found that the maturity of Tamarix seeds just coincides with the time of flood, the very small seeds with pappus are easily carried by wind to float in air. And therefore, there will be no need to establish a nursery and seeds sowing. From this point of view that it can be concluded that local people has strong enthusiasm to cooperate in revegetating and exclosing such Tamarix revegetation by use floods. As stated in the project document, the revegetation or artificial plantation area is not allowed to deforest or graze for three years before they grow up. Although the implementation and management of the projects are easy, we still have to sponsor public awareness and organize training course, disseminate technical materials, and educate local people with TV cassette, films, posts and information kits. This is an effective activity to strengthen public awareness and consciousness for revegetating and protecting Tamarix shrub communities.
3.7 Execution
The protection and enlargement of Tamarix will benefit local people and the principle of who plant who own will be adhered continuously. And therefore, the execution of such projects will be conducted generally in voluntary way and only the small scale of experiment is needed for demonstration.
3.8 Management and
Utilization
After the successful revegetation of Tamarix by use of floods, the question is how to make a reasonable utilization of the revegetation. The objectives of the projects are to develop the roles in wind protection, in stabilization of dune and in control of saline and alkaline soils in one way, and to achieve the function of high economic efficiency as much as possible in another way. According to the result analysis, it is recommended that the belt-shaped rotation cutting should be arranged after every 3 or 4 years, namely, every two belts in a width of 100 metres could be cut. By applying this measure, the function of revegetation protection will be effectively played in one hand and biological income of local people will be gained in another.
4.1 Land degradation
control
After completion or the projects, serious land degradation can be remarkably controlled. For example, the wide area at the periphery of Cele Oasis was sparsely vegetated, the villages were threatened by accelerated wind erosion and serious sand encroachment, and former fixed dunes were reactivitated into semi-shifting and mobile dunes. Through several years’ efforts of flood irrigation, the vegetation dominated by Tamarix community is rehabilitated, the community cover is raised up to 60%, the semi-shifting and mobile dunes were fixed with vegetative coverage, and sand encroachment is essentially blocked. The positive effects for controlling land degradation are fruitful.
Although salinization and alkalization in Jiashi County was very serious, and the project site was just a bare salined area. A huge area of bare salined land was transformed into Tamarix shrub woodland by bringing floods to wash down salt and grow salt-resistant species of Tamarix for only a fewer years. It does not only brings down the trend of further deterioration of salined and alkalined soils but also transform the salined-alkalined soils under the protection of desert shrub communities, and originally untamable lands suffered from salinity were turned into arable lands again by growing Tamarix.
4.2 Changes in
productivity on both arable and non-arable lands
Before implementation of the projects, the productivity on arable lands was very low because of secondary salinization of soil caused by high meter table level. In 1985, the average cereal productivity was 325 kg/person, the per capita income was just 450 RMB Yuan, and the total yield of grain was 3 million kg Since 1986 the project was implemented to revegetate Tamarix shrub woodlands by use of floods in a large scale, it brings water table level 1 meter down by ”Bio-drainage”, and therefore secondary soil salinization was reduced greatly, and therefore productivity was raised year by year. In 1992, there were more population, but the average cereal productivity has been increased by 600 kg/person, total cotton production has been increased by 18 million kg, and per capita income has been increased by 800 RMB Yuan/person. As for the large extent of non-arable lands, which was heavily impacted by salty soil, not only barren lands have been turned into woodlands, but also have been improved as productive rangeland, and even some has been reclaimed as the crop fields.
4.3 Soil Fertility
Soil fertility has not been analyzed, but it can be seen that there are a lot of Tamarix humus was formed every year, which can increase the organic matter in soil and improve soil fertility.
4.4 Impact on public
facilities
There will be no any impact on public facilities, because the project area is far away from living quarters.
4.5 Unusual treatments
In past, it was questioned that why there was a lot of afforestation projects did have poor efficiency and low livability. One of the most important reasons is that the protection and management of artificial plantation survival rate is low. As that mentioned above, the belt-shaped rotation cutting was recommended, so that it does not only increase the productivity of shrub woodlands, but also the local people’s per capita income and living standard. For example, during the recent two years, there are 140 ha of Tamarix have been harvested by belt rotation cutting in 8 villages of Jiashi county, and the income has been increased by 100 thousands RMB Yuan.
5.1 Project Investment
The project was planning to apply 6670 ha from 1986 to 1988, and the total investment was 100000 RMB Yuan. The real completion was 18000 ha in the four counties, and the project objectives were reached.
5.2 Cost of treatments
Opening channel and building flood dam cost a few, because most of work was completed through voluntary contribution. The construction of floodgate and overhead ditch needs some expenses, but not too expansive.
If the machinery facilities are taken to open channel and build flood block dam instead of man labours, the cost of revegetation will be higher, but the speed for revegetating will be quicker and result will be obvious.
5.3 Cost-sharing and
benefits distribution
There is few NGOs involvement in the implementation of the projects. The provincial and county governments contributed their investments for building floodgates and overhead ditches, and constructing flood block dam with machinaries. The main input is voluntary man labours contributed by collective organizations, and so the final benefit will be enjoyed by the collective organizations themselves. The provincial and county governments do not share the economic benefits besides the ecological and social benefits.
5.4 Benefit analysis
In general, the ecosystem is essentially improved from poor to better, because a large area of sandy and salty lands were revegetated by Tamarix shrub since the implementation of the projects for three years. The Tamarix shrub woodlands do not only protect crop farming, but also turn these infertilized lands into productive rangeland, and therefore, both ecological and economic benefits are evident. It will produce 15 tons of fine fuelwood per ha after three years growth of the revegetation. The market price of the fuelwood is 200 RMB Yuan/ton, and obviously the cost and benefit ratio is very high, 1∶100, namely invest just one RMB Yuan, and will produce 100 RMB Yuan after three years’ efforts. It can be seen that this project has low cost and high benefit, and it is worth to popularize such technique in desert region where sand dunes are prevailing under poor climatic conditions.
6.1 Extension scope of the
project
This measure, which has the most evident characteristics of low cost, fast growth, high efficiency, can be widely adopted in arid and semi-arid lands of different regions both in China and the abroad, as long as there are extra summer floods and Tamarix distribution.
6.2 Policy consideration
The project can be easily implemented to achieve the planed target if preferential policies have been formulated at county, provincial or national levels．
6.3 Negative effects
The final result of the project execution shows that it does not only turn the sandy and salty lands into rangeland and improve ecosystem, but also do raise up lands productivity and local people’s living standard. From this point it can be seen that there will be no negative effects.
6.4 Women Role
In China, men and women are equal in all fields. Particularly women involved in this project made greater achievement and their contribution accounts for 30% of total labors. Women can play a same important role in implementation of the project.