HORIZON INTERNATIONAL SOLUTIONS SITE

Summary:

Tamarix is a natural resource on which the communities depend for fuelwood, tools, and basket making. In an effort to re-establish groundwater recharge, rejuvenate soil conditions, reduce waterlogging effects and salinization, and restore Tamarix populations, four counties have joined forces to implement the Tamarix project, including Cele, Yutian, Mingfeng, and Jiashi, an integrated approach to agricultural production and forest rehabilitation in dryland regions. Now communities, which at one time suffered extensive land degradation, can effectively manage utilization of the rejuvenated Tamarix populations for local needs and provide long-term soil protection for cropping.

Problem Overview:

Desertification due to population growth and agricultural mismanagement.

Population growth and agricultural mismanagement have exacerbated desertification problems in regions worldwide. Extensive clearance of natural vegetation, grazing of livestock, agricultural expansion, and soil salinization have contributed to land degradation, reduced water supplies and limited agricultural production in desert areas.

Water resources become a critical natural resource on which the livelihoods depend. Settlements on the southern margins of the Taklimakan Desert, in the south-west of China’s Xingiang Uygur Autonomous Region, maintain their livelihoods through cultivation of the land and herding of livestock.

The Taklimakan Desert in the Tarim Basin has historically overtaken communities since the large sand dunes can shift periodically. Despite the vulnerability of the area, many local populations had previously exacerbated this problem through over-utilization of indigenous Tamarix forests for fuelwood and of scarce water supplies for irrigated food. Jiashi County suffered the greatest effects of salinization on irrigated cropland since floodwater accumulates extensive flat and poorly drained areas and is high in salt concentrations due to clearance of natural vegetation. It was estimated that nearly 60 per cent of agricultural land in the county was threatened by salinity problems.

Background:

Areas in the Taklimakan Desert in the Tarim Basin between the Tianshan mountains and Kunlun Mountains are situated in a narrow belt of alluvial hills and plains where agriculture is possible. Precipitation in the mountains replenishes surface and groundwater through a network of nearly 100 rivers. Without this natural water source, the area would suffer drastic desertification since the area only receives between 31 mm and 46 mm of rainfall annually but experiences 1600 mm of evaporation per year. The region also experiences extreme temperatures and wind storms. Agriculture is the main activity of local populations and each village functions as a co-operative in the provision of water through irrigation channels, planting and watering of trees, and management of other common property resources such as roads.

Tamarix is a unique tree species in that it lives up to 100 years in both waterlogged and saline soils, making it an ideal species to reverse environmental degradation. Under natural conditions, Tamarix disperses seeds through floodwater during the summer months, and this natural method was employed to regenerate the species in large areas by controlling and directing water flow from floods.

Two main strategies were used to this effect. The first was to build a soil embankment around the treated area, which was subsequently inundated with water. The second was to construct small parallel channels, about 3 m apart, with a large mould-board plough attached to a bulldozer. The floodwaters were then released into these areas along the channels. The latter method completed channels across an area at the rate of 1 hectare an hour and covered 2-3000 ha each year. The water flow requirement to achieve this rate is between 750 and 1500 m3 ha-1. Once the area has been flooded, the area is protected to allow seed and Tamarix growth to 2-3 m, and then one third of the area is designated for a controlled system of fuelwood collection each year on a 3-year rotation system.

Protection of the seedlings is accomplished by three main methods. The first is a forest guard to whom a small salary is paid partly by government subsidies and partly by community income from fuelwood. Guards are also permitted to supplement their income through farming and livestock rearing. The second method is a volunteer based system in which the volunteers are paid a small honorarium from the proceeds of fuelwood sales. The final strategy was contingent on village participation to uphold a system of forestry laws and to charge fines to those who violated those laws.

Benefits:

Based on this management system, it has been possible to maintain a sustainable resource for fuelwood production of about 5 tons per hectare. The cultivation has also increased the supply of fodder as food for livestock with a consequent increase in the number of livestock per capita. In Jiashi County, for example, the average number of animals has increased from 1.7 per person in 1985 to 2.7 in 1993. Many villagers have also adopted a cut-and-carry feeding system, so that uncontrolled grazing of the forest areas on the oasis margins has been dramatically reduced.

Tamarix species has also helped rehabilitate the land for a more viable agricultural production. Agricultural productivity has increased the average annual household income in Jiashi County from RMB 2179 in 1985 to RMB 3374 in 1992. Furthermore, the marketing of products which use Tamari, such as basket making, earth carriers, and trolleys, has also improved livelihoods of the 33% of total households involved in cottage industries by generating a profit of approximately RMB 6000 per year per household.

Given that the project has simultaneously enhanced both economic and ecological conditions of the people by employing a simple technique, has influenced the budgetary allocations within county governments for Tamarix cultivation within management activities, has stimulated interest in the scientific community at Xinjiang Institute of Biology, Pedology and Desert Research to promote the approach, it is likely that enthusiasm for the project on a local and governmental level will result in long-term benefits for future generations.

Constraints:

Since implementation of the project relies on whole-community participation to improve conditions, one limitation for future replication might be in persuading all members of the importance and effectiveness of the project. It is also important that native tree species with characteristics similar to Tamarix, but not necessarily Tamarix itself, be considered for the particular area in question. For the best results, it is important to tailor strategies used in this study to other regions.

Status:

Currently, more than 15 Tamarix species have been re-established in project areas, achieving a vegetative cover of up to 60 per cent within a period of 4 years. This includes 6600 ha each in Cele and Yutian Counties, 13 300 ha in Mingfeng County, and more than 40 000 ha in Jiashi County. In Cele, Yutian and Mingfeng Counties, the re-established Tamarix have been successful in combating sand dune encroachment and providing a sustainable source of wood. Of the total area treated in Jiashi by 1994, 5300 ha has been subsequently returned to agricultural production. The lines of Tamarix trees act as a ‘biological pump’ to keep the water-table well below the surface, and crops are grown in the strips between the Tamarix. It is planned that up to 50 per cent of Jiashi County areas that have been treated to date will eventually be used under this system of forest-cropping. This method of forest and agricultural rehabilitation has now been fully adopted by all four counties and is in the beginning stages in 50 other counties throughout Xinjiang, and in two counties in Gansu Province, a neighboring region.

Documentation:

World Atlas of Desertification Second Edition, UNEP, 1997

Submitted by:

Clare Parker
Email: cparker@rona.unep.org
United Nations Environment Programme
2 UN Plaza
Rm. DC2-803
New York, NY, 10017
USA

Information Date: 1997-01-01
Information Source: World Atlas of Desertification, Second Edition, UNEP