Forest genetic resources / Projects / China
Summary of project activities
The project's strategy concentrated on three complementary activities: widening of the genetic base; introduction of appropriate mechanized afforestation techniques; and integrating forestry as one element in a holistic approach to combating desertification.
1. Widening of the genetic base
Widening of the genetic base of clones used in reforestation, shelterbelts and afforestation programmes in order to increase productivity, introduce resistance to frost and drought, and reduce overall susceptibility to pests and diseases, was a major goal. Three strategies were implemented towards achieving this goal.
(i) The development of a long-term poplar breeding and selection programme, to continuously produce new material from a wide genetic resource base. Through recurrent selection, using and surveying the performance of indigenous and introduced species and clones, the programme relied on intra-specific and inter-specific hybridization and crossing to obtain new genetic combinations. The plan envisaged the use of a wide base collection of native poplars.
(ii) Ex situ and in situ conservation of the remaining pockets of genetic resources of Populus simonii and the related P. pseudosimonii, the only fast-growing indigenous species adapted to the extreme climatic conditions and to the poor soils of the region. Whenever possible, this unique genetic material was conserved in situ (on site). When this option was not possible, individual trees were collected, propagated and then stored in ex situ collections, such as gene banks and arboreta.
(iii) The development of a short-term poplar selection programme, to rapidly improve the vigour, form, and resistance to frost and pests of the clones used for afforestation, through collection, testing and evaluation of poplar clones already available in northern China and similar ecosystems elsewhere. The programme was intended to quickly provide improved and already existing material for forest managers.
2. Introduction of appropriate mechanized afforestation techniques
The second major activity was to develop and fine-tune mechanized afforestation techniques suitable for large-scale tree planting and plantation establishment. The project advocated the use of deep-planting techniques for poplars, as already successfully used for decades in Europe, the Americas, and other parts of the world.
It was, however, necessary to adapt this technique to the local environment, through a series of systematic scientific experiments and associated field data collection. The technique was first tried out to increase survival for the clonal selection programme; later, standard procedures for large-scale reforestation were developed: planting at a depth of 130 cm, using 1-year-old cuttings without roots buried over winter for spring planting, or 2-year-old cuttings for autumn planting.
It was found that burying the cuttings over winter starts a physiological process that rejuvenates the plant tissues so that rooting capacity is increased. Cuttings should be soaked in water for 24 hours before planting. Specially designed mechanical augers have been produced by the project for drilling holes to facilitate the planting technique.
Although assuring excellent survival rates (over 95%), the technique of using a mechanical auger to dig holes to a depth of 130 cm was considered too slow for large-scale afforestation applications. Therefore, another method was tried using 80-cm-long cuttings pushed as deep as 70 cm into the sand. This can be done in autumn or even in spring if the cuttings have been buried over winter. One- or two-year-old cuttings that had been soaked in water before planting were used. The project developed a special planting machine based on a single-shank soil ripper, providing attachments for carrying planting stock, three operators and packing wheels.
The development of this fast planting machine (called a Medium-Depth Planter, or MDP) involved fine tuning to ensure that it was technically viable cost effective in operation. The MDP proved to be a cost-effective method for tree planting and it was considered a major achievement of the project in an area where human labour is itself scarce or unavailable for forestry activities.
Utilizing this new planting technique involved a new nursery technique in order to produce planting stock of mostly 2-year-old cuttings with a maximum length of 100 cm. This nursery production technique was improved through systematic trials on fertilization, spacing density and other aspects.
The big advantage of using specially designed and adapted techniques (augers and the MDP) compared to traditional planting is that it allows the use of unrooted cuttings, thereby diminishing drastically the area and costs of the nurseries, given that stool beds can be used for many years. The project undertook trials aimed at further reducing costs, using each unrooted sapling in a nursery to produce two viable cuttings for planting with the MDP technique.
Meteorological data and information on soil conditions at the experimental sites were systematically recorded and kept in databases for use in the analysis of the results of the trials. Trials on preparation techniques for plantation sites showed that for plantation establishment it was not necessary to do extensive site preparation or tending, and it was in fact better not to do so, in order to minimize wind erosion of soil. Pilot areas were established to demonstrate fixation and greening of shifting sand dunes, and to demonstrate to local farmers appropriate cultivation and soil conservation techniques.
Data on costs, effectiveness and efficiency of the afforestation techniques being tested and developed were stored and analysed carefully. At the same time, databases were maintained to store the information collected on trial measurements and observations, and on the poplar genetic materials being collected from all over northern China and elsewhere.
3. Integrating forestry into combating desertification
The project was fully aware that the battle against land degradation and desertification in this region can not be limited to a focus only on forestry related activities. The project also promoted an integrated approach, with a well-defined strategy that highlighted the issues that lead to desertification and stressed the need for agreed and sustainable land use and management of natural resources. The project strategy included:
- the promotion of more appropriate land cultivation techniques, emphasizing the recycling of organic material into the soil;
- the incorporation of trees into the productive system of farms through the use of fruit and other cash-crop trees (agroforestry);
- the establishment of windbreaks with tree and shrub fodder
- species and with species capable of improving soil fertility;
- the sustainable management of grazing lands and pastures.
In addition, several themes were incorporated in the project's work plans with the aim of contributing to the objectives of the Three-North Shelterbelt Programme. They included the development of small-size shelterbelts for the protection of individual farmers' crops; the establishment of pilot productive shelterbelts on poor sites; and the fixation and revegetation of shifting sand dunes.
The project also tried to identify suitable forest species that could complement the productive role of poplars, offering more biological diversity. Trials were undertaken with native Scots pine (Pinus sylvestris var. mongolica), introduced pine species and provenances, and other indigenous species, such as elms (Ulmus spp.) and willows (Salix spp.), as well as a series of other broadleaf species, both collected locally from protected areas and introduced from other regions, such as Robinia spp.
Rapid rural appraisals were implemented to learn more about the needs and requirements of the rural population, in an attempt to promote and secure their involvement and participation in project activities in order to better target project outputs. Based on the results obtained and cost analyses, a draft investment proposal was formulated at the end of the project (available on request from FAO, Forest genetic Resources Programme. A study of the natural resources of the Korqin Sandy Lands, carried out by the project using satellite based remote-sensing imagery, led to definition and mapping of four site classes for potential revegetation, based on the depth of the groundwater table, topsoil characteristics and topsoil texture. This site classification map proved to be a powerful tool, not only for the planning of afforestation and revegetation activities but also for all involved in land use and rural development in the area.
Enhancement of topsoil fertility through restoration and implementation of biological anti-erosion techniques also formed part of the project objectives. The methodologies were based on the most cost-effective options and aimed to enhance biological processes to speed up the incorporation and integration of organic matter into the soil.
The project activities were not limited to the most degraded areas, but also included preventing erosion on the still relatively intact sandy lands before the degradation process there becomed too severe.
Training and dissemination of information
The institutional capacities of various agencies and bureaus were strengthened through a comprehensive training programme, including in-service training, and local and international study tours and fellowships, in areas related to project management, forestry and forest management, economics, mechanization, tree breeding and improvement, pine nursery techniques, English language training and computer use. International study tours were organized to Australia, Belgium, Canada, France, Israel, Italy, the Netherlands, New Zealand, Thailand and the United States, and international fellowships were organized in Belgium, the United Kingdom and the United States.
FAO. 2002. Technical project review document. Rome.