Research Achievements of the Dongmen Eucalyptus Demonstration Project, Guangxi State Forest Farm Company Guangxi, China - Wei Ju

Forest Department, Guangxi, China

ABSTRACT

Achievements of the China-Australian project at Dongmen State Farm are reviewed. Project objectives included: selection/species/provenance trials; tree improvement; vegetative propagation; plantation management techniques; nutrition and biomass studies; and wood property studies. Results: of 38 species, 83 provenances tested, 16 species are promising; 1,400 ha demonstration plantations and the largest eucalypt gene pool in China were established. Seed production areas (SPA) of E. camaldulensis, E. grandis, E. propinqua, E. tereticornis and E. urophylla are established; the SPA can supply south China needs; 5 ha of clonal seed orchards are established. Some 9 species were used in hybrids; 1,207 crosses made and growth trials established. The average volume production at age 4 for hybrids was 110 m³ ha, 39% more than open pollinated progeny. The best hybrid family was 207 m³/ha the advantage being 41 and 128 % over the open pollinated male and female progeny and 187 and 137 % above the mother tree plantation and pollen tree plantation. A tissue culture unit will produce one million plants/yr.; 10 best of 200 clones will be multiplied. Hybrid urophylla x grandis is replacing E. exserta in new plantings; Dongmen clone plantations are replacing seedling plantations. Management techniques stress site preparation, improving soil properties, reducing weed competition, promoting growth and reducing length of rotations; contour preparation avoids soil erosion; spacing is 1,000~2,000 trees/ha depending on end use. Fertilizer trials indicate significant response to combined N and P; large, persistent response to K; a general application of N 100, P 50 and K 50 kg/ha recommended. Wood quality density variability, provenance and tree to tree; density is highly heritable; there is a wide range of density among clones; density increases with age. Dongmen techniques and superior gene resources will influence a vast expansion of eucalypt planting in south China.

Key words: Eucalyptus, China, tree breeding, clonal seed orchard, tissue culture, yield.

INTRODUCTION

Eucalyptus is important in world afforestation and is very popular on account of high yield, powerful adaptability to diverse sites and wide ranging end use. Eucalypt was introduced into China in 1890, and has a history of more than 100 years. It has spread over more than 600 counties and cities in 15 provinces, some 460,000 ha of plantation is established and 1.5 billion trees planted in “four sides” of agricultural fields. Guangxi is one of the earliest provinces where eucalypt was introduced. According to an investigation in 1983, Guangxi has approximately 400,000 ha of land suitable for planting eucalypts; over 200 species have been introduced to plant 100,000 ha eucalypt forest and to plant over 50 million trees in “four sides” techniques over Guangxi. A recent forest resource survey shows that an average stand stocking volume was 27 m³/ha. There is an urgent need to: introduce and test new species, improve afforestation techniques and increase volume productivity.

DONGMEN EUCALYPT FOREST DEMONSTRATION PROJECT

The China-Australia Eucalypt Afforestation Technical Cooperation Project was signed in 1980 to develop the Dongmen eucalypt demonstration forest project, starting December 1981, though the project actually commenced in May 1982 and ended in 1989. A large amount of scientific research and technical management has been achieved and the development and use of eucalypt has been promoted.

Objectives and scope of the project

The main objective was to increase the productivity of eucalypt plantation in southern China through the introduction of new seed strains and modern techniques of plantation silviculture. All activities and actions were carried out under this goal. Main activities included: selection of species and provenances; tree improvement programs; vegetation propagation and utilisation of hybrid vigour; eucalypt plantation silvicultural techniques; eucalypt nutrition and biomass studies; and wood property research.

From 1982 to 89, 1,400 ha demonstration forest were established and 60 trials instigated. After 1990 research have continued under Chinese direction. In this latter period a further 150 ha demonstration plantation and an additional 26 experiments have been established. The achievements of the project are being extended into large scale routine application.

Location and environment

Dongmen State Forest Farm is situated in the south of Guangxi Zhuang Autonomous Region, between latitudes 22^o17' and 22^o30'N and longitudes 107^o14' to 108^o00'E with an elevation of 100~340 m. The landscape is characterised by numerous limestone karst and has a tropical monsoon climate. Figure 1 provides basic climatic data for the site.

Rainfall is concentrated May-December, making up 79-83% of the total. The dry season, November~April, has a rainfall of less than 60 mm per month, similar to the east coast of Australia. The plantation soils are classified as lateritic red earths. The pH range, Dongmen lateritic soil, is 4~6; the organic matter and available P and K content are very low.

Figure 1. Climatic data for Dongmen

Dongmen Forest Farm

Dongmen Forest Farm started in 1965. It is the largest eucalypt afforestation farm in Guangxi. The total land area is 20,000 ha; 70% of the area has a slope of 15^o degrees or less. Eucalypt management has been through three periods since its foundation. Large scale eucalypt planting began in 1966; E. kirtoniana, E. exserta and E. citriodora were the common species. E. kirtoniana was dropped from the programme on account of poor growth performance (3~4 m³/ha/yr) and large form variation. After 1974, only E. exserta and E. citriodora were included. The mean annual increment (MAI) increased to 2.5~8.5 m³ through the introduction of simple intensified management techniques and the use of only these two species. From the late 1980’s, the mean annual increment at Dongmen has increased to 15~25 m³ through the use of new species as E. urophylla, E. grandis x E. urophylla and modern techniques of plantation silviculture introduced in the project.

Design and scale of trials

To insure complete and valid conclusions and to lead to increased eucalypt productivity, all project experiments were scientifically designed; split plot randomised complete block and randomised complete block designs were mainly used for experiments. The scale of trials were varied. The plot numbers of each trial range from the minimum of 32 with E. urophylla provenance trial (planted in 1985) to the maximum of 6,000 with E. grandis family trial (planted in 1988). The fertilizer trial established in 1983 was the largest trial, covering an area of 170 ha. The least was about 2 ha. The total demonstration forest covered an area of 1,400 ha.

ACHIEVEMENTS OF THE PROJECT

Project established 1,400 ha demonstration plantations during its life (8 years) through the good cooperation and hard work of the Australian and Chinese staff. A large number of research results, 53 technical reports were finished and four technical seminars were held. A summary of the project research and main achievement follows.

Selection of species and provenances

Project selected 38 species and 83 provenances for species and provenance screening. Selection criteria for species introduction are:

1) Capability of rapid growth;

2) Demonstration of considerable variability;

3) Capacity for high adaptability to sites and environment;

4) Capacity for wood production desired in the region; and

5) Successful introduction in other places (availability of adequate information).

Results from the trials showed that the volume production of E. urophylla, E. cloeziana, E. grandis x E. urophylla, E. acmenoides, E. propinqua, E. tereticornis, E. grandis, E. camaldulensis was respectively greater than 57.5%, 111.3%, 60%, 49.4%, 44.6%, 34%, 58.1%, 9.8% of the traditionally and widely planted E. exserta.

Because of different biological characteristics, each species and provenance differed greatly in earlier and later stages of growth. E. camaldulensis gave the best growth at 1~2 years after planting and then slowed down. E. cloeziana and E. acmenoides showed poor performance in the early growth stage, but after 4 years, the volume production jumped up to the first and second place. Therefore, selection of species should be made only after the mid point of rotation age to decrease the risks of inferior selection.

Species and provenances included in project screening trials are: E. urophylla 12 provenances; E. grandis 11 provenances; E. camaldulensis 11 provenances; E. tereticornis 17 provenances; E. cloeziana 11 provenances; and E. dunnii 9 provenances. The trials showed promising provenances were: E. urophylla - Alor island, Vlanur River and Mt. Egon at altitudes from 400~700 m; E. grandis - Ingham, Gympie and Mt. Lewis; E. camaldulensis - Katherine and Petford; E. tereticornis - Kennedy river; E. cloeziana - Hungry Hill and Ravenshoe.

Great differences can be found between eucalypt species provenances. For example, the results of 4 year E. urophylla provenance trial showed a mean annual increment (MAI) of 19.88 m³/ha for Alor island, and 13.65 m³/ha for Flores island. The volume advantage of the top provenance was 45% above the poor performance provenance (Figure 2). The greatest variation was found in E. cloeziana provenances; volume production of best provenance was 2.5 times that of the poor provenance (Figure 3).

Figure 2. Details of growth of the E. urophylla provenance trial at four years

Tree improvement programme

The tree improvement programme became one of the most important research items. It was used to demonstrate techniques for increasing wood production and quality in the long term through the implementation of a breeding plan. The breeding strategy and plan were designed by Dr. D.G. Nikles in 1987. The breeding plan had a simple appropriate structure, wide content and flexible form. The breeding objective were to increase wood production; supply high quality raw materials for paper making and artificial fibre; operate in short rotations. Tree improvement programmes involved the establishment of the 4 basic populations, the main breeding activity is undertaken in these populations. These basic population are:

1) Base population (species and provenances trials, and other experiments of the project).

2) Breeding population (family trials, plus tree and hybrid progeny trials).

3) Propagation population (seed production areas, seed orchards and clonal multiplication bank).

4) Production population (high yielding plantations).

Four population of the first generation have been built under the improvement plan. Breeding is being carried out continuously into the next cycle; new genetic materials are being introduced, base and breeding populations for next generation are being established. A large number of promising clones have been selected for the vegetative propagation programme.

Figure 3. Details of growth of the E. cloeziana provenance trial at three years

Establishment of eucalypt gene pool

There are about 100 timber producing species of the 618 eucalypt species, but only 40 species are widely planted in the world. During the centenary of eucalypts introduction more than 300 species have been brought to China, and while 211 species have capacity for establishment, only about 10 have been used for plantations. In Guangxi, 89 species were reserved out of more than 100 introduced. Only E. exserta and E. citriodora have been widely planted over a lengthy period.

Most early eucalypt introductions came from Italy, France, England and Southern Asia. Difficulties have arisen in eucalypt research and improvement on account of these introductions complicated origin, often lacking original records and the wrong name of some offspring. As a result of this experience, it became essential to introduce new species and to establish a valid eucalypt gene pool for the improvement programme. Thus, the project provided a good opportunity for a scientific gene pool establishment.

Two methods were employed to build the eucalypt gene resource. Firstly, through the establishment of species and provenances trials, 38 species and 83 provenances were introduced during project life. Secondly, through the establishment of a eucalypt arboretum, built in 1987 including 131 species and provenances. The project establishment of this largest eucalypt gene resource pool in south east China contained about 174 species and provenances introduced from Australia, Indonesia, Brazil, South Africa, America, France, Thailand and Burma. Of 134 introductions, 131 had enough seedlings for arboretum entry; 12 species had more than one provenances; E. regnans died after planting. There were significant differences in growth between species and provenances. Some species were like shrubs, about 16 species shown potential in growth, they are: E. bloxsomei, E. brassiana, E. camaldulensis, E. citriodora, E. cloeziana, E. dunnii, E. grandis x E. urophylla, E. maculata, E. microcorys, E. pellita, E. peltata, E. propinqua, E. saligna, E. tereticornis, E. urophylla.

The establishment of the eucalypt gene resource bank provides a good base for research and the starting base for a tree improvement programme.

Establishment of seed production areas (SPA)

Better performing species introduced from Australia and Indonesia have been selected for conversion to seed production areas where the stands have good growth and are at convenient isolation distances. A seed production area of 45ha of E. urophylla, E. grandis, E. camaldulensis, E. tereticornis and E. propinqua has been developed, including 30 ha E. urophylla. A harvest of 400 kg E. urophylla seed has followed, allowing the establishment of 20,000 ha of E. urophylla plantation. The SPA can provide sufficient seed for the planting programme in South China.

Establishment of family trials; conversion to seedling seed orchards

Some 1,150 families representing 6 promising project species were included in a series of family trials; the first was planted in 1987. Some of the family trials have been converted into seedling seed orchards; 15 ha of family trials will reach the seed production stage in 3~5 years.

Establishment of clonal seed orchards

An area of 5 ha of clonal seed orchards of selected E. urophylla, E. tereticornis, E. grandis and E. camaldulensis had been established to provide high quality seed. The clonal seed orchards have several functions for clone test, pure breed seed production and F1 hybrid seed production. This method can reduce the breeding cycles into 5~10 years.

Hybrid programme

As Eucalyptus is cross pollinated, natural hybrids occur commonly. As more new eucalypt species and provenance were introduced, further opportunities and a larger genetic base is provided for producing man-made hybrids and natural hybrids as well. Prior to the Dongmen project, eucalypt hybrid work was being undertaken in China. Some hybrids were man-made and some occurred naturally; these included E. globulus x E. robusta; E. Leilin No.1; E. saligna x E. exserta. The first planted hybrid of E. grandis x E. urophylla from Brazil was in 1984; at 4.5 years a volume production of 96.9 m³/ha was achieved. Another four hybrids from the Florida program were planted in 1985; only E. grandis x E. robusta has shown outstanding performance, volume production, four years age, is 88.5 m³/ha.

Controlled pollination under Dongmen project began in 1986. To date nine eucalypt species were involved (Figure 4) and 1,207 crosses made. Seed from 905 crosses were collected and a series of hybrid trials set up in 1988, 1989 and 1991. The trials area covers 14 hectares.

Figure 4. The species involved in Dongmen hybrid program

1. "X" - hybrid crosses

2. B - E. brassiana
G - E. grandis
E - E. exserta
L - E. leizhou No. 1
R - E. robusta
T - E. tereticornis
U - E. urophylla
GxU- E. grandis x E. urophylla
C - E. camaldulensis

Outstanding performance of local origin hybrids has been shown at an early stage; 70 families were included in the 1988’s hybrid trial and by age 4 years, average volume production of 110.23 m³/ha for hybrid families was achieved. The volume advantage of the hybrid was 38.81% above the open pollinated progeny (79.41 m³/ha) and was 45.79% above the parent population (75.61 m³/ha). The mean total volume production of the top 23 hybrids families was over 120 m³/ha at age 4 years - the volume advantage was 126.67% and 136.62% above the open pollinated progeny and parent population respectively. The best hybrid family was 207.7 m³/ha, the volume advantage 41.7% and 128.29% over the male and female open pollinated progeny, and 187.67% and 137.51% above the mother tree plantation and pollen tree plantation parent respectively.

The second hybrid trial was planted in 1989; 20 families were involved; 6 hybrid families were polycross, the volume advantage of these families was 24.03% ~ 63.95% above the parent open pollinated progeny at age 3 years. The volume production of the best hybrid family was 95.86 m³/ha at age 3 years, the volume was increased by 76.31% compared with that of open pollinated progeny (54.3 m³/ha).

The third hybrid trial (planted in 1991) included 91 families. The top hybrid families was 5.31 m in height at one year, the height advantage was 51.71% above the parents.

VEGETATIVE PROPAGATION - HYBRID VIGOUR

Clonal forestry is a great progress in forest plantation history, eucalypt clonal forestry has been developed for twenty years. Brazil is one of the earliest countries to use eucalypt cutting techniques. The M.A.I. has been increased from 33 m³ to 70 m³; large profit has been achieved through vegetative propagation. The two major techniques for propagation are rooted cutting and tissue culture. Vegetative propagation using rooted cutting began in 1983 at Dongmen, concentrating work on E. Leilin No.1, E. urophylla, E. grandis, E. tereticornis, E. camaldulensis and other superior hybrid families. Some 1,129 plus trees have been selected from these species. Of these plus trees, 394 individuals are selected from superior hybrid families; 737 clones have produced cuttings plantlets; 397 clones were selected from clones test trials to set up a five hectare cuttings multiplication bank.

Tissue culture techniques have been developed through cooperation. About 50 clones (22 were hybrids) were chosen for tissue culture research undertaken in Qin Zhou region Forestry Research Centre. All of these clones cultured in vitro have been successful, some of clones have been put into mass production stage.

To capture genetic gains through mass vegetative propagation of superior individuals and families of pure and hybrid breeds, a tissue culture centre was set up in March 1993 at Dongmen. The facilities provide for the minimum production of one million plants per annum; 200 clones will be selected from the cuttings multiplication bank for tissue culture research; the ten best clones will be selected from mass vegetative propagation. While 400 ha of eucalypt clonal plantation was established in 1993 in Dongmen, seedling plantation are being gradually replaced by clone plantations.

WOOD QUALITY STUDIES

Wood property studies at Dongmen concentrated on basic density to provide a high quality forest resource for the production of paper and fibre. Basic density is highly correlated to pulp yield and pulp quality; it is the most important wood property criteria for selection. The annual volume production in a unit area (m³/ha/yr) is critical for fast growing plantations if the objective of the plantation is to produce pulp (wood chips); the annual dry wood production in unit area will be the important criterion (BDMT/ha). Basic density is another important criterion for plus tree selection besides growth rate. Significant profit can be made if these criteria have been considered.

Species studied for wood quality improvement included E. urophylla, E. grandis, E. camaldulensis; E. grandis x E. urophylla, E. tereticornis, E. propinqua; about 1,500 plus tree were selected for study. The research indicated:

1) Basic density varied from species to species from provenance to provenance and individual to individual. Large potential gains can be made through the tree improvement programs.

2) There are wide ranges of basic density among clones. Uniformity of wood properties can be found in the same clone. Basic density is highly heritable.

3) Basic density increases as trees age.

4) Basic density can vary from different parts of the tree, but the one meter height sample disc can be used to indicate the average basic density for whole tree.

EUCALYPT BIOMASS PRODUCTION, NUTRIENT POOLS

A study was undertaken in Eucalyptus grandis at Dongmen to estimate biomass production and nutrient pools in various fractions of the above ground biomass. The nutrient content of the soil and potential for nutrient losses through litter removal and burnt soil pro-duction were also assessed. The stands examined were 2.8 years (due for first thinning) and 4.8 years old (oldest stand available). The results obtained from the study showed that:

1) Biomass production of E. grandis in Dongmen of 9.8 ton/ha/yr was towards the lower end of the values reported (16 ton/ha/yr) for Eucalyptus species with short rotation and high intensity management by Jorgensen and Wells (1986). Biomass production can be increased by introducing high yield species and advanced silviculture techniques in Dongmen conditions.

2) The greater proportion of nitrogen in the tree is held in the crown (60%) even though total crown contains only 20% of the total above ground biomass. The removal of litter from the forest floor and burnt soil production are significant sources of direct nutrient loss. Nutrient removal from the site must be avoided if long term forest productivity is to be maintained at Dongmen.

SILVICULTURAL TECHNIQUES, RESEARCH

Site preparation

Two site preparation trials were set up in 1984 and 1985. The treatments were included:

1) Treatment with stumping: a) no ploughing; b) overall ploughing; and c) one ploughing with winged ripper.

2) Treatment without stumping: a) pit plant; b) one ploughing between stumps; and c) mounding over stumps.

The objective of trials was to find the optimum site preparation treatments for growth and for cost under the Dongmen condition. Decreasing the effect of soil erosion must be considered for any treatment chosen.

The study indicated that the machinery site preparation is of great importance for high growth rates in eucalypt plantations. The physical and chemical soil properties can be improved greatly and weed competition decreased through site preparation, and results in increasing growth rates and shortening the rotation length.

Results show the optimum treatment for stumping requires stumping and ploughing be done by one pass with a winged ripper of a D7 bulldozer; another treatment is stumping using a front mounted rake on a D7 bulldozer and soil cultivation in one pass by the D7 with 3 rock rippers. The best economic treatment without stumping is one pass by D7 with a winged ripper between the stumps of the previous rotation. Cultivation be done on the contour to avoid soil erosion problems.

Planting spacing

Eucalypt spacing selection is affected by a number of factors, including: site situation; end product; rotation and species. The aim of spacing study is to provide a basic rule for planting stand density selection in the future for eucalypt plantation.

Two spacing trials for E. grandis and E. camaldulensis, species with greatly differing characteristics, were established in 1984 and 1985. The treatments ranged from 494~3,333 stems/ha. Results obtained from the spacing trials show that:

1) The planting spacement has significant effect on diameter growth, but little effect on height growth.

2) Over bark volume production can be increased as stand density increases; this trend can be maintained for 5 years. The bark percentage increases as stocking increases so the planting stand density cannot be increased beyond a certain limit.

3) Spacings recommended are 1,000~2,000/ha. The high stocking is adopted for the narrow crown species and for fibre product; the low stocking is recommended for dense crown species and large timber products.

Fertilizer application

There is a worldwide trend towards the use of fertilizer as a silvicultural option to improve forest productivity. Although some fertilizer treatments can be applied widely, a basic understanding of the particular site situation and of appropriate fertilizer regime is necessary if maximum benefits are to be gained. The study concentrated on finding the optimum fertilizer element combinations. A total of 24 trials were established, some 40% of total number of trials made by project.

The fertilizer trials can be divided into three groups: i) species and provenance fertilizer trial; ii) fertilizer trials on selected species; and iii) mid rotation fertilizer trials.

The trials covered 1,000 ha; some 34 species and provenance were involved. Most experiments were made on the typical Dongmen lateritic soils, some on other forest farms. The experiments were established to scientific design, linking species were used for comparisons between experiments. Application of foliar analysis in interpreting the results was made for some trials. The first trial was set up in 1983.

Results obtained through the experiments on main effects of fertilizers on species and growth in 1983~1985 indicated that:

1) There was no response to nitrogen or phosphorus fertilizers applied alone, but in combination a significant response in growth appeared. There was a slight response to nitrogen and phosphorus applied alone with some species.

2) There has been large persistent response to potassium fertilizer, which increases as trees age. The effect was still evident after 4 years, potassium fertilizing has resulted in a more persistent response than from nitrogen and phosphorus. Foliar nutrient data has indicated the same results.

3) There can be major differences in productivity between species, but all have responded in a similar fashion to the fertilizers. However the low productivity species commonly are less responsive to fertilizing. The response to fertilizing appears to be more dependent to productivity of the species rather than of taxonomic grouping within the genus Eucalyptus.

4) The response to basal fertilizer faded obviously during the two-three years compared with control treatment.

5) There has been some growth response to nitrogen and in combination with phosphorus and potassium applied in two year old stands. The response varied from species, E. grandis with dense crown has larger response than E. camaldulensis. This effect is still apparent after two years.

6) A fertilizer dressing of nitrogen (100 kg/ha), phosphorus (50 kg/ha) and potassium (50 kg/ha) is recommended for all eucalypts at Dongmen.

7) Foliar nutrition concentration varied with season. It is impossible to set up a critical range for eucalypt species.

BENEFITS FROM THE DONGMAN PROJECT

The project achievement not only provides important data for scientific research, but also technology now being applied in routine practice, promoting increased productivity and so realises the main goals of the project.

Extension use of improved Eucalyptus seed

Since the project was established, the breeding, production and application in use of improved eucalypt seed has achieved very significant results. This result was achieved by introduction, selection, breeding and propagation. Currently, the introduction, improvement, tissue culture, cutting production and seedling breeding of E. urophylla in the Dongmen Project ranks in the leading place in China. In recent years, some 12,000 ha of plantation have been established using the selected E. urophylla and GxU hybrids. Following investigation, species used in new plantings have been reviewed in recent years, and E. urophylla and GxU have replaced the traditional species, E. exserta, on a large scale. The MAI in volume of the high yielding stands of E. urophylla at Dongmen Forest Farm reaches 36.38 m³/ha at age 5; the MAI in volume of E. urophylla at Qinlian Forest Farm attains 24.66 m³/ha at age 4.8; there are 33 ha of GxU plantation (tissue culture seedlings) at Qinzhou, the MAI in volume is 36.3 m³/ha at age 2; a new plantation of 800 ha at 7 months old in Maomin county Guangdong Province, by using seed provided by Dongmen, has an average tree height of 6.5 m, and average DBH 4.2 cm this is about 2-3 times greater than growth of the local E. exserta plantation.

Comparing E. urophylla with E. exserta, the volume/ha occasioned by the use of improved seed, for a 5 year old plantation at the same cultivation level, is 91.11 m³ for E. urophylla compared with 46.6 m³ for E. exserta. Converting this volume into timber sale value, the planting of E. urophylla returns an extra 10,200 yuan in RMB/ha.

Providing more and better clones for Eucalyptus tissue culture

For large scale clonal plantations, it is safer to have a wide ranging genetic base. Therefore, the best artificial hybrids and some promising families were selected to establish a clone trial at Dongmen; 397 families were selected to establish a multiplication bank, and 50 families were used for tissue culture. These activities provide a wide range of genes for large scale plantation establishment and it is quite sure that clonal forestry will have rapid development in Guangxi.

Project demonstration promotes accelerated development of eucalypts

The development of eucalypt in Guangxi Province has involved a tortuous process. At the end of 1960’s, the area of eucalypt plantation had reached 100,000 ha, but up to early 80’s, there was little increment in the area and no significant increase in the per unit area productivity. A general understanding of eucalypt is that it grows fast, but the yield is low; it needs a high input, but the benefit is low.

The application of scientific technologies in eucalypt plantation through the implementation of the Dongmen Project has changed the perception of people. After an expert team organised by the Forestry Department of Guangdong visited Dongmen, they then developed a strategy of eucalypts for Guangdong Province. Guangxi Province has also organised professors, experts and management officers to hold a Eucalypt Development Workshop and it determined that the development of eucalypt should be considered as an important aspect of forestry. By the end of this century, the area of eucalypt plantation in Guangxi Province will reach 333,000 ha.

At present, great attention has been placed on the seed and seedlings, based on the Dongmen project results; 3 eucalypt tissue culture centres and 13 centralised nurseries have been established. These centres and nurseries will provide a large amount of good quality seed and seedlings for plantation, and promote the development of eucalypt at high speed.

Good quality raw material for industry

The species selected have objectives of achieving high production of fibre and pulp as the end use. The plantation can be the raw material base for the Nanning Paper Mill and Beihai, Short Dissolving Fibre Factory, of which the construction work are being undertaken. Eucalypt in Guangxi and south east China will become a pillar of industry and export industry in China’s forestry.

The superior eucalypt genetic strains provided by the project have positive characteristics; they are easy to cultivate, fast growing and are harvested in 6 years. They have become the main species for afforestation, and will play an important role in recovering vegetation, afforestation and improving the ecological environment.

REFERENCES

Li Haijia. 1992. Introduction of Dongmen eucalypts improvement programme. The exploration of eucalypts new techniques.

Li Qiongchu. 1992. The report on Dongmen eucalypt wood basic density and variation study. Eucalypt technology 1992 - 1, 2.

Mo Qiping. 1989. Dongmen Eucalypts Arboreta. In proceedings of the Third Technical Exchange Seminar. Dongmen Eucalypt Project, Guangxi Zhuang Autonomous Region, China.

Mo Qiping., Mannion, E.G. 1989. The effect of planting espacement on eucalypts. In: proc. Fourth Technical Exchange Seminar, Dongmen project.

Nikles, D.G. 1989. Developing genetically improved eucalypts in south east China: background information and appropriate strategies. In: proc. Fourth Technical Exchange Seminar, Dongmen project.

Pegg. R.E. 1989. Summary of Dongmen project achievements. In: proc. Fourth Technical Exchange Seminar Dongmen Project.

Qu Yangquan. 1990. The main experiences of Eucalyptus introduction. Collected papers of eucalyptus in Guangxi.

Simpson, J.A. 1989. Biomass production, nutrient pools and potential nutrient losses in young Eucalyptus grandis plantations at Dongmen. In: proc. Fourth Technical Exchange Seminar, Dongmen project.

Simpson, J.A. & Mo Qiping. 1989. Long term fertiliser responses in eucalypts at Dongmen. In: proc. Fourth Technical Exchange Seminar, Dongmen project.

Wei Ju. 1992. The exploration and development of eucalypts techniques. The exploration of new eucalypt techniques.

Xiang Dong Yun et al. 1993. Eucalypt hybrid program and vegetative propagation in Dongmen. In: proc. Eleventh Technical Exchange Seminar, China Eucalyptus Society.