Fay Banoun, D. Morgan, Marcel Viart and Louis Zsuffa
Fay Banoun is a free-lance journalist and photographer based in Rome.
D. Morgan works with the Ontario Tree Improvement and Forest Biomass Institute, Maple, Ontario, Canada.
Marcel Viart is President of the Executive Committee of the International Poplar Commission.
Louis Zsuffa is Professor, Faculty of Forestry, University of Toronto, Toronto, Canada, and chairman of the International Poplar Commission's ad-hoc committee on biomass production systems for the Salicaceae.
PRUNING A TUNISIAN POPLAR - five years after a UN-funded plantation
Marcel Viart
This piece is extracted from a longer paper presented at the Thirty-first Session of the Executive Committee of the International Poplar Commission, held in Casale Monferrato, Italy, between 6 and 8 September 1982.
The genera Populus and Salix - commonly known as poplars and willows - offer an extraordinary variety of possible products and thus are extremely useful in forest development. In addition, many of their species are easy to hybridize and propagate from cuttings, so that they lend themselves to the kind of genetically improved growth and disease-resistance more commonly associated with agricultural and horticultural crops than with forest tree species.
Following the devastation of the Second World War, their utility as a fast-growing source of industrial wood was highlighted by the creation of the International Poplar Commission, the history of which is closely bound up with that of the poplar commission of France. When the French commission was created by the Ministry of Agriculture, on 25 January 1947, the government instructed it to do its utmost to develop international cooperation in studying poplar cultivation and timber use. In the first months of operation, therefore, the commission devoted considerable efforts to preparing a meeting of specialists from several European countries to discuss problems faced by poplar growers and users. The idea of an international meeting had been welcomed by Mr Leloup, the then Director of the Forestry Division of FAO.
The prerequisite for success had thus been created, and the Poplar Commission of France organized an "International Poplar Week" from 19 to 26 April 1947. Eight European countries accepted the invitation of the French Minister of Agriculture: Belgium, Czechoslovakia, Italy, the Netherlands, Poland, Sweden, Switzerland and the United Kingdom. Their representatives quickly agreed on the principle of establishing an International Poplar Commission, and Mr Leloup gave FAO's formal backing to it.
Organization The International Poplar Commission (IPC) is governed by a Convention that places it within the framework of FAO and that the FAO Conference adopted at its Tenth Session, in November 1959. The purpose of IPC is to facilitate exchanges of ideas, information, research results and plant material among the member countries so as to promote poplar cultivation and the use of poplar wood. The same objectives cover all Salicaceae, or members of the willow family cultivated for timber use.
The Commission is summoned in ordinary session every four years (formerly every two years, until the most recent amendments) by the Director-General of FAO. But it may be assembled in special session if necessary. A session is organized by one of the IPC member countries after the Director-General of FAO has accepted its candidacy. The FAO Forestry Department provides the permanent secretariat.
Scientific and technical problems are investigated by three working parties - on diseases, pests, and logging and utilization of poplar wood. Technical development and scientific progress have called for the establishment of an ad hoc committee on breeding and improvement.
Registration and nomenclature The Commission at its seventh session, in 1953, decided to set up a subcommittee on registration and nomenclature to investigate the best way of establishing a register of poplar names by adapting the nomenclature used by IPC to the new rules on horticultural nomenclature. This job was of special importance in view of the designation of IPC as the official body for the registration of forest cultivars of the genus Populus (International Code of Nomenclature of Cultivated Plants, Utrecht, 1958).
As the success of poplar cultivation depends very largely on the appropriate choice of cultivars, poplar improvers are engaged in research leading to the creation of new cultivars with good ecological properties for growth in areas where poplar-wood production is envisaged and with the greatest possible resistance to pests in those areas. In this way, the number of usable cultivars is gradually increasing. It therefore becomes necessary to identify them correctly and as precisely as possible to avoid possible confusion and to facilitate exchanges among users, regardless of whether or not such exchanges are on a commercial basis. At present, 52 cultivars are described in line with this form and another 8 are candidates for registration.
Activities of working parties
Logging and utilization The working party on logging and utilization assembles periodically all experts interested in questions of logging and utilization of poplar wood. For each member country, the meeting is an opportunity of summing up and reporting on research under way and on the progress achieved. The working party is drawing up a standard form for technological trials which should describe and qualify the wood of the cultivars used by the member countries. It also deals with the use of wood and with developing new possibilities for its utilization.
Poplar diseases Each meeting of the working party on poplar diseases serves to provide information about the health conditions of poplar plantations in the member countries and about the work done and research results.
Joint research programmes are designed for the pathology laboratories concerned. International arrangements have been made for the study of the susceptibility of cultivars to Marssonina brunnea and for a research programme on sensitivity to Xanthomonas populi. In carrying out these programmes, pathologists help one another, exchanging information. techniques and some times their own material. The working party in 1981 published a synthesis entitled Les maladies du peuplier.
Insect pests The working party on insect pests was created in 1957, after entomologists pointed up the significance of insects, mainly xylophagous (wood-eating) ones, for the development of modern poplar cultivation. The whole chapter on Salicaceae pests, including both insects and other animals, of the handbook published by FAO in 1979 was drafted in collaboration with members of the working party.
Breeding and development Systematic work done mainly in Belgium on the hereditability of certain genetic characters showed that poplar genetics should have its place among the concerns of IPC, which then, in 1971, agreed to the establishment of a new ad hoc committee on breeding and improvement.
Table 1. Present use of Populus and Salix wood biomass for energy by direct burning
|
Country |
Quantity per year |
Percentage of total energy |
Percentage of biomass energy used |
Source (percentage) |
|||
|
Natural stands |
General plantings |
Special plantings for energy |
Other |
||||
|
Europe |
|||||||
|
Fed. Rep. Germany |
50000 m³ |
(total of all biomass - 0.5) |
0.4 |
94.6 a |
- |
5.0 |
|
|
Greece |
9300 m³ |
- |
- |
- |
100.0 |
- |
- |
|
N. America |
|||||||
|
United Stales |
100 million tonnes |
0.25 |
8.3 |
95.0 |
5.0 |
- |
- |
|
S. America |
|||||||
|
Argentina |
37000 tonnes |
- |
- |
- |
100.0 |
- |
- |
|
Asia |
|||||||
|
Pakistan |
53000 tonnes |
0.05 |
0.14 |
- |
100.0 |
- |
- |
|
Turkey |
270000 tonnes |
4.0 |
19.0 |
- |
95.0 |
- |
5.0 |
Note: Countries included were those that indicated that energy was obtained by direct burning of Populus and Salix biomass.
a. Composed of 58.2 percent forest plantings and 36.4 percent other plantings.
Other important activities have included close liaison with the Poplar Council of the United States and, thanks to its cooperation, several harvesting drives for seeds from various sources of Populus deltoides, then Populus trichocarpa, which were subsequently distributed to European countries involved in research programmes concerning those species; and, because of an offer from the Academy of Forestry Science of the People's Republic of China, a first harvesting drive for propagation material from various sources of Populus maximowiczii, Populus simonii and Populus yunnanensis, to be distributed widely among member countries.
Biomass production Created at the sixteenth session of IPC in 1980, the ad hoc committee on biomass production aims to promote the coordination of the work of poplar specialists concerned with the production of biomass from Salicaceae. Since this is a novel kind of poplar cultivation - for its choice of cultivars and its cultivation and harvesting techniques - the delegates to the sixteenth session preferred to assign the problem to one group rather than splitting their study among the existing working parties.
Spreading poplar cultivation
In spreading knowledge and promoting poplar cultivation, IPC activities are not limited to preparing the handbooks mentioned earlier. It should be noted that when a country organizes a session or international congress, this is always an opportunity of mobilizing the media in favour of poplar cultivation, and the consequences may be very important.
The Commission was directly involved in the creation of the Populetum mediterraneum. The first plantations were made in the spring of 1956 on a farm of the Agricultural and Forestry Experiment Centre at Tivoli, near Rome. Continued in the following years, the plantings have assembled a living collection of some 300 clones of several poplar species.
In 1966, IPC sponsored the establishment of a populetum near Cologne, in the Federal Republic of Germany, which groups about 60 clones cultivated in Central and Western Europe. Another populetum, for the Near East, was established near Ankara, Turkey. The poplar commissions of Italy, Turkey and the Federal Republic of Germany are requested to report on their observations and growth measurements. The data gathered in this way permit useful comparisons and are a remarkable source of information on the behaviour of the species or varieties represented.
Technical assistance The International Poplar Commission has been a source of technical expertise for FAO, as well as coordinating programmes, providing candidates for consultants' posts in poplar cultivation, and facilitating the reception of foreign colleagues by specialists, generally in Europe, for varying periods of time.
In this way, a network of relations has gradually been built up between the countries most advanced in poplar cultivation and countries where cultivation is being modernized - Near Eastern countries, for example - or where it is evolving - the case with some countries in Asia: the Republic of Korea, for example, now has more than 400000 ha of poplar plantations.
|
Present membership of the International Poplar Commission Argentina The last country to be admitted as an IPC member was China, which, in this capacity, attended the sixteenth session, organized by Turkey in November 1980. |
Fay Banoun
France - a problematic present but a promising future
In a recent book (Le peuplier aujourd'hui et demain: Paris, 1982, Institut pour le développement forestier. 279 p. Price: F 95), Jean Chardenon examines poplar culture in France, but his observations apply at the same time to the whole of the vast geographical area occupied by the poplar, an area that extends from the polar circle to 25° north latitude and includes one island in East Africa, south of the equator.
The poplar requires deep, light, chemically rich soil; above all, its soil must be well fed by water, because it has a weak capacity for ground-water absorption. It is, however, very adaptable, since it also grows well in semi-desert areas; but, of course, those areas should be well irrigated. Some species have been widely planted in all the Mediterranean basin: Chardenon notes that they "followed the Arab and Turkish conquerors and subsisted after their departure". The poplar does not grow spontaneously in the Southern Hemisphere but may be cultivated in corresponding latitudes in the North. It is widespread in Argentina, South Africa, Australia and New Zealand.
POPLAR LEAF RUST - a concern of the international Poplar Commission
During the last few years, the poplar has been the object of extensive research, specifically in the field of genetic selection. The third chapter of part two of Chardenon's book examines the characteristics of approximately 20 clones created as a result of studies carried out throughout the world. But there is another side to the story, which is that poplars from the same clone react in the same way to adversities. A lone diseased tree can cause the destruction of the entire plantation. That is why it is important, before planting, to make a judicious choice of clones that are both high-performing and disease-resistant.
Poplar wood has various uses: veneer for the manufacture of plywood and light packing; sawnwood for furniture and construction, paper-making, and particle board. The author notes that in some countries poplar consumption has diminished. In packing, for instance, poplar wood is often replaced by cardboard, producing price stagnation.
However, during the last 15 years, poplar culture has seen its costs multiplied by a factor of seven or even eight, while at the same time the price of the wood has only doubled. In order for production to remain profitable, exploitation expenses should be reduced, particularly those for maintenance. But in order to diminish maintenance costs, the choice of what to plant should be concentrated on selected cultivars and on poplars "capable of defending themselves against competition".
"Can we still plant poplars?" asks Chardenon on behalf of the poplar growers. Although specialists foresee a net reduction in production in the short term, it is unlikely, in the light of forecasts of wood shortages by the end of the century, that this fast-growing species, with its great tolerance of various meteorological conditions, will not succeed. Some future uses for poplars: as a source of energy in the forms of alcohol and combustion gas; and as a food rich in high-quality protein for livestock.
Greece - determining the cost of poplar plantations
Because of a Mediterranean climate favourable to the rapid growth of vegetation, Greece has a great number of physical and biological characteristics necessary to the development of an irrigated poplar culture. Within the framework of the national policy promoting the plantation of poplars, George A. Sakkas, in an article in Forêt méditerranéenne ("Une analyse coût-avantages de la populiculture irriguée en Grèce", Vol. V, No. 1, 1983), analyses two fundamental factors: the future demand for poplar wood and the profitability of its cultivation.
Over the last several years, the production of poplar (roundwood) in Greece has been in the order of 200000 m³ per year, while predictions for 1990 foresee a supplementary demand of 260000 m³ which could bring the total to 460000 m³ But how much will this cost and what kind of benefits will the country receive?
To establish a system of comparing revenues earned (at present costs), Sakkas selected a plantation 6 m square in the region of Thessaly and, by applying a highly detailed table, calculated the cost of establishment, management and harvest. One element of cost determination in this evaluation is the revenue that would be obtained from a hectare of irrigated alfalfa or mane if it were replaced by a hectare of poplars. The resulting gain in profit is 9 percent, a return Sakkas considers very appealing in comparison with the profitability of agricultural activity.
More appealing still would be the annual revenue if agricultural revenue were not considered. In this case the rate of profit could well reach 20 percent. For this to be implemented, poplars could be planted in government-owned areas: riverbanks, roadsides, dams - all areas, in other words, not appropriate to agriculture.
An equally efficient way, according to Sakkas, of promoting the development of poplar culture is to encourage private investment by means of subsidies or short-term loans in the agricultural sector, with interest rates of 5 percent.
Encouraged by state subsidies and by a net increase in their revenues, agriculturalists could thus take part in a plantation programme of 776 ha per year, which would be enough to satisfy the total demand of 260000 m³ of wood foreseen for 1990.
Marcel Viart
The following is an extract from a 1983 FAO Consultant Report prepared for the Forest Research Institute of the Chinese Academy of Forestry, Beijing, China.
With its extremely large territory, China is very rich in natural poplar species belonging to the five sections of the genus Populus. Moreover, after the founding of the People's Republic of China, poplar breeding work started, and several species, varieties and cultivars have been introduced from abroad. The present situation is therefore characterized by a very rich genetic patrimony that opens good opportunities for further improvement work.
In the 1950s, after the founding of the People's Republic of China, several cultivars of P. x euramericana (wrongly named P. canadensis) were introduced from the USSR and Eastern Europe. The exchange with foreign countries was stopped during the Cultural Revolution but was resumed in 1978, after the restoration of the Chinese Academy of Forestry. Some very interesting varieties selected in Europe, mainly in Italy, were introduced. Examples are the American poplars Lux and Harvard and the Euramerican poplar San Martino.
It is interesting to note that the Chinese breeders have focused their hopes on material selected abroad that is not necessarily the best fitted for cultivation in China on account of the Chinese ecological conditions, which are different from those of the countries, such as Italy, where the selection was made.
Until now, the extension of poplar cultivation in other parts of the world has depended on European institutes for the supply of cultivars. It seems necessary to underline again the fact that there is always a potential risk in the susceptibility of these foreign cultivars to indigenous diseases. The Chinese institutes would therefore be well advised to intensify their programmes of poplar improvement with the object of producing some cultivars with a Chinese species such as Populus simonii as a parent, either male or female, duly selected on the ground of its resistance to indigenous diseases.
POPLAR PLANTATIONS IN HUNGARY - an effort in genetically improved growth
The present situation offers evidence of the possibilities for the intensive production of poplar wood in China. In view of the potential disease risk, it would be highly advisable to gradually utilize some indigenous cultivars duly selected for afforestation in suitable sites with appropriate techniques. The ultimate stage of evolution will be characterized by the utilization of Chinese cultivars produced in China by Chinese plant breeders.
The following research programme must be considered as a minimum to achieve this objective:
· An exhaustive survey of the indigenous species of Populus in China and adjacent countries for the purpose of improving the basic knowledge about their identity, position in the nomenclature, distribution, variability, ecophysiological requirements, etc.· An inventory of the indigenous pests and diseases and a study of their behaviour in relation to these Populus species.
· A delimitation of some provenances on the grounds of behaviour, growth and productivity and a selection of some individuals with a good level of resistance to these pests and diseases.
· Experimental crossings in order to check the inheritability of these criteria of selection and to study the crossability of indigenous poplars among themselves or with foreign species.
· Techniques of controlled hybridization with a view to obtaining good offspring F1 with intraspecific or interspecific crosses having a high level of heterosis and to propagate the best of them by means of vegetative multiplication.
Utilization
At present, these are the main modes of utilization of poplars in China:
· Avenue trees In the main cities, poplars are planted in parks and along avenues. A typical example is the P. x tomentosa in Beijing. Poplars are often associated with Salix matsudana, a weeping form of which is very interesting. Some other tree species such as Ginkgo biloba, Sophora japonica, Pinus tabulaeformis, Pinus bungeana, Platanus sp., etc. are utilized to a lesser extent.· Roadside plantations In Shandong and Shaanxi, poplars are quite common as roadside plantations. They are planted in several parallel rows on both sides of the roads. In Shandong, for example, there is a continuous belt of poplars all along the main roads.
· Shelter-belts In the North China Plain, where sandstorms can be very damaging, poplars are being planted in multiple rows to provide shelter for farm crops. A good example is the network of shelter-belts of the Zhao He Production Brigade in Yanzhou County (Shandong Province). The total area used for agriculture is 3534 ha. Poplar plantations started in 1975. A network of shelter-belts was established in connection with roadside plantations and irrigation systems so that the mesh is around 250 m square. Several hybrids of P. simonii x P. nigra have been utilized. Damage caused by dry winds was greatly reduced, and consequently the crop yield increased.
· Afforestation Poplars are planted by foresters in forest farms, which are generally located along rivers where the soil is mainly composed of coarse sand that is unsuitable for agricultural crops. Here the primary purpose of poplar plantation is soil protection, with wood production only secondary. There is obviously a need for poplar clones able to withstand such adverse conditions.
· Intensive cultivation Intensive cultivation of poplars in relation to farm crops is carried out by "production brigades" on good soil types that are often subject to floodings. Good techniques of cultivation are practiced, with very promising results, to the extent that farmers express great enthusiasm for poplars.
Recommendations
Management of poplar wood production
· In view of the enthusiasm shown by some production brigades for poplar planting, attention should be drawn to the benefits to be derived from a well-balanced rotation of crops, not only to regularize the annual output but also to provide continuous employment.· A periodic inventory of the growing poplar biomass should be carried out to determine not only the total quantity of wood resources but also the distribution of this resource, by size classes, types of plantation, cultivars, etc.
International cooperation
· In order to avoid confusion and the mismanagement of genetic resources represented by living material imported from abroad, it would be advisable to establish a special office or laboratory whose duty it would be to check the identity of the material as well as to collect information from the senders about ecological requirements, resistance to pests and diseases, etc.· Research in the field of micro-propagation and tissue culture of poplars should be encouraged, to facilitate the international exchange of living material and to enable pathologists to submit the newly obtained clones to early tests of susceptibility to diseases.
· Exchange of information should be organized with other countries, especially in the Asia-Pacific region, to enable China to benefit from the experience they have gained in the field of afforestation and watershed management. Study tours would certainly be useful whenever possible.
Fay Banoun
La culture du peuplier. Barneoud and Bonduelle. 1979. 274 p. Manuel de populiculture. Barneoud, Bonduelle and Dubois. 1982. 319 p. Both published by AFOCEL (Association Forêt-Cellulose), Paris.
La culture du peuplier reports on experiments carried out by AFOCEL during the period 1960-1976. Their main purpose was to test cultivation techniques such as soil preparation, upkeep and fertilization and plant types likely to increase production.
The book makes available to the poplar grower the practical conclusions drawn from experiments made throughout France, from the Paris region to the east and to the southwest: in 76 places covering 23 departments.
Manuel de populiculture, as its title indicates, covers in six chapters all aspects of interest to those who want to plant trees of the poplar and willow family, either as a tree-growing forest or in short-rotation coppice.
Particular attention should be given to the part devoted to short-rotation coppicing, and also to the economic considerations that conclude the book. High-quality illustrations contribute to making this basic work easy and pleasant reading.
Louis Zsuffa and D. Morgan
POPLAR PLANTATIONS IN ITALY - long tradition In genetics
Biomass, particularly forest biomass, has traditionally been used as a source of energy, primarily for cooking and heating. Even today, in some developing countries it still supplies up to 90 percent of the total energy required. In more developed countries, however, the use of other energy sources has resulted in the almost total abandonment of fuelwood as an energy source. However, interest has recently revived in biomass as an alternative energy source owing to the increased costs of other energy forms.
Natural forests can supply significant amounts of biomass for energy production. Significant quantities of wood are sometimes left as waste at the harvesting site, and residues remain after processing at the mills. When and if these wastes become economical, they can supplement other sources of energy.
Where large amounts of energy are needed and natural sources of biomass do not exist, plantations of fast-growing trees such as poplar and willow can create significant amounts of biomass for energy use. Traditional forms of poplar and willow plantings, such as row plantings and widely spaced plantations, can supply either whole trees or merely branches and stumps for energy production. Where land availability, the need for an energy source and the economics are favourable, specially designed plantation-management systems can be applied for biomass energy production.
Important research problems that have been identified concern species suitability and selection of clones for different areas; dry-matter production under different site conditions and spacing; determination of optimal growing conditions; mechanical site preparation and harvesting equipment; vegetative propagation (rooting of cuttings); silvicultural treatments for maximum yield; and pest and disease control.
There has been a tendency recently to increase the productivity of different sites through species selection and technology. Planting densities are becoming more diversified, with more plantations at higher densities being used. Harvesting periods, mostly 10 years or more at present, will be reduced in many places to 5-10 or even 1-5 years.
While research and development work is proceeding in most countries, no country reported either having commercial-scale energy plantations or having finalized plans for such plantations up to the year 1995. However, there are indications that large-scale plantings of poplar and willow for energy use are imminent in several countries, such as the United States. The future of these enterprises will depend largely on economics, energy markets and the appropriate application of research and development.
Country survey
A survey was conducted among 32 member countries of the International Poplar Commission on the present and planned sources of energy, and especially on the use of Populus and Salix biomass for energy. Among countries responding to the survey, a significant decrease in the use of crude oil is planned. Most countries plan to achieve self-sufficiency in energy primarily by increasing their use of nuclear energy, natural gas, coal, hydro-energy and, to a lesser degree, biomass.
The present use of biomass for energy is significant only in developing countries, where poplar and willow represent less than 20 percent of the total biomass energy used. Intensive research into the development, production and utilization of poplar and willow biomass is being conducted in many countries. However, plans for planting and production are not yet finalized.
Interesting trends in energy planning can be seen when the countries are classified according to their level of self-sufficiency in crude oil. In more self-sufficient nations, the planned reduction in crude-oil use will be compensated for by increases in the use of almost all other energy forms. In most of the import-dependent countries, however, nuclear energy is programmed to cover most of the anticipated increase, even replacing portions of other energy sources. An exception is Sweden, which plans significant increases in biomass energy and in a recent referendum voted against the installation of any new nuclear stations beyond those already planned.
Biomass is used for energy at all self-sufficiency levels, but to a larger extent by those countries highly dependent on imports of oil. Most of these plan to increase their use of biomass for energy. For example, total biomass use will be increased by 1.5 percent in the Federal Republic of Germany and 3.5 percent in France, and large increases in the establishment of forest tree plantations are planned in the Republic of Korea.
Several countries report fairly extensive use of biomass sources. Such sources are peat (Ireland), agricultural waste and by-products (Argentina, India and the Republic of Korea), cow-dung (India) and biogas (the Netherlands). Tree species other than poplar and willow are also used, such as black locust (Robinia pseudoacacia), pitch pine (Pinus rigida) and alder (Alnus spp.) in the Republic of Korea; and Eucalyptus, Platanus, Liquidambar and Fraxinus species in the United States. Fuelwood of various tree species constitutes a major component of total energy in India, Pakistan and Turkey, where it is used directly for cooking and heating.
Present use Only six countries surveyed indicated that they currently use poplar and willow as an energy source, and then only in a minor way. Poplar and willow biomass comes from general plantings in Argentina (100 percent), the Federal Republic of Germany (94.6 percent), Greece (100 percent), Pakistan (100 percent) and Turkey (95 percent) and from natural stands in the United States (95 percent). No country indicated the use of commercial-scale poplar- or willow-energy plantations.
Use of the whole tree varied with countries. Total above-ground tree biomass was effectively used only in the United States (50 percent). Forest waste and industrial residues constitute 100 percent of the biomass used in Argentina and a significant proportion of the material used in the United States (50 percent), Turkey (45 percent) and Pakistan (20 percent). Tops and branches make up the remainder in Turkey (55 percent) and Pakistan (80 percent).
At present, biomass is converted to energy by direct burning. Other conversion forms, such as gaseous fuels, liquid fuels and densified wood, are only in the experimental stage.
Future plans (to 1995) Almost all countries report scientific and development work in poplar and willow biomass-energy plantations. However, firm plans for such plantations were reported only by France, the Republic of Korea, Tunisia and the United States.
Significant increases in biomass-energy production may also be expected from general poplar and willow plantations. The needs and economics at harvesting will determine what proportion of their biomass will be used for energy and how much will be used for other products.
Energy plantations envisioned are of a modest scale. However, plans are not yet finalized, even for countries reporting specific figures, and within the next 15 years the extent of the plantation programmes will depend on needs and the economics of energy plantations, as well as on the results of research and development work at present under way. Energy plantations are planned on both agricultural and forest sites. In some countries, such as Ireland and the United States, peat-land plantings will also be important.
Most plans are for poplar plantings, but willows also have high priority, especially on peat lands. Countries did not specify species, hybrids or clones, except for the Republic of Korea where P. alba x P. glandulosa and P. x euramericana were indicated. Planned densities are usually less than 10000 trees per ha. However, research and demonstration projects include higher densities for both poplar and willow. In general, poplar and willow plantations are currently harvested at intervals of 10 years or longer. The plans for energy plantations call for shorter harvesting periods, from 1 to 10 years.
Country plans
Australia There are no present plans for poplar and willow plantations, although the economics of such projects are being monitored in the light of new technologies for liquid-fuel production from biomass and changing relativities of cost for other fuel sources.
Canada Research and development work on poplar- and biomass-energy plantations is very active, but definite plans for the period to 1995 have not been finalized.
France Euramerican poplars will represent only a small part of the biomass programme because they need agricultural soils. Use of aspen, and perhaps balsam poplar, on forest soil would change this situation.
Hungary A research programme on biomass has existed for the past two years at the University of Forestry in cooperation with the Forest Research Institute. Experiments are being conducted on plantations and on the possibilities of biomass conversion and utilization.
India Problems relate to the selection of suitable species/clones for different areas; the study of morphological and phenological variation in indigenous poplar species; spacing trials to maximize biomass production; vegetative propagation (rooting of cuttings); the introduction of poplar into existing stands; improving silvicultural treatments; the production and economics of poplar plantations; and the study of pests and disease control.
Ireland Involvement is as yet only at the experimental stage. This includes species-suitability trials and the assessment of dry-matter production levels on various soil types, and a demonstration trial of 200 ha of Populus and Salix species on cut-over peat on a five-year rotation. The production objective is to produce biomass fuel for conversion to electricity.
Italy Approximately 3 million m³ per year of biomass are used for direct burning (heating and cooking), including conifers and broad-leaved trees other than poplar and willow. Programmes and plans for biomass energy are still at the experimental stage.
United States Research into biomass energy is active, but plans are not finalized. Private enterprises are becoming involved, which may result in significant areas being planted in the near future.
P. x euramericana IN TURKEY - useful for border plantation
HUNGARY'S "GREAT PLAIN" where forestry was reborn after 1920
