Information on wood products markets
Forest economic maps
Walking in the eroded footprints of the Maya
Supertrees
A review by L.D. Pryor
L.D. PRYOR, Emeritus Professor, is visiting Fellow, Department of Forestry, Australian National University, Canberra, ACT, Australia.
Eucalypts for planting, FAO Forestry Series No. 11, 677 pages, Food and Agriculture Organization of the United Nations, Rome, 1981. Price: US$30 (subject to change).
The second edition of Eucalypts for planting is a landmark in the literature of the eucalypt. It is a fitting memorial to the late Dr M.R. Jacobs who was the main author and it reflects with great credit the major contribution of Mr R.L. Willan as technical editor just as the first edition did that of Mr A. Métro.
The second edition is virtually a new work as there has been a major increase in the knowledge and use of eucalypts in the 30 years since the appearance of the first edition. Eucalypts for planting is a unique source of information since, among other things, it brings together data on the performance of very many species of planted exotics from about one hundred countries and as such it is the only composite source of such information. The performance of planted eucalypts can be gauged fully only by turning to such records.
The physical characteristics of the sites of natural occurrence of the various species of the genus have been documented and are well known, but information from the natural habitat is only one part of the story since many species have been shown to perform well silviculturally in climatic and soil conditions considerably different from any of those in which the species occur naturally.
It might be said that the extent of site tolerance as a planted tree goes considerably beyond that indicated by the area of natural distribution for a great many of the species. This does not mean that information about the natural habitat is without relevance - on the contrary, it is of considerable importance, but for the would-be user of eucalypts as a silvicultural crop it is most important that the additional information on the performance of the tree as a planted crop should be known.
A striking example of this is afforded by Eucalyptus globulus, one of the longest planted and most widespread of plantation eucalypts. This species occurs naturally in a relatively small area in Tasmania and the adjoining southern tips of Victoria along Bass Strait. This covers a latitudinal range from about 38.5° to 43.5°S. In this area, it does not occur at elevations above about 1 000 metres. In spite of the limited range of the natural habitat, E. globulus has been a most successful species in the highlands of Ethiopia, in the vicinity of Addis Ababa at about latitude 12°N, in the Nilgiri hills in India at about latitude 17°N and in several South American localities of low latitude at high altitudes. Thus, there was nothing in the natural habitat to indicate that the species would perform well in these sites.
In forestry in general, the shifting of species from latitudes such as that of the natural occurrence of E. globulus to the very low latitudes in tropical highlands is not feasible since numerous plant species are sensitive to day-length, and the change occasioned by such latitudinal differences precludes the use of many species or provenances of species if such a transfer were attempted. There is no evidence at present that any such day-length physiological relationship in eucalypts has much bearing on this situation; shifts to very different latitudes from that of their origin have been successful with a wide range of species.
A different example is provided by Eucalyptus parvifolia, a small tree of very restricted occurrence in southeastern New South Wales. The climate of the natural habitat has cool winters where the temperatures are occasionally - 10°C but, planted in Western Europe and particularly in the United Kingdom, it has proved one of the most cold-resistant of eucalypts, enduring temperatures lower than - 15°C which is considerably colder than the area of its natural habitat. There is no way of learning from the natural habitat of the capacity of the species to resist temperatures lower than the coldest experienced there.
On the evidence available, it can be said that the potential ecological amplitude of any given eucalypt species is likely to be considerably greater than the ecological amplitude of the area of natural occurrence, and that the limits of any given species to perform well in other habitats can be ascertained only by trials made in those areas.
It follows then that there is a great deal more to be learned about the performance capacity of various eucalypt species, as the planted silvicultural crops and the continual collation of records of such trials on a world-wide basis will be of importance in the future. When it is borne in mind also that within many species there are major provenance differences, the amount of information still to be collected is very great indeed and undoubtedly much greater than that already recorded.
Furthermore, the fact is that the botanical systematic exploration of the genus is far from complete. It had seemed some 20 or 30 years ago that most of the species were known as there had been extensive collection within the genus over the previous 200 years. However, as more sites, often of limited extent, have become accessible and been explored botanically, it has been shown that there are still undescribed species awaiting systematic treatment as more of these specialized localities are examined. The rather unexpected condition is that there is a quite substantial number of species which are very restricted endemics of small geographic extent. Some of these species are now known to be capable of good growth performance and to have interesting silvicultural characteristics. These occurrences suggest that the species are relicts. On the basis of what is now known of such occurrences, it seems likely that a good many more remain to be discovered and described. Among these, there will probably be some of distinct silvicultural value, although the trials of such species, particularly when grown as exotics outside Australia, have yet to be undertaken. Some species Of this type which may be of significance are E. kartzoffiana, E. benthamii and E. badjensis. It should be noted that they are so restricted in occurrence as to be classified as endangered species in terms of survival in the natural habitat and that their introduction to cultivation trials will be rather slower than has been the case with the more widespread species in the past. While some of these endangered species are of small stature and slow growth, there may well be others with characteristics such as the cold resistance of E. parvifolia, which would make them of particular value not for direct use but as contributors to future breeding programmes.
In the Yemen Arab Republic E. camaldolensis controls erosion one of the world's most adaptable trees
The particular international significance of Eucalyptus has been the capacity displayed by many species, when grown in silvicultural plantations as exotics, to produce large quantities of wood in a short tune. World-wide, this feature is of great value, with wood famine becoming increasingly acute as human populations continue to grow at very rapid rates. The reason for such growth capacity in eucalypts has been analysed frequently in the past. To some extent it stems from the biological characteristics of many species of the genus which allow the growth of large, bored trees on sites of very low nutritional status, particularly sites which are deficient in phosphorus and nitrogen. While they respond to added fertilizer, their demand on fertilizer as a cultivated crop is not high owing to their capacity to thrive at low nutrient levels.
Good performance has also clearly been associated with the absence of various insect pests associated with the genus in the natural habitat. These are usually left behind when introductions of species are made by seed. In those relatively limited number of cases where there has been accidental introduction of insects specifically dependent on eucalypts, the result has sometimes been catastrophic. For example, the damage to E. globulus in New Zealand by the hemipterous insect Rhynchopeltella; by the snout beetle Gonipterus in Africa or by the longicorn beetle Phoracantha in the Mediterranean area reach disastrous levels. Once such insects are introduced, especially without their natural predators, the result can be devastating. Biological control is perhaps the only really effective method of overcoming this disability but, to achieve this, a major effort is required. Apart from control of the snout beetle in Africa, this has seldom been done.
The possibility of more extensive insect introductions being made from Australia must be viewed with alarm. This is foreshadowed by proposals which are made from time to time to export living plants from Australia to various parts of the world rather than to raise plants in those regions from seed in local nurseries. In some of the areas with a harsh climate and where substantial financial resources are available, as in some of the oil-producing countries, the possibility of such introductions is very real and one which the world community should seek to regulate as far as possible. If this is not done and there is further movement of insects peculiar to eucalypts, the loss of potential production will be enormous and the living standards of people in many parts of the world greatly impaired.
While spectacular results have been achieved by planting eucalypts to produce wood destined for industrial use, particularly in paper making, the production of fuelwood and timber for simple construction is probably of more significance for human well being. In this context, it is important to note some world-wide adverse reaction to further planting of eucalypts at present. The objection to the use of eucalypts is also raised with regard to the use of exotics in many countries. In some aspects, the points raised are valid. In countries outside Australia where they are exotic, the eucalypts do not support much of the indigenous fauna and, if the preservation of the natural vegetation and associated animals is the prime object of management, then eucalypts should not be planted. However, as with all crops, a balanced view would be that, to ensure human wellbeing, a certain amount of plantation should be established on areas which are set aside for wood production while the preservation of samples of the natural environment would be achieved by setting aside appropriate reserves within the total land area.
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If there is further spread of Eucalyptus insects in the world, the danger to these trees will be enormous. Living standards of people who depend upon them for fuel and other uses will be impaired. This can happen if countries insist on importing living eucalypts from Australia instead of raising them locally from seed. |
Another objection to eucalypt planting which is sometimes voiced is that they consume excessive amounts of water and thus lower the water table, reducing available water supplies in areas where there is critical need. There is some ground for thinking that the amount of wood produced by eucalypts in relation to the amount of water consumed is more than in most other species - therefore it is a more efficient user of water in terms of wood production. The fact that often it does grow quickly, of course, implies that it will consume a considerable amount of water. As with the use of all resources, planning must be based upon a compromise in partitioning the use of the various resources. If planting of eucalypts or other trees is extended so far that the amount of water available for other essential use is reduced to an unacceptably low level, then the planting target must be circumscribed before that position is reached; and land-use decisions, in determining the amount of wood to be produced as opposed to the water yield allowed, made on the basis of compromise implicit in such planning.
Also frequently voiced but with somewhat less validity are the claims that eucalypts cause erosion and lead to inferior water quality in catchments. The evidence for erosion associated with eucalypts seems to stem largely from the fact that the litter - leaves, twigs and bark - which forms under eucalypt stands is itself good, light fuel. In wood-starved areas, gathering of such fuel from underneath stands is a common occurrence with the result that the surface of the soil in the plantation is exposed to erosion which may become severe if they are on steeper slopes. The problem is often exacerbated, too, by trampling and sheltering of domestic stock.
The view that eucalypts adversely affect water quality is sometimes mentioned but it does not seem to have any factual support. It should be borne in mind that, in the natural Australian environment, most of the water catchments are covered with eucalypt forest and the water quality for domestic use from such catchments is not in any way inferior to that from any other areas either within Australia or outside.
Eucalypts have already made a great contribution to world wood production and amenity planting. They are especially indicated in the warm-temperate and tropical regions of the world, particularly in those areas where there are periods of marked water stress. They will continue to be of great importance for a long time in the future. It follows that information on the performance of species and provenances will continue to grow in different countries and that the rate of this store of information will accelerate. At the same time, there will be developments in tree improvement programmes and in modifications in silvicultural techniques for handling eucalypts. There may be also some as yet unforeseen problems.
The amount of progress in eucalypt silviculture would hopefully presume that a third edition of Eucalypts for planting will appear as soon as new information equal in amount to that added by the second edition can be collated and published, estimated at little more than ten years hence.
It is equally important that the source material in Australia be subject to continuous scrutiny to make it still better known and, above all, to ensure that the gene resource be preserved in the natural habitat not only for its own sake but for future use by the international community.
The International Trade Centre of UNCTAD/GATT in Geneva has called to our attention four of their publications dealing with markets for wood products. The books are: Major import markets for wooden household furniture (1975), Selected markets for wooden household articles (1975), Selected markets for wooden toys (1976) and Survey of selected Middle Eastern markets for wood-based building materials from developing countries (1980). Among the useful information in these publications are lists of names and addresses of importing firms, trade and buying offices, fairs and exhibitions and trade journals. They are available in English, French and Spanish and may be obtained from the International Trade Centre, UNCTAD/GATT, Palais des Nations, 1211 Geneva 10, Switzerland.
World forestry atlas. Edited by Richard Torunsky. Published for the Federal Research Institute of Forestry Production, Federal Republic of Germany by New York, Paul Parey Scientific Publishers, 1981. Price: single maps US$33.70 (subscription price $29.00), complete set $1 505.00.
The world forestry atlas provides up-to-date, detailed economic statistics on maps and diagrams. In all, there are 62 maps, each measuring 75 x 60 cm. Topics covered include timber trade, afforestation, accessibility of forest areas, silvicultural systems and forest formations. Order from. Paul Parey Scientific Publishers, 461 Park Avenue South, New York, N.Y. 10016, USA.
Building a sustainable society by Lester R. Brown. W.W. Norton and Co., 1981, 372 pages, notes and index.
A thousand years ago the Mayan civilization collapsed. It was a great agricultural society and it lasted 17 centuries. Lester R. Brown begins his examination of the problem faced today in Building a sustainable society by discussing the big mistake that the Maya made. Their society disappeared rather suddenly because soil erosion literally eroded the productivity of their natural resource base. This, he asserts, is also one of three major threats to existing civilization. Deterioration of biological systems and depletion of oil are the other two.
Food production demands require practices harmful to land which may result in a loss of topsoil that could create a food problem in the 1980s as serious as the energy problem in the 1970s. Brown says that the productive resource base from forests, grasslands and fisheries on which the economic system depends is being consumed. The petroleum culture is quickly running out of petroleum because alternative sources of energy are being developed too slowly.
Dreary as this may sound, the latter two thirds of the book is devoted to solutions. Each country, he explains, will have to plan according to its indigenous renewable resources. "Creating a sustainable society will require fundamental economic and social changes, a wholesale alteration of economic priorities and population policies." Of the many dimensions of the transition, the most crucial is time. Brown urges, "Every person, every organization, and government at every level has a role to play in the transition... What we will soon discover is whether we have the vision and the will to do it."
ADELYN M. JONES Sierra Club Bulletin
Tree improvement: an important part of forest management (brochure), Georgia-Pacific Corp., Portland, Oregon.
This brochure deals with the technique of identifying superior trees in the forest and then using seed from them to reforest harvested areas. The trees are chosen for such characteristics as size, growth rate and shape.
Georgia-Pacific foresters are already seeing a 10 percent yield improvement in the first generation of "supertrees" and are predicting about 25 percent from the second generation. Some research authorities foresee eventual increases of 50 percent.
Brochures are available from Educational Services, Georgia-Pacific Corp., 900 S.W. Fifth Avenue, Portland, Or 97204, USA.
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