General
Forestry education
Fundamental science
Silviculture
Logging and engineering
Forest injuries and protection
Measuration and surveying
Forest management
Marketing and trade
Forest products and their utilization
Forest policy
The items appearing here are condensed selections of news thought to he of interest to readers of UNASYLVA. They are grouped alphabetically by countries under headings currently used lay the Forestry Division for reference purposes. The Editor will be glad to receive direct from readers authenticated items of interest and of news value for this part of the review.
CANADA
· In the hope that they will inspire public interest, the Pulp & Paper Magazine of Canada has published reproductions of a group of forest landscapes by six eminent Canadian artists. The original canvases are the property of the pulp and paper industry of Canada which, through its Association, commissioned the artists to depict, each in his own terms, the chief tree species at present employed in the manufacture of pulp and paper. The paintings will be used in many ways. The original canvases will tour Canada and be displayed in art galleries from coast to coast. Black and white reproductions will be used in advertising. As these paintings and their reproductions appear throughout the and, they will serve not only as a permanent reminder of the economic significance of the forests, but also as a reminder to Canadians of their forest responsibilities. For Canadians are often unmindful of the feet that they own nine-tenths of the woodlands, and that the forests and the forest industries account for almost a third of the primary production of this country. On this primary production is based the vast edifice of all Canadian trade and commerce. Thus, directly and indirectly, the forests generate at least a quarter of the income of all Canadians, and of total forest wealth, pulp and paper accounts for one half.
The paintings, too, will be used to emphasize the feet that the pulp and paper industry, recognizing its responsibilities, has adopted and publicly declared a forest policy of perpetual yield; and that by improved management, better utilization, research, and by many other means, substantial progress has already been made towards the implementation of this policy.
CYPRUS
· In the course of the past twenty-five years considerable progress has been made in forestry in Cyprus. Among the specific results achieved are the widespread elimination of goat grazing in the forests; the construction of a fine road and telephone network; an extensive program of afforestation; the establishment of an annual Arbor Day; a spectacular reduction in forest fires; the setting up of a Middle East Forestry School; the conversion to oil from wood burning, and the removal of, squalid, poverty-stricken villages. These results have been accomplished through slow, persistent and sympathetic work with the villagers themselves and with the active support of the Government.
One little-known aspect of forestry in Cyprus is that there is a large-scale demand for the seed of such species as Aleppo pine (Pinus halepensis), cypress, acacia and eucalyptus by neighboring countries, and that collection of seed on a large scale gives employment to scores of villagers. The collection, drying and storing methods have been worked out on a simple basis which is practicable for the village people. Jordan, Lebanon and Israel have all bought tree seed in quantities.
NEW ZEALAND
· The New Zealand Institute of Foresters, Inc., continues its active and varied program. The annual general meeting consists of one day devoted to Institute business and to presentation and discussion of technical papers, with usually one or two days spent in field trips to plantations and indigenous forests of particular interest. The 1951 meeting was held in June at the Château Tongariro.
There are four grades of members: honorary members; members; associate members; and student members. The official publication is the New Zealand Journal of Forestry, which is published annually and is now in its sixth year.
The Institute participates in the work of the Nature Protection Council, a body recently set up to co-ordinate efforts toward reservation and protection of natural associations of plants and animals. It also took part in May 1951 in the Seventh New Zealand Science Congress, held at Christ church. A section of Forestry, Agriculture and Soil Science at the Congress dealt with marginal land, hydrology and land use, and other problems of land use with particular reference to soil, agricultural and forest problems of several of the major geographical and soil areas of the country.
A Terminology Committee has prepared the draft for a glossary of technical terms. The Institute has prepared data to support the case of foresters as a group for consideration in the general regarding of the Public Service to be undertaken soon.
SWITZERLAND
· Mr. A.-J. Schlatter, former federal inspector, has been appointed by the Swiss Federal Council to the post of Inspector General of Forests, Hunting and Fishing in succession to the late Mr. E. Hess. Mr. Schlatter, who entered the Government Service in 1930 had for thirteen years been Inspector of Forests for the second district (arrondissement) of the Canton of Vaud at Aigle (Ormonts).
UNITED STATES OF AMERICA
· The City of New York has one of the world's great surface water supply systems. It must produce an average of 800 million gallons (3,028 mill. liters) of fresh water a day and, during midsummer, consumption reaches 1,400 million (5,299 mill. liters). To meet the average daily consumption and at average yields, an area of 1,200 square miles (3,108 km²) of watershed is required. In fact, the present area of the city's supply is only 1,250 square miles (3,238 km²), and thus reservoiring is required to equalize supplies. On the city watersheds a wide range of watershed problems is found, since they are situated on both private and public land, on untouched public forest preserves and state parks and heavily exploited grasslands used for dairy farming. There is also a wide variety of topography and geology.
With present information, it is at least doubtful that complete closure of forest lands to utilization is efficient from the standpoint of obtaining maximum usable water yields. On the contrary, if forests were maintained to prescribed composition, basal area and age class and unnecessary vegetation removed, transpiration losses might be significantly reduced and water yields thereby increased to give a greater margin of yield over consumption than now exists.
The use of sloping land for pasture is as much as 44 percent of the total area in some drainage basins, and as much as 80 percent of the land shows moderate erosion; especially on steep and rocky areas, pasture yields are low and erosion severe. Thus one major watershed problem is to change the form of land use over substantial areas. It is particularly desirable to exclude cattle from steep lands with thin soil by fencing, so as to eliminate unproductive pastures and to substitute forest for grass cover. The lack which this presents is not insurmountable, and it would seem that selected areas should be placed under public ownership as a prerequisite to planting of forests. In past decades a great dead of forest planting has been done successfully on the older of the two major watersheds, and beneficial results are evident.
Such a remedial program would necessarily include detailed land use surveys, and detailed field examinations of critical areas. Land use adjustments are needed on stoop, unproductive and overtrampled pastures. Public acquisition for the purpose of streambank protection and channel control, protection of sub-marginal and unproductive lands, as wall as of steep slopes and thin soils is also required. In many areas improvement in the harvesting of wood products from private land is also necessary. Better management of forest lands is needed through stand improvement to improve infiltration, to assist in the accumulation of snow and delay of snow melt, and through the reduction of transpiration by controlling the cover.
UNITED STATES OF AMERICA
· In 1950, the forest schools of the U.S.A. conferred 2,321 bachelor's degrees, compared with 1,443 in 1949; 275 master's degrees, compared with 205; 29 doctor's degrees, compared with 12. All these figures represent new peaks for the schools. Of the bachelor's degrees 2,039 were conferred by the 22 accredited schools, the remainder by the 12 non-accredited schools. Of the master's degrees, 268 were conferred by the accredited schools, as were all the doctor's degrees. Under-graduate enrollment has dropped from 7,469 in 1949 to 5,935, and the number of seniors from 2,501 to 1,730. On the other hand, the number of graduate students, working both for master's and doctor's degrees, has increased. The proportion of veterans among undergraduates has dropped from 75 percent in 1948 to 43 percent in 1950, whereas among graduate students, the proportion has changed only from 77 to 74 percent.
UNION OF SOVIET SOCIALIST REPUBLICS
· Armenia, one of the smaller Transcaucasian Republics of the Soviet Union, borders in the southwest and south on Turkey and Iran. From the standpoint of forestry, Armenia is of interest not because of the extent of its forests, which are small, but because of the important hydrological role which they play in its national economy. The country is poor in coal and oil, but rich in water power resources. One of the most important sources of hydro-electric energy is Lake Sevang, situated at an altitude of 1916 meters (6,286 ft.) above sea level, and the river Zanga which flows from it, and along which a number of powerful electricity stations have been constructed. Armenia is also water conscous for another reason; from time immemorial its agriculture has depended on irrigation. Water conservation for electric power development and for irrigation purposes through forestry is therefore the most important task of the recently created Armenian Ministry of Forestry.
The forests of the Armenian Republic cover only 10 percent of its territory or about 330,000 hectares (815,430 acres); many regions, in fact, are entirely treeless. The absence of a protective forest cover and primitive land use in the past caused excessive erosion and the formation of gullies and torrents which assumed alarming proportions over large areas. To control the water regime and check erosion, the Ministry has instituted a comprehensive forest policy for existing forests, is undertaking engineering works to stabilize mountain slopes and carrying out extensive afforestation of treeless areas. The forests have been divided into two groups: one group, covering 91 percent of forest land, or about 300,000 hectares (741,300 acres) has been declared protection forests. Here no commercial cuttings are allowed, only removal of dead trees, thinnings and other cultural operations to improve the stand and increase its density. The protection forests are located chiefly in the northern part of the country, along shores of mountain streams, on steep slopes and divides. The other group - covering 9 percent or 30,000 hectares (74,130 acres) - is open for exploitation in the form of gradual cuttings within the limits of the annual growth with obligatory renewal of the cut-over land. These commercial forests are located in the Alaverd and in the Noemberansk regions. The dominant species of the forests are hardwoods (oak, beech, ash, basswood, etc.) All forests are worked according to definite management plans to be revised at the end of each 10-year period.
In addition, the Ministry is engaged in a campaign of checking erosion by afforestation. The mountain slopes in the vicinity of the cities of Kirovakan, Dilijan and Kafan which in the past were burdened each year with erosion debris, have now been planted and erosion checked. During the last two years more than 5,000 hectares (13,355 acres) of eroded land have been afforested. Some 800 hectares (1,977 acres) of bare, stony and rocky mountain slopes on the northern and northeastern sides of the capital of Armenia, Erevan, are now covered with forest plantations. To protect agricultural crops from hot dry winds, in 1949 shelter-belts were planted over an area of 1,500 hectares (3,707 acres). Three forest nurseries covering 400 hectares (988 acres) are in the process of being established. A forest school with a 2-year course in the city of Kirovakan trains foresters of lower grades and in 1950 some 50 students graduated from it.
UNITED STATES OF AMERICA
· An interesting combination of two recent scientific techniques has been made in studies of the bogs of the Quetico-Superior country in the Lake States area of the northern United States and southern Canada. The pre-historic course of development was studied by use of the pollin grain technique, which showed that the first invaders after glaciation were white spruce (Picea glauca), balsam fir (Abies balsamea) and some jack pine (Pinus banksiana). Then a major climatic change resulted in replacement of the spruce fir by a predominantly jack pine forest which persisted for a longtime and then gradually merged into a forest of jack pine associated with red and white pines (P. resinosa and Abies concolor) and finally in an increase of spruce and fir again. Estimates of the time interval involved in any or all of these steps depend on the depth of bogs and estimates of the time interval per vertical foot, or on similar inexact estimates. However, the method of determining the loss of radio-activity in the carbon found in the bogs makes it possible to estimate the years which have elapsed singe a particular bog sample was laid down, with a possible plus or minus error of 4 or 5 percent.
The bogs show that great fires have occurred and have left carbon deposits, and the radio-active carbon method indicates that the most severe fires were from 3,000 to 3,500 years ago. Formation of peat has apparently proceeded at the rate of about one foot (30 cm.) in 438 to 500 years. The combination of the two techniques seems to offer an opportunity for more accurate determination of the time intervals involved in the development of existing forests.
· In a study recently made in the northwestern United States, southwestern Canada and Alaska, the techniques of estimating dates of recent glacier advances and recessions have been improved-through study of tree growth layers. It is possible to estimate the time singe a glacier advanced beyond a given point, and the approximate rates of recession, by studying gross sections of the trees injured or tilted by ice, since such glacial action changes the form of growth layers from concentric before tilting, to asymmetric after tilting. Similarly, the age of the oldest tree along the trimline - that is, the edge of the undestroyed forest - indicates the period of the occupancy of the land by glacier, and the age of young forest following recession indicates the date of recession.
The methods developed, expanding those previously used, will be valuable too, in studying glacial behavior in various parts of the world.
· Precise measurements of the radial width of annual growth rings of big trees and ponderosa pine, and the sequences of different width rings, have hitherto been made by Huntington and MacDougall and interpreted as indicators of rainfall characteristics of individual years and groups of years for periods before the establishment of standard rainfall records. Acceptance of this method depends on the valid correlation of tree growth and rainfall within the period of formal rainfall records. If the method is valid, the results of such studies may be of great value to scientists in indicating, for example, long-term changes in precipitation, the alternation of above and below normal precipitation, and the relation of such shifts to historical facts such as the migration of primitive peoples, expansion or contraction of forests, currents and severity of forest fires.
A study of selected dominant trees of several species growing in several locations in north central New Mexico has recently been reported, the data from the cores having been subjected to detailed statistical analysis. Rainfall records from stations relatively near the forest plots were used. Among the conclusions were: (1) correlation between rainfall from March to July and tree growth was high; (2) trees respond very nearly 100 percent to fluctuations of rainfall on the immediate site, (3) quality of correlation is little affected by the nature of the species; (4) within the groups, disagreement correlation among individual trees emphasizes the extremely local effect of site factors, the divergence increases with the increase in distance, as measured in yards rather than miles. The highly localized microscopic site factors are extremely important in determining the behavior of individual trees; (5) the higher the correlations among the trees, the higher their correlation with rainfall, (6) trees from wetter sites showed the highest correlation and also the greatest increases in growth, whereas trees from drier sites were poor recorders of changes in rainfall characteristics. General conclusions are that variations in tree growth follow variations in March-July rainfall from year to year of the immediate site. Secondly, it is believed that changes of internal agreement among trees, changes of the average variation, and the average departure from the mean variation, can be used as a method to reveal changes in rainfall through years where the amount of rainfall and derived soil moisture approximate to those at the site of the primary forest stations used. It does not appear that this study validates on a wholesale and generalized basis the use of growth rings as a measure of precipitation.
AUSTRALIA
· Small plantations of Pinus radiata were established on the predominantly sandy soils in the south-east of South Australia as early as the 1870's and sawmilling operations began in the early years of the twentieth century. Most of the forests which have been clear-cut were maintained in an unthinned condition for up to ages of from 20 to 40 years, and therefore provided information on yields of unthinned forests at various ages and on various site qualities. Although thinning had been done on some plantations, systematic records were not kept. Therefore, in 1935, the Woods and Forests Department established a series of sample plots on which it has maintained systematic measurements to study the problems of thinning. The view has been held that the prime purpose of public forestry is to produce maximum yields of all the kinds of usable material required by consumers, and thus the studies have not been concerned with the economic aspects of forestry.
|
Thinning density
|
350-400 |
275-325 |
200-250 |
150-200 |
|
(Age in years)
|
||||
|
S. Q. I |
10-11 |
14-15 |
19-20 |
24-25 |
|
S. Q. II |
12 |
17 |
22 |
27 |
|
S. Q. III |
13 |
19 |
25 |
31 |
|
S. Q. IV |
14-15 |
21-22 |
28-29 |
- |
|
S. Q. V |
16-17 |
23-24 |
30-31 |
- |
While the soils may appear similar superficially, there is in fact an enormous range of yield, and a series of five site quality classes has been worked out. The enormous yields of such plantations are well-known and even mediocre sites produce an average yield of nearly 8,000 cubic feet (227 m³) in 30 years. Thinning studies are by no means complete and are weak in relation to the highest site qualities, but analysis has made it possible to establish guides applicable to this forest zone. The more important conclusions are:
1) Initial spacing. Taking into account both utilization of the soil and tree form, optimum spacing is 6 ft. (1.8 m.) for site quality I, 7 ft. (2.1 m.) for site qualities II and III 7-8 ft. (2.1-2.4 m.) for site quality IV, and 8 ft. (2.4 m.) for site quality V.2) Effect of thinning on volume production. For site qualities II, III and IV, a comparatively moderate thinning after 10 years to a density of from 350-400 trees per acre (860-990 per ha.) increases volume production over both the unthinned stand and one thinned to 300 trees (740 per ha.) This superiority is maintained till near or after 20 years, after which stocking of 300 is preferable.
3) Danger from wind. Development of windfirm stems is a mad or objective of thinning, and for this purpose the time for the first thinning is when the dominant height is around 60 to 65 ft. (18-20 m.) and not more than 70 ft. (21 m.). This corresponds to 10-11 years on site quality I, 11-12 years on site quality II, 13 years on site quality III, 14-15 years on site quality IV, and 16 years on site quality V. Adoption of this schedule is necessary to safeguard against windstorms.
4) Intensity and frequency of thinning. The recommended schedule is as follows:
5) Thinning yields and techniques. The use of modern methods of extraction requires the clear felling of extraction rows at regular intervals to allow the entry of trucks, and this inflates the yields from the first thinning, which will run from 1,000 to 1,500 cubic feet or more per acre (70 m³ - 105 m³ per ha.). In addition, trees of undesirable form, and suppressed trees should be removed. In the second thinning, reserved trees capable of making the best growth should be not less than 40 percent of the total height in green crown, or 50 percent for production of large diameters.
Because of the very rapid growth and because material from trees of as low as 6 inches (15 cm.) diameter is saleable, economic opportunity does exist for widespread application of systematic, frequent and moderate thinning to these forests. In general, it is recognized by the Department that very short rotations are unlikely to build up or even maintain the soil, and the general opinion is to work toward longer rotations with selected crop trees rather than toward short rotations. Experiments to date show that the recommended spacing and thinning practices will increase the growth and yield over those of unthinned stands and, in addition, supply the market with usable material from the thinnings.
CANADA
· As part of its woodlands research, the Pulp and Paper Research Institute of Canada has produced a study on cutting in the pulpwood operations of eastern Canada. The study does not cover all conditions but does deal with many of the different ecological environments where pulpwood operations are now in progress. Each of the many situations has its own combination of geographical conditions such as latitude altitude and exposure; of climatic factors (temperature, precipitation and light); and of edaphic factors (soil requirements, soil temperature, soil moisture soil reaction and organic layers). Each of these, in various situations, has a dominant effect on the type of cutting which will obtain the most successful regeneration and result in satisfactory utilization of the growing capacity.
The four basic cutting systems - clearcutting, seed tree cutting, shelterwood cutting, and selection cutting - were studied, in each case as to effect on soil and regeneration, on age composition, and on advance growth, and the techniques of each are described. The economic considerations, both in the short run and in the long run, vary under each system, and an analysis is made of these factors. Cutting systems must be related to soil temperature and soil moisture conditions as they, in turn, effect establishment and growth of regeneration, and, in addition, must be related to the type of stand whether even-aged or uneven-aged.
At present, the system most commonly used is clearcutting, largely because it is cheapest in harvesting virgin stands. It may not be the cheapest under a long-term plan of obtaining satisfactory regeneration.
The conditions under which each of the basic systems constitutes good forestry practice are: (1) Clearcutting when satisfactory advance reproduction is present, when stands to be cut are overmature and are composed of intolerant species, and when raw humus is prevalent as in northern regions. (2) Shelterwood cutting when neither clear-cutting nor selection cutting will give best results and when previous stand treatment mainly thinning, has been applied. (3) Seed-tree cutting when large areas are ready for a final cut but advance growth has not become established and, since seed trees must be wind firm, when the stand has had previous thinning. (4) Selection cutting when growth conditions are favorable, the stand is uneven-aged and is composed of tolerant species.
In general, forest management is best served by keeping stands as even-aged as possible, since then natural units are well-defined, better control can be exercised over forest operations, and estimates of growing stock increment and depletion are more readily obtainable.
Even though departure from clearcutting tends to increase the cost of pulpwood, it is known that there are offsetting considerations, such as the fact that leaving small trees reduces the average cost per unit of volume. The system used will always have to balance silviculture and cost considerations, but in order to obtain suitable regeneration, which is now not universal, it will be necessary to accept some increases in cost. Even with the most intelligent application of cutting systems to the particular problem of individual sites, there will be failures of natural regeneration and some planting may become necessary, but the degree of success of natural regeneration should be substantially increased if the findings of this study are put into practice.
EGYPT
· The practice of growing shade trees along main roads is being extended. Farmers are also growing timber trees for shade, as windbreaks, or for boundary demarcation. In the Sinai Peninsula, a belt of trees five km. (3 miles) long and five meters (16 ft.) wide, is found to be essential to stop the movement of sand: dunes which hinders the extension of cultivation in this region. Already 850,000 boos have been grown in this belt. Another belt in the western desert has been started, where 1,700,000 trees have been grown.
UNITED STATES OF AMERICA
· For 20 years the U.S. Forest Service has sown common mustard seed on burned mountain watersheds in Southern California, as the quickest method of restoring the protective cover. When sown promptly after fire, the seed germinates rapidly and the plants hold the soil until the slower growing native grasses and brush come back. Eventually the mustard disappears.
The first sowing was done by hand, but is slow and costly. Later, airplanes were used, thereby halving the cost, but resulting in poor distribution of seed over the rugged country, since not all areas could be covered. Recently, the helicopter has been used effectively. In one case, 1,045 acres (423 ha.) were covered within 8 ½ flying hours. The cost was slightly in excess of that by airplane, but the seed distribution was uniform and as good as that obtained by hand. In another case, 44,000 acres (17,807 ha.) in two areas were seeded by helicopter. It is evident that the use of this machine in such work will increase, singe it is as cheap as any other method, is far safer to operate in rugged country than the airplane, and results in excellent distribution of the seed.
· It would be impossible to produce the many millions of trees in various nurseries throughout the United States if hand weeding had not been superseded by chemical weeding in many nurseries. Chemical weeding is now cheap, safe and effective, and provided proven techniques are utilized, it is in no way a questionable practice. However, although satisfactory techniques have been evolved for various places, there is still much to learn. Weeding has always largely contributed to nursery maintenance costs, and any country would be well advised to investigate thoroughly the possibilities of chemical weeding.
· In part of the high-site-quality pine and fir types in California, the sprouting habit of tan oak (Lithocarpus densiflora) and madrone (Arbutus menziesii) make stand improvement cuttings very difficult. Recent research has shown that, when the cut stumps of the hardwoods were treated with a one percent water solution of the isopropyl ester of 2,4-D with half-a-pint (0.28 l.) of solution on stumps under 6 inches (15.24 cm.) in diameter and one pint (0.57 l.) on larger stumps, the sprouting of tan oak stumps was reduced to 64 percent, the sprouting of madrone stumps was reduced from 36 percent to 28 percent, and the number of sprouts per sprouting stump was reduced to about one-third. Treatment in midsummer seems to be best to prevent sprouting of the madrone, and in late fall or early spring for tan oak.
· In the Lake States, natural stands of young red pine (Pinus resinosa Air.) are often overdense, from 5,000 to 20,000 stems per acre, (18,355 to 49,420 per ha.), and the question of desirable spacing to be attained by thinning in such stands has been studied by the Forest Experiment Station for a quarter of a century. The main conclusions are that for stands of from 20 to 40 years old, an average of not rigidly applied spacing from ¼ to 1/5 the height of the stands is desirable, and for older stands, an average spacing of a little less than 1/5 the average dominant height. In plantations on average sites, a spacing of 7 x 7 ft. (2.1336 m. x 2.1336 m.) will give desirable stocking at the time when the first commercial thinning for pulpwood is made. On better sites the number of trees should be less and, on poorer sites, more. Determination of spacing in relation to stand height is simple and desirable, singe the stand height is an indication of site quality and stand age. In thinning, the most valuable trees should: be retained, even though resultant spacing is not completely regular.
· In the pine and mixed conifer forests of the Sierra Nevada mountains in California, previous methods of silviculture have not been effective in providing adequate restocking of pine. The most commonly used method of cutting has been by tree selection, depending on classification of the individual tree, and much weight has been given to taking out tree classes of high-risk and leaving low risk trees, that is, those which can be expected to survive at least during the calculated cutting cycle. Analysis of 40 years of research and experience has now led to the conclusion that a new concept is needed, and this is called "unit area control." It depends on identifying the often small and irregularly shaped patches of timber in the forest each of which has its own characteristics, and each of which will, in cutting, be given treatment specifically adapted to its own problems. The classification involves, first, the recognition of silvical characteristics. The sugar pine (Pinus lambertiana) and ponderosa pine, for example, are intolerant and grow best in even-aged groups, prefer bare mineral soil for germination, grow rapidly if they start free of competition and need thinnings and gleanings for best growth; they do not establish themselves as rapidly under competing cover and, where they do, grow poorly; they do not prune themselves naturally. Moreover pine seeds are the favorite food of numerous rodents. Classification of stand conditions includes determining the age group of the overstory, the species to which the unit area is best adapted, the degree of stocking, the availability of suitable seed trees, and the presence or absence of brush or other competing vegetation. Cutting may have one of several primary purposes, which include cutting for natural restocking, where suitable seed trees are present and when a seed crop is on the trees; cutting for artificial restocking, where seed trees are absent or no seed crop is visible, cutting for release, where advance growth is already established and cutting for improvement of young saleable stands to remove old malformed or defective trees. In the first two categories the unit is clear-cut, slash is piled and burned, competing vegetation is eradicated, and the bare mineral soil is exposed. In applying unit area control, it is necessary to have, first, a detailed inventory so that the amount to be out can be correctly estimated and a management plan can be prepared. Short cutting cycles are desirable in order to maintain full control of the stand and to convert the old growth into a regulated forest. Problems of logging are no different from those with other systems of cutting, but it is particularly important to minimize logging damage to reserve trees and established young growth. Application of the new method, which was devised after many years of research, will, in fact, speed the effective conversion of old growth forest to managed forests, and will result in more complete use of the growing capacity of often highly productive forest soils.
UNITED STATES OF AMERICA
· In the State of Oregon, the method of log transportation has changed in the past 20 years from water or rail to the almost exclusive use of logging trucks, duo to the fact that the timber now used is farther away from rivers and can be reached only by maximum grades greatly in excess of those suitable for railroads: thus the wide dispersal of timber ownership makes it necessary to operate, in many oases, in relatively small tracts of timber. This development has resulted in utilizing many stands which wore formerly marginal and in increased utilization amounting to as much as 25 percent of the timber opened up.
Recent studies have been made of the costs of log transport on different type roads, with different speed limits and with different truck loadings, and of the amount of timber which will be hauled over each of the numerous existing highways during the next 10 years. These data are expected to provide a sound basis for determining priorities and scheduling work on highways in the interests of resource utilization. The cost per thousand board measure of logs per round trip mile decreases for example, from $0.24 to $0.19 on 20-mile (32 km.) per hour gravel surface roads when the gross vehicle weight increases from 50-60,000 lb. (23-27,000 kg.) to 60-80,000 lb. (2736,000 kg.). Further additions to vehicle weight either reduce the cost slightly or, with very heavy vehicles, increase it. Cost for 60-80,000 lb. (27-36,000 kg.) vehicle weights are $0.15 on 30-mile (48 km.) per hour gravel surface roads and $0.12 on 30-mile (48 km.) per hour concrete surfaces - all the figures based on an average haul of 30 miles (48 km.). In view of the continuing importance of truck transport of logs, and of the known economies of operation, the timber industry organization making this study recommends an increase in legal weight limit to a total vehicle load of 72,000 lb. (33,000 kg.) and an axle load of up to 18,000 lb. (8,000 kg.)
CANADA
· Recent experiments in poisoning the Deer mouse (Peromyscus), which is one of the main obstacles to successful reforestation by direct seeding, have been conducted in British Columbia utilizing the new poison, sodium fluoro-acetate, commonly known as "compound 1080." Effectiveness was determined by trapping on sample plots before and after the poisoning operation, which was conducted in early spring and involved broadcasting poisoned bait at the rate of one tablespoonful on every 50 feet (15 m.) of the surveyed lines. It was found that although the rodent population was heavily reduced - and that this reduction extended well beyond the date that germination of seed might be expected - by the fall the rodent population had been measurably re-established through infiltration and by breeding of the surviving mice. There was no evidence, however, that desirable birds or animals were destroyed. The poisoning was followed by seeding to Douglas fir. It was over three times as effective as the work conducted on the control plot.
· Through the co-operation of the Post Office Department, the Forestry Branch has been permitted to use the services of the postal cancellation machines to carry a brief forest fire prevention message during the spring and fall fire season on all letters from key post offices throughout Canada. The Post Office Department has further cooperated with the Forestry Branch by providing space in all Post Office lobbies in Canada to display forest fire prevention notices during the dangerous fire season.
NEW ZEALAND
· In New Zealand the problem of the interactions of forests and alien animals is receiving much attention, both on the part of foresters and others. The National Forest Survey is systematically recording information on the effects of deer upon indigenous forests and, although the Survey is not completed, enough information has been accumulated to publish partial analyses. Broad generalizations on the relationships are impossible because so many variables determine the degree and kind of damage; for example, the period of development of the deer population itself is important. After deer are established, there is a period of rapid population growth during which preferred foot plants are eaten out, which may or may not result in detriment to the forests. Then, in the absence of heavy culling of the herd, a period of overpopulation follows during which the food habits change rapidly and the most noticeable damage to the forests occurs. This is followed by a downward readjustment of herd population during which much of the damage is repaired but the browsing of desirable forest species by a relatively stabilized population continues.
The indigenous forests themselves have changed in composition in the recent past, and in some areas are still changing. Displacement of the podocarp forests by silver beech and of the latter by mountain beech while irregular, is a widespread process of ecological change. Thus the forest-deer relationship depends on both the stage of forest evolution and on the stage of herd development. Culling of the herds by hunting which, in some areas, has been very heavy, is a further factor to be considered. If done during the period of population increase, it merely prolongs this period. If done during the period of over-population, it tends to shorten this period and the period of normal recovery. Culling of stable herds is beneficial only if carried out systematically each year, since otherwise herds strengthen and recover. A true measure of culling is the percentage reduction accomplished, not a mere statement of the number of animals taken, and methods of compiling inventories have not been fully worked out.
Studies so far made in the Western Southland have served to identify the plants most commonly browsed and those which are never browsed. In addition, studies have been made on six forest types of podocarp forest, silver beech, mountain beech and mixed forests to determine the effect grazing on each and to estimate future development if deer grazing continues. Here, as elsewhere in the country, it is evident that the correct relation between forest and deer depends on the factors in each situation. In some oases where desirable tree seedlings are heavily used, the best action in terms of forest values may range from extermination of deer herds to maintenance of large populations. Since the studies are being made with full understanding that deer and other animals such as opossum are now integral parts of the forest estate, and singe particular situations are being studied on a thoroughly factual basis, it is to be expected that the eventual outcome, when the survey and special studies are completed, will be the development of definite plans of management.
A recent book entitled "Introduced Mammals of New Zealand" has accumulated and analyzed the available information and, although not attempting broad generalizations, it is expected to provide a useful source of information for students of the subject.
NORWAY
· Operating in Norway singe 1912 the Norwegian Mutual Forest Fire Insurance Company has now insured 80 percent of the private forest value in Norway. Compensation is paid for damage to the forest floor and to young stands not yet merchantable. As fire-killed timber of dimensions larger than about 8 in. (20 cm.) diameter at breast height can be readily disposed of without much loss in stumpage, insurance is normally effected up to the limit of non-merchantable D.B.H., and further in Norway, the value of larger trees is not seriously affected by fire. Insurance rates are low and since its inception the Company has built up satisfactory reserves. From the outset it was realized that protection of the forest from fire was the essence of forest fire insurance. Laws were enacted and a modern system of detection and suppression established.
UNITED STATES OF AMERICA
· For five days beginning August 18, 1951, lightning storms started fires on national forest and state-protected areas in Northern California, Oregon and Washington. The earlier storms were largely dry, and many of the resulting fires made fast starts. Thus immediately available suppression forces were committed early, and the problem of manning later fires became unusually difficult. On the California National Forests a total of over 500 separate fires occurred during these five days and, with the additional large numbers over other areas, it is evident that this is one of the major lightning fire concentrations in the 50 years of organized protection on the West Coast.
Unusual steps were taken to man fires as they wore discovered or spread. Skilled personnel were shifted by piano from unaffected regions, organized Indian crews were brought in by piano from the southwest crews of state prisoners were moved to major fires by truck and bus, and lumber companies released woods and mill employees. Smokejumper crews wore moved from the northern Rocky Mountain region and elsewhere to selected local headquarters. On the fifth day smoke from the fires was so dense as to form continuous blankets over part of the affected area, making air operations impossible and reducing the chances of detecting new fires. Small crews of selected men were then dispatched to patrol individual drainages and to detect and suppress the incipient fires thus: discovered.
Despite the unusual and severe difficulties, by the end of the fifth day there remained only five fires ranging in size from 1,000 to 8,000 acres (400-3,240 ha.), on which suppression work was under way but not yet completed. In former major lightning fire concentrations of this order the number of fires remaining uncontrolled after so short a period has been much larger and the area burned over much greater, due to the then unsolved problems of rapidly mobilizing competent additional help from outside the affected area.
· Blister rust control work in the western states of Washington Oregon California, Montana and Idaho, is assisted by the U.S. Forest Service the National Park Service, the U.S. Bureau of Land Management, the U. S. Bureau of Entomology and Plant Quarantine, the State of California, and by two lumber companies. In 1950, $1,290,000 were spent, control work was done on over 121,000 acres, (49,000 ha.), pine surveys to determine whether lands are to be boated were done on nearly 147,000 acres (59,000 ha.) of private lands and on a large area of national forest land, ribes surveys were made on nearly 230,000 acres (93,000 ha.), and disease surveys were made on over 13,000 acres (5,000 ha.). In general, rust on ribes was light throughout the western white pine (Pinus strobus) and sugar pine (P. lambertiana) region, and while the rust is spreading from previously known infection centers, there is no evidence of long distance spread to new centers.
Much of the control and survey work is now contracted rather than done by agency crews and this is apparently reducing costs. There is a wider use of chemicals for destroying ribes and the long-term program of research in this field is being continued. Nearly 800 sample plots have been laid out during the past few years to study the effectiveness and cost of (1) mixtures of 2,4-D and 2,4,5,-T, (2) mixtures of 2,4-D with chemicals other than 2,4,5-T both applied as dilute aqueous (relatively high volume) sprays, mist concentrate (low volume sprays) with oil or water base, and basal stem treatments - all applied to several species of ribes. In addition, a comprehensive research program dealing with physical and chemical methods of eradication and with ribes ecology in relation to control work and white pine management is under way. A great many sample plots are under observation to determine effectiveness of control, relation of different degrees of logging and of fire to germination of dormant seed and similar questions.
· Exploratory surveys of the role of forest pathology in future forest practice have been conducted for a number of years in Alaska, covering both the coast forests and those of the interior. A great many species of damaging fungi have been identified and their places of occurrence in different forest types and zones have been at least partly worked out. Many of the organisms are circumpolar in distribution and included in the group are several species which, while not notably damaging in virgin forests, may cause damaging epidemics in disturbed forests, that is, those logged or burned over. Many of the forest species are subject to wood-destroying fungi and, since the loss of heartwood begins at relatively small tree size, it is probable that forest management will have to work on a basis of better utilization of defective material than by attempting to out it by pathological rotation.
In general, it is evident that disturbance of the forest by fire and logging commonly leads to epidemics of destructive diseases, and thus great care and continuing study of the problem are necessary. It would be desirable to reserve areas of virgin forest in the different types and zones so that the studies in forest pathology may go ahead concurrently with the programs of utilizing the great forests of Alaska which are now being undertaken.
UNION OF SOVIET SOCIALIST REPUBLICS
· The Ministry of Forestry, in its report which appeared in January 1951 on the progress of forestry during the five-year period 1946-1950 states that there has been a marked improvement in reducing forest fires. If 1947 is taken as the base year, 39, 61 and 50 percent of the area was burned over in 1948, 1949 and 1950 respectively. Forest fires, however still continue to cause great losses to the national economy, and the fight against them continues to be the Ministry's most important task. The following are among the fire control measures adopted. (1) On the basis of the close relationship between meteorological factors and inflammability calculated by Prof. V.G. Nestorov, long and short term prognoses of the approaching dangerous fire conditions to forest administrative units throughout the country. (2) Aerial patrol for speedy detection of incipient forest fires is widely used. Over a large area of northern European Russia Siberia, and the Far East this is the only available means of discovering and locating forest fires. (3) The use of aviation in actual fire suppression. Specially trained firemen are dropped from airplanes either direct to the source of the fire or at the nearest settlement. In the former ease they try to extinguish the fire by their own efforts: in the latter, they organize the local population for fire fighting. (4) Within recent years, liquid solutions of different chemicals have been widely used either for extinguishing fires directly or for creating fire-proof lanes to obstruct the spread of fires. The chemicals most commonly used are calcium chloride, magnesium chloride, ammonium phosphate, ammonium sulphate and similar fire extinguishing chemicals. To facilitate the use of chemicals in fire suppression some 400 so-called "chemical stations" have been established. At each station there is usually a crew of 6-8 men, equipped with knapsack sprayers or pumps. (5) The forest communication system has been extended. From 1947 to 1950 some 5,000 km. (3,000 miles) of telephone wires were strung, 2,400 telephones installed, and 527 radio stations put into operation. In 1951 an additional 3,000 km. (1,200 miles) of telephone wires are to be strung and 200 more stations set up.
· Considerable progress has been made during the last five years in controlling insect damage and the diseases of forest trees. The maintenance of a minimum of sanitary conditions has been made obligatory for all forest of the U.S.S.R. Stress has been laid on the importance of observations over a wide area on the health conditions of the forest, a system has been devised for reporting promptly the appearance of serious damage by insects and diseases, continuous stationary observations have been instituted on the most dangerous insects and diseases and a series of preventive and exterminative measures applied. The work was carried on most intensively in the forest plantations of the prairies. During four years (1947-1950) forest pathological reconnaissance covered more than 10 million hectares (25 million acres); aerial reconnaissance, with checks on the ground, extended over an area of 26 million hectares (64 mill on acres), and preventive and exterminative measures were applied to more than 1.3 million hectares (3.2 million acres). Aerial reconnaissance and the use of poisonous chemicals became very common. Of the chemicals, DDT and benzene hexachloride were found most effective in combating insects either by dusting from the air or by application on the ground. The latter treatment proved especially successful in combating insects attacking the roots of trees, resulting in a high survival of trees planted in soils infested with June bugs and similar insects. At present a great deal of attention is being given to finding effective means of protecting acorns and seed of various species of trees and shrubs from attacks by insects or disease.
UNITED STATES OF AMERICA
· Recent research dealing with hardwood stands in the Central States indicates that reasonably effective volume tables can be constructed from aerial survey data whereby the total per acre volume can be determined with satisfactory accuracy. Volume per acre depends on correlation of crown diameter, average stand height, and percentage of crown cover, and may be expressed either as board feet or cubic feet. The measurement or estimation of these variables from photographs is subject to variations, depending on the observer, but these individual variations can be adjusted. The tables reflect average conditions over wide areas and give the total volume of all species, since it is impractical to determine species from photographs. Thus, adjustments in the general tables are necessary for local use, but these can be made much more economically than constructing new tables.
The great advantage of the tables is that they give approximate volumes from aerial photographs with little or no ground work. Thus for certain types of inventory, their use seems to offer a chance for speedier and less costly work than before.
· The traditional method of measuring National Forest timber sold to operators has been by scaling on individual logs. This is not only costly, but is unproductive in that it diverts skilled manpower from the essential job of supervising sales and seeing that needless damage to residual stands and young growth is avoided and that other protective measures are carried out. The current expansion in timber business on National Forests, and the increasing difficulty of obtaining appropriations to hire competent officers needed by traditional methods, has emphasized the need for less expensive methods of measuring the volume of timber cut in a satisfactory way.
One such method - determination of volume by sample tree measurement - has recently been studied in the Northern Rocky Mountain region. The starting point is the feet that good silvicultural practice demands that each tree to be cut shall be individually marked and therefore a competent officer must go over the area in any event. The plan depends on a system of sample tree measurement done concurrently with the marking. The cost of marking averages 8 gents per tree, the cost of measuring a selected sample number of trees is about 12 cents per tree and the saving by sampling is estimated at about 10 cents per tree.
The size of the sample to be taken depends on the accuracy desired the amount of variation in tree volumes from the average, and the degree of stratified sampling - that is, the breaking down of the total population into two or more general size classes. The accuracy desired depends both on the stumpage rate paid, already high and getting higher, and on the degree to which individual purchasers are prepared to accept inevitable variations in volume as determined by sample trees in comparison with log scaling. The seller can consider that his interests are protected by the averaging out of a large number of sales, but the purchaser naturally is not interested if an overscale on his sale is offset by an underscale somewhere else. The variation of tree volume expressed as a co-efficient of variation can be determined by well-known methods or by the simpler process of the judgment of experienced officers.
The number of trees required in an adequate sample increases at more than an arithmetic ratio as accuracy standards increase and as the total number of trees to be cut increases, and the sale officer can thus determine how many sample trees will; be required. The individual bias in selecting sample trees is off set by stratified sampling in which the large trees which contain a high percentage of the volume will have a higher percentage measured as samples than medium size and small trees. Then some system for random selection of trees to be sampled needs to be enforced. A further element of inaccuracy arises from the errors in existing volume tables when used for particular local stands, and until form glass volume tables are used, this cannot be wholly overcome. But experienced officers can make adjustments if they know the basis on which the tables were constructed.
As when sealing individual logs some check of the results will be necessary, but from the standpoint of the seller the method of sample tree measurement as worked out in detail in this region is practical, economical and accurate.
UNITED STATES OF AMERICA
· The Pacific Northwest Forest and Range Experiment Station has carried on an extended research project in applied forest management in the Douglas fir (Pseudotsuga taxifolia) region. Practices that appear promising are tried out on commercial scale experimental logging operations in co-operation with both private and national forest managers. The small-scale sample plots which have been under observation for more than 30 years have given many promising leads, but show above all that there is no one best method for the process of changing old virgin forests into thrifty managed forests, because of the great variety of stand, site, ground cover conditions. On the contrary, flexible combinations of staggered setting, clearcutting, and partial cutting by tree selection must be worked out in relation to specific conditions. The main objectives sought in clear-cuttings and the techniques by which they may be reached included: (1) harvesting the mature crop with the most effective possible utilization; (2) providing abundant seed for regeneration (3) providing favorable seed bed; (4) obtaining optimum species composition in new forests; (5) avoiding creation of excessive fire hazard; (6) minimizing windfall loss in the remaining stands; (7) avoiding severe erosion and maintaining favorable watershed conditions Although the results of many partial cuttings by tree selection have repeatedly been unsuccessful, there is a place for such cuttings when made on a stand improvement for example, by harvesting low vigor trees and by making a out of not more than 30 percent of the standing volume, by returning fairly frequently to cut additional volume as conditions justify. The principal steps in applied management research are, first, an inventory and silvicultural analysis of the specific areas, then topographic mapping, study of ground conditions, classification into areas to be logged by different methods preparation of a road and logging plan, and finally, the marking out of the plan on the ground to make final adjustments in the location of roads, landings, cutting boundaries, and timber to be removed by tree selection.
UNION OF SOVIET SOCIALIST REPUBLICS
· Wages of workers in forest operations are based on piece work or according to the job with progressive bonuses for work in excess of the agreed standards. In forest planting operations, for instance, bonuses are paid in excess of the regular wage depending on the percentage survival of trees in the plantations after the first, second and third year after planting. By this system of payments, the Ministry of Forestry claims that the average level of efficiency of the forest workers has been markedly increased. Thus when the Ministry of Forestry was first created the average efficiency of the forest worker was 90.6 percent of the fixed norm, at the end of 1947 it rose to 97 percent, in 1948 to 104 percent, in 1949 to 106 percent and in 1950 it reached 107 percent.
UNITED KINGDOM
· The Timber Development Association, Ltd., has summarized information available on the economies of the substitution of other materials for timber. Timber imports have been drastically cut in recent years, due to a stringency in foreign exchange rather than to a shortage of world supplies of timber. At the same time, the importance of coal and steel to the country's industry and credit cannot be exaggerated and although the relation of these materials to timber is not always obvious the relation exists. Deficiencies of timber imports have been met by rigid economy in: (1) refinement of design and elimination of wasteful forms of construction, (2) prohibition of use of timber for non-essential purposes, and (3) use of substitute materials. The limits of development of (1) and (2) have probably been reached.
Steel has been used as a substitute for timber, and is generally more expensive than the timber it is used to replace. For example, wooden window-frames of an ordinary house cost about £18 and steel windows about £24. An annual saving of at least £500,000 a year could have been made by use of wood instead of steel. If the 50,000 tons of steel used in the manufacture of metal doors and windows had been exported to dollar countries, the sale would have produced about £5,000,000 worth of dollars, and imported timber to replace the products would have cost less than £1,000,000 worth of dollars. Steel is the country's most precious material asset, and conserving it for export is of the greatest importance. American and British construction experience shows that, in many types of structural assembly, a ton of timber will do about 15 percent more than a ton of steel, and the cost per ton of imported timber for such uses is much less than the equivalent value of steel.
Cement has been used as a substitute and official efforts have been made in the production of pre-stressed concrete joists which involve the building of special plants and therefore the use of scarce materials and labor. Ordinary reinforced concrete is about 5 times as heavy as timber members of the same strength and even pre-stressed is about twice as heavy. Pre-stressed concrete sleepers cost about double the price of timber.
The total demand for cement can at the moment only be met by imports. Coal is a limiting factor in the reconstruction of British industry, and studies show a consumption per sq. yd. of 1.70 cwt. (190 lb.) for steel framing covered with asbestos-cement sheeting; 0.56 cwt. (63 lb.) for pre-cast concrete flat slab; 0.45 cwt. (50 lb.) for "in situ" concrete flat slab, 0.40 cwt. (45 lb.) for timber framing and tiles; and consumption of timber framing and shingles or boarding is nil. The substitution of timber for steel for domestic uses would indirectly increase the amount of coking coal available.
Aluminum has also been used in place of timber; it is imported from Canada at a far greater cost than timber, and in finished form is very much more expensive.
Studies have been made of the use of steel and softwoods in experimental nontraditional type houses in Scotland. These show a use of steel ranging up to 8 tons per dwelling, compared with ¼ ton in the pre-war traditional house. Of the 20 experimental types studied, 14 used one ton or more of steel. In the traditional house 2.5 standards of softwood were used. Of the experimental types, 13 used 1.5 or more standards. Grants paid for non-traditional houses have been from £70 to £785 per dwelling, with none on traditional type houses. The use of substitute materials is one of the most important causes of increased building costs.
A list of the more common items in which steel and concrete have been substituted for timber shows 128 specific items, taken from all types of building, civil engineering and transport activities, as well as furniture and allied trades.
Conclusions are: (1) that, it is necessary not only to reverse the policy of using substitutes for timber, but to extend the use of timber to new applications which in the past, have been reserved for steel, reinforced concrete and aluminum; (2) British industry can only be restored by increased production of coal and steel, and the most wide-spread use of timber instead of these vital materials will not only reduce imports but will increase exports, save manpower, and reduce the cost of living.
BELGIAN CONGO
· Since it has become known that mixtures of forest species can be pulped to produce various kinds of paper, practical ways of organizing pulp manufacture have been under investigation. Similarly the preparation of pulp from papyrus which extends over enormous areas in the region of the Kisale Lakes, has been examined, and a syndicate has been set up to study the cultivation of papyrus in the Belgian Congo.
A body of Belgian financiers is particularly interested in the production of wood cellulose, with the help of an American agency and with the support of the authorities. The possibilities for pulp are virtually unlimited, and the installation of several factories in the Belgian Congo is contemplated.
CANADA
· A Canadian report to FAO states that the relation, previously established, between the density of wood and its dielectric properties has been confirmed. This information is of value in the industrial application of dielectric heating to the edge-gluing of lumber. It serves in determining optimum glue spread, power requirements, and the durability of joints made by this process. Development of a method for measuring the radio-frequency energy expended in a gluing operation is an important advance, as it will have a direct influence upon the application of the dielectric technique to industrial gluing problems.
· Canada and the United States import 99 and 85 percent respectively of their vegetable tannin requirements, largely Quebracho which now commands an almost prohibitive price. The American chestnut, (Castanea dentata), formerly a large source of supply, has been largely eliminated by blight disease. One alternative source is the bark of western hemlock (Tsuga heterophylla) which could, if fully utilized more than fill requirements.
Most hemlock logs on the west coast are floated on ocean water and since the bark absorbs salt, it has been questionable whether such bark could be utilized. A recent study of this question has been made by the Forest Products Laboratory of Vancouver. It was found that: (1) Hydraulic barking is the most advantageous process of bark removal singe the bark is relatively free of wood and the barking process removes a considerable amount of salt. (2) The tannin content of bark from seawater floated hemlock logs is roughly proportional to the time spent in the water. (3) The rate of loss of tannin from floated logs is about the same in fresh and salt water and is at the rate of 5 to 10 percent per month. The bark acquires the major part of its salt content during the first month. (4) A laboratory method has been devised for ion-exchange treatment which successfully prepares the bark for tanning good sole leather. (5) Results of the laboratory work merit investigation in a pilot plant.
UNITED STATES OF AMERICA
· The U.S. Bureau of Agricultural and Industrial Chemistry, co-operating with industry, has developed a box board made from straw which can replace wood veneer generally used in making wire-bound shipping containers. As much as 1,500,000 million sq. ft. (139,350 million m²) of wood veneer is used annually for wire-bound boxes, and 500,000 tons of straw, would replace the wood. The process uses standard equipment, and the thickness of the board can be varied from 1/6 to ¼ in. (0.40.6 cm.). The problem of cutting the straw board by wires was solved by putting a metal edging on the board. Straw board boxes withstood the standard handling tests.
· The Yale School of Forestry recently released information on the gluing properties of 29 species of tropical American woods as part of the program on tropical woods conducted in co-operation with the Office of Naval Research. In addition Burma teak and American white oak were tested as standards of comparison. Standard procedures are used in selecting materials for testing, preparing them, and in the gluing procedure followed on the instructions of adhesive manufacturers, and in testing procedures on the sample brooks. Results given for each species include the specific gravity on an oven-dry basis, moisture content actual strength in pounds per square inch, and percent of wood failure. Several adhesives were tested, all of which are equally satisfactory Of the species tested, 21 are classified as easy to glue; nine require special care in the gluing operation; and one, lignum vitae, requires special preparatory surface treatment for gluing.
· No economical means have yet been developed for efficient utilization of unavoidable waste produced in the manufacture of redwood lumber, although the existence of chemical constituents which render the wood resistant to decay indicates that they could be valuable as preservatives and insecticides, and the high phenolic content indicates the possibility of isolating raw materials for the production of phenolic resins.
The Stanford Research Institute has conducted a preliminary evaluation of the possible extractives. Mill waste is rendered susceptible to saccharification by hogging the waste, pre-steaming and extraction with water and with dilute caustic. The extract thus obtained contains various recoverable chemicals of a phenolic nature, including furfural, phenolics, neutral oils, charcoal, gypsum and lignin, the latter yielding 562 lbs. per dry-ton of waste (approx. 281 Kg. per m.t.) Destructive distillation of the extract, solids and lignin residues would be required to recover the available chemicals. Indications are that total recovery, including sugar, might have a market value of nearly $ 20.00 per dry ton.
CZECHOSLOVAKIA
· In 1948 the Czech Government completed and fulfilled its two-year plan to the extent of 105.9 percent. In 1949, it entered on its first five-year plan (1949-53). The nationalized wood-using industry is now said to comprise 744 plants of every description and employs 56,000 workers and other personnel. The industry is supplied principally by domestic raw materials. According to the latest official statistics (1948) one-third of the entire Czech Republic, or about 4 million hectares (10 million acres) is covered with forests. Conifers (spruce) predominate, occupying 46 percent of the total forest area, hardwoods (chiefly oak and beech) 26 percent, mixed forests 13.6 percent, and the remainder (shrubs) 14.4 percent. The average volume of timber cut each year is about 11 million m³ (388 million cu. ft.); of this 73 percent is softwood and 27 percent hardwood timber. It is evidently intended to maintain this average singe during the five-year period it is planned to cut only 55.18 million m³ (1,948 cu. ft.) of timber made up as follows: 27.2 million m³ of round logs, 1.8 million m³ of railroad ties 3.4 million m³ of mining timber, 8.8 million m³ of pulpwood, 1.3 million m³ of other constructional timber and 12.68 million m³ of firewood. The wood-using industry hopes to increase its output by 30 percent over that of 1948 and 48 percent over the prewar output, not by increasing the total out, but by more rational utilization of production. The cut is to remain not only within the limits of growth, but some 231,000 hectares (570,801 acres) of new land are to be brought into forest cultivation by 1953.
The character of the products now put on the market differs substantially from that of previous years. Sawmilling is assuming an important role. In 1949, for instance, sawmills delivered 3,165.000 m³ of sawn lumber and ties. The manufacture of veneer is being stepped up as shown by the following figures:
|
|
1947 |
1948 |
1949 |
1953 |
|
(estimated) |
||||
|
Veneer glued in 1,000 m³ |
50.0 |
70.9 |
84.1 |
111.5 |
|
Veneer not glued in 1,000 m³ |
6,485 |
11,279 |
- |
15,200 |
Furniture-making features prominently in the five-year plan owing to the great abundace in Czech forests of beech, which is particularly suited to this industry. Another new industry is the manufacture of prefabricated houses and other structural parts as a means of meeting the housing shortage. Efforts are being made to bring wood-using industries to the more remote and economically less developed regions of the country.
NEW ZEALAND
· The Government set up a Tax Committee of Enquiry early in 1951, and the Forest Service, which has been greatly concerned over the unsatisfactory state of forest taxation, brought this subject to the Committee's attention. As a result, the Committee now considers the subject of forest taxation so important that it has set up a special Sub-Committee to investigate and report in detail. It is hoped that as a result of this enquiry the remaining anomalies in forest taxation will be abolished.
UNION OF SOVIET SOCIALIST REPUBLICS
· The U.S.S.R. has set aside a large forest area as "protection forests" - an area, it is claimed, as large as the entire forested area of western Europe excluding Scandinavia. The regulations for the management of these "protection forests" are very rigid. Only sanitary cuttings, i.e. removal of dying and diseased trees, are allowed; and thinning and cultural operations tending towards converting pure conifer stands into mixed stands, and one-storey forest into two or three-storeyed forests. All clearings in the forest must be planted up. The practical and silvicultural value of these regulations is now seriously questioned, especially the elimination of commercial cuttings, as this leads to a large accumulation of overmature trees. At a particular ace these trees begin to deteriorate the stands thin out and lose their protective importance, the overmature trees become easy prey to insect and fungus infestations and it often becomes necessary to cut out entire stands and resort to replanting, thus defeating the purpose intended In addition, by eliminating commercial cuttings, the creation of mixed many-storeyed stands is hampered. Important economic considerations, therefore, weigh heavily against the elimination of commercial cuttings in "protection forests."
By eliminating commercial cuttings the country loses between 20-30 million m³ of structural timber each year in the form of annual growth. Sanitary cuttings remove only a small percentage of this annual growth and such timber has already lost much of its value. For these reasons there is a growing demand that commercial cuttings of mature timber be allowed in "protection forests" - not clear cuttings, but gradual selective cuttings.
