PIERRE AUGER
A survey, Current Trends in Scientific Research, which analyzes the main trends of inquiry in the field of the natural sciences, the dissemination of scientific knowledge and the application of such knowledge for peaceful ends, has recently been published jointly by the United Nations, New York, and the United Nations Educational, Scientific and Cultural Organization (UNESCO), Paris. The volume, which is not only the first of its kind but is also likely to be one of the most important basic scientific works of the coming decade, has this to say on trends in research related to forestry and forest products.
Natural science applied to forestry
BASIC to effective management of soil, water, forest and grass resources are current studies of the factors of environment. These include research in soil relations to determine those characteristics of forest, brush and rangeland soils that affect their hydrology and stability, with special regard to infiltration of water, storage of moisture and percolation and erosional processes. The elements of local climate as affected by vegetation types and conditions and changes in such vegetation are studied by measurement of soil and air temperatures, precipitation, wind movement, snow storage, humidity, evaporation, and radiant energy under various topographic and geographic locations and under natural and modified vegetation conditions.
Evaporation-transpiration losses are being investigated with special effectiveness. The establishment, development and yield of herbs, grasses, shrubs and trees are examined in the light of these weather factors. These results in turn are integrated into studies of rehabilitation, protection and improvement of soil and vegetation to achieve conservation through careful use of land and water, and to prevent excessive erosion and stream sedimentation.
Recently through the use of radioisotopes much of value is being learnt of the physiology of trees and shrubs with regard to nutrient requirements and water conduction. Flowering, fruit and seed production, and effects of growth-promoting substances in vegetative propagation are being studied with good effect. Studies in photosynthetic efficiency and photoperiodic response of forest trees are making clearer the question of light requirements for growth, particularly in relation to competition among trees in forest stands.
Progress is marked in genetics research in variation and selection, manner and strength of inheritance of economically important factors such as fibre length and thickness, and in production of interspecific and intraspecific crosses for superior characteristics of form, growth rate, and resistance to pests.
The phylogenetic relationship between species is being studied, in the case of the genus Pinus, for example, on the basis of their oleoresins. The task of identification, classification, and distribution of herbaceous and shrubby forage and range vegetation and of forest trees continues in its unspectacular, but highly important, methodical course.
The silvics, or study of establishment, growth and development of trees and forests, is receiving concentrated attention locally as the foundation for silvicultural practices. Special effort is devoted to the effect of such silvicultural practices as thinning, and use of controlled or prescribed burning on the productivity of forest soils.
Protection of forests and ranges against fire, diseases and insect pests is the subject of research into such elements as:
(a) fire behavior, fire-danger rating, psychological factors in people's motives and habits for preventing fires, use of aircraft, chemicals for firefighting, beneficial use of fire, lightning prevention and cloud seeding; the pathology of foliage diseases, rusts, cankers, dieback and wilts, malformations, decays, and root ailments, genetic resistance, disease survey techniques, seed and seedling pathogens, rot of wood in transit, storage, processing and use;(b) the incidence and behavior of bark beetles, sawflies, spruce bud-worm, weevils and moths, and the interrelationship of insects and diseases as in the case of elm phloem necrosis, Dutch elm disease, and oak wilt. Special attention is being given to the prediction of epidemics and to the chemical and biological control measures against diseases and insect pests.
Forestry science proper
The management of forests and ranges for the volume and quality of product desired at the time required is the integrated result of research in silvicultural and vegetational control methods. Studies are accordingly being made of harvesting techniques which will assure regeneration of desired species and maintenance or increasing of soil productivity. This involves research into species composition, stocking density and age-class distribution for each major forest type and condition. Such cultural techniques as pruning, thinning, and use of arboricides and mechanical means for stand improvement through elimination of undesirable species and individuals of inferior form, are the subject of local research of an applied nature.
The control of grazing on forest and open ranges to attain sustained yields of nutritious forage and efficient livestock production at maximum levels consistent with soil and water conservation requires careful investigations of such elements as season, intensity and system of grazing, forage value of range species in terms of herbage, yield, digestible nutrients, or undesirable properties, standards for judging current condition and productivity of specific range types, and of effectiveness and costs of supplemental food or minerals, and water developments. In this field a also, investigations are carried on with regard to forage and other improvements in the habitat of game animals for hunting.
Considerable attention is being given to the artificial establishment of forests through planting which involves concentrated research in seed collection and handling, nursery practices, site preparation and direct seeding and planting methods, as well as more basic studies of species adaptability, both native and exotic; production of seed of superior genetic strains and individuals in tree seed orchards; and spacing requirements in relation to pruning and early thinning for specific products.
A special form of tree planting to protect agriculture, involves careful studies of shelterbelts and windbreaks, particularly in areas and under conditions not favorable to tree growth. Tests are made of native and exotic species, methods of planting and care, and of shape, size and direction of belts in relation to modifying wind movement to reduce excessive. evaporation from crops and soil.
Systematic mathematical research is being carried out on such problems as volume estimation, growth, mortality, defect, and yield prediction, sampling to determine log and standing tree contents, and inventory methods for appraisal and management purposes.
Considerable research of an applied character is done in adapting engineering techniques and design of machinery and equipment to the needs of forest harvesting and cultural measures in the forest. Although it is largely mechanical, the natural science aspects of forestry guide the studies which are conducted to render forest operations more efficient from the labor-input angle and less destructive to the residual forest from a biological standpoint.
Primary forms products
Research continues into the structure and identification of woody species, their physical and mechanical properties, the factors affecting the strength of wood, machinery and wood-working qualities, finishing, gluing, veneering, seasoning, fire-resistance treatments, preservation, chemical properties, and suitability for pulp and paper, and hydrolysis. Of late, increasing attention is being devoted to studies of the electrical properties of wood, vibrational characteristics, and effect of temperature on strength which are important in improving kiln drying and preservation.
An important field of investigation is the variation in structure, chemical composition and properties related to growth conditions, particularly as regards soil properties, spacing and age of trees, elevation, exposure, and climate of the growing site, as well as the effects of thinning, pruning, intermediate cutting, and heredity.
Great advances have been made in developing a variety of new wood products in the form of fibreboard, particle board, and combinations of such reconstituted materials with plywood and paper. This involves careful research into the effect of particle size, kind and shape, adhesives, and processes. Investigations are aimed at improving processing and developing new pulp and paper products, and discovering the chemical microstructure of wood. Research into the colloid chemistry (fundamental surface chemistry) of wood has opened up new possibilities through such studies as the absorption of water vapor at different temperatures for calculating bonding energies, the bonding of concentrated alkalies by cellulose using radioactive tracer techniques, diffusion of material through wood, limiting sizes of molecules that can penetrate and swell cell walls, the change in molecular weight of cellulose accompanying hydrolysis. and the distribution by size of pit-membrane pores which control flow through wood.
Similarly, efforts are continuing in modifying properties of wood for special uses, including stabilizing dimensions of wood based upon treatment with wood-derived furfural and its conversion to a resin within the structure: altering resin-treated woods for molding purposes. The chemistry of wood preservatives is receiving an increasing amount of attention, particularly as to their toxicity toward wood-destroying agencies to prolong the life of wood in use.
The merging of the results of these investigations with the information obtained by the silvicultural. research worker will inevitably lead to a greater variety of marketable wood products and the more profitable and effective management of forest vegetation, particularly in the underdeveloped forested regions of the world.
