Our national forests

by Richard H. D. Boerker

Figure 28. A planting crew at work setting out small trees. The man ahead digs the hole, and the man behind plants the tree. Wasatch National Forest, Utah

THE ORGANIZATION AND SCOPE OF FOREST EXPERIMENTS AND INVESTIGATIONS

The Need of Scientific Experiments. No science can make progress without intensive experiments and investigations, least of all a new science like forestry. The science of forestry as it has developed in Europe is several hundred years old, but the science of forestry as applied to American conditions is still in the infancy of its development—probably not over 20 years old. Therefore we know very little about our trees, our forests, and the wood which they produce, and the professional foresters who handle the scientific work on our National Forests are very much handicapped. To supply the needed information about the requirements of many of our tree species, the uses to which their wood can be put, and many other related subjects, the Forest Service has established 8 Forest Experiment Stations (recently reduced to 6) and one Forest Products Laboratory. It has become the business of these institutions to study the laws governing the life of the tree and the forest and their effect upon the final product—wood. The Experiment Stations are working on the solution of the many problems which confront the Forest officers in the management and the protection of the National Forests; while the Forest Products Laboratory was organized to promote the most profitable utilization and the most economical disposition of the forest products of the National Forests. Both sets of institutions, in doing this, are helping materially to build up the science of American Forestry, which even to-day can hardly be said to exist.

The Science of Growing Timber. In order to better understand the many diversified problems which are being studied at the Forest Experiment Stations, it is necessary to give the reader a few ideas concerning the science of forest ecology. This science is the basis of all problems dealing with the growing of timber and is therefore a study of the utmost importance to forestry. Forest ecology is the study of the relations of trees and forests to their surroundings. By surroundings (or environment) we mean all the factors which influence their growth and reproduction, such as soil temperature, soil moisture, soil texture, rainfall, light, wind, air temperature, relative humidity, altitude, slope, exposure, and surface. Forests, we must remember, are not warehouses of standing logs; they are not merely aggregations of individual trees; but they are complex communities of living organisms, which are affected in many ways by climate and soil and which, in turn, affect in no small degree the climatic and soil conditions in their immediate vicinity. The forester cannot treat the forest as an aggregation of individuals, for forests have laws which govern their behavior which are entirely different from those that govern the individual tree. Some foresters and botanists prefer to call this science by the name of "tree sociology," and they compare it with human sociology. Individuals, as we well know, are governed by different natural laws than communities. Just so with trees and forests. In order, therefore, to grow a never-failing supply of timber intelligently and economically we must understand these complex organisms and communities, we must study their behavior under different soil and climatic conditions and ascertain the conditions under which they grow best. Only by doing this can the forester achieve all the objects of forestry, namely, to help Nature to produce more and better timber, in a shorter length of time and at the smallest possible cost.

The experimental work of the Forest Experiment Stations is grouped under such categories as these: dendrological studies, forestation studies, studies in forest influences, studies relating to forest management, studies in forest protection, commercial tree studies, and grazing studies.

Dendrological Studies. Dendrological studies include studies in tree distribution and wood identification. For each tree species growing in the United States (and there are about 500 of them) it is desirable to know its geographical distribution, its commercial distribution, and its local distribution. The first of these deals with the entire range of the tree by geographical divisions; the second of these with the distribution of those bodies of timber that are of commercial quantity or size; and the last deals with the distribution of the tree by local divisions, such as lowlands, slopes, ridges, valleys, plateaus, etc. This information is usually placed on maps for permanent record. Observations by Forest officers on the many National Forests are recorded by them and at the first opportunity sent to Washington. Very often it happens that the range of a species of tree is considerably extended and that a tree is found growing in a locality where it was never reported from before. The identification of woods is done at the Forest Products Laboratory. The distinguishing characteristics of the woods of many American tree species have been determined. The wood of different trees is studied under the microscope to discover in what way it differs from other woods closely related. Many such results are published for the benefit of both the lumber dealer and the general public in the form of bulletins. Both the subject of dyewoods and that of the many woods now sold as mahogany have been investigated in this way. The resulting data have been used by many companies and have helped to protect the public from frauds.

Seed Studies. Experiments in reforestation are grouped under seed studies, nursery studies, and sowing and planting. Considerable work has been done in developing the best methods of seed-extraction. Much valuable information has been gathered on the largest amount of seed that may be extracted from pine cones of different species per unit of time at different degrees of temperature; the maximum temperature which may be applied to seeds of different species without impairing their vitality; the germinating power of seed extracted at different temperatures; the comparative length of time required for the germination of seed extracted with or without artificial heat; and the most economical type of seed-extracting plant. Studies have been made upon the comparative germination of tree seeds in the field and the greenhouse. The ultimate success of the plantations being established on the National Forests in a large degree depends upon the character of the seed used. Hence studies are being conducted of the effect of altitude, soil, age of the tree, density of stand, insect damage and disease infection, and other factors that affect the mother tree, upon the character of the seed collected from those trees, and the growth and form of the resulting seedling. Also tests to show the effect of the source of seed on the form and growth of young seedlings have indicated very clearly that with all species the seed grown in the locality where the trees are to be planted give as a rule better results than seed imported from another region.

Nursery Studies. Nursery studies endeavor to show the most efficient methods for growing young trees for field planting for each species of trees. It is of great importance to know how much seed to sow per foot in the nursery beds; what is the best time (spring or fall) for sowing; to what depth the seed should be covered in order to give the highest germination; whether better results are obtained by drill sowing or by broadcast sowing; the best methods of shading, fertilizing, watering, and cultivating the seed beds; the methods of securing the best root development of the young seedlings; the best time and method of transplanting from the nursery beds to the transplant beds; the best methods for retarding spring growth in seedlings to be used at high altitudes; and other problems of similar nature.

Forestation Experiments. Experiments in forestation have, year after year, proven that planting is much safer than direct seeding and ultimately less expensive. For this reason a greater emphasis has been placed upon planting studies. These studies have attempted to show the best season for planting each species; the best methods of planting; the most advantageous classes of stock to use; and what the most suitable sites are for each species of tree.