Fifth World Forestry Congress
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Proceedings of the Fifth World Forestry Congress VOLUME 2 University of Washington, Seattle, Washington United States of America August 29September 10, 1960 I CONTENTS of VOLUME 2 Page Section II.Genetics and Tree Improvement 675 Session A.Progress in Tree Improvement and Proposals for Inter- national Cooperation 675 Réalisations en matière d'amélioration des arbres et propositions de cooperation internationale Adelantos en el Mejoramiento de Arbolesy Proposiciones para la Cooperación Internacional Session B. 716 Session C. 775 Section III.Forest Protection 833 Session A.Weather and Climate in Forest Protection 833 L'incidence des conditions atmosphériques et du climat sur la con- servation des forêts El Estado del Tiempo y el Clima en Relación con Ia Protección de Bosques Session B.Forest Pathology 868 Pathologie forestière Patologla Forestal Session C.Forest Entomology 924 Entomologie des foréts EntomologIa Forestal Session D.Forest Fires 971 Incendies de forêts Incendios de Bosques Section IV.Forest Economics and Policy 1007 Session A.Policy and Economic Problems 1007 Politique forestière et probièmes économiques PolItica Forestal y Problemas Económjcos Session B.Supply, Demand, and Marketing of Forest Products 1048 Approvisionnement, demande et marketing des produits forestiers Oferta, Demanda y Venta de Productos Forestales Session C.Institutional Arrangements for Forestry 1096 Dispositions administratives visant la sylviculture Medidas Forestales Institucionales Session D. How To Achieve Better Management on Small Wood- lands 1137 Comment améliorer l'aménagement des petits terrains boisés Metodos para Mejorar la Administración de Bosques Pequenos Section V.Education (for Countries With Newly Developed Forestry Programs) 1183 Session A.CriteriaforDeterminingTypes,Size,and Scope of Programs 1183 Critères destinés a determiner le genre, l'envergure et la portée des programmes sylvicoles Criterio para Determinar los Tipos, Amplitudy Alcance de Planes SilvIcolas Session B.Developing Technical Education Programs 1210 Establissement de programmes d'enseignement technique Planes de Desarrollo de Enseñanza Técnica Session C.Enlisting Support and Participation in Forestry by Landowners and the Public 1244 Nécessité de s'assurer le concours et Ia participation du public et des propriétaires terriens en matière de sylviculture Desarrollo del Interés de Terratenientes y del Péblico Respecto a la Necesidad de la Silvicultura Section VI.Forest Products 1277 Session A. Wood:ItsStructureand Physical and Mechanical Properties 1277 Le bois: Sa structure et ses propriétés physiques et mécaniques Madera: Su Estructura y sus Propiedades FIsicas y Mecánicas See page 2063, Volume 3, for index of authors. II Section II Genetics and Tree Improvement Session A Progress in Tree Improvement and Proposals For International Cooperation Réalisations en matière d'amélioration des arbres et propositions de cooperation internationale Adelantos en el Mejoramiento de Arboles y Proposiciones para la Cooperación Internacional Progress in Forest Genetics and Tree Improvement CARL SYRACH LARSEN Director, Arboretet, Horshoim, Denmark Life, inallits phases, is the dominion of genetics. Our trees resemble structures or edifices rather more This, in turn, is one of the most powerful natural forces than field cropsstructures which, afterfifty or one and one of the newest sciences of today. The rapid de- hundred years,haveacquiredcertaindefinitechar- velopment of that science has placed in our hands a acteristics. The work of our scientific silviculturist has a valuable instrument which enables us to intervene in and strong resemblance to that of a designing engineer who to influence the capacity for reproduction of plants and must first analyze the materials at his disposal before he animals and modify them to our own needs. can use them in what he desires to construct. We face, The uses to which plants and animals may be put, in other words, technical research with a very practical together with the possibilities which we glimpse for their purpose. improvement, have resulted today throughout the world At our disposal, on the one hand, is a large fund of in beautiful gardens, abundant harvests and excellent, knowledge about genetics, botany, and other branches of highly bred domestic animals. Modem tools and imple- biology; on the other, generations of practical experience ments, fertilizers and improved feeding stuffs should by insilviculture.We must unifyallthisfor use in no means be underestimated, but without the improve- forestry without being led to believe that itis a new ments due to genetics, production could not have been abstract science for the gratification of its disciples, how- so enormously increased as has actually been the case. ever charming and fascinating it may seem. A plant or an animal must possess those characters It is characteristic for silviculture, and, in particular, which make it possible to utilize the improved environ- for afforestations,that a new generation begins with mental conditions. human intervention. Whether the seed is sown from an One of the fundamental rules of genetics is expressed by airplane or the plant is raised in a nursery, it is the alter- the equation: nation of generations passing through our hands. More- over, the entire technical apparatus is equally expensive, Phenotype = Genotype + Environment whether the seeds and plants have good or poor hereditary This means that the final result depends both on the characters. From the moment the seed lies in our hand inherent character of the individual as well as on the until fifty or one hundred years later when the full-grown environment in which it develops. Improved environment tree is felled, each valuable characteristic latent in the usually means a continuous expenditure for fertilizers, seed is at work, free of charge, for the larger economic care or other maintenance, but a better genetic effect return.In an industry run on a long-time plan, it is a is obtainable from a once-for-all expenditure for breeding. satisfying thought that itis possible to isolate so very In silviculture, foresters have greatly improved growth small a part of the production process for closer examina- conditions for trees through planting, determination of tion and treatment. the proportion of different tree species to be used, thin- The necessary living material for raising one hectare flings, etc., but this is no reason for ignoring the pos- of mature forest is a quantity of seed not larger than sibilities offered by genetics for improvement of forest can be held in two hands. The single tree which requires trees. We must be wide awake if we are to increase the both a derrick and a truck for transportation to the saw- returns from our forests within a reasonable time. mill has developed from a seed which weighed a few grams When agriculturists and horticulturists improve their or a fraction thereof. One can hardly find any other plants by breeding, the start is made with selection and industry where so small a "cog" plays so important a continued with a fascinating puzzle of cross-pollination. part in so large a production. To make the work less difficult, the plants may be dug up It is no new idea, however, among foresters to try to and collected on experimental areas where they can be influence this "cog" in the forestry production.Long studied and worked over at leisure. The problem is quite before the advent of genetics in the early years of the different for the forester. He is unable to move trees, and present century, there was much discussion in many itis not pleasant for him to picture himself on high, countries on the increased use of seed from the most climbing in the treetops to control pollination. However, valuable forest stands. Experiments with seed from char- this does not mean that he is baffled by the problem. It acteristicallydifferenttreesdemonstratedclearlythe simply indicates that he must try to solve it in other ways. importance of hereditary factors.Due to vague ideas Modern forest tree breeding has fortunately been able to about these matters, there was little talk of "improve- show theseways,andtheirapplicabilityhas been ment" but much of "genetics" in general. "The Eddy Tree demonstrated by the great use which has been made of Breeding Station" (1925) was the first institution with them in recent years. sufficient courage to acknowledge the term in its true sense. Genetics and Tree Improvement 677 Work along the same lines was done at forest experiment creased growth energy by selection and controlled pol- stations, and it was included in forest botanical teaching lination. Experiments from the early part of the century, where the importance of the subject had been recognized. now classical, have proved that characters such as branch- However, in the middle thirties great advances were made. ing, forking, and large and small knots are heritable. Favored by the general development and recognition A difference in ability to withstand affects of soil and of the importance of technical research, there have been climate is known to us from ecotypes of the single species established of late years in many parts of the world a developed in nature.Studies of these was included in great number of institutions whose common aim is a study experiments with forest trees more than one hundred of genetics in silviculture and its economic utilization. years ago.However, recently, our knowledge of these Some institutions concentrate on genetics, others on the has