C—3a

A. Aerial Forest Surveys " The Congress considers " That aerial photography provides a valuable aid to the preparation of forest maps and forest inventories and " That it is of special value for the surveying of large forest areas, " That, in the present stage of technical development, aerial surveys must be supplemented by examination of the forests on the ground, in order to secure additional information essential to forest management, and " That the choice of aerial survey methods in each country must be governed by the nature of the forests of that country, and 40. " Recommends (a) " That all countries should review their forest inventory procedures in order to ensure that the potential usefulness of aerial survey methods is being fully realized, (b) " That research and development of improved methods and equipment for making and interpreting aerial photographs should be energetically pursued, and (c) " That all institutions for higher forestry education should, where practicable, offer courses in photogrammetry to their students." The national forest survey, which commenced the inventory of all New Zealand indigenous forests in 194-5, has covered more than 1,600,000 acres to date. The current progress (500,000 acres in 1948-49 year) is only made possible by co-ordinated aerial photography and the use of modern statistical methods. New Zealand is represented on a Technical Committee on Aerial Survey of Forests set up by the Government of the United Kingdom, upon the recommendation of the fifth British Empire Forestry Conference. The procedure of the survey is constantly under review to maintain the highest standards. B. Methods of Determining Forest Increment 42. " The Congress, recognizing that knowledge of forest increment is essential to forest management for sustained and progressive yield, and that determination of increment entails the solution of problems of great complexity, " Recommends " That the International Union of Forest Research Organizations be requested to undertake, through its constituent Organizations, an investigation of methods of rapidly ascertaining the increment of forests on a regional basis." The New Zealand Forest Research Institute is a member of the International Union of Forest Research Organizations and would be willing to co-operate in such an investigation, subject to limitations enforced by the nature of podocarp forests. The problem of regional increment in beech forests is likely to claim precedence in New Zealand. C. Comparative Study of Inventory Methods 44. " The Congress reviewed the objectives of the world-wide study of forest inventory methods which had been undertaken by the Forestry and Forest Products Division of FAO." 45. "In this connection some discussion arose as to whether future silvicultural treatments should aim at production of trees of high quality or at production of maximum volume of wood. It was informally agreed that ' quality ' was not the

13