Show canada uses air air maps ps to plan timber timber aca experiments and field work conducted by the dominion forest service of the department of mines and resources in co operator with various other organizations have pruned proved the value of air photographs for forest surveys in canada already more than square miles of forests have been classified from air photographs and maps prepared for various projects in british columbia saskatchewan manitoba 1 1 ontario quebec new brunswick bruns wick and nova scotia scota scot a these air surveys were later p roved proved to be as accurate as expensive sive ground surveys in all cases where air photographs are used for mapping and estimating timber limber their effect has been to cut ground work to a minimum and to reduce the time required to produce an estimate air photography which has been employed emp loyed with such remarkable success in canada for the preparation of topographic maps now permits a minute examination of timber holdings and is being used to pr prepare forest inventories A good air air photograph faithfully records a wealth of information that may later be employed to classify and map the forest types and by means of special methods recently developed to provide surprisingly accurate estimates of existing stands of timber the estimating of timber stands from the air is an accomplished fact and a science rapidly advancing through research instituted and developed by the dominion forest service to this end methods of determining ter the heights of trees have been developed by measuring their 1 mages images or shadows in the photographs t to not only are air photographs being used to advantage in mapping and estimating forest types but berth holders are employing them tor for actual woods operations equipped with air photographs and a stereoscope the woods foreman can obtain a clear picture of the area in which operations are to be conducted |