RESEARCH METHODS IN STUDY OF FOREST ENVIRONMENT. 173 



ity, insolation, wind exposure, etc., be witnessed by photographs and 

 topographic map. The former should be taken from as many posi- 

 tions as possible to show the general position of the station with re- 

 spect to topographic features, to show the position of the trees which 

 may influence atmospheric factors, to furnish a map of the canopy 

 (by vertical view) which affects the insolation at the ground, and 

 finally to show in detail the nature of the ground and ground cover. 

 The view of the canopy should be taken as nearly as possible from the 

 position which will be occupied by solar apparatus and evapori- 

 meter. 



The local topographic map should be made on a scale adequate to 

 show in detail the immediate surroundings and those which are close 

 enough to have appreciable effect on insolation, wind velocity, etc. 

 Especially when two or more stations in close proximity, but different 

 presumably in some essential aspect, are being studied, should the 

 map be made full enough to bring out clearly the contrast which 

 exists in conditions. In such cases a joint map for the several sta- 

 tions may well be used. Such maps should, if possible, be restricted 

 to the size of the tabulating forms used. 



Form 1. 



[U. S. Forest Service, Physical Survey.] 



DESCRIPTION OF OBSERVATION POINT, LIMITED AREA, TREE ENVIRONMENT. 



Project 



Station No Area involved , 



Forest type Absolute elevation 



Permanent sample plot No Block No 



National Forest Nearest post office 



County State 



Legal location Exact location 



TOPOGRAPHIC FEATURES. 



Aspect Gradient 



Distance from ridge Distance from channel 



Elevation above water Wind exposure 



Air drainage '-our lit ions 



Elevation of horizon t<> east ; west ; north ; south 



Character <>r topography ' 



FOREST ENVIRONMENT. 



ice "i aearesl trees to north ; east ; south ; wes( 



Height 



Diameter Trees per acre 



Stand, feel i>- m Stand, cubic feet 



h pate; height, diameter, or cubic feet per a. a 



Shading, amounl P'rom trees on 



Light ;ii the ground, pet cenl Determined by 



