RESEARCH SUMMARY 



Mortality rates specify the proportion of trees with a given set of characteristics that are expected to 

 die in a fixed time interval. Knowledge of these rates is the weakest of the key components of yield 

 predictions. This lack of knowledge of mortality rates is primarily due to a lack of suitable data and 

 inappropriate or inefficient data collection procedures. The objectives of this study, stated as questions, 

 are: 



1. Can 1- and 2-year-old mortality be accurately identified on large-scale aerial photography? 



2. Can species identification of mortality trees and of green trees be accurately done on large-scale 

 aerial photography? 



Test results indicate that 1-year mortality can be dated and that, with acceptable accuracy, species 

 can be assigned to green trees and to 1 -year mortality trees on 1 :1 600 and 1 :2400 scale color aerial 

 photography. These results have led to the design of a mortality sampling procedure that uses a quarter 

 mile strip (8 frames) of 70 mm true color aerial photography at a scale of 1 :2400 as the primary sample 

 unit. At a scale of 1 :2400, each frame covers 2.25 times the area covered by a frame at 1 :1 600. Use of 

 this larger sample unit increases the likelihood of including some mortality on each sample unit. The 

 procedure was designed for the Northern Region, USDA Forest Service. 



CONTENTS 



INTRODUCTION 1 



METHODS 2 



Photography Obtained 2 



Photo Interpretation 2 



Ground Examination 2 



RESULTS OF PHOTO INTERPRETATION 3 



DISCUSSION 8 



PUBLICATIONS CITED 8 



