Volume Estimation of Cutting class III by means of aerial photographs

1991

28 S.

3 Abb., 17 Tab.

Bandaufführung

2693

37935

Cutting class (relative age class) and tree species group have a significant effect as independent variables in a regression function for prediction of stand volume by means of aerial photos. A Norway spruce function and a coniferous forests function for cutting class III (young forests, with a mean height roughly abouve 7-8 m) are developed. The functions are based on field- and photo measurements on 151 plots of size 1000 m2. The independent variables are Lorey's mean height measured in the field, and photo estimated crown closure. Due to errors in photo interpretation of tree species mixture, the coniferous function should be used for prediction purposes in all stands. Two persons have predicted the volume in 25 tallied test stands by means of photo interpretation and the coniferous function. The standard deviation for the differences between photo-estimated and tallied volume is 4.4-4.5 m3/decare (33.1-33.8%).