such cases crown diameter measurements are not reliable due to various 
factors. Better results could be obtained in coniferous forests of 
Himalayas and with Sal and Teak species provided suitable scale and 
quality of photographs are available. The use of this parameter has 
been discouraged in forest type classification in forest inventories. 
"Crown Closure Estimations" 
The parameter has provided a good substitute for conventional 
ground density and has been practiced in India in 2 0% classes. On 
medium and large scales it has given good results while on small 
scales it had to be limited to three classes only. Usual methods of 
dot grid and artificial nomograms provided reliable results. It was 
commonly used for forest type delineation and for stand aerial volume 
tables. JOSHI ( 4 ) found no significant difference on scales 1:5 000 
to 1:2 0000 and photo crown closure and ground density estimations were 
within 2 0%. It is experienced that better estimates are obtained on 
aerial photographs than from the ground due to better appreciation of 
the overall stocking of the crowns on photo. This is true for the bulk 
of deciduous forests of India where the forests are varied and irregular 
and have a tendency to occur in clusters and poor overall impression is 
experienced on the ground. 
"Tree Counts" 
The experience is in general agreement that counting of trees 
on aerial photographs is under estimated. On medium and small scale 
photographs the count has never bettered than 6 0 % of the total trees. 
On larger scale (larger than 1:10,000) tree counts were successful upto 
9 0% (Allapalli teak forests). As a part of resource inventories this 
parameter on aerial photos has not been given any importance. 
"Tree Aerial Volume Tables" 
Poor individual tree species identification possibilities on 
panchromatic films have restricted the scope of preparation of tree aerial 
volume tables. Of the species which can be identified an attempt has 
been made for Teak. The important limitations being the availability of 
good quality, larger scale and recent photographs. GUPTA ( 3 ) used 
photo height and crown diameter as initial independent variables and 
correlated with ground tree volume as dependent variable of 148 teak 
trees on 1:10,000 scale. A number of equations between photo height 
and ground height, photo height and ground dbh, photo height and ground 
volume and also photo crown diameter with ground height, dbh and volume 
were tried with initial stratification into converted and non-converted 
crop. No significant result with crown diameter was obtained and best 
results were obtained with photo height and ground volume. The S.E. 
of theregression line ranged from 4% to 24% at 95% probability level 
with a correlation coefficient of 0.4 to 0.8. Efforts for the preparation 
of tree aerial volume tables of Sal and Chirpine are in progress. 
"Stand Aerial Volume Tables" 
The scope for the use and preparation of stand aerial volume 
tables is better than tree aerial volume tables. GUPTA ( 3 ) attempted