Friday, January 16, 2015

Tree Rings Again

Another post on tree rings. A comparison of Douglas fir from a sandy east facing slope near sea level and one from an overall southwest aspect but a flat location shows marked difference in growth rate. I estimate the trunks to be about the same but I did not nail the size and the hands for scale are from different humans.  

Douglas fir - sandy soil on Camano Island

Douglas fir - bedrock on Orcas Island

1 comment:

Geoffrey Middaugh said...

The site is important, but for trees its also what's happening to its neighbors. From my observation, the tree grew well for its first 15-20 years probably after a clear cut or fire (even age). Then it got crowded, the canopy closed, and things slowed down. Then it was released, or became dominant in the 'hood, and it took off again. Doug-fir are classified as intermediate shade tolerant.