Wednesday, March 4, 2015

Fire and Forests on San Juan Island

Fire played a large role in shaping the landscape of San Juan Island and likely lots of other areas in western Washington. Tom Schroeder has assembled a site (http://www.rockisland.com/~tom/)devoted to observations and interpretations he has made  on the San Juan Island forests that is very consistent with my own observations and has greatly aided me in understanding the forest ecology of the San Juan Islands. 
 
On a recent venture to San Juan Island I passed through a mix of fire scarred trees with a mix of old growth. Most of this forest was Douglas fir. But with the dry aspects of the site and thin soils areas of open ground still persist. 
 
Sam sniffs the ground near a fire scarred Douglas fir
 
Weather beaten firs on the upper slopes of a bald area

Old Douglas fir with very heavy limbs would have had no appeal for lumber value

More fire scars

Large fir on summit



Heavy limbed Douglas fir
No need to loose limbs when growing on open ground 

Large old snag

Open meadows and old growth firs and snags

Another fire scarred tree

Older fire scarred tree with younger trees and open understory 

I did have some historic information that this area was impacted by multiple fires well into the 20th century. A review of aerial photographs showed a slow encroachment of forest into open ground as fires became less frequent and grazing and logging diminished.

1 comment:

Geoffrey Middaugh said...

Have you ever seen any Ponderosa Pine on the Islands (not introduced). Also, ever find any foxtail pines, and their sisters bristlecone (aristata), limber, or white bark? They could be there at elevation, on the harshest sites. Just like the geology, the islands are a convergance of a lot of biophysical forces--wet dry, elevation, aspect, soils, sunlight, etc. And of course fire.