170 foot Doug Fir dying from top down

[dhamblet]

I just had to take down a 170' Douglas Fir (4' at the stump), that was dying from the top down. The top 20 feet had turned brown and it was working its way down and it all occurred this summer. Stump was healthy, no signs of root rot. Cambium at the top showed signs of pest activity -- small trails under the bark but no apparent wood borer activity. We are in Western Washington State on 12 acres and there are a lot more firs close at hand, in fact within 20 feet there are 6 more big firs and hundreds on our property. Anyway, I was wondering if anyone might have a thought what this might be and if I have more of this to look forward to in the future.

 

[Raintree]

 

[dhamblet]

Definitely not lightning struck.

 

[ch woodchuck]

Sounds like engraver beetle.Depending on your rainfall..(not enough)...could be drought coupled with beetle.Local foresty service might be able to ID the galleries or larvae.

 

[Ed Roland]

Cytospora can infect fir. Typical progression of disease is top down. Ipps are specialised now and infest fir. They too kill from the top down. Lots of suspects.

 

[Raintree]

Considerations for a lightning strike:

- 20% of struck trees carry no visible injuries. (Op denies tree being hit)

- Significant factor of probability is height & location. (Op's tree is 170ft)

- Struck trees have inefficient defense systems & are prone to insect attacks. (Op's tree with signs of pest activity)

- Lightning disrupts the vascular system. (Op's tree declining from the top down)

- Lightning strikes are considered an abiotic disorder. (Trees within 20ft of the op's damaged tree have no symptoms)

- Lightning hit can wilt a tree in short period of time. ( op's tree turned brown "this summer")

- Common for lightning to side flash to an adjacent tree then to ground. (Op's tree stump appears healthy)