Prevention of further fir tree death

Asked March 23, 2019, 11:47 AM EDT

Hello, I have 10 acres of land with about 5 acres of fir trees and the balance of oak and grass land. In the past 3 years many firs have died. Is it important to remove the dead trees to prevent disease spread? That is what I have been doing. Please le me know. Eric Gunderson

Lane County Oregon forestry

1 Response

The trees have likely been dying as a result of the drought, so leaving the trees will not spread a disease. However if there are more than 3 trees per acre that are of 12 inches or larger in diameter then it could invite beetles to the property which may exacerbate things. If the trees are drought stressed and a beetle is killing them then cutting and removing the trees from the property will decrease the likelihood that the beetles will outbreak on your property. Leaving the trees on site As they are shown in the picture will not deter beetles either. If there are no signs of beetles then what you are doing is fine as long as your removal of trees isn’t damaging the healthy ones you are leaving behind. If you are seeing signs of beetles then I would recommend trying to get the trees cut into firewood or off the site as soon as you can, typically we recommend before April. If you can’t do that. Then we recommend that you use a capsule called MCH it is a pheromone that deters Douglas-fir beetle from going after trees on your property. Here is some more information and feel free to contact me at 541-579-2150 if you have additional questions. Info on Douglas fir beetle- https://www.oregon.gov/ODF/Documents/ForestBenefits/Douglas-fir-beetle.pdf Info on Douglas fir engraver -https://www.oregon.gov/ODF/Documents/ForestBenefits/FirEngraverBeetle.pdf Info on MCH - https://www.oregon.gov/ODF/Documents/ForestBenefits/MCH_2016.pdf Info on slash management to deter beetles- https://www.oregon.gov/ODF/Documents/ForestBenefits/Slashmanagement.pdf