Oregon’s Department of Forestry on Wednesday encouraged tree and forest owners to watch for continuing drought symptoms like dead tops, dead branches, thinning canopies and stressed cone crops. Given the warm end to last summer and drier than normal winter, the agency expects a higher chance of trees dying from drought or secondary attack by bark beetles this summer.
Oregon Department of Forestry Entomologist Christine Buhl said, “Above-average temperatures this spring mean beetles may come out sooner than normal. If this happens, beetles may attack trees sooner than usual.”
Drought has long-term consequences. Plants and animals are still experiencing the effects from the 2012-2015 drought. Drought damaged trees may have collapsed vascular tissues and fine-root dieback. These tissues and roots absorb much of the water a tree needs. This damage takes time to repair and trees may not fully recover.
Following the 2012-2015 drought, Oregon had one good year of rain. But, it takes more than that for trees to rebound. Last summer ended with a long stretch of higher temperatures and days without much rain. This winter has also had less than normal rain and snow, so soils are not as saturated as expected.
“Given the recent drought and below average rain and snow this winter, trees will likely be drought-stressed this season – unless precipitation boosts back to normal levels,” Buhl said. “What we need is a longer, lighter rain to allow trees time to soak up the water.”
From KTVZ 21 News: https://www.ktvz.com/news/odf-warns-drier-weather-may-bring-more-bark-beetles/737530871