Drought helps stave off some tree diseases, worsens others

Trees aren’t just nice to look at, they play a critical role in our ecosystem. They release oxygen, absorb carbon dioxide, and provide shelter and food for animals. That’s why keeping trees healthy is important for everyone.

If there is a small silver lining to the drought, it’s helping to stave off a deadly tree disease called Sudden Oak Death. The disease has killed hundreds of trees from Monterey County all the way up the coastline into southern Oregon over the last few years. It’s a mold that needs water and moisture to thrive.

During this long drought, many homeowners have found they’ve been able to keep their trees safe by trimming them and allowing wind to pass through. The dry conditions are actually helping these trees. Make no doubt, Sudden Oak Death is still a very serious concern and new areas keep popping up. But without the moisture it needs, it’s not spreading rapidly the way it was a few years ago.

“We are still seeing some activity from it,” said Cal Fire Unit Forester Jonathan Pangburn. “However it has slowed down. It’s caused by a water mold so the drought has actually helped the trees by slowing the spread. However in general, the drought is obviously not very beneficial to the plants that are hurting for water.”

Unfortunately, many oaks face a different problem caused by insects called oak girdling. While those bugs aren’t killing off trees, they are killing off branches. The oaks are expected to survive these attacks, unless our drought continues for years to come. Experts say the oak girdler insects are being seen all over Monterey County, especially in Monterey and parts of Carmel Valley.

A bit of good news on another local tree, the Monterey pines. The Pitch Pine Canker fungal disease has been a problem on the Central Coast for years. However, it seems to be leveling off.

“So the Monterey pines are still having issues with it,” Pangburn said.”However, there appears to be a somewhat leveling off and there’s some sort of natural resistance to it that is prevalent in some stands and we are even seeing some regeneration that is resistant to the Pitch Canker.”

Other pines in other areas of the state are being impacted by other diseases. According to Pangburn, the forest health and drought issues in the southern and central Sierra Nevada ranges are dire.

“There are many stands of especially pine trees in the Sierra Nevada ranges that are seeing in excess of 50% mortality,” Pangburn said. “Some places are as high as 80% mortality. Literally millions of dead trees throughout the mountains. “

While the Central Coast isn’t seeing this, inland ranges like Gabilan and Diablo are. Pangburn says there’s a die off with gray pines. It’s a concern for fire departments, especially when as we enter fire season.