TRUCKEE, California (KGO) -- California forests are under extreme threat right now with more than 60 million trees killed by insects and drought in the past five years. And it's not just dead trees that create problems.
All the tree cutting is happening in an unlikely spot: Sagehen Experimental Forest, which is run by UC Berkeley in the High Sierra near Truckee.
Sagehen is protected and designated for research with all kinds of gadgets and cameras recording decades of data about this very diverse eco-system. Even a rare wolverine was spotted here.
Now like a lot of the Sierra, the forest is sick with too many trees competing for too little water.
Sagehen Manager Jeff Brown used to think he would never approve of cutting trees here, but that's changed.
"Okay, so the prescription in here is any tree under 10 inches is gone," said Brown.
On this day, more than 30 people from 18 agencies are here to see a range of forest thinning operations that could become a model for the Western United States.
"We designed the project to figure out what it might look like if we were mimicking the more natural conditions," said Joanne Roubique, with the U.S. Forest Service:
Natural conditions include variety and that's what this project is aiming for.
Some sections are being thinned by hand crews, taking out small trees with chain saws. Left over logs and brush are piled up to be burned or taken away in the future.
"These big trees will now be able to get the resources they need to thrive," said Brown.
Researchers believe the thinned out area is what much of the Sierra used to look like.
"When you read the stories of people who came through here on wagon trains, they could drive wagons thru the Sierra forest easily. If you look around here now, you can't do that," he said.
That's because decades of putting out fires made forests much more dense than nature intended and with lots of unhealthy trees many ravaged by insects. A watershed expert compares each tree to a straw.
"It sucks water up so it can make leaves and continue to grow. And the more trees we have on the ground, the more straws there are pulling water out of our eco-systems and out of our watersheds," said Rachel Hutchinson, with the South Yuba River Citizens League.
The project also includes areas being thinned with a huge machine called a masticator that essentially chews up smaller trees. This is a faster, cheaper method, but the results are more extreme, so scientists want to see how eco-system responds over time.
Other patches of forest are being left alone for animals.
"Most of the wildlife in this part of the world like the safety of dense areas, but they tend to do their hunting, their foraging along the edge looking out into more open place," explained Brown.
The Sagehen pilot program got input from both environmental groups and the timber industry and both are watching closely for results.
The tree cutting and research cost about $700,000 paid for with a combination of state and federal money.
Written and produced by Jennifer Olney