Summit County Citizens Voice

A U.S. Forest Service map shows the spread of blister rust across the Rockies.

Citizen scientists wanted to help identify key mushroom species growing with limber pines and bristlecone pines in the southern Rockies

By Bob Berwyn

SUMMIT COUNTY — A humble mushroom may help foresters restore blighted whitebark and limber pine forests across the Rocky Mountains that have been attacked and killed by blister rust, a non-native fungus introduced via trees from Europe.

In some parts of the northern Rockies, the pathogenic invader has wiped out 90 percent of the whitebark pines. It has been spreading southward steadily, with reports of infested limber pines in Colorado becoming more common.

In 2003, blister rust was reported on bristlecones in central Colorado, more than 200 miles from the nearest infected tree. Widespread mortality of pines in the five-needle family could have significant environmental, cultural and economic impacts, documented in this U.S. Forest Service research paper.

And visit this U.S. Forest Service website for detailed information on the spread, lifecycle and potential impacts of white pine blister rust.

Working together through the Whitebark Pine Foundation, federal and state foresters, as well as private stakeholders, are trying to restore the trees, It turns out that certain fungi in the suillus family help whitebark seedlings grow faster and stronger, according to Cathy Cripps, one of the top fungi experts in the Rocky Mountain region

“Certain species are really important,” Cripps said, explaining that whitebark pine seedlings grown in nurseries are being inoculated with spores from various mushroom species to help them establish themselves when they’re planted out in the mountains.

A Summit County suillus growing with lodgepole pine.

Suillus are part of a group of mushrooms that have a spongy mass beneath the cap as a spore-bearing area, instead of the gills most commonly associated with mushrooms.

Here’s how it works. Many species of fungi grow in a symbiosis with trees in what’s called a mycorhizzal (mike-o-rye-zul) relationship. The hair-like underground strands of fungi, called a mycelium, ensheathe tree roots and extend into the surrounding soil, helping trees absorb nitrogen and phosphorus. In exchange, the fungi get carbohydrates leaking from the roots. The root-associated fungi also buffer the trees from drought and protect against pathogens. In aspen stands growing near abandoned mines, the fungi block toxic heavy metals from reaching the trees. Learn more here.

In lab tests, aspens that were inoculated with fungal spores in some cases grew 300 percent faster, Cripps said, adding that the technique could also be helpful for aspen re-forestation efforts.

Whitebark pines associate with at least 32 species of mycorhizzal fungi just in the Greater Yellowstone ecosystem, possibly more over its entire range. In many cases, certain species of suillus are very specific to their host trees, growing only in association with one species. And since the fungi don’t produce fruiting bodies each year, scientists are still on the look-out for new species that could help with the re-forestation effort.

So Cripps has enlisted the help of citizen scientists, especially in the southern Rockies, to help find suillus species growing together members of the five-needle pine family. Most recently, a member of the Colorado Springs mycological society chapter discovered the first-ever suillus associated with limber pine.

And it’s not just a theoretical exercise. Each fruiting body (mushroom) produces thousands and thousands of spores that can be used to help inoculate nursery seedlings.

Cripps will be a featured speaker at the upcoming annual meeting of the North American Mycological Association, held this year here in Colorado at the YMCA of the Rockies Snow Mountain Ranch. She’ll be discussing the ecology of the whitebark pine family with its associated fungi, birds and mammals.

Filed under: Environment, forests, public lands, Summit County Colorado Tagged: | fungi, mushrooms, mycology, North American Mycological Association annual meeting Colorado, suillus fungi, Summit County Colorado, Summit County News, White Bark pine blister rust