The invasive Russian olive tree can cause havoc in river ecosystems around the
West. It competes with native plants and destroys habitat for native wildlife. Plus, it can be
incredibly challenging to remove from river ecosystems. But a group of organizations outside of
Durango has found a way not only to remove the trees, but also to help the community in other
ways. As part of the Western Slope Resources Reporting collaborative, KSJD’s Austin Cope has
Despite their name, Russian olive trees have little to do with real olives. You can’t make oil out of their fruits, and they are only very distantly related to true olive trees. They’re only called “olive” trees because of their medium size, their silvery green color and their small dry fruits.
If you travel in the West, you’ll likely see lots of these trees along rivers and in riparian areas. But they haven’t always been here. They were introduced to the United States as an ornamental plant sometime around the turn of the 20th century.
But when Russian olive trees enter an ecosystem, they often take over. They grow faster than other native plants and out-compete them for water and nutrients. Their dying leaves upset the balance of nitrogen in the ecosystem. Native birds and wildlife don’t nest in them, so it knocks their populations out of balance as well.
Kuenzi 1337 (0:05): “One way to think of invasive plants is sort of like biological pollution”
That’s Amanda Kuenzi (“KEN-zey”). She’s the Community Science Director at Mountain Studies Institute in Durango.
Kuenzi 1334 (0:07): ”If we had an oil spill, it’s terrible, and it’s really bad, but we can clean that oil up, and it’s out of the river.”
But invasive species are different.
Kuenzi 1354 (0:12): “They reseed...every year that they’re putting out seeds, just exponentially reproducing, and each one of those seeds becomes a new tree that can reproduce, and so the problem just grows and grows and grows.”
Some Russian olive stands in deserts and the warmer low elevations are too thick to remove all at once. But along the Animas river above Durango, Kuenzi says temperatures are a little too cold for the trees to really take hold. But it may not always be like that. Warming average temperatures may make it easier for the trees to grow at those higher elevations in the future.
Most public lands agencies have programs to get rid of Russian olive trees. But Kuenzi explains land ownership boundaries like a checkerboard between public and private lands. Public lands agencies don’t work on private lands. So Mountain Studies institute has teamed up with land conservancy organizations to reach out to private landowners and help them clear the trees from their properties. The landowners share costs and workloads of the species removal with the organizations.
Kuenzi 1203 (0:10): “As those people were willing to eradicate Russian olives on their parcels, they could talk to their neighbors...I found that neighbors talking to neighbors was the most powerful tool.”
But you can’t just cut down a Russian olive tree. The plants quickly begin to re-grow after they are cut.
Kuenzi 0910 (0:12): “I’ve seen literally hundreds and hundreds of re-sprouts come from one cut stump.”
So Mountain Studies Institute hopes to eradicate the trees by cutting them down and also applying herbicides. But she says they’re being careful.
Kuenzi 1526 (0:27) “When it comes to herbicides, we definitely don’t want to see tons of chemicals going into our waterways...that’s not the way herbicide should be used. The way we’re using herbicide in this case is extremely localized, just very carefully applying it stump by stump.
Some of the smallest trees can be sprayed at the base to kill them completely. The larger ones can be sliced at the trunk and injected with a small amount of chemical to create standing dead trees for wildlife habitat. And the trees can also be cut down completely and sprayed at the stump so they won’t grow back. Young people from the Southwest Conservation Corps do most of the labor.
Kuenzi 0523 (0:13) “The landowners that I’ve worked with are just so impressed that the kids are in there day in and day out with chainsaws, and it’s hot sometimes, and they’ve got chaps, and hard hats, and all the safety equipment…”
The goal is to return the habitat back to how it was before the Russian olives were introduced.
Kuenzi 0319 (0:08) “We really want to restore our watershed back to being dominated by native cottonwoods, river birch, and willows.”
The organization says it has cleared almost 300 acres of Russian olive trees so far. They have used the same tactics for the similarly-invasive tamarisk trees. And Kuenzi’s team has found a way for their project to have even more impact in the community.
Kuenzi 0545 (0:05): “One of the problems we ran into was what to do with all the waste materials after we cut down the Russian olives.”
But she says the answers sometimes present themselves. One of the Rotary clubs in town distributes firewood to low-income seniors and families in the area to help them heat their homes. Travis Ward is a member of Durango Daybreak Rotary.
Ward 0245 (0:15): “Amanda would call, and say ‘we’ve got a pile out by animas school,’ so we’d go out there and load it up (whoever could volunteer that day) and take it out to our wood site…and hopefully it’ll be aged enough to use next winter.”
Kuenzi says there is a lot of community support for the program, and she’s hoping it can continue. She is working with local organizations and state agencies to secure funding for the upcoming summer.
For KSJD and Western Slope Resources Reporting, I’m Austin Cope.
This story is part of Western Slope Resources Reporting, a collaboration between KSJD and four other radio stations in rural Colorado. It provides in-depth coverage of how people and organizations are finding creative and positive ways to overcome natural resource-related challenges.