How the Russian Olive Became a Villain

Yesterday's hero (famous writer, movie star, politician) is the villain of today. There is a lot of that going around — even with trees. Take kudzu. That was like the Fatty Arbuckle of introduced species; everybody "knew it."

My area has seen some heavy snow and quite a few high winds in the past month. Anybody with a chainsaw and a wood chipper has lots of new close friends. At one nearby house, the snow broke a big old Russian olive tree, and while the people there decided to keep its thick trunk as a sort of lawn ornament, I ended up with the branches.

I rarely turn down free firewood. I have never burned Russian olive, a.k.a. oleaster, but when your go-to firewood is pine, any hardwood seems like a bonus.

Among Dad's old forestry books and field guides was Common Forest and Windbreak Trees of Colorado, published by the Colorado State Forest Service in 1963, and like most of that agency's work, geared toward private landowners, particularly those wanting to plant shelterbelts (windbreaks) around houses and outbuildings on the windswept prairie. 

Russian olive (Columbia Univ.)

Elaeagnus angustifolia was praised. "Drought resistant and makes rapid growth . . . the fruit is relished by insect-eating songbirds and other wildlife."

In the West, tamarisk is our kudzu— and both are being hunted with insects. But Russian olive has been "cancelled" too.  

I learned that at some conference in northern New Mexico a few years back, when I ended up talking trees with the environmental manager for Pícuris Pueblo, and she was like "Death to Russian olives!"  True: In New Mexico and Nevada it is officially a "noxious weed," while California, Nebraska, Wisconsin, and Wyoming label it an "invasive weed."

Background from a Columbia University site on introduced species (archived version):

The Russian olive was introduced to the central and western United States in the late 1800’s as an ornamental tree and a windbreak, before spreading into the wild. By the mid 1920’s it became naturalized in Nevada and Utah, and in Colorado in the 1950’s. . . .

 Its value for wildlife is a "yes, but":

The "olives" (Columbia Univ.)

Over 50 different species of mammals and birds do eat the fruit, 12 of them being game birds. Deer and other livestock feast on the leaves of the Russian olive and beavers use the branches for constructing dams. The canopy of the Russian olive provides good thermal cover for some wildlife species. Doves, mocking birds, roadrunners and other birds use the thick growth of branches as nesting sites.

The Russian olive, with its tendency to spread quickly, is a menace to riparian woodlands, threatening strong, native species like cottonwood and willow trees. They are responsible for out competing a lot of native vegetation, interfering with natural plant succession and nutrient cycling and choking irrigation canals and marshlands in the western United States. This displacement of native plant species and critical wildlife habitats has undoubtedly affected native birds and other species. The heavy, dense shade of the Russian olive is also responsible for blocking out sunlight needed for other trees and plants in fields, open woodlands and forest edges. Overall, areas dominated by the Russian olive do not represent a high concentration of wildlife.

And they are hard to kill, spreading from suckers when the main trunk is cut. It sounds like brush-hogging with some herbicide is the way to control them; there is no natural pest to be imported, according to the site that I linked to.

Dad planted one in our backyard in Lakewood, Colo., along the high cedar fence he built. I remember its silvery leaves. But when I look down at that yard in Google Earth today, it appears to have been replaced by other trees, a pushback against the invasion.

Could We Have a Natural Control for Horrible Cheatgrass?

A cheatgrass monoculture (Bureau of Land Management).

If it were possible, I would nominate these scientists for a prize.

Now, some 65 years after famed naturalist Aldo Leopold summed up the general consensus in the battle against cheatgrass as hopeless, there might be hope.

"We're in a better position to fight back than we have ever been," said Susan Meyer, a U.S. Forest Service research ecologist working with fungus at the Shrub Sciences Laboratory in Provo, Utah.

 Why is cheatgrass a Bad Thing?

• It comes up early in the spring. At that point it is soft and green. It looks good to eat, hence the "cheat" part.

• But very soon it sets its seeds in horrible, prickly awns that hurt grazing animals' mouths, puncture people's shoes and socks, catch in other animals' coats, and spread wherever they are  carried. 

In addition to being a wildfire threat and an ecological problem, cheatgrass can harm animals. Its stiff, spiny seedheads, called awns, can work their way into the ears, eyes or mouths of everything from cats to cattle.

• Because it dries out early in the summer, it carries fire easily.

The keys to cheatgrass spread are its short life cycle and prolific seed production. Because cheatgrass stands dry out by mid-June, fires are more likely to occur earlier in the season. These mid-summer fires are tough on native forbs and grasses.

Cheatgrass seeds drop prior to fires and will germinate with fall precipitation. This gives rise to dense, continuous stands that make additional fire ignition and spread more likely. Fire return intervals have gone from between 60–110 years in sagebrush-dominated systems to less than 5 years under cheatgrass dominance. With every reoccurring fire, cheatgrass becomes more dominant and expands its range further. 

• It has damged the West by reducing feed for both wildlife (elk, deer, pronghorn antelope) and domestic animals:  

“Cheatgrass has probably created the greatest ecological change in the western United States of anything we’ve ever done,” said Steve Monsen, a retired Forest Service botanist in Utah who conducts research for the agency.

It can be grazed when young and green, but unlike native perennial grasses, it does not "cure" on the stem for winter consumption.

On my own little patch of Colorado, I watched cheatgrass move from roadsides, seemingly leap over healthier pastures, and appear in groves of pines trees.

So what Is the new development?

There are pesticides that work against cheatgrass, but the invasion is too big to spray it all. Susan Mayer and others are looking at bacteria instead:

Meyer and Ann Kennedy, a scientist in Washington state working with bacteria, are drawing attention from top land managers and policy makers — and research money — after showing that the seemingly invincible cheatgrass might have an Achilles' heel. 

"We've found several organisms that are really good at colonizing the root of the seed, and reducing the elongation of that root," said Kennedy, who works at Washington State University. "Then that cheatgrass is less competitive the next spring."

This will all cost a whole lot of money. But isn't the West worth it?

Primroses, Wild Mustard, and Homiletics

Having a sort-of average spring after several dry years means seeing old friends, plus some plants we regard with suspicion.

Cutleaf primose scattered in pasture.

I mentioned the purple/blue mustard. They were succeeded in May by cutleaf (or prairie) primroses—not the huge banks of them sometimes seen on the remaining High Plains grasslands, like Pawnee National Grasslands, but a lot for us.

Cutleaf evening primose, Oenothera coronopifolia

Here is a close-up —these were a little shredded by hail on the previous day.

They have been followed by a yellow-flowered wild mustard that has a sort of rotting-soap smell (or "stale dishrag") when stepped or driven upon. It looks like this one: Sinapis arvensis, but the distribution map does not show it in Colorado. Maybe a relative? Can't mow it all to stop the seeding, so it will be back when conditions are right.

Or as the gospel says, "But when it is grown, it is greater than the herbs, and becomes a tree, so that the birds of the air come and lodge in its branches."

If preachers ever interacted with the natural world, they might dust off their sermons on the parable of the mustard seed this year. People could visualize it.

Fighting Cheatgrass with Fungus

Whoever can stop cheatgrass deserves a Nobel prize and the thanks of a grateful continent.  A fungus holds some promise.

“Cheatgrass is a very insidious kind of biotic virus,” said Stephen Pyne, a Western fire historian at Arizona State University. “It takes over and rewrites the operating system. Because it grows earlier, it can burn earlier,” then in its regrowth “drive off all the other competitors. That makes for a complete overthrow of the system.” 

Mike Styler, head of the Utah Department of Natural Resources, said simply: “It’s changed the entire ecology of the West.” 

But the black fingers of death — Pyrenophora semeniperda — may help restoration ecologists like Dr. Meyer reclaim some beachheads in the vast swath of land already conquered by cheatgrass.

I have been seeing it a lot more around here lately, thanks to two drought years in a row, which just makes me sick to contemplate.