Showing posts with label ecology. Show all posts
Showing posts with label ecology. Show all posts

February 25, 2017

Colorado Forests Are Changing. Part of Me Likes That.

Pine beetle-killed lodgepole pine in Colorado (University of Colorado).
I spent last weekend camping with friends on the White River National Forest in Summit County, Colorado. The mountain pine beetle worked its magic there some years ago, which means there is lots of firewood in the form of dead trees.

As humans, I think we are hardwired for orgies — not talking about sex here, but more in the sense of "Run all the buffalo over a cliff and eat meat until you fall down!" "Dig all the gold!" "Drink all the beer!" Or in our case, "Build big fires!" Really, it makes our little ape-hearts feel good.

Let's take the long view, if we can. Only what we think is a long view is just childhood for a tree.

According to the Colorado State Forest Service, one in fourteen forest trees in the state is dead, for a total of 834 million standing dead trees. (A projection from sample counts, that has to be.)
Infestations of mountain pine beetles and spruce beetles are the main cause of the die-off, [State Forester Mike] Lester said. Beetles are native to the state but have caused far more damage than normal over the past 20 years, attacking more than 7,900 square miles of forest, or more than 20 percent of total forested land.
Standing dead trees made fighting last summer's 38,000-acre Beaver Creek Fire more difficult, fire  commanders said. Earlier studies about dead trees' effects on fire were more ambiguous, so I wonder if the pendulum will swing.

A big post-fire issue is flooding with associated erosion — I will be writing more about that later this spring.

And then there is Our Friend the Spruce Beetle.
At this point, there’s nothing stopping the spruce beetle. We’re observing it. We’re going to let nature run its course,” said state entomologist Dan West, who helped run aerial surveys with the U.S. Forest Service involving 40 flights over forests.
Some people are saying that the highly visible, highly visited forest along the Front Range will "never look the same."
Limited conifer regeneration following wildfires in dry ponderosa pine forests of the Colorado Front Range, by Fire Ecologist Monica Rother and CU-Boulder Professor of Geography Thomas Veblen, surveyed conifer regeneration at six low-elevation Front Range sites that burned eight to 15 years before. Released in December and published in the journal Ecosphere, it found that "current patterns of post-fire seedling establishment suggest that vegetation composition and structure may differ notably from historic patterns and that lower density stands and even non-forested communities may persist in some areas of these burns long after the fire[.]"
That prospect does not bother me on one level. I find the "start-up phase" of forests to be interesting. The big-game hunting is better too. Now if your house in the woods burned to the ground, you may not feel that way. And if you look at trees just as unharvested timber, you may not agree with me.

(But some of the land that has burned around me was never logged, because it is just too steep and rough. Other areas were logged in the late 19th and early 20th centuries, but then not managed for timber sales after that because of low productivity.)

"Lower-density stands"? Bring 'em on. Along with a predilection for orgies of food, drink, and firewood, I favor those evolutionary psychologist who think that human inherently like a meadow-and-forest (or savannah-and-trees) environment better than dense forest or grassland.

October 22, 2015

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?