Monday, July 14, 2014

Summer Snowstorm

Look carefully for the "snowflakes" against the dark trees in the background
We're experiencing a "snowstorm" in my preserve this month.  Non-native Canada thistle (Cirsium arvense) (a real misnomer and a "slight" to Canada since this thistle is actually a native of Eurasia) has exploded in our grasslands.

The culprit in flower
All stages -  from flower to fluff
The incredible infestation is the result of a perfect storm of unfortunate events.  First, our boom sprayer was out of commission in the spring so our land manager couldn't spray the thistle when it was most susceptible.  Second, the herbicide we've been using to try to control the thistle, Transline, seems to be losing its effectiveness, so we're going to have to find an alternative.  And third, by the time we realized the mess we were going to be in, migratory birds and rabbits had begun to nest in the fields, so we couldn't mow the thistle to prevent it from going to seed.
A patch with countless seeds
Non-native wineberry (Rubus phoenicolasis) cloaked in thistledown
Everything in the fields that's not green is thistle
One silver lining to these thistledown clouds: the American Goldfinches (Carduelis tristis) are having a field day (so to speak) feasting on the abundance.


John "By Stargoose And Hanglands" said...

You're very welcome to them! I once had to stack a few thousand straw bales from a farm which seemed to specialise in the growing of thistles - a very painful experience!

packrat said...

Just the kind of snowstorm to make an ecologist fret about next season.

(Scott: Did you hear about the two people who were struck by lightning and killed in Rocky Mountain National Park? Tragic.)

Scott said...

John: Yow! The Canada thistle plants don't have too large a prickle, but if your straw bales had huge bull or sow thistles (the kind I associate with Scotland) amongst the straw, I can certainly appreciate your painful experience.

Scott said...

Packrat: We've already contacted a commercial herbicide firm called Weeds, Inc. to line-up a major spray application next spring. We can't fool around with this plant; as you can see, it's already nearly out of control and will only get worse if we don't "nip it in the bud" (so to speak).

I DID hear about the two people killed by lightning in RMNP. (In addition, several people who were near the people killed were injured by the strike.) From what I understand, it sounds like both strikes were in the high, exposed tundra at the top of Trail Ridge Road as it crests the Continental Divide in the park.

Mark P said...

It's amazing how much work it can take to maintain a relatively small native area.

A coworker used to vacation at RMNP. He talked about having to leave before dawn to hike to the top of Longs Peak so you could get back down before the afternoon thunderstorms started.

Scott said...

Mark: Just another note (in case you read this): WordPress won't let me leave comments on CaniConfidimus. When I press the Submit Comment button, the Comment box reappears and it's blank. Do you know what's wrong?