Alien Invasion!

March 2, 2011

new paper recently came out in Conservation Biology that emphasizes the positive aspects of invasive species. The authors claim that invasive species can replenish damaged ecosystems and sustain at least some natural health in generally unnatural areas. They also predict that many non-native species that are perceived poorly today will be looked upon more positively in the future.

Generally I live under the assumption that everything is more complicated than we can ever understand. Nothing is 100% bad or 100% good. In places where humans have completely destroyed everything that is natural like Washington DC,the cesspool of the universe,  an invasive dandelion poking up out of the sidewalk might be a welcome sight. I also truly enjoy honey and honey bees are not from around these here parts.

But let us consider another invasive:

Bromus tectorum – The Scourge of the West

Negatives of cheat grass:

1. It is an annual grass that out-competes native grasses and lets face it, native grasses are down on their luck all ready.

2. Since it is an annual it browns much earlier than perennial grasses and therefore extends the fire season. It also has an extensive root system that sucks water away from any nearby plants. I am definitely of the mindset that fires are not always bad, but once the ground is disturbed from fire there isn’t much of a chance of anything but cheatgrass sprouting back up.

3. Wildlife and livestock do not generally call it tasty.

4. Its seeds get in your socks, are extremely difficult to remove and itch like nobody’s business.

5. It’s called cheat grass. Who likes a cheater?

And now for the positives:

Okay, I really can’t think of anything that is not facetious or sarcastic. Cheat grass is gross. Step into a native prairie and you see tons of colors, tons of species and tons of insects. Step into a cheat grass prairie and you see tons of purplish brown and you end up with itchy ankles. I understand that cheat grass can fulfill a role in the ecosystem, but it is more like a selfish toddler than a member of an ecological community. I also agree with the authors of the paper that scientists have a bias against invasives and that we need to address this bias. I also don’t think we can deny the damage invasives do to native ecosystems.

I am not a grass person. If I were to choose a favorite plant it would be a tree. But last summer I grew to love the bluebunch, fescues and grammas of the northern great plains. I can’t help but cringe to know that cheat grass and its fellow invasives are almost inevitably going to wipe out what is left of the semi-intact prairie ecosystem. Yes, it will still function, but it will function as a monoculture. Humans have created enough of those.