Tuesday, June 26, 2007

The Green Miles vs. Mile-a-Minute

I arrived at Potomac Overlook Regional Park on Saturday to find the hill covered knee-high in invasive plants. Just two months earlier, we'd planted small saplings (only a few inches high) at the site. With the web of mile-a-minute weed, Japanese stiltgrass, and other non-native plants taking over the area, it was going to be a challenge to find the saplings, never mind clear enough space for them to be able to continue to take root.

It was my first time dealing with mile-a-minute, a vine that combines the worst characteristics of several invasive species. It grows as fast and climbs as quickly as kudzu, and its thorns are just as painful as multiflora rose. In short, a real bastard.

On top of all of that, a grand total of zero Community Role Models volunteers showed up to help. I spent an hour clearing some multiflora rose roots out of the top of the hill, but I had no idea where to even start with the mile-a-minute and stiltgrass below. Things were looking bleak for The Green Miles.

But a surprise visit would turn the tide.

First, a step back. People often ask me why invasive plants are such a concern. After all, if they beat out native species, isn't it just survival of the fittest.

Survival of the fittest applies to species that have had millions of years deal with predators and competitors, carving out roles in an ecosystem. Expecting trees to suddenly be able to deal with mile-a-minute would be like dropping a pack of wolves onto an island with a flock of penguins and telling the penguins, "Better evolve some flying or running skills in a hurry!"

Trees are the backbone of the American ecosystem, providing shelter for birds and mammals and holding topsoil in place so other plants can grow. Ordinarily, a dead tree would just be replaced in the canopy by younger trees.

But invasives smother young trees before they can ever grow. Some even release chemicals into the soil that retard the growth of young trees. Deer are known to ignore invasives and stick with their usual diet of native plants, exacerbating the problem.

So invasives are a problem that we need to deal with. Especially since we introduced them into the ecosystem. Ooops.

And thanks to Jake and Wilson, I was able to win my first battle in the war on mile-a-minute.

Jake and Wilson are interns at Potomac Overlook who heard there was some wacko trying to clear a whole hill of invasives by himself and took pity on me. They came armed with rakes, tools they've found works much better than the simple grab-and-pull technique I'd been using. Within an hour I had two shoulder-high piles of mile-a-minute and other invasives. OK, so it's not like I'd stormed the beach at Normandy, but it was pretty damn satisfying.

And best of all, we uncovered over a dozen of the saplings CRM volunteers planted back in April, still marked by their little strips of orange tape (at the center of the picture to the left). Even though they were getting hardly any sun under the net of invasives, almost all showed signs of growth, sprouting new leaves.

In a matter of weeks, the invasives will have reclaimed the hillside, so let's hope the saplings can take advantage of this window. But Jake and Wilson promised to keep an eye on them, and I'll be back later this summer for round two against the invasives.

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