Saturday, December 10, 2005

Species Invaders, part 2

So as to get extra credit and FINALLY have an A in my bio class, I helped clear French broom from Alta Avenue/Tennessee Valley up in Marin City (which I had only gone there before either to buy stuff at Best Buy and Ross at the mall off that exit).

French broom is apparently a plant from the Mediterranean that was brought over as an ornamental, and like the ice plants from South Africa that I helped clear a few weeks ago, spread all over the Bay because our climate is similar to the Mediterranean, is similar to the South African coast, etc. In order to get to the hillside where we cleared these plants, we (Joanna, the girl who I took a picture of after we had finished clearing the hillside, and me) had to hike about a mile and a half through privately owned land, where the French broom was left unchecked. There was a big difference, especially after we had finished clearing. The French broom was rampant all over the private land, and by the time we had cleared the hillside, all you could see were native grasses, a few coyote brush shrubs, and some dried out blackberry bushes.

Clearing the hillside required using weed wrenches, which are exactly what the name implies, 2-1/2 foot tall wrenches that are used to grab onto the weeds at their base, and leverage is used to pull the plants out of the ground, especially the roots. Considering we were on a hillside and that we had to hike quite a bit, it was pretty exhausting doing it, and I had to slow down because my back wasn't too happy with having to twist and turn in ways it wasn't used to.

My friend and I did this with a group of other biology students from CCSF, some of whom asked why this was necessary. "If the plants are already doing well, why is it such a bad thing?" some guy asked. The volunteers organizing (sweetly) talked to them about the importance of biodiversity--if these plants are left unchecked, then other species (such as monarch butterflies) that depend on the original plants have nothing to eat, since these plants have taken all the nutrients in the soil and are thriving because there are no natural predators for them in the Bay, thus leading to a major domino effect. She also went to talk about how plants from the Bay are also posing the same types of problems in Europe and South Africa, particularly a type of fern that's grown in the redwood forests, but are a huge problem in Europe and South Africa, similar to the French broom. The first picture is of my friend Joanna, and the second is the cleared hillside.

Originally uploaded by stkyrice.

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