Editor's Note: Below is a really interesting guest post by Bobbi Peterson on a topic important to all of us that hike the Green Earth trails. In addition to the ways to avoid spreading invasive species (like the exotic invasive Garlic mustard Alliaria petiolata shown here) that she mentions, we have boot brush stations at some of our trail heads that we encourage everyone to use as you enter and leave the trail. The photo to the right shows the boot brush station at our Brush Hill preserve trail head. (Photos © David Gibson)

Invasive species are a growing problem in many areas of the world. From the wooly adelgid to the hydrilla, newly-introduced plants and animals can disrupt vulnerable ecosystems and wipe out native species at a ridiculous rate. To date 91 species — of 170 listed — have been eradicated in part by invaders. Once invasive species are there, they tend to stay, creating more headaches for ecologists. But how are they initially introduced?

Here’s a list of ways hapless travelers have helped introduce destructive new species to local biomes, and how you can avoid doing the same.

1. Firewood

Don’t bring firewood when you go camping across state lines. If you don’t want to buy from the nearest Walmart then prepare by bringing an axe or a saw and some elbow grease. Alternatively, go scavenging — if you’re in the woods seek out fallen trees and utilize them for your campfire. But please, do not travel with firewood.

The aforementioned woolly adelgid is in the process of obliterating local hemlock and spruce populations across the U.S. because people tend to travel with firewood. You’ll risk introducing the adelgid wherever you bring a piece of wood that has been infested. That white gunk might be moss, or it might be the secretions of a burrowing fiend.

2. Boats

Remain diligent about where you dump your bilge after a long boat ride, particularly when traveling from one body of water to another. It is possible to transfer unwelcome hitchhikers when dumping bilge.

The infamous zebra mussel came to America by this same method — traveling through the Eerie canal in the ballast tanks and undersides of large shipping vessels. Scientists are still struggling to find a way to control them. If you suspect an invasive species in your local lake or pond, proactively implement treatment strategies for invasive species before it gets out of hand.

3. Clothing

Whenever you finish a walk or run in the woods during the summer or spring, you should check yourself for two things. First make sure you don’t have any ticks, then make sure there’s nothing else hitching a ride on your clothing. This goes double for anyone returning or shortly leaving on a long trip. If you get the chance to wash your clothes take it. The local species will thank you.

4. Pets

Like you, your pets have clothing. Theirs is thicker and lower to the ground. It's even easier for new and interesting species to cling to your dog's coat, so brush off any stray insects or seeds that may hide on your friend. Also keep in mind that one of the most efficient way for seeds to spread is through animal stool. Pick up and properly dispose of your pet's waste, especially after a trip.

5. Ignorance

This is not reprimanding. It's really easy to mistake or mischaracterize an invasive species. Blackcaps — those delicious blackberries that are not blackberries — are non-native to Washington state, for instance. For some reason nobody is complaining. In other cases an invasive species may have flowers or be aesthetically pleasing. The Japanese knotweed looks a lot like bamboo, but is also wiping out whole tracts of forest all over the Northern states.

Bobbi Peterson is a green living and environmental writer. She regularly posts about sustainability and simple living on her blog, Living Life Green. You can find more from Bobbi on Twitter @bobbi_peterson_.

Top 5 Ways People Inadvertently Spread Invasive Species

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