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Lucy Irons


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Are you concerned about the spread of invasive species?

Invasive species are non-native species that have a negative impact on their introduced environment. Invasive species are a huge issue not only due to their environmental impacts, but their economic ones as well. According to the National Invasive Species Information Center, there are currently about 50,000 invasive species in the United States alone that cost over $138 billion annually to manage. invasive species have a number of distinctive traits, including A general diet, large amounts of genetic variation, the ability to survive in a wide range of climates, a continuous breeding season, and the production of many offspring every year. What role do these versatile organisms have in a world where many species and ecosystems potentially lack the diversity required to survive rapid changes in their environment? Is it possible that, in the face of global climate change and biodiversity loss, invasive species can contribute something positive to biological systems?


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  • Mar 16 2012: I live in Hawaii, where invasive species is almost an everyday topic. I've seen first hand that not all species were invasive at one point. Hawaii has an endemic hibiscus, among many other plants. Very little grows on fresh lava flows. Ferns and Ohia are the first things to grow. It is possible to have only native plants in an area, but humans have to leave that area alone. Humans, birds and the ocean are the great seed carriers. I live in one of Hawaii's last rainforests and when I look out into my yard, I see a variety of native, indigenous, endemic and invasive. The strawberry guava is one of the worst. Not only does it canopy and spread like fire, but it's leaves also add acid to the ground, so that nothing can grow in it's place. Hawaii has struggled for decades, if not centuries, to preserve the native flora/fauna. You can look at the history to see how things have been bio-controlled here with little success. Usually what ends up happening is, whatever thing you bring to control the invasive thing, becomes invasive itself (i.e. mongoose). Kipuka are a great example of endemics. There's a hau variety that lives only in one kipuka near Kilauea. So what do we do to keep the invasive species down? I think we should study these plant more and maybe we could find a use, then encourage exploitation in the areas where they're invasive, creating benefit out nuisance.
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      Mar 16 2012: I like your point about finding benefits of invasive species. I also agree that in a lot of situations, the best thing is for humans to leave well enough alone. However, as humans how often does that actually happen? For some reason we always feel the need to fuss with our environment.
    • Mar 17 2012: I enjoyed reading your post. Biological control is a popular method of curbing the growth of invasive species. Using a predator to target the invasive species is generally more preferable than using a pesticide or some other immediately destructive method of control. Pesticides affect other plants, species that eat the target plant, and they also contaminate the ground water and thus pose a threat to the entire ecosystem.

      However as you have indicated, introducing a predator has a huge drawback in that this predator will naturally have a bountiful food resource since the invasive species is so prevalent. The predator will experience a high rate of growth. Quite often it consumes other resources other than just the original invasive species. By these means, the predator which was intended to control the invasive species becomes an invasive species itself.

      If introducing a predator is the preferred method to control an invasive species, we should introduce a predator that is as species-specific as possible to the invasive species, in order to limit the damage and disruption it will have on the native species.
    • Mar 17 2012: I really like your idea that we should find a use for the invasive species, so that we can make it a resource rather than a problem. It would take research to see where it would benefit, but if you could find a use for an invasive plant or animal then you could reduce the population size and benefit our own population. That is a great suggestion versus other methods that might not be as effective.

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