• Invasive plants crowd out native vegetation

  • There are several different types of invasive plant species.

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  • Katie Peterson | Staff Writer
    There are many factors that contribute to why flowers, trees and grass die, including lack of moisture and the hot, summer sun, but just as big a problem are invasive plant species that can become overgrown and suffocate the healthy plants.
    “Invasive plants are plants that seem to be released from environmental pressure and they’re constantly expanding and crowd out other vegetation,” said Neil Bass, natural resources specialist for the Department of Public Works. “The big danger with invasive species is that the healthier an ecosystem is, the greater the diversity and different types of plants that will be there.”
    There are several different types of invasive plant species, Bass said.
    “In most cases, invasive plants are introduced non-native plants that come from other countries and other parts of the world that have no local predator and they don’t have anything to knock them back,” he said. “They can just expand and out compete the native vegetation.”
    However, there are local, native invasive plants that can cause problems as well. The most common around post are Johnson grass, cut-leaf teasel, garlic mustard, Sericea Lespedeza and Japanese hops, Bass said.
    “Teasel in particular is expanding across the region in both Kansas and Missouri. It grows to be about eight feet tall and has a white flower at the head. It’s really invasive and nasty and its number is really expanding,” Bass said. “(Teasel) was starting to grow in these old landfill sites that are capped and planted with vegetation and I’ve been trying to mechanically control it. If you cut it before it goes to seed, it prevents it from creating seed and increasing the next year.”
    While completely stopping invasive species from growing is nearly impossible, Bass said, there are three effective controlling methods one can use.
    First is mechanical control.
    “That’s where you go out and actually chop it down or dig the plant up,” Bass said. “That’s really labor intensive. (Mowing) is a pretty effective way to slow or stop its spread.”
    Due to mowing schedules on post being shifted three weeks earlier than in past years, Bass said the labor time to control the teasel was greatly reduced. Other mechanical control methods include pulling, digging and cutting.
    Second is prescribed burning.
    “If you time your burning, it is basically the same as mechanical control,” Bass said.
    Third is chemical control.
    “Herbicide is the most effective and is necessary to have any kind of impact,” he said. “For a lot of the really aggressive invasive species, chemical control is the best method.”
    Page 2 of 2 - Bass said each method has its own pros and cons.
    For example, chemicals are expensive and introduce potential toxins into the environment.
    “I believe that the impacts from the invasive far outweigh the impacts from the herbicide, but there can be some negative effects of herbicide especially if they’re not applied properly,” Bass said.
    In contrast, mechanical control has almost zero risk factors.
    “Mechanical control doesn’t really require anything but sweat equity,” Bass said. “You just have to go out and actually do it. If you have a small, localized infestation, mechanical control can be successful.”
    Bass said the more effective method will really depend on the situation.
    “A lot of it has to do with what your goals are,” he said. “You have to really be on top of it. In most cases, it’s a constant battle. You’re just going to have to be really vigilant.”
    Bass said the problems with invasive species increase the larger the area gets.
    “In a vegetable garden, invasive species don’t really cause a lot of issues because it’s small enough that you can stay on top of it,” he said. “In a large-scale agriculture, invasive species take a huge monetary toll and the whole reason is to compete against Johnson grass (and other invasive species).”
    For farmers in this situation, there is a danger with their animals, too.
    “In the summer, Johnson grass can become toxic as it produces cyanide,” Bass said. “If cattle eat large quantities, it can kill them.
    “There’s a whole ripple effect with invasive species,” he said.
    Different invasive species grow at different times. Therefore, the best way to control the species, no matter which method is used, is to treat them as soon as they come up.
    “They’re more susceptible to treatment (in the early stages),” Bass said.
    Invasive species are not limited to plants. Though currently not a problem near Fort Leavenworth, animals such as wild hogs carry bacteria known as brucellosis, which is transferrable to domestic cattle. Many other animals are considered invasive species as well.
    For more information on invasive species common in the United States, visit www.invasivespeciesinfo.gov.
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