Francis Skalicky

for the News-Leader

If you didn’t know, next week, Feb. 21-27, is National Invasive Species Awareness Week.

Don't feel bad, it doesn’t show up on many calendars. OK, to be honest, it probably doesn’t show up on any calendars.

That’s too bad, because the purpose of this week is to bring attention to all the non-native species that pose threats to our outdoor habitats.

Unfortunately for our habitats and our native species that call them home, there are a lot of these non-native invaders and they can be extremely harmful.

Feral hogs, Asian carp and the aquatic plant hydrilla are some of the recent non-native newsmakers, but there are many others. In the plant world, kudzu, musk thistle and several honeysuckle species lead a long list of exotic invaders. Zebra mussels and rusty crayfish are among many aquatic invaders. Don’t forget insects such as gypsy moths and emerald ash borers. Starlings, Norway rats, house mice, Johnson grass — it seems the list goes on and on.

Non-native species are nothing new. Numerous plant, insect and animal species have been introduced to North America in the 500-plus years the continent has been explored, settled and developed. Some were introduced on purpose, others by accident. These introduced species are collectively termed "exotic" species because they’re not indigenous to North America. The opposite of exotic are native species, which are those that were originally growing or living on our landscape.

Though the non-native species that have arrived here are diverse, the reasons they’ve flourished to the point of becoming problematic are similar.

When introduced to a new location, many exotic species no longer have the natural controls — browsing animals, predators, harsher weather, etc. — to keep their populations in check like they had in their native lands. This resulting over-abundance of exotic species has often come at the expense of native plants and animals that formed the foundation of our habitats. This take-over has earned many of these newcomers the term "invasive."

Wise conservation practices that utilize native species pay by enriching our economy and quality of life. Conversely, exotic invasions can have negative repercussions.

From an agricultural standpoint, when exotic plants take over pastures and fields, they can turn what had been money-making acres into financially unproductive tracts of land.

In urban areas, when exotic species invade an area and crowd out native species, habitats often change for the worse. The pollinating insects that were attracted to native flowers go elsewhere, the native birds can’t find food and, in some cases, sites to nest and raise young. This may not sound like a big deal, but significant negative impacts to plant and animal populations can lead to changes that can have significant economic and aesthetic impacts for humans, too.

It’s hard to put exact numbers on this problem, but biologists estimate more than 4,000 exotic plant and 2,300 exotic animal species have become established in the U.S.

Non-native species are a contributing factor to the habitat problems of 42 percent of native animals and plants in the U.S. that are presently classified as endangered or threatened.

If those numbers don’t raise eyebrows, maybe this one will: It’s estimated that non-native species cost the U.S. somewhere around $123 billion per year.

Fortunately, Missourians care about conserving forests, fish and wildlife and are always looking for ways to improve the habitats around them.

Using native plants in agricultural and landscape management strategies is one way to help solve these troubles. Following state and federal guidelines that involve eradicating or limiting the spread of non-native plant and animal species is also important.

More information about how to promote native species can be found at www.missouriconservation.org.

Francis Skalicky is the media specialist for the Missouri Department of Conservation’s Southwest Region. For more information about conservation issues, call 417-895-6880.