The Great Conservation Debate...

What constitutes a species as "invasive?" Who are we to decide that a species is "invasive?" 

Endangered Southwestern Flycatcher Nest in an "Invasive" Tamarisk (Salt Cedar) along the Colorado River.

(Photo credit: USGS)

Are most of us not, as residents of the U.S., an "invasive" species in America? Did the majority of Americans living in this country NOT make their way over to America nestled on boats and planes?  Birds have been the main vehicle of plant migration so "invasive" species aren't unnatural by any means. Ancient man also played a huge roll in what species are present in many locations. It would be naive to assume that todays migration of species isnt in some way normal.

An estimated 1,500 plants and animals across the U.S. were brought into the country for cultivation, or hitchhiked rides on the trains, boats and planes of international commerce. They ended up in places where most scientists say they don’t belong. When I think of invasive species, a few come to mind. Namely, Zebra Mussels (native to Eastern Europe), and Tamarisk (also called Salt Cedar, native to Eurasia), to name the top two that I, as a ranger, see all the time.   

Every year trillions of dollars are spent in the U.S. in an effort to “eradicate” or “control” these “invaders”.  In my opinion, it’s time to re-think our relationship with these species—and you can call them whichever terrible name you prefer—most of them are here to stay. These “exotics,” “invasive,” "alien," and “nuisance” species are now residents of our parks, forests, and communities.

Species have been evolving, migrating, and going extinct long before we, as a species, arrived on this planet. To identify one as "native" and another as "invasive" is almost drawing a line in time.  I will agree that management is key, however—can’t one argue that “invasion” is normal process of nature? In doing so, can’t we learn to manage BOTH what we call “invasive” and “native” species, living together?

Isn’t the fabric of the world woven by constant change? 

 EVOLUTION is CHANGE.

Here's a cool article from 2009: Don't Sweat the Invasion!