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A Response to an Inaccurate “Opinion” about Invasive Species

By Rob Stroh

Edited by Andy West

I read an opinion article in the Southern Illinoisan newspaper a few months ago, and it has bugged me ever since so here is my response. It was an article about how we shouldn’t bother treating invasive species, because “Almost all species, at some point, arrived from somewhere else.” He was proclaiming that the government should not be spending money on a problem that will “fix itself”. His main argument was that invasive species are just “relative newcomers” and if they would have arrived 100,000 years ago they would have naturalized by now. I agree with him. It is true exotic species have not changed, but what has is the number of exotics arriving and the ecosystems that are here to greet them.

In order to explain let’s put ourselves in the role an exotic species that arrived 100,000 years ago. We would first have to make the long trip from Europe to North America before humans traveled from continent to continent. If we made it a crossed the vast ocean, a 3,475-mile journey, we would have accomplished an extraordinary feat! However, when we arrived it was to a land that hadn’t been affected by humans. Ecosystems functioned the way they should and all niches were filled. This would make it difficult for us to find the resources we need to survive. Compounding the problem, if the climate wasn’t right for all of us to flourish, many of us would die. If a strong few had the right traits to necessary to survive and we were lucky enough to find a niche that could be exploited, we would be able to establish a population. This would have been very unlikely occurrence.

Eileen Eck controlling a garlic mustard population at Larue Pine Hills in southwest Illinois

Eileen Eck treating a garlic mustard infestation at LaRue-Pine Hills in southwest Illinois

Why wouldn’t it be the same for exotic species today if we give them enough time? There are some differences in this story told above and the story told today. The first is the ease with which species are now transported. Everyday exotic species make that 3,475-mile journey by catching rides in the cargo and ballast water of ships and more are brought over as garden plants, or for erosion control. Not all of these exotic plant become invasive. However, it only takes one species to severely alter a native ecosystem. The second difference is the shape of our current environment. At the time of European settlement approximately 307,000 acres of wetlands, 19.5 million acres of prairie and 14.7 million acres of forest existed here. To date we have lost 90% of the wetlands, 99.9% of prairie communities, and 36% of our forests. (IDNR, 1996)  Healthy, functional ecosystems have been converted to farms and urban areas. I’m not knocking agriculture and cities. Civilization as we know it wouldn’t exist if it wasn’t for our ability to feed ourselves and live together. However, we must acknowledge that we have changed the dynamics of our ecosystems. Ecosystems affected by humans are weaker and dysfunctional. Gaps left in destabilized ecosystems are vulnerable to colonization by invasive species. In my opinion, since we are responsible for making the mess, we are responsible for cleaning it up as well!

Invasive species are vastly different than our native plants and animals. By taking advantage of our weakened ecosystems, they multiply uncontrollably, and rob resources to form massive monocultures that drastically change the dynamics of our native ecosystems. So something needs to be done. We can’t sit back and witness the collapse of our natural areas.  Mistakes and accidents happen, but we are still responsible for the mistakes we make.

For more information on the species of plants are currently invading our state. Visit this site for a full list of the invasive species in Illinois http://www.invasive.org/illinois/speciesofconcern.html

 

Illinois Department of Natural Resources. 1996. Illinois Land Cover, An Atlas. Critical Trends Assessment Project –                            Phase 2. Illinois Department of Natural Resources, Springfield, Illinois.

Why Prescribed Fire is Beneficial to the Health of your Forest

timber harvest

Many of us are aware of the devastating wildfires that occur in the western section of the United States. These wildfires occur largely because of years of fire suppression that occurred in a misguided attempt to protect land and communities.  This suppression led to a buildup of fuels and overcrowding of stands that historically were not as dense thanks to natural low intensity fire occurrence.  Because of this buildup, when a natural fire or a human caused fire occurs there is now a rapid spread of fire up into the crowns of trees. This causes large scale spread and burning throughout entire stands.  These effects are devastating and very easy to recognize. What many people are not aware of though, are the effects that have been happening in the central hardwood region as a result of decades of fire suppression.  Although we don’t see effects that are quite as catastrophic as entire forest stands going up in flame, there is a slower force of negative change at work here.  The central hardwoods in Southern Illinois and surrounding areas have historically been predominately oak and hickory forests.  These forests would have naturally occurring low scale fires every 5-20 years depending on the specific ecosystem location and vegetative community.  In addition to natural fires, Native Americans were the first land stewards in this area and used low scale fire as a tool for hunting and land management.  Since fire has been taken off of the landscape for more than a century in many areas, there is a phenomenon happening that is called mesophytic encroachment.  Oak and hickory cannot easily regenerate without light and somewhat xeric soils.  On the other hand, maple and beech can easily flourish in areas without much light and prefer mesic and wetter soils.  Most maple species and beech are considered to be more Eastern species.  Although they have their place here in the landscape in bottomlands and north facing slopes, they are becoming a problem by flourishing in the under and midstory of areas that should be predominantly oak and hickory.  Because of the overshading they create and the density mesic species can grow at, oak and hickory are not able to regenerate and compete with these more mesic species as they quickly grow and take over.  Not only does this affect forest firecomposition, it affects our ability to grow timber, our wildlife, our soils, and the ecosystem in general.  Oak and hickory are mast producing species and provide food to many of our native wildlife species.  As non-mast producing maple and beech takeover, mesophication poses a threat and negatively impacts the wildlife populations of the central hardwoods.  In addition to thinning through timber stand improvements, our best option to slow the spread of mesic species and to help the regeneration of oak and hickory species is prescribed fire.  Low scale prescribed fires when applied correctly will help to keep fuels at a reasonable level while also keeping maple, beech, and other mesic species in check.  Fire will also help cycle nutrients and expose mineral soil to acorns, allowing for oak seedlings to germinate and prosper with increased light levels.  Mesophication is becoming a serious issue; if we hope to preserve the legacy of the central hardwood oak and hickory forests we need to start using prescribed fire as a widespread management tool.

 

written by: Eileen Eck, OKES