On the Concept of Native Gardening, Part Three.

Part One.

Part Two.

In the years following the Spanish conquests and explorations of the sixteenth century, entire populations of Native Americans started dropping dead.  The Spanish had brought (inadvertently) a host of diseases with them which the isolated populations of the Americas had thus far managed to avoid.  While Europeans, Asians, and Africans had managed to build up immunity to certain diseases, maladies like smallpox now had the chance to affect a vulnerable population in the New World.  Along with their diseases, the newcomers also brought plants and animals that would find an open market to thrive and threaten to overtake their native counterparts, a tragedy which continues to this day.

So? Who cares?  Nature can't take care of itself?  Well it can, and sometimes nature can respond rather rapidly to sudden introductions between environments, but in many cases, we are a force of change that outpaces natural evolutionary process.  Sure, nature can be catastrophically destructive on its own, too, so we should not get upset when a hurricane or tornado wipes out homes and such, right?  You see the point...

So how bad are invasive plants?  Unlike the exotics that will rarely reproduce or do so at the same pace and type of spread of other plants, invasives are species that can do any or all of the following, in the absence of their native biological controls:

1. They grow much faster in their new home to the point at which they simply outgrow other things.

2. They can thus also crowd out other vegetation, meaning that if other things would start to grow along with them, they would be denied sunlight and nutrients, or even just sheer space, by the invader.

3. In doing this, and even when native plants do hold their own in competition, the invaders take away from the available food sources for animals.

4. They release either salts or chemicals into the soil to actually prevent anything from becoming competition again.

And then also, dependent on us yet again,

5. We still find such invaders beautiful and tasty and actually remove natural vegetation in favor of the invaders.

Now, this does far more than just outrage native purists like myself who like to see the landscape as it was designed by the Creator (yes, yes, I know, a loaded statement on all sides of the debate of Darwin vs. everyone else).  While I would like to illustrate the heinous nature of Kudzu (Pueraria Montana, and don't ask me how an Asian plant got a Latin name like that), it appears that I missed out on some photo ops of the deadly vine.  You can read more about it, and find some amazing pictures, here:

http://www.jjanthony.com/kudzu/houses.html

Instead, we can take a look at the forests and wooded places of Michigan yet again and stare sylvan death in the face.  I speak, of course, of Garlic Mustard (Alliaria Petiolata).  Garlic Mustard bears all five of the above marks of destruction.  Here we have two pictures of our "friend", the first for an example of how densely packed it can grow, the second for an example of what it can do to a forest.

Now, if the second image did not look at all that terrifying, keep in mind that that spread of the stuff goes well back into the underbrush.  It crowds out everything else, even itself, and when it dies it releases over a thousand seeds that explode into a decent cover of the area around each plant.  As if this were not enough, it releases allelopathic chemicals into the soil which its roots grow in.  If for some reason the plant would not reseed and germinate successfully, it would prevent anything else from doing that either.  It spreads like crazy, enough so that eradicators such as myself have been completely demoralized by seeing it everywhere. (And yes, this is what I do with my days, tromp through the forest, swamps, and prairies looking for stuff like this and removing it).

What happens when hopeless cases like me don't get out there and tell it to die and never come back?  You see that lovely forest up there?  That would become a memory.  Sure, it will not kill the trees outright, but eventually, they will fall or die by some other means and not produce future generations...  This thing literally not only harms biodiversity, it outright eradicates it.  In its native lands of Eastern Europe there are things that eat it and plants that have some degree of defense to its chemical warfare.  Here, even a starving deer will not even touch it, and our normally robust native plants get all wimpy around it.    Perhaps in time plants would adapt to this pest, but by then our natural lands would look very, very different and be quite dead... So how did it get here?  People thought it was tasty.  It tastes like garlic, well... bland garlic.  A bag full of the stuff smells like someone torched an Olive Garden, meaning it can make even a garlic lover like myself want to turn my nose.  Some people even think it is pretty and consider it a wildflower, which they either try to replant or let wreak havoc on the margins of their gardens and properties.  In this case, the choice to not garden with natives actually destroys the local ecosystem rather than simply result in an "also ran" landscape. 

Perhaps this would not be so bad if it were only Garlic Mustard engaging in ecological war crimes, but the truth of the matter is that we have a lot of invaders out there.

http://plants.usda.gov/java/noxComposite

Now don't get me wrong, this happens elsewhere in the world too.  We send stuff to Europe that has already had fun in destroying what little virgin landscape they have left there.  Invaders are just bad news everywhere.   Before you plant or before you decide not to weed, look up what you are introducing/neglecting.  Likewise, when traveling, be aware that not everything you see might belong there, which can sometimes kill the mood when you are impressed by the local flora, but can also help one appreciate what does belong there even more.  We are blessed in that for the most part, our continent still has a fair portion of its natural appearance intact where the lands remain undeveloped or have reverted to the wild.