Thursday, October 26, 2006

Invasive definitions: native and exotic

I would like to finish my information gathering about Miscanthus, but I find myself side-tracked by my political writing on a local issue, which consumes much time. However, as I read through postings under the heading of invasive species, I continue to discover tangential topics for conversation and discussion. While reading about Miscanthus as a bio-fuel source in an article entitled "Adding Biofuels to the Invasive Species Fire?", I stopped short when I read the following:

“Although invasive species are traditionally thought of as introduced species, a native species also can become invasive through alterations to the environment, Wiedenmann said. One example: the removal of oak and chestnut trees along much of the east coast has led to sugar maples becoming invasive in some areas.”

Taking into account that the description above may be a natural areas succession sequence or, in fact, the makings of an invasion and resulting biological desert, this is my old friend, the fuzzy definition. Let me quote the federal definition as explained in a white paper (April 27, 2006) for those of you who have not moved on to something more exciting:

“Preamble: Executive Order 13112 – defines an invasive species as “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.” In the Executive Summary of the National Invasive Species Management Plan (NISMP) the term invasive species is further clarified and defined as “a species that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health.”

This is the native versus alien controversy that derails many attempts by differing interests group to come to some agreement. The native only sub goal rides under the radar of invasive species issues. A few years ago, the thought of placing a native on an invasive list was taboo in some circles. Today, a realization that any species can become invasive, a definition held by some, demonstrates the ever-evolving nature of understanding the science of invasive species. What this means for mortals, not daily involved in the discussion, is shifting perceptions of what an invasive species is, and therefore, at best, skepticism that there is a problem. When the definitions change so fast, coming to terms at a basic level is unclear in the best of circumstances. And further, trying to legislate, with fuzzy goals, leads to unintended consequences. Politically, a conservative, cautious stance is the usual response.

This caution in turn produces its own challenges. What we need is an early warning system and eradication special forces, a new eco-green-beret, ready to quash an invading species before it becomes to large to handle and a detriment to our environment. But fuzzy definitions blur distinctions for decision makers who control the financial purse and economic priorities. They do not see at best more than twelve months into a financial reporting document, whose balance sheets and profit/loss statements make no allowances for fuzzy futures and changing ecologies.

And while I am on this, let’s look up the definition of weed. I happen to belong to a long-winded, generation which feels compelled to use big words usually of a Greek or Latin origin when a simple plain good old Anglo-Saxon word would do just fine. And so the definition of a weed from PennState:
“A weed is a plant out of place not intentionally sown; whose undesirable qualities outweigh its good points. Some crop plants even can become weeds when they grow where they are not wanted. In contrast, a number of plants usually thought of as weeds may actually be helpful in controlling erosion or serving as food for wild animals and birds.”

For the general public, this just about sums it up. What about you? Any thoughts?

1 comment:

susan harris said...

Interesting topic and you're bringing some new sources into the discussion - always a good thing.
Other factors I can think of that can change plant behavior are climate change, the introduction of new (nonnative) pests like anthracnose, and reduction in certain animal populations.
What caused deer to get out of control - elimination of their predators?
Keep up the research, you guys. susan