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<DIV><FONT face=Arial size=2>APWG: </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Definitions, to be useful in moving a discussion
forward as opposed to spinning its wheels in polarizing dialectics, must be
understood equally well and agreed upon by all participants. While it would seem
unnecessary to engage in such a discussion with respect to "alien" and
"invasive," I find that different posts seem to define these key terms
differently. Therefore, I will propose some definitions (particularly as they
relate to plants, but they should hold true for any organism). I ask that
responses be confined to corrections to the definitions in the form of
alternative definitions to keep the discussion from wandering off into the
intellectual weeds. Separate footnote discussions about the reasoning that
supports the definitions will be welcome, of course, but I respectfully request
that we keep it simple and stick to the subject. It is not my intention to
preserve these definitions, nor to start arguments; my hope is that definitions
will evolve that will serve to communicate these concepts clearly. If no
unanimity can be found or resolved, clarity in communication can still be served
by using modifiers to define the kind of "alien" or "invasive" is intended.
Anyone can define anything any way one wants, but only one person may understand
that definition in the same way as the originator. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. <EM>Alien</EM> (plant or other organism). An
organism that did not evolve with other organisms in a given habitat.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2. <EM>Invasive</EM> (plant or other organism). An
organism that exploits niches that meet its requirements for life. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Relevant comments:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. All plants and animals reconcile their
requirements for life with environments that meet them. Invasions may occur, but
the invading organisms must "find" or create environments that are suitable for
their requirements in order to establish and maintain populations that are able
to reproduce. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2. Environmental change is the rule, and there are
no exceptions. Change may be very fast or very slow, but nothing stays the same.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>3. Organisms "track" changes within their sphere of
influence/capacity. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>4. Analogously, human cultures acquire places to
live in which they exclude others (aliens). In that process, other species
exploit the effects of human cultural differences. Some species of rats, for
example, have become almost entirely dependent upon human cultures for their
existence and would be restricted to non-cultivated or undeveloped habitats and
might not survive, at least in large populations, outside the boundaries of
human cultures. Certain plants have become highly dependent upon human cultures
for their existence ("crops" and "weeds"), and may have evolved as a result,
perhaps to such an extent that they could not otherwise exist (or could be
highly restricted to certain habitats) in its absence. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I look forward to alternative definitions and
supportive reasoning and discussion. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>WT</FONT></DIV></BODY></HTML>