LTER CROSS-SITE ACTIVITY:
DOCUMENTATION OF THE PRESENCE AND
ABUNDANCE OF NON
INDIGENOUS SPECIES
What
is this all about: The first wave of European
explorers/colonizers to regions represented by our LTER network intentionally
or unintentionally introduced new species (here identified as "non-
indigenous species or "non-native species"), and this wave of species
introductions has continued to date.
Why
documentation of these species is important: Non-indigenous
species introductions have been
identified as the second most common threat to
native species presence and abundance. (Just after habitat destruction, and
since habitat destruction is not usually an LTER focus, non-indigenous species
may emerge as the most important threat to native diversity at our sites.)
Biotic change is a component of global change. (and whether this change is
`cause' or `effect' is often a research question). Some LTER sites remain
pristine (i.e., few non-native species) but that may change in the future.
Indeed, the transformation of species composition across the landscape, and
particularly in those sites where these changes are accidental, is believed to
be an important and relevant LTER
cross-site activity for years to come. The
mechanisms required to exclude these species are both fundamental research
questions and management concerns. In short, invasive species is currently a
hot ecological topic and likely to remain so into the future.
What's
needed: The enclosed example from the Shortgrass Steppe
is shown to indicate the first round of data collection. Even this simple
analysis requires that each site a) have a species list and b) have the ability
to identify native and non-native species on this list. The current working group is very
plant-biased, but we hope to get a fauna (and, eventually, microbial) group
going.
So,
where do we go from here:
Please consider this a data request that a) your
group has already filled (see below), b) you may be able to fill without
assistance, or c) you need to take this to the attention of the person in
charge of your diversity data set(s). (Again, the bias here is plants, but
we're willing to act to put together a fauna working group if anybody contacts
us about this.). Essentially, the minimum data
requirement is
a) A
species list. By habitat or community type is better than
just a list. But, if all you have is a list, you
can participate.
b) A
designation to whether a species is "native" "non-native"
or
"native status unknown". Informed
guesses are often used here and, in our mind, are acceptable.
Someone in your group will be the cited
authority for this designation.
c) If
abundance or cover data are also available by species (better, by species and
habitat), we would value this. We realize this data set will be harder to
obtain, and may be restricted to only certain small areas of your LTER. That's
ok. If you've got the metadata, we've got the time to work on this!
When you've completed this activity, you'll have
a benchmark data set that can now form the basis for prior research efforts on
your site. And, you'll have a contribution to an exercise that hopefully will
be presented at the Coordination Committee Science Meeting in Sept., 2002. We
need your help to make this a useful and interesting science exercise!
Current participating sites: NWT, SGS, KNZ, JRN,
VCR.
Please send any comments, questions or data to:
Possible interested LTER personnel for
invasives:
KBS Kay Gross, Stuart Gage
NTL Tom Hrabik, Karen Wilson
HJA Julia Jones, Charles Halpern
HFR Kristina Stinson
HBF Tim Fahey
CWT Kitty Elliot
Note:
These folks have not been contacted since the
first data request was made- so therefore they will be unaware of our plans-
however these are the likely folks for the data managers to contact at their
sites.
Ex.
Proposal for inter-site activity on invasive
plant species.
The LTER network represents an important
opportunity to collect data on exotic and invasive plant species over wide
range of environments and associated ecosystem types. While there are a large
number of potential activities we could engage in with respect to
exotic/invasive plants, we are proposing a modest beginning with the
expectation that additional activities will be added in the future. The
objective of our proposal is to encourage an activity to compare floristic
surveys of plants for each LTER site. Ideally these surveys will be conducted
by landscape types. By floristic we mean that only an assessment of presence is
required. If an individual of a particular species in present in a particular
landscape unit, it is added to the species list for that unit. By landscape
types we mean important units of the landscape diversity of the site that
affects the composition of the plants that grow there such as uplands, riparian
areas, etc. Corridors that may function as avenues for invasive plants move
into the site should also be included. Table 1 provides and example of the
results of such a survey for the SGS LTER site (Hazelett 1998)
