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Report on Scientific sessions
The Second International Symposium was
held on July 7-13, 1996 at the University of Wisconsin
in Madison, Wisconsin, USA. The Organizers were
Monique Feist and Ingeborg Soulie-Märsche of the
University of Montpellier, and Linda E. Graham, the
local host
at the University of Wisconsin. The 34 participants
representing ten countries enjoyed the beautiful
lakeside location of the university campus, the excellent
meeting
room, the gracious hospitality of the local host,
Dr. Linda Graham, and the comradery of their fellow
participants.
The symposium began with registration and a welcome
reception in stately lobby of Birge Hall (home
of the Botany Department) on Sunday evening.
The program session began on Monday
morning in the modern lecture auditorium of Weeks
Hall (home of the Geology Department and the Geoscience
Museum). The opening session, like the remainder
of
the program, contained an interesting mixture of
different types of research beginning with two presentation
on
DNA sequencing studies followed by presentation
on morphological characters and then of "charophytivory." The
remaining presentation session (Monday afternoon
and all day on Tuesday) covered topics such as the
ecology,
ecophysiology, and distribution of extant taxa,
extant gyrogonite populations of Chara spp., and a
series
of papers on fossil studies.. The latter series
included presentations on paleoecological studies on
community
structure, biozonation, and charophyte diversity.
The oral presentations were complemented by several
poster
displays in the auditorium and adjoining lobby
area.
During the symposium the IRGC business
session and election were held (see other articles
in this newsletter to read about the election results
and other decisions made at the meeting). The successful
symposium ended with a reception in the botanical garden
near Birge Hall at which time a thank you gift was
presented to the local host, Dr. Linda Graham. Many
of the symposium participants took part in the excursion
to Northern Iowa to collect charophyte fossils with
Gilbert Klapper and to to watch Vernon Proctor lead
the group incollecting some living material.
Russell L. Chapman, Louisiana State
University
Report on Excursion 1:
Field Trip to Devonian Charophyte collecting sites
in Northern Iowa.
Twenty three of those attending the
Madison, Wisconsin, meeting of the IRGC participated
in the four day field trip to northern Iowa to
collect Devorüan and Modern Charophytes. The first
two days were devoted to travel and to collecting fossil
specimens, led by Gilbert KLAPPER of the University
of Iowa.
The route westward from Madison traversed
Late Cambrian sandstones and dolomites as well as Early
Ordovician dolomites of the Prairie du Chien group.
After a picnic lunch at Pikes Peak State Park in Iowa
overlooking the Ivhssissippi River, atop cliffs of
Ordovician formations (Prairie du Chien, St Peter,
Plattsville, Decorah and Galena), the group continued
westward to the first collecting stop at Bird Hill
East near Mason City, Iowa. There small roadside exposures
of the limy shales in the upper part of the Cerro Gordo
Member of the Lime Creek Formation (Late Devonian-Frasnian)
were explored.
Monique Feist presented a brief discüssion öf
the Charophytes that she and Gil Klapper had previously
collected there, which were identified as Moellerirra
greenei and Karpinskya bitineata. Orientation of
these primitive gyrogonites was discussed, as there
continues
to be problems concerning their orientation and
the relationship between Moellerina and Karpinskya.
After
several minutes search, the first specimen of a
Charophyte was found by Michelle Casanova ; then many
more were
found along with various megafossils.
The second day the group spent several
hours, including lunch, at the former Rockford Brick
and Tile Quarry, now a Nature Preserve. Here again
the Cerro Gordo Member, as well as the uppermost Juniper
Hill Member of the Lime Creek Formation are exposed.
Gyrogonites were seen in limestone samples, while shales
were collected for later washing.
Dr Day of the University of Iowa gave
a brief presentation and interpreted the depositional
environment of the Lime Creek as that of a shallow
restricted and open marine carbonate shelf and shelf
margin. Thus the Charophytes were probably washed in
from bordering non-marine areas.
Barbara and James Conkin, University
of Louisville (Kentucky, USA)
Report on Excursion 2:
Freshwater lakes and ponds of Northern Iowa with
extant characean species
The second excursion of the Wisconsin
meeting of the IRGC started out where the first excursion
finished: Rockford quarry. As well as being a site
for the discovery of Devonian charophyte gyrogonites,
there were several habitats for extant Chara in the
area. Professor Vernon Proctor led us down to a pond
where there was a lot of Chara contraria and a little
Chara globularis. Elodea ccmadensis also occuzred there
as well as lots of herbivores. The charophytes were
therefore species that were resistant to grazing by
scuds and beetles. We also visited another pond at
the site and there was some discussion about the relative
importance of the age of the water body and herbivore
abundance in determining charophyte species abundance.
At this site there were species of Cyperus, Juncus,
Eleocharis, Najas, Potamogeton as well as assorted
frogs, damselflies, dragonflies and birds. The lake
was in a nature reserve where there were planted prairie
grasses and wildflowers. Many characteristics of ponds
play a part in the determination of charophyte abundance,
Professor Proctor's constant contention was that herbivore
abundance plays an important part.
We arrived at Iowa Lakeside Laboratory
later that day, in time to hear a history of the site
by the manager. After a stroll around the shore, making
a meal for mosquitos, we ate a cheerful dinner with
the students and staff of the laboratory. We eventually
retired to the Super 8 Motel for a good nights sleep.
We had an early start the next morning
and headed off to Jackpot pond, one of the Iowa prairie
potholes that Henry Crum worked on for his PhD thesis.
Crum found that this one had up to 8 species of charophyte
present, although not all at the same time. For the
visit of the IRGC there were three species present,
Chara brauii, C. contraria, and C. globularis. Chara
braunii was scarce and the scuds and hydrophyllid beetles
were abundant. The coexistence of C. braunii and scuds
was contrary to expectations since Crum had described
the site as being `ephemeral'. It was explained that
`ephemeral' in the local sense meant drying every 3
to 5 years. It is likely that the diverse charophytes
would be present in the seed bank of the pond, and
present in the spring or in years following a dry spell.
The pond has also been divided into 4 separate ponds
by intersecting roads, and it is possibly different
in each of the four sections. As it was, Jackpot pond
was not the same as when Crum sampled there.
Our next stop was at Silver Lake Fen.
A fascinating site with Chara contraria in small ponds
down a slope where spring water seeped through. Most
of the participants ended up with wet shoes, or bare
feet as we squelched among the sedges, charophytes
and Triglochin. Utricularia was also present at the
site.
On return to the Lakeside Laboratory
we were given the opportunity to examine flowering
specimens of Lemnaceae. Most of us took the opportunity
to examine, what is in some places, a rare event. This
interlude was followed by a spirited boating party
onto West Lake Okoboji to look for charophytes. We
found Chara contraria at depths from 30 cm to up to
4 m deep. A cheer went up when charophytes were collected
from these depths. Despite lots of diving and looking
we found no Tolypella on this occasion. Upon return
we took advantage of the facilities offered by the
Lakeside Laboratory and examined the specimens collected
under the microscope. The people at Iowa Lakeside Laboratory
made us feel most welcome and provided us with all
that we could need.
The rest of the trip involved much discussion
about charophytes, and some sampling of beer. I found
it a delightful experience to be surrounded by so many
enthusiastic charophyte aficionados. Culture and language
appeared to be no barrier to communication about charophytes.
I am unlikely to experience the same again before the
next meeting of the International Research Group on
Charophytes, possibly in China. Congratulations to
the organisers of the conference and excursions, they
were an experience that I look back upon with pleasure!
Michelle Casanova University of Armidale
(Australia)
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