historical biogeography: practical request

Joseph Kirkbride jkirkbri at ASRR.ARSUSDA.GOV
Thu Jan 14 09:34:13 CST 1999


For the Centroeste do Brasil there is a very detailed study of pollen
cores which show that it was much colder and wetter than any of us
expected.  There were extensive Podocarpus forests, perhaps 40-50%
Podocarpus, covering much of Minas Gerais at higher elevations.  This
work was done by a brasileiro as a doctoral dissertation.  I hope that it
was published, but I have never seen it:

  De Oliveira, Paulo Eduardo.
  1992.
  A palynological record of Late Quaternary vegetational and climatic
  change in southeastern Brazil
  Ohio State University
  Advisor: Paul A. Colinvaux

>From the conclusions:
1. 40,000 yr BP the winter temperatures in Minas were 7-9 degrees C.!
   During this period Araucaria forests covered much of Minas.
5. 20,000 yr BP higher elevations dominated by forests of Podocarpus and
     Caryocar.
6. Cooling lasted from 20,000 to 13,685 BP.
7. Podocarpus and Araucaria disappeared from Minas about 10,000 yr BP
     when there was an extensive dry period.
9. "There is no moment in the climatic history of the last 40,000 years
     of this region [Minas] that can be described as arid."
   "There is no evidence for the Late-Pleistocene Forest Refuge
     Hypothesis during the Late-Quaternary vegetational history of
     western and eastern Minas Gerais."
11. A new theorey for the high biodiversity in Minas has to be found
      because the refuria theorey has been refuted.

Joseph H. Kirkbride, Jr.
USDA, Agricultural Research Service
Systematic Botany and Mycology Laboratory
Room 304, Building 011A, BARC-West
Beltsville, Maryland 20705-2350 USA
Voice telephone: 301-504-9447
FAX: 301-504-5810
Internet: jkirkbri at asrr.arsusda.gov


On Wed, 13 Jan 1999, Thomas Schlemmermeyer wrote:

> ....if there is anything in the web about wet/dry-cycles in
> the southern hemisphere I would appreciate it as well!
>
>       Thomas
>
> On (    Wed, 13 Jan 1999 17:10:10 -0800), Gayle Hansen
> <gayle.hansen at HMSC.ORST.EDU> wrote:
>
>
> >Taxacom members:
> >
> >The historical biogeography WEB pages showing plate tectonics are
> >wonderful.  However, I wonder if there are comparable WEB pages for the
> >different glaciations and their extent.  I am particularly interested in
> >Alaska and the northern hemisphere.
> >
> >Sincerely,
> >
> >Gayle Hansen
> >Hatfield Marine Science Ctr.
> >Newport, Oregon
> >
>
> ------------------------------------------------------------------------------
> Thomas Schlemmermeyer
> Museu de Zoologia, Universidade de Sco Paulo
> Caixa Postal 42694
> CEP 04299-970
> Sco Paulo, SP, Brasil
>




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