historical biogeography: practical request

Thomas Schlemmermeyer termites at USP.BR
Thu Jan 14 14:24:25 CST 1999


Thank you! That sounds interesting!
Araucaria angustifolia can be found still today in higher elevations
in Minas Gerais (exclusively quite old trees, maybe 300 years old)
which lead to the hypothesis of a small cool period a few centuries ago.

Still today, winters in Minas Gerais can be quite hard
(from a brazilian point of view) , with ice and frost in the
higher elevations.

As far as I know, today4s vegetation is result of the extensive forest
destruction by european settlers. So that, if one compares human impact
with quaternary impacts, it seems to be more like a dry cycle with forest
retreat.

   Cheers,   Thomas

On (    Thu, 14 Jan 1999 09:34:13 -0500), Joseph Kirkbride
<jkirkbri at ASRR.ARSUSDA.GOV> wrote:


>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
>>
>

------------------------------------------------------------------------------
Thomas Schlemmermeyer
Museu de Zoologia, Universidade de Sco Paulo
Caixa Postal 42694
CEP 04299-970
Sco Paulo, SP, Brasil

Residjncia:
Thomas Schlemmermeyer
Caixa Postal 00276
CEP 14001-970
Ribeirco Preto, SP, Brasil

Fone, Fax: 016 6371999
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