Biogeography
What is it?
Biogeography
is the division of Biological Sciences that studies the creatures’
existance (animals and plants) on the Earth surface (continentes and
oceans and, also, the causes of this distribution in terms of space and
period.
Divisions
Biogeograpphy is divided in:
- ecological biogeography which studies the environmental factors that
determine orgamisns
distribution;
- Historic biogeography that based on historical factors studies
the spacial and temporal distribution of creatures.
Also considering the creatures division, biogeography
is divided in:
-
Fitogeography: when it is
related to plants distribution;
-
Zoogeography: when the
animals distribution is studied.
In both there is a subdivision in:
-
Terrestrial when the
terrestrial environment is studied and
-
Marine: when there is a
relation to marine plants or animals.
History-temporal Component
As well said
by Prof. Dr. Gustavo Augusto S. de Melo in his studies, from the São
Paulo University Zoology Museum, biogeography can’t be resumed to the
actual species distribution. There must be an historical proceed. There
always must exist an historical component, because there must be an
explanation on how the distribution was in the geological past, and in
wich way the studied species have reached the actual distribution.
For example, it is informed by the quoted professor that the marine
zoogeography, in which he is specialist, that studies the animals
distribution at the seas and oceans and the causes of this distribution in
relation to space and time, which would be the spaces and what does it
mean?
Space: all of the regions that are called marine, as the beaches,
continental plataform etc.
Time: geological events succession, as the islands raising in
Panama, at the end of Plioscene or at the beginning of Pleistoscene,
closing the link between Atlantic and Pacific Oceans, separating these two
faunas, that until that were only one. This separation, with the
geological time (million of years), made these two faunas (Atlantic and
Pacific) having own
characteristics, so they progressivily got less homogen, as one of the
mainly factors that influence on the species differenciation of species,
genes, families, or even faunas, is its isolation.
It is also said that the above example ios just one of the
countless aspects treated by Marine Zoogeography. Among these studies, we
can quote: seas and oceans notions, sea’s diversity, marine fauna
composition, biogeographic barriers or limits, ecology and the sea
evolution, marine fauna origin, the temperature importance in relation to
animals distribution.
Also for Helmut Troppmair, the space component is always present.
Ecoregions
In the
terrestrial biogeography there is a division that adopts units called
Ecoregions, for better ecossystems’ definitions and studies.
Nowadays thare are
869 ecoregions that are distributed in 14 terrestrial environments around
all the Globe, and in Brazil there are 78 of these areas (WWF and Ibama
notes).
The classification in
ecoregions helps a lot in studies projects and environmental management,
because it joins somer areas with similar characteristics, making easier
the local fauna and flora studies.
Conclusion
So, biogeography is a very important Science that studies life on the Earth, dividing it in regions, observing space and time, being a complex Science that can imensurable contribution to global environment studies, and consequently collaborating to environmental preservation programs and projects, as also giving subsidies to the growing Environmental Law, so the reason for our unserstanding about the necessity of this page in our site.
Basic Bibliography:
- BRIGGS,J.C. 1966. Zoogeography and evolution. Evolution,20(3): 282-289.
- BRIGGS,J.C. 1974. Marine Zoogeography. New York,
McGraw Hill. 475p.
- DARLINGTON, P.J. 1957. Zoogeography: the geographical
distribution of animals.New York, John Wiley (ed.). 675p.
- EKMAN, S. 1953. Zoogeography of the sea. London, Sidgwick and Jackson (ed.). 417p.
- MELO, G.A.S. 1985. Taxonomia e padrões distribucionais e ecológicos dos Brachyura (Crustacea: Decapoda) do litoral sudeste do Brasil.Instituto de Biociências Univ. São Paulo. 291p [Tese de Doutorado].
- TROPPMAIR, H. 1987. Biogeografia e Meio Ambiente. Edição própria. Rio Claro.São Paulo
- WOODRING, W.P. 1966. The Panama landbridge as a sea
barrier.Proc. Amer. Phil.Soc., 110 (6): 425-433.
Sites:
- http://www.geocities.com/RainForest/Canopy/1464/
- http://www.biogeography.org/
- http://www.fortunecity.com/campus/biology/752/biog1.htm
Collaboratin in this page by Prof. Dr. Gustavo Augusto
S. de Melo, From São Paulo University Zoology Museum (definition and
Marine Biogeography information).
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