Geography Reference
In-Depth Information
als found in each region (Briggs 1995). Forster understood that biotas are
living communities, characteristic of certain geographic areas, giving rise to
the concept of natural biotic regions (Briggs 1987). He found the tropics to
be the richest areas, where nature reached its highest expression (Browne
1983).
German zoologist Eberhardt August Wilhelm von Zimmermann
(1743-1815), in
Geographische Geschichte
(1778-1783), proposed that
species were created in the areas where they are distributed today. The cli-
mate that prevails today in these areas is the same that prevailed in the time
of the species creation. Zimmermann held that naturalists should avoid fruit-
less speculations and concentrate on solving more modest problems (Lar-
son 1986).
Karl Willdenow (1765-1812) was a German botanist and head of the
Berlin Botanical Garden. In
Grundriss der Kräuterkunde,
Willdenow (1792)
outlined the elements of phytogeographic regionalization. To account for the
differences between botanical provinces, he envisioned an early stage of
many mountains surrounded by a global sea. Different plants were created
on their peaks and then spread downward, as the water receded, to form
present phytogeographic provinces (Briggs 1987, 1995). Willdenow insisted
that many features of present distribution were products of historical devel-
opment (Larson 1986).
German naturalist Alexander von Humboldt (1769-1859), one of
Willdenow'sstudents,studiedLatreille'sandCuvier'sworksandgeneralized
Buffon's law to include plants and most terrestrial animals (Brown and Lo-
molino 1998). His
Essai sur la Géographie des Plantes
(Humboldt 1805)
was the result of extensive field work on Mount Chimborazo in the Andes.
Humboldt invented “botanical arithmetic,” a phytogeographic technique that
enabled naturalists to reduce the absolute number of species from different
regions into statements of proportions, which could be arranged with others
in a table. After calculation of the ratios of species of one plant family to
another, the predominant taxa of a region could be discovered objectively.
Humboldt, Robert Brown, and de Candolle made “botanical arithmetic” an
extremely useful tool, and although it was short lived, it was instrumental in
making the studies of geographic distribution a scientific exercise (Browne
1983). Humboldt's (1815)
Personal Narrative of Travels to the Equinoctial
Regions of America
was a key element in captivating a generation of natur-
alists, including Charles Darwin, Alfred R. Wallace, and Joseph D. Hooker.
