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Galapagos Islands plants
 The
desert vegetation of
Baltra Island
comes as a shock to most visitors arriving at the archipelago's major
airstrip. After the lush greens of mainland Ecuador, the browns, greys, and
only occasional greens of this island seem inappropriate as an
introduction to one of the world's most famous wildlife paradises.
Baltra is one of the driest islands, but, even so, most of the
archipelago's land area is covered by semi desert or desert vegetation.
The islands lie in the Pacific Dry Belt and only the higher parts of the
larger islands receive enough rain to be considered tropically lush.
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The plants of the
Galapagos Islands
had a great influence on
Charles Darwin's
work. His interest in plant geography and dispersal mechanisms was closely
tied to the results of his collections on the islands. The first scientific
guide to the flora of the archipelago was prepared by Joseph Dalton Hooker
(1846), an eminent botanist, and was based mostly on Darwin's specimens.
Field work in the Galapagos is not easy. Lack of water
and tough terrain make it difficult for botanists to undertake extensive
collecting trips. The flora is still not as well known as we would like,
especially that of the uninhabited islands.
The number of plant species known from any island was
recently shown to be strongly related to the number of collecting trips made
to that island, rather than to any ecological factors.
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The number of plant species known from any island was recently shown to
be strongly related to the number of collecting trips made to that
island, rather than to any ecological factors.
Recent collecting trips have continued to discover numerous new species
and records. How-ever, as a result of Ira Wiggins' and Duncan Porter's
Flora of the Galapagos (1971), the plants of the Galapagos are
relatively well known.
 Duncan
Porter has calculated that less than 400 original colonists account for the
550 or so indigenous species. (The 250 or so endemics thought to have arisen
from about 110 arrivals.) To botanists it is n number of species that is
most important in the Galapagos but their nature. Leaving aside the plants
introduced by humans (which will be discussed in Chapter 12), 34 per cent of
the vascular plant species are endemic, while varieties and subspecies are
considered, 42 per cent of the taxa are en (Porter 1984).
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