Biology Reference
In-Depth Information
the New World. They are listed below and defi ned the fi rst time they are
used in the text (see also table 1.1).
The New World at 100 Ma consisted of eight plant formations that
formed the vegetation component of the terrestrial ecosystems: (1) polar
broad-leaved deciduous forest, (2) notophyllous broad-leaved evergreen
forest, (3) paratropical forest, (4) tropical forest, (5) mangrove, (6) aquatic,
(7) herbaceous bog/marsh/swamp, and (8) beach/strand/dune (chap. 5).
These formations were unique or only shadowy versions of their modern
counterparts in structure, composition, ecology, and distribution. The task
is to understand how, when, and why these eight ecosystems transitioned
into the twelve modern ones listed in table 1.1 that now characterize the
New World and support its human and other animal life. The expectation is
that this information will be useful in planning for the future as fl uctuations
in CO
2
, temperature, and rainfall approximate conditions already known
from former geologic times.
I characterize each plant formation by citing representative species.
These names, along with the terminology for vegetation types, can be for-
midable obstacles to understanding ecosystems. Even the greatest minds—
Humboldt, for one—can be daunted: “He maintains a horror for the single
fact—hence his distain for botanical nomenclature” (De Terra 1955). Even
so, a familiarity with the types of communities, and some of their repre-
sentative species, is necessary to conceptually project them back in time
and to envision their change and movement over the landscape in response
to evolutionary and environmental processes. There are several ways to do
this. Each plant formation I mention is illustrated either in this work or in
Graham 1999 (I, chap. 1) and 2010 (II, chap. 3). Table 1.1 provides a guide
to all these illustrations. The Web offers additional examples as electronic
illustrations retrievable through the various search engines. For example, a
search for
Larrea tridentata
(creosote bush, a prominent plant of the New
World deserts) will yield several images of the plant in its natural habitat.
Other sources of illustrations, along with distribution maps, bibliographic,
and ecological information, are the virtual herbaria of the Missouri Botani-
cal Garden (www.mobot.org), the New York Botanical Garden (www.nybg
.org), and other botanical institutions. As of 2008 the TROPICOS database
at the Missouri Botanical Garden contained 1,008,141 names; 3,406,030
records; 111,521 bibliographic entries; and 70,111 digital images for the ap-
proximately 6 million plants in the collection. There are three thousand
herbaria in the world, and efforts are underway to link the major ones into
a single, searchable database. Consideration is also being given to the feasi-
bility of iPhone digital fi eld guides (Eisenberg 2009) and using barcoding
