Getting Started - A Natural History of the New World - page 11

Figure 1.1 Vestige of the tropical forest, Guatemala. Photograph by Bruce Graham.
cal subcaducifolio (tropical semideciduous woodland) is known by sixteen
other names (Rzedowski 1978). The lowland neotropical rain forest is
known as the bosque tropical perennifolia, selva alta perennifolia, tropical
wet forest, fl oresta tropical húmida, and more informally the hylaea (the
name used by Humboldt). To the extent possible, a single name is applied
to each vegetation type throughout its range.
Second, the scheme must accommodate the ancient analogs as well as
the modern derivatives of the vegetation. Names using prominent genera to
defi ne units (e.g., pine-oak association) are convenient because they often
include modern representatives that are present and recognizable in the
fossil record (e.g., Pinus , pine; and Quercus , oak).
Third, the system need only be as complex as required for paleovege-
tation analysis. For example, in Mexico the height and deciduousness of
tropical forest trees varies with moisture, so it is possible to recognize a
gradational series ranging from the selva alta subperennifolia (tall semiever-
green forest), through several drier types, to the selva baja caducifolia (low
deciduous selva). Forest height and humidity are not directly evident from
fossil fl oras, so these selvas are grouped together here into the lower to up-
per montane broad-leaved forest formation.