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is used is rarely specified suggests that its meaning is taken for granted. How-
ever, Merriam-Webster's dictionary (1981) provides two different definitions
and Morrison et al. (1992) observed that use of the word
habitat
remains far
from unambiguous. The latter distinguished two different meanings: one con-
cept that relates to units of land homogeneous with respect to environmental
conditions and a second concept according to which habitat is a property of
species.
Our literature review provided us with a variety of definitions and uses of
the term
habitat
that are wider than the dichotomy suggested by Morrison et
al. (1992). We arranged these various meanings according to two criteria:
whether the term relates to biota (either species and or communities) or to
land, and whether it relates to Cartesian (e.g., location, such as a position
defined by a northing and easting) or environmental space (e.g., the environ-
mental envelope defined by factors such as precipitation, temperature, and
land cover) (table 11.1).
Although the classification in table 11.1 allows us to partition the different
definitions of habitat we have traced, in reality this partition is rather hazy. For
instance, definitions range from the place where a species lives (Begon et al.
1990; Merriam-Webster 1981; Odum 1971; Krebs 1985), which is a totally
Cartesian space-related concept, to the environment in which it lives (Collin
1988; Moore 1967; Merriam-Webster 1981; Whittaker et al. 1973). In this
last case habitat is seen as a portion of the environmental space. At both
extremes of the range of definitions, the slight differences in the terms used
allows us to define a continuous trend between the Cartesian and the environ-
mental concept, which is further supported considering a few definitions that
combine the Cartesian and the environmental space (Morrison et al. 1992;
Mayhew and Penny 1992). These last authors define habitat as the area that
has specific environmental conditions that allow the survival of a species. Note
that all of these definitions relate habitat to a species and some describe it as a
property of an organism.
With a similar range of definitions, another group relates habitat to both
species and communities. For instance, Zonneveld (1995:26), in accordance
with a Cartesian concept, defined it as “the concrete living place of an organ-
ism or community.” Others relate it to both Cartesian and environmental
space, defining it as the place in which an organism or a community lives,
including the surrounding environmental conditions (Encyclopaedia Britan-
nica 1994; Yapp 1922).
All of the definitions cited so far defined habitat in terms of biota. Zon-
neveld (1995) remarked that the term
habitat
may be used only when specify-
ing a species (or community). Yet
habitat
has been used as an attribute of land.
