separately, the geographic distribution of animal
species or communities may change due to hunting, a circumstance usually independent of habitat loss. This reality needs to be understood in a
multicultural context because not all cultures
limit or otherwise regulate hunting in a manner
that sustains game species populations.
In contrast to systems that accommodate
human influence by recognizing “anthropogenic
biomes” (e.g., Ellis and Ramankutty 2008), we
need to recognize naturally occurring ecosystem
boundaries so that we can more meaningfully
map them by screening out the effects of disturbance and succession. Mapping based on present
biota characteristics and combinations does not
allow for such screening; but screening allows us
to recognize, to compare, and to work with
ecosystems regardless of land use or disturbance.
The potential of any system makes it possible to
understand and manage it wisely. One way to
illuminate this potential is through the concept
of the climax. This concept, developed largely
by Frederick Clements (1916), recognized that
vegetation develops through a series of stages
until the whole region is clothed with a uniform
plant and animal community. The final stage is
determined solely by the climate, and is known as
climatic climax vegetation. Although theoretically possible, variations in local environments,
particularly in soil parent material, prevent largescale homogeneity so that a region is more likely
to have several or many climax vegetation types.
This realization led to the polyclimax concept
(Tansley 1935), which recognizes that the climax
vegetation of a region consists of not just one type
but a mosaic of climaxes controlled primarily by
soil conditions. These are the edaphic climaxes.
To look at any given area regarding the ecological consequences of human activities, we must
understand that area’s full range of features as
understood by geologists, biologists, and others.
To the point: we must look at that area from the
standpoint of its status as an ecosystem, and not
just locally but also much more expansively
including the larger land area of which it is a part.
Regarding the delimitation of geographic land
units and the purpose driving this endeavor—to
create a system for an ecological division of the
world—the term “ecoregion” is comparable to
those regions referred to by other authors. Specific examples would include, among others, the
following seminal contributions:
• Major natural regions (Herbertson 1905)
• Landscape belts (Passarge 1929)
• Habitat regions (James 1959 et seq.)
• Landscape zone (Isachenko 1973)
• Terrestrial landscapes (Biasutti 1962)
• Morphoclimatic zones (Tricart and Cailleux
1972)
Ecoregions differ from these particular divisional units explicitly because they are based on
the distribution of ecosystems. However, the
ecoregion concept is much older than it might
seem. The ancient Greeks recognized such a
concept; and in the eighteenth century, Baron
Alexander von Humboldt provided an outline
that described latitude zonality and elevation
zonality of the plant and animal world in relation
to climate (Jackson 2009). The significant work
of Dokuchaev (1899) developed the theory of
integrated concepts. He explained that extensive
areas (zones) share many natural conditions and
features in common, but he further explained that
these change markedly in passing from one zone
to another. One could consider the efforts of C.
Hart Merriam (1898) to define life zones of the
United States as one approach to delineating
regions. He described seven transcontinental
belts, or life zones, based on associations of
plants and animals. His work asserted that these
natural zones were suitable to certain varieties of
crops; and based on this work, the United States
Department of Agriculture later developed the
Plant Hardiness Zone Map that divides the country into 11 zones and shows whether a crop or
garden plant will survive the average winter
(Cathey 1990).
Each ecoregion is typically characterized by a
single climax, but two or more climaxes may be
represented within a single ecoregion. This often
happens on mountains where each elevation zone
may have a different climax.
The concept of “ecoregion” differs from that
of “biome,” for a biome is coincident with its
climaxes. Every area having the same climax,
however far detached from the main area of that
148
Appendix D: Comparison of Ecoregion and Related Approaches
species or communities may change due to hunting, a circumstance usually independent of habitat loss. This reality needs to be understood in a
multicultural context because not all cultures
limit or otherwise regulate hunting in a manner
that sustains game species populations.
In contrast to systems that accommodate
human influence by recognizing “anthropogenic
biomes” (e.g., Ellis and Ramankutty 2008), we
need to recognize naturally occurring ecosystem
boundaries so that we can more meaningfully
map them by screening out the effects of disturbance and succession. Mapping based on present
biota characteristics and combinations does not
allow for such screening; but screening allows us
to recognize, to compare, and to work with
ecosystems regardless of land use or disturbance.
The potential of any system makes it possible to
understand and manage it wisely. One way to
illuminate this potential is through the concept
of the climax. This concept, developed largely
by Frederick Clements (1916), recognized that
vegetation develops through a series of stages
until the whole region is clothed with a uniform
plant and animal community. The final stage is
determined solely by the climate, and is known as
climatic climax vegetation. Although theoretically possible, variations in local environments,
particularly in soil parent material, prevent largescale homogeneity so that a region is more likely
to have several or many climax vegetation types.
This realization led to the polyclimax concept
(Tansley 1935), which recognizes that the climax
vegetation of a region consists of not just one type
but a mosaic of climaxes controlled primarily by
soil conditions. These are the edaphic climaxes.
To look at any given area regarding the ecological consequences of human activities, we must
understand that area’s full range of features as
understood by geologists, biologists, and others.
To the point: we must look at that area from the
standpoint of its status as an ecosystem, and not
just locally but also much more expansively
including the larger land area of which it is a part.
Regarding the delimitation of geographic land
units and the purpose driving this endeavor—to
create a system for an ecological division of the
world—the term “ecoregion” is comparable to
those regions referred to by other authors. Specific examples would include, among others, the
following seminal contributions:
• Major natural regions (Herbertson 1905)
• Landscape belts (Passarge 1929)
• Habitat regions (James 1959 et seq.)
• Landscape zone (Isachenko 1973)
• Terrestrial landscapes (Biasutti 1962)
• Morphoclimatic zones (Tricart and Cailleux
1972)
Ecoregions differ from these particular divisional units explicitly because they are based on
the distribution of ecosystems. However, the
ecoregion concept is much older than it might
seem. The ancient Greeks recognized such a
concept; and in the eighteenth century, Baron
Alexander von Humboldt provided an outline
that described latitude zonality and elevation
zonality of the plant and animal world in relation
to climate (Jackson 2009). The significant work
of Dokuchaev (1899) developed the theory of
integrated concepts. He explained that extensive
areas (zones) share many natural conditions and
features in common, but he further explained that
these change markedly in passing from one zone
to another. One could consider the efforts of C.
Hart Merriam (1898) to define life zones of the
United States as one approach to delineating
regions. He described seven transcontinental
belts, or life zones, based on associations of
plants and animals. His work asserted that these
natural zones were suitable to certain varieties of
crops; and based on this work, the United States
Department of Agriculture later developed the
Plant Hardiness Zone Map that divides the country into 11 zones and shows whether a crop or
garden plant will survive the average winter
(Cathey 1990).
Each ecoregion is typically characterized by a
single climax, but two or more climaxes may be
represented within a single ecoregion. This often
happens on mountains where each elevation zone
may have a different climax.
The concept of “ecoregion” differs from that
of “biome,” for a biome is coincident with its
climaxes. Every area having the same climax,
however far detached from the main area of that
148
Appendix D: Comparison of Ecoregion and Related Approaches