regional-scale ecosystems, or ecoregions.
This book classifies and plots their distribution based on specific criteria that define
what type of region each is. It provides
illustrated descriptions of 31 terrestrial and
15 oceanic ecoregions in a comparative
context.
5. A unique feature of this book is its coverage
of both oceanic and continental ecosystems.
Oceans occupy some 70 % of the Earth’s
surface. In a hierarchical sense, they are
the environment of the continental system
embedded within, controlling their behavior,
through their influence on climatic patterns.
Understanding continental systems requires
a grasp of the enormous influence that
marine systems exert on terrestrial climatic
patterns and thus the character and distribution of continental ecosystems. The surface
of the ocean is differentiated into regions
with different hydrology, defined as the seasonal variation in temperature and salinity.
Ocean hydrology controls the distribution
of life in the oceans and is the basis for
regional-scale ecosystem units. The book
includes extensive discussion of the factors
controlling ocean hydrology. Building on the
work of Gu ¨nter Dietrich, it focuses on the
roles that latitude, wind systems, precipitation, and evaporation play in affecting the
distribution of the Earth’s major oceanic
regions.
6. Based on macroclimate and on macrofeatures of the vegetation determined by
those conditions, the continents are
subdivided into ecoregions with three levels
of detail. Their boundaries are determined
using the Ko ¨ppen–Trewatha climate classification system as a starting point in combination with potential natural vegetation at the
level of plant formation. The arrangement of
the ecological climate zones depends largely
on latitude and continental position. To further complicate matters, the Earth’s internal
energy causes irregular patterns of high
mountains on the continents. These modify
the climate that would otherwise exist on a
flat continent. Mountains exhibiting
elevational zonation and having the climatic
regime of the adjacent lowlands are distinguished according to the character of the
zonation. These will differ according to the
climatic zone in which they are embedded.
7. We have the knowledge base, the mapping
tools, and the analytical protocols necessary
to evaluate factors affecting the distribution
of the Earth’s major ecoregions. Our
objective, therefore, should shift from
mere empirical description of site-specific
localities to discovering and documenting
the mechanisms that are responsible for producing the world pattern of ecoregions.
Understanding spatial relationships between
causal mechanisms and resultant patterns is
the key to understanding ecosystem dynamics and how they respond to management.
8. We can interpret the patterns of both ocean and
continental ecoregions through macroclimate.
Ecoregions recur in similar form in various
parts of the world. Because of this predictability, we can transfer knowledge gained about
one region to another; and because data can be
reliably extended to analogous sites within a
region, we may greatly reduce data sampling
and monitoring.
9. As with the larger ecoregions, the pattern of
sites within each continental region also
recurs predictably; but the pattern of local
ecosystems is controlled by finer scale climatic variation that result from differences
in landform. Local variation in landform
(geology and topography) will cause smallscale variations in the amount of solar radiation received, create topoclimates, and affect
the amount of soil moisture. These variations
will subsequently affect the biota, creating
ecosystem sites as subdivisions of a larger
ecoregion.
10. With recognition that climate is the primary
controlling factor for ecosystem distribution,
there exists a need to study potential climate
change on ecosystem distribution, from the
regional (ecoregion) to the local, site scale.
Knowing where ecological shifts will most
138
14 Summary and Conclusions
This book classifies and plots their distribution based on specific criteria that define
what type of region each is. It provides
illustrated descriptions of 31 terrestrial and
15 oceanic ecoregions in a comparative
context.
5. A unique feature of this book is its coverage
of both oceanic and continental ecosystems.
Oceans occupy some 70 % of the Earth’s
surface. In a hierarchical sense, they are
the environment of the continental system
embedded within, controlling their behavior,
through their influence on climatic patterns.
Understanding continental systems requires
a grasp of the enormous influence that
marine systems exert on terrestrial climatic
patterns and thus the character and distribution of continental ecosystems. The surface
of the ocean is differentiated into regions
with different hydrology, defined as the seasonal variation in temperature and salinity.
Ocean hydrology controls the distribution
of life in the oceans and is the basis for
regional-scale ecosystem units. The book
includes extensive discussion of the factors
controlling ocean hydrology. Building on the
work of Gu ¨nter Dietrich, it focuses on the
roles that latitude, wind systems, precipitation, and evaporation play in affecting the
distribution of the Earth’s major oceanic
regions.
6. Based on macroclimate and on macrofeatures of the vegetation determined by
those conditions, the continents are
subdivided into ecoregions with three levels
of detail. Their boundaries are determined
using the Ko ¨ppen–Trewatha climate classification system as a starting point in combination with potential natural vegetation at the
level of plant formation. The arrangement of
the ecological climate zones depends largely
on latitude and continental position. To further complicate matters, the Earth’s internal
energy causes irregular patterns of high
mountains on the continents. These modify
the climate that would otherwise exist on a
flat continent. Mountains exhibiting
elevational zonation and having the climatic
regime of the adjacent lowlands are distinguished according to the character of the
zonation. These will differ according to the
climatic zone in which they are embedded.
7. We have the knowledge base, the mapping
tools, and the analytical protocols necessary
to evaluate factors affecting the distribution
of the Earth’s major ecoregions. Our
objective, therefore, should shift from
mere empirical description of site-specific
localities to discovering and documenting
the mechanisms that are responsible for producing the world pattern of ecoregions.
Understanding spatial relationships between
causal mechanisms and resultant patterns is
the key to understanding ecosystem dynamics and how they respond to management.
8. We can interpret the patterns of both ocean and
continental ecoregions through macroclimate.
Ecoregions recur in similar form in various
parts of the world. Because of this predictability, we can transfer knowledge gained about
one region to another; and because data can be
reliably extended to analogous sites within a
region, we may greatly reduce data sampling
and monitoring.
9. As with the larger ecoregions, the pattern of
sites within each continental region also
recurs predictably; but the pattern of local
ecosystems is controlled by finer scale climatic variation that result from differences
in landform. Local variation in landform
(geology and topography) will cause smallscale variations in the amount of solar radiation received, create topoclimates, and affect
the amount of soil moisture. These variations
will subsequently affect the biota, creating
ecosystem sites as subdivisions of a larger
ecoregion.
10. With recognition that climate is the primary
controlling factor for ecosystem distribution,
there exists a need to study potential climate
change on ecosystem distribution, from the
regional (ecoregion) to the local, site scale.
Knowing where ecological shifts will most
138
14 Summary and Conclusions