rich in humus and moderately leached with a
distinct, light-colored zone under the upper dark
layer. The red-yellow podzols (Ultisols) have a
low supply of bases and a horizon of
accumulated clay. Where topography is favorable, diversified farming and dairying are the
most successful agricultural practice. Because
the gray-brown podzols (Alfisols) are soils of
high base status, they proved highly productive
for farming after the forests were cleared.
Most of the native forest has been cleared.
The forest is preserved throughout the mountainous terrain of the Appalachians Mountains and
the woodlots throughout the farmed belt. Much
of this forest consists of second- or third-growth
tree stands. Many farms in the forested area were
abandoned and have since been covered by successional forest. The original animal life was
abundant with deer, bear, panthers, squirrels,
and wild turkeys. Large mammals became scarce
during the peak of agricultural use, but
populations have increased with return of the
forest environment.
In China and Korea, the effects of prolonged
deforestation are evident everywhere. Throughout central Europe, large areas have been under
field crops and pastures for centuries, while at the
same time forests have been cultivated. Cereals
grown extensively in North America and Europe
include corn and wheat. In north China, wheat is
the principal crop. Rice is the dominant crop in
both south Korea and Japan. Soybeans are intensively cultivated in the midwestern United States
and in northern China and Manchuria, but very
little in Europe.
6.4
230 Subtropical Division
The humid subtropical climate, marked by high
humidity (especially in summer) and the absence
of really cold winters, prevails on the eastern
sides of the five continents in lower middle
latitudes, and is influenced by trade and monsoon
winds. These areas include the southeastern
United States, southern China, Taiwan
(Formosa), southernmost Japan, Uruguay and
adjoining parts of Brazil and Argentina, the eastern coast of Australia, and the North Island of
New Zealand.
In the Ko ¨ppen-Trewartha system, this area
lies within the Cf climate, described as temperate
and rainy with hot summers (see Fig. 6.3, climate
diagram for Shanghai, China). The Cf has no dry
season; even the driest summer month receives at
least 30 mm of rain. The average temperature of
the warmest month is warmer than 22
C. Rainfall is ample all year, but is markedly greater
during summer. Rivers and streams flow copiously through much of the year. Thunderstorms,
whether of thermal, squall-line, or cold-front origin, are especially frequent in summer. Tropical
cyclones and hurricanes strike the coastal area
occasionally, always bringing heavy rains and
flooding. Winter fronts bring precipitation,
some in the form of snow. Temperatures are
moderately wide in range, comparable to those
in tropical deserts, but without the extreme heat
of a desert summer.
Soils of the moister, warmer parts of the
humid subtropical regions are strongly leached
red-yellow podzols (Ultisols) related to those of
the humid tropical and equatorial climates. Rich
in oxides of both iron and aluminum, these soils
are poor in many of the plant nutrients essential
for successful agricultural production. They are
susceptible to severe erosion and gullying when
exposed to forest removal and intensive
cultivation.
Forest is the natural vegetation throughout
most areas of this division. Along the outer
coastal plain of the United States and in a large
part of southern China and the south island of
Japan, the native broadleaf forest was of the
evergreen type. This forest consists of trees
such as the evergreen oak, and trees of the laurel
and magnolia families. Near its northern limits,
vegetation of this region grades into broadleaf
deciduous forest. Another type of rainforest is
found in southeastern Australia and Tasmania
and consists of many species of eucalyptus,
which may reach heights of 100 m (Fig. 6.6).
The rainforest flora found in New Zealand
consists of large tree ferns, large conifers such
60
6 The Humid Temperate Ecoregions
distinct, light-colored zone under the upper dark
layer. The red-yellow podzols (Ultisols) have a
low supply of bases and a horizon of
accumulated clay. Where topography is favorable, diversified farming and dairying are the
most successful agricultural practice. Because
the gray-brown podzols (Alfisols) are soils of
high base status, they proved highly productive
for farming after the forests were cleared.
Most of the native forest has been cleared.
The forest is preserved throughout the mountainous terrain of the Appalachians Mountains and
the woodlots throughout the farmed belt. Much
of this forest consists of second- or third-growth
tree stands. Many farms in the forested area were
abandoned and have since been covered by successional forest. The original animal life was
abundant with deer, bear, panthers, squirrels,
and wild turkeys. Large mammals became scarce
during the peak of agricultural use, but
populations have increased with return of the
forest environment.
In China and Korea, the effects of prolonged
deforestation are evident everywhere. Throughout central Europe, large areas have been under
field crops and pastures for centuries, while at the
same time forests have been cultivated. Cereals
grown extensively in North America and Europe
include corn and wheat. In north China, wheat is
the principal crop. Rice is the dominant crop in
both south Korea and Japan. Soybeans are intensively cultivated in the midwestern United States
and in northern China and Manchuria, but very
little in Europe.
6.4
230 Subtropical Division
The humid subtropical climate, marked by high
humidity (especially in summer) and the absence
of really cold winters, prevails on the eastern
sides of the five continents in lower middle
latitudes, and is influenced by trade and monsoon
winds. These areas include the southeastern
United States, southern China, Taiwan
(Formosa), southernmost Japan, Uruguay and
adjoining parts of Brazil and Argentina, the eastern coast of Australia, and the North Island of
New Zealand.
In the Ko ¨ppen-Trewartha system, this area
lies within the Cf climate, described as temperate
and rainy with hot summers (see Fig. 6.3, climate
diagram for Shanghai, China). The Cf has no dry
season; even the driest summer month receives at
least 30 mm of rain. The average temperature of
the warmest month is warmer than 22
C. Rainfall is ample all year, but is markedly greater
during summer. Rivers and streams flow copiously through much of the year. Thunderstorms,
whether of thermal, squall-line, or cold-front origin, are especially frequent in summer. Tropical
cyclones and hurricanes strike the coastal area
occasionally, always bringing heavy rains and
flooding. Winter fronts bring precipitation,
some in the form of snow. Temperatures are
moderately wide in range, comparable to those
in tropical deserts, but without the extreme heat
of a desert summer.
Soils of the moister, warmer parts of the
humid subtropical regions are strongly leached
red-yellow podzols (Ultisols) related to those of
the humid tropical and equatorial climates. Rich
in oxides of both iron and aluminum, these soils
are poor in many of the plant nutrients essential
for successful agricultural production. They are
susceptible to severe erosion and gullying when
exposed to forest removal and intensive
cultivation.
Forest is the natural vegetation throughout
most areas of this division. Along the outer
coastal plain of the United States and in a large
part of southern China and the south island of
Japan, the native broadleaf forest was of the
evergreen type. This forest consists of trees
such as the evergreen oak, and trees of the laurel
and magnolia families. Near its northern limits,
vegetation of this region grades into broadleaf
deciduous forest. Another type of rainforest is
found in southeastern Australia and Tasmania
and consists of many species of eucalyptus,
which may reach heights of 100 m (Fig. 6.6).
The rainforest flora found in New Zealand
consists of large tree ferns, large conifers such
60
6 The Humid Temperate Ecoregions