Agriculture Reference
In-Depth Information
Northeast China and Inner Mongolia having a frostless season of 4 to 7 months, with an accumulated
temperature of
C, belong to the temperate zone. North China
having a frostless season of 5 to 8 months, with an accumulated temperature of 10
≥
10
C being about 1,700 to 3,500
ο
ο
C being
ο
3,500Ï4,500
C, belongs to the warm temperate zone. The regions south of the Changjiang River
are subtropical zones. The regions north of the Changjiang River and south of the Huaihe River
having a frostless season of 8 months, with an accumulated temperature of
ο
≥
10
C being 4,500 to
ο
5,300
C, are recognized as the northern subtropical zone. The vast areas between the Nanling Range
and the Changjiang River having a frostless season of 9 to 10 months and an accumulated temper-
ature of
ο
C belong to the middle subtropical zone. The regions south
of the Nanling Range and Southern Yunnan Province, with no winter and no snow, with an
accumulated temperature of
≥
10
C being 5,300 to 6,500
ο
ο
C, belong to the southern subtropical zone.
Hainan Province, the southern extremity of Guangdong Province Taiwan Province, and Yunnan
Province, generally have no temperature below 0
≥
10
C being 6,500 to 8,000
ο
ο
C and no frost all year round; with an accumulated
ο
temperature of
≥
10
C being 8,000 to 8,500
C or more than 8,500
C, these regions belong to the
ο
ο
ο
tropical zone.
In China, the coastal areas have a much higher annual rainfall, which decreases northwestwards,
while the evaporation rate is changing in the reverse direction. According to annual precipitation
and aridity, China is divided into four climatic regions, i.e., the humid region, semihumid region,
semiarid region, and arid region. Southeast China and the northern part of Northeast China, where
the annual precipitation is over 800 mm and the degree of aridity is less than 1.0, belong to the
humid region, covered by good forests and with rare incidence of drought. The Northeast China
and North China Plains and southern part of the Qinghai-Xizang Plateau where the annual precip-
itation is about 400 mm, with an aridity degree of about 1.5, belong to the semihumid region; in
this region, the natural vegetations are forests and steppe (or meadow), the soils are mostly
calcareous, and drought happens rather frequently in spring. The semiarid region covers Inner
Mongolia, the Loess Plateau, and Qinghai-Xizang Plateau, where the annual precipitation is usually
less than 400 mm, with an aridity degree of about 2.0. In this region, the soils are calcareous and
are usually salinized, and drought is rather serious in spring. The natural vegetation is mainly
steppe, and the soils are used for agriculture with appropriate irrigation. The arid desert region
includes Xin-jiang, western Inner Mongolia Plateau, and northwestern Qinghai-Xizang Plateau,
where the annual precipitation is less than 200 mm with an aridity degree of 2.0 to 8.0.
The natural vegetation in China is divided into three belts, i.e., the forest belt, the grassland
belt, and the desert belt. The forest belt covers the conifer-broadleaf mixed forest areas in the
northern part of Northeast China, the deciduous broadleaf forest areas in the hilly lands of Liaoning
and the Shandong Peninsulas, the North China Plain and the Loess Plateau in warm temperate
zone, the subtropical ever-green broadleaf forest areas south of the Qinling Mountains, and the
Huaihe River and tropical rain forest areas of the southernmost China. The grassland belt is located
in the northwest of the forest belt. It covers the Song-Liao Plain, the Hulunbeier Plateau, the Inner
Mongolia Plateau, the central part of the Loess Plateau, and the central and southern parts of the
Qinghai-Xizang Plateau. The desert belt is located in the inland basins of the Qinghai-Xizang
Plateau and the Xinjiang Plateau. It is covered by desert bushes and steppe.
Major Ecological Regions of China
China is divided into six major ecological regions, based upon a broad climatic and physio-
graphic zonation (Figure 10.2).
The cool, subhumid Dongbei Plain (1a) in the Northeast and the
humid temperate Huabei and Changjiang Plains (1b) in the East comprise the Chinese lowlands.
1.
The cool, subhumid Da Hinggan, Xiao Hinggan, and Changbai Mountain ranges in the Northeast.
2.
The semiarid to arid Nei Mongol Plateau with the adjacent, partly dissected, and subhumid Loess
Plateau in the central northern part.
