Forest biodiversity
1 Forest plant
species diversity
3 Species
diversity of forest wildlife
4 The current
situation in terms of threatened forest biodiversity
5 Biodiversity
preservation and its sustainable use in China¡¯s forests
China has
an area of 158.941 million ha of forests, with forest stock of 11.27 billion m3
and forest coverage of 16.55%. There are many types of forest, that is,
coniferous, mixed coniferous and broad-leaved, deciduous broad-leaved,
ever-green broad-leaved and tropical, as well as their secondary types,
According to the classification system adopted in the ¡°Vegetation of China¡±, there
are 210 forest formations, 36 bamboo forest formations and 94 shrub, or bush
formations (with the exception of semi-shrub and herb formations), in China. In
addition to natural forests, there are many other types of man-made forest,
including those for artificial timber, shelter, other economic uses and
agroforests, which further enrich China¡¯s forest ecosystem diversity. Temperate
and subtropical montane altitudinal zonation is well developed in China. The
northern boundaries of montane and monsoon rain forest in the northern
hemisphere are located in China. China also has the richest species diversity
of Larix, Pinus, Picea, Abies, and Quercus, The extraordinarily high productivity
of a spruce forest occurs in the Yaluzangu River Valley.
Abundant
and diverse wildlife inhabits the various kinds of forest. There are 6,347
species of vertebrates in China. Among these, 581 species are mammals, 1,244
are birds, 280 are amphibians, and 376 are reptiles. Most of them inhabit the
forest or the fringes of them. Many animals are either endemic, or are mainly
restricted to China. For example, of the 276 pheasant species in the world,
China has 56, i. e., 20% of the total, and 19 are endemic. Other animals, such
as the Giant panda, Golden monkey, Cervus
albirostcis, Talim, and Elaphodus cephalophus, also only occur in China.
1
Forest plant species diversity
There are
about 2,000 species of trees and 6,000 species of shrubs in China, and include
floral components with global, tropical, temperate, pan-mediterranean and
Chinese native distributions. Geographically, although most tree species are
tropical and subtropical, almost all temperate genera of woody plants, such as Acer,
Betula, Juglans, Carpinus, Quercus, Picea, Abies and Elaegnus, also grow in
China. In China, there are still many ancient and relic tree species that are
extremely valuable globally. During glacial periods in the Caenozoic, vast
areas of south, central and southwest China were not influenced by glacial
movements, except for a few mountainous areas, and many Chinese endemic relic
species were retained, such as Gingo
biloba from before the Carboniferous/Permian, Podocarpus spp., Dacrydium
pierrei, Cephalotaxus spp., Taxus chinensis, Amentotaxus argoenia and Pseudotaxus
spp., all of which originated from the Mesozoic to the Old Tertiary. There
are other relict broadleaved species, such as Magnolia spp., Liriodendron
chinensis, Disanthus cercidifolius, Exbucklandia popunea, E.
tonkinensis, Rhodoleia parvipetala, Cercidiphyllum japonicum, Rhoiptelea chiliantha, Aphananthe aspera, Pteroceltis tatarinowii,
Annamocarya sinensis, Cyclocarya
paliurus, Eucommia ulmoides, Apterosperuma oblata and Euryodendron excelsum. There are many endemic tree species,
such as Tetrapanax papyriferus, Semiliquidambar cathayensis, Camptotheca acumimata, Bretschneidera sinensis, Davidia involucrata, Chimonnanthus praecox, Nyssa sinensis, Emmenopterys henryi,
Sinojackia xylocarpa, Sinowilsonia
henryi and Tapiscia sinensis.
Little
primary forest remains in China and is mainly distributed in the northeast and
southwest. According to the morphological characters of their trees, forests
can be classified into three categories, i. e., coniferous, broadleaved, and
mixed coniferous-broadleaved forests, and which make up 49.8%, 47.2% and 3%,
respectively, of the total.
(1) Coniferous forest
Coniferous forests are
distributed widely throughout the country. However, zonal coniferous forests
occur mainly in northeast and northwest China, as well as in the sub-alpine
areas of southwest and southeast Tibet. In addition, there are secondary
coniferous forests, such as secondary pine forests, and some man-made
coniferous forests, such as the Cunninghamia
lanceolata forest. They are not only rich in terms of plant species, but
are also inhabited by many animals, and act as habitats and refuges for
numerous endemic species.
A. Boreal
coniferous and sub-alpine coniferous forests
These
represent the horizontally zoned type forests at high latitudes and the
sub-alpine type at low latitudes, respectively. Although they have different
distributions and different geographical environments, they still belong to the
cool-temperate vegetation type, with a similar community morphology,
composition and structure.
a. Larix forest There are 10 species and 2
varieties of Larix in China. The
edificator species of this forest type are Larix
gmelini, L. sibirica, L. pricipis-rupprechtii, L.
chinensis, L. mastersiana, L. potaninii, and L. griffithiana.
b. Picea and Abies forest Most of the
China¡¯s spruce forests and fir forests belong to montane altitudinal types,
with broad distributions and large stocks. The main edificator species of this
type of forest in China are Picea
jezoensis var. microsperma, P.
koraiensis and Abies nephrolepis in
the northeast, Picea meyeri and P.
wilsonii in the north, Picea
crassifolia, P. schrenkiana and Abies sibirica in the northwest, and Picea likiangensis, P. likiangensis var. balfouriana, P. likiangensis var. litziensis, P. barchytyla var. complanata, P. barchytyla, P. asperata, P.
purpurea, Abies fargesii, A.
faxoniana, A. ernestii, A.georgei, A. squamata, A.
spectabilis, A. delavayi, A. fabri and A.
forrestii in the mountains of the southwest.
c. Pinus forest The main edificator pine
species of this forest type are Pinus
sylvestris var. mongolica, P.
pumila and P. sibirica in northern China, and many others in the south.
d. Sabina forest Sabina forests are mainly
distributed on the southern slopes of sub-alpine areas in southwest and west
China, at elevations of from 2,800 to 4,500m. The main edificator species are Sabina saltuaria, S. przewalskii and S.
recurva.
B.
Warm-temperate coniferous forests
This type
of forest is mainly distributed in northern China and the Liaodong Peninsula.
The main ediphicator species are Pinus
tabulaeformis, P. densiflora, Platycladus orientalis and
Pinus bungeana.
C.
Subtropical coniferous forests
There are
many types of coniferous forest in subtropical China. The main species are Pinus massoniana, P.
yunnanensis, P.
yunnanensis var. tenuiformis,
P. kesiya, P.
armandi, P. densata, Cunninghamia
lanceolat, Cryptomeria fortunei, Cupressus
duclouxii, C.
funebris, Keteleeria fortunei, K. davidiana and Cathya argyrophylla.
D. Tropical
coniferous forests
There are few coniferous species in
tropical China. They used to be scattered and rarely developed as pure forest.
The main species are Pinus latteri, P. fenzeliana
and P. roxburghii.
(2)
Mixed coniferous and deciduous broadleaved forests
a. Pinus
koraiensis and mixed broadleaved forest
The mixed forest of Pinus koraiensi and some broadleaved species is a zonal type in
temperate China and is mainly distributed in the Changbai Mountains and Xiao
Hinggan Ling Mountain of northeastern China, and extending to the Amure State
in Siberia and the northern part of Korea. The main edificator species are Pinus koraiensis and some broadleaved
species, such as Juglans mandshurica,
Fraxinus mandshurica, Tilia amurensis, Acer mono and Ulmus davidiana var. japonica.
b. Mixed Tsuga and broadleaved forest
The mixed forest of Tsuga and broadleaved species is mainly distributed in mountainous
areas of subtropical China and is the transition from ever-green broadleaved
forest to the sub-alpine coniferous forest of subtropical mountains. The main
species of the forest are Tsuga
longibracteata and T. chinensis, mixed with broadleaved species of
the Fagaceae.
A special zone of mixed Tsuga and broadleaved species is formed
at elevations of between 2,500 m to 3,000 m in the western part of subtropical
China, and in which Tsuga dumosa is
often dominant.
(3)
Broadleaved forests
a. Deciduous broadleaved forests
Deciduous broadleaved forests are
distributed widely in temperate, warm-temperate and subtropical China. The main
types in north and northwest China are mixed deciduous broadleaved forests of Quercus, Alnus, Chosenia
arbutifolia and Elaeagnus Oxycarpa. In subtropical China there are
secondary forests of Castanea, Alniphyllum
fortunei and Liquadambar formosana which
formed after the ever-green forests were destroyed. Secondary types of boreal
coniferous forests and sub-alpine coniferous forests comprise Populus davidiana and Betula, respectively. In subtropical mountains there are Fagus forests and in limestone mountains
are Platycarya strobilacea, Pteroceltis
tatarinowii and Ulmus parvifolia, and Pistacia chinensis forests.
b. Evergreen broadleaved forests
The evergreen broadleaved forest is a
zonal type in moist subtropical China, and where many plant and animal species
live, e. g., the number of higher plant species in the ever-green forest is
more than half the total number of higher plant species in China, There is
usually no distinctive dominant species in an evergreen forest. The most common
types are Cyclobalanopsis, Castanopsis, Lithocarpus, Machilus, Cryptocarya, Schima, Altingia
and Manglietia forests.
c. Sclerophyllous forests
In ancient regions of West Sichuan, North
Yunnan and Southeast Tibet, there are some relic communities similar to the
sclerophyllous forests of the Mediterranean and which are mainly distributed on
the southern slopes of mountainous areas at elevation of between 2,000-3,000m.
The common sclerophyllous forest types are Quercus
aquifolioides, Q.
pannosa, Q.
longispica, Q.
gryvaefolia, Q. gillian and Q. semicarpifolia forests on the mountain
slope, and Quercus cocciferoides,
Quercus rehderiana, Quercus franchetii and Quercus
senescens forests in the valley floors.
d. Mixed deciduous and ever-green
broadleaved forests
The composition and structure of mixed
deciduous and evergreen broadleaved forests are complex. They can usually be
divided into several types, e. g., the mixed deciduous and evergreen
broadleaved forest in northern subtropical China, in mountainous areas at
elevations of between 1,000-1,200m to 2,200m in subtropical east China, and the
mixed evergreen and deciduous broadleaved forest restricted to limestone
mountains in subtropical China.
e. Monsoon forests
The monsoon forest is representative of
monsoonal tropical China, and which is mainly distributed in upland, basin and
valley areas with a dry season in winter. They are mostly derivative forest
communities. For example, the most common forest types are Chukrasia tabularis, C.
tabularis var. velutiae,
Macaranga denticulata, Trema orientalis, Erythrina stricta. Bombax malabaricum,
Albizia chinensis, Terminalia hainanensis,
Lannea coromandelica, and
Liquidambar formosana and Schima forests.
f. Tropical rain forests and seasonal
rain forests
Rain forests are found in mountainous
areas at elevations above 500£700m in tropical China. Dacrydium pierrei and Lithocarpus forests are common in
mountains areas of Hainan Island, while Podocarpus
imbricatus and Nephelium chryseum are
distributed in southern Yuannan. The seasonal rain forests on limestone
mountains with luxuriant species diversity occur in southwestern Guangxi.
3
Species diversity of forest wildlife
Various
kinds of forest provide diverse habitats for wildlife. Forest wildlife
resources are extremely abundant in China, and are estimated at over 1,800
species. Among these are the precious and endangered ones, such as Alces alces, Lepus timidus, Panthera
tigris altais, Martes zibellina, Cervus albirostris,
Ailuropoda melanoleuca, Rhinopithecus roxellanae, Bos
gaurus, Hylobates spp. and Elephas maximus. Birds,
insects, reptiles, amphibians and various lower animals are also abundant. The
inventorying of these species is not comprehensive.
(1) Wildlife in cold-temperate coniferous
forests
Wildlife in
cold-temperate coniferous forests are distributed in Daxing¡¯ anling and
Xiaoxing¡¯ anling mountains in northeastern China and in the Altai mountains of
northern most of Xinjiang. The north and of Xin¡¯anling Mountains is adjacent to
the Siberian Taiga forest, and has the latter¡¯s characteristic fauna.
Ungulates
such as Alces alces,
Cervus elaphus, Capreolus capreolus,
Moschus moschiferus and Sus scrofa have
wide distributions. Among these, Cervus
elaphus and Sus scrofa are
common. Alces alces is a typical
inhabitant of the coniferous forest zone and mostly inhabits mixed forests with
broadleaved trees such as Populus,
Betula and Salix and eats tender
leaves.
Canivorous
animals include Mustela sibrica,
M. altaica, Ursus arctos,
Martes zibellina, Felis lynx, and Mustela nivalis. They are valuable
fur animals.
Rodents
include Sciurus vulgaris,
Petinomys spp., Eutamias sibiricus,
Clethrionomys rufocanus, C.
rutilus, and
Apodemus flavicollis.
Forest
birds are Tetrao parvirostris,
Bonasa spp., and Lagopus lagopus. Being typical cold-temperate birds,
they nest on the ground and are adapted to cold weather. In addition, there are
Nucifraga caryocatactes,
Upupea epops, Phylloscopus inornatus,
Picoides tridactylus, Dryocopus martius,
and Accipiter virgatus.
Beyond the forest, near water bodies, there are Anas crecca, Tadorna ferruginea,
T. tadorna and Anser anser. These water fowl all
propagate in the forests.
(2) Wildlife in temperate forests
Wildlife in
temperate forests are distributed in the vast temperate monsoonal area from the
south of the northeastern coniferous forest to the north of the Qinling-Huaihe
river line. In the mixed coniferous-broadleaved forest zone, ungulates are Capreolus capreolus,
Cervus elaphus, Moschus moschiferus,
Naemorhedus goral, and Sus
scrofa. Of these, Capreolus
capreolus, Cervus elaphus, and Sus scrofa are common. Carnivores are Panthera tigris, P. pardus, Selenarctos thibetanus,
Ursus arctos, Nyctereutes procyonoides,
Martes flavigula, Felis bengalenris and Martes zibellina. Owing to the
destruction of habitats and human interference, Panthera tigris, P.
pardus, Selenarctos thibetanus, Ursus arctos, Nyctereutes procyonoides,
Martes flavigula, Felis bengalenris and Martes zibellina have become rare. Small
rodents, such as Sciurus vulgaris,
Eutamias sibiricus, Clethrionomys rufocanus,
C. rutilus and Odemus speciosus occur everywhere and
are dominant species. In the forest rim of the northeastern mixed
coniferous-broadleaved forest, Phasianus
colchicus, Cyanopica cyana interposita,
Dryocopus martius, Picoides tridactylus and Carrulax davidi are the most common
birds. Grus japonensis,
Aix galericulata, Anser cygnoides, A. fabalis, Anas platyrhynchos and
A. crecca also
reproduce here.
(3) Wildlife in sub-tropical forest
Only a few
sub-tropical forests survive with small acreages, For example, Mandrillus arctoides and Rhinopithecus roxellanae are seen only
in a few montane forests in northwestern Yunnan, Sichuan, Guizhou and Southern
Anhui, and are endangered. Callosciurus
pygerythrus, Dremomys pernyi and Tamiops swinhoei are dominant species
and Sciurotamias davidianus is also
common. The ungulates Muntiacus reevesi,
Elaphodus cephalophus and wild boar, are frequently seen in reclaimed
mountainous areas and secondary shrubs and grasslands of hills. Rhizomys sinensis, which relies on the
shoots and roots of bamboos, inhabits sub-tropical dense forests, with Manis pentadactyla and Hystrix hodgsoni as representative
species. Carnivores are Panthera tigris
amoyensis, P.
pardus, Neofelis nebulosa, Felis bengalensis,
Viverra zibetha and Paguma larvata. Among these, Panthera tigris amoyensis, P. pardus and Neofelis nebulosa are all endangered.
(4) Wildlife in tropical forests
This is the
most diverse category of forest and has many endemic families, genera and
species, e. g., Tupaidae, Hylobateidoe, Viverridae and Elephantidae. Some of
the widely distributed categories of tropical forests occur frequently with
high ratio. Within a small area often rest many kinds of animals with similar
life habits, such as Callosciurus
erythralus and Callosciurus
pygerythrus which inhabits the depths of the forest, Tamiops swinhoei, Macaca
mulata, Macaca arctoides, Presbytis spp. and Nycticebus coucang each live in their own territories.
Representatives of the Buceros e. g., Nectarinia
alnae, Hypogramma hypogrammica and
Pericrocotus spp. Are the major birds
of tropical forests.
4
The current situation in terms of
threatened forest biodiversity
(1) The current situation
The forest
area per capita is only 0.12 ha in China, 12% of the world average. Forest
stock per capita is less than 13% of the world average. Forest coverage is low
and only the half of the world average. The forests are distributed unevenly.
Despite the increasing trend in forest cover during recent years, mainly due to
an increase in artificial forests, the natural forest, as a treasure house of
biodiversity resources, is still decreasing. Furthermore, most natural forests
are deteriorating. China¡¯s forest and natural forest areas during the inventory
period of 1973£1976 were 121.86 million and 98.17
million ha, respectively. The corresponding figures for 1977£1981 were 115.27 million and
93.08 million ha, again respectively. Heilongjiang province, as a key virgin
forest area, Its natural forest acreage in 1977£1981 was 14.64 million ha but
this decreased to 13.96 million ha in 1984£1988. It is estimated that
between 4000£5000 higher plants species are endangered
and threatened, i. e., 15%£20% of the total species, while the world
average is 10%. The first list of rare and endangered plants has been issued
and includes 388 species. Among the believed extinct or nearly extinct plants
are Thuja sutchuenensis,
Firmiana hainanensis, Ostrya rehderiana,
Apterosperma oblata, Euryodendron excelsum,
Ormosia howii, Craigia kwangsiensis,
Nyssa yunnnanensis, Parakmeria omeiensis,
Abies beshanzuensis, Amentotaxus formosana,
Keteleeria pubescens, Hopea mollissima, Otophora unilocularis,
Mussaenda anomala, Vatica guangxiensis,
Betula halophila, Carpinus putoensis,
Fleutharrhene macrocarpa, Manglietiastum sinicum,
Bhesa sinensis, Reevesia rotundifolia,
Sonneratia hainanensis, Tangtsinia nanachuanica,
Archineottia gaudissartii and Diplandrorchis
sinica. There are probably no more than 10 existing plants of these
species and they are distributed in only one site. At present, four hundred
species of wildlife are endangered or threatened The disappeared or extinct
species in China include Dicerorhinus
sumatrensis, Equus przewalskii,
Panthera tigris lecoqi, Pygathrix nemaeus and Elaphurus davidianus,
while Ailuropoda melanoleuca,
Rhinopithecus roxellanae, Neofelis nebulosa nybulosa,
Panthera tigris altais, Panthera uncia, Hylobates spp., Cervus eldi hainanus,
Camelus ferus ferus and Nycticebus
coucang are on the verge of extinction. Obviously, most of the endangered
species in China belong to the forest. Their distribution areas are gradually
shrinking and their populations and communities are decreasing rapidly.
The species
diversity decrease also mirrors the loss of, or severe stress to genetic
diversity. For example, evergreen broadleaf forests formerly widespread in
subtropical regions have been extensively felled and substituted by Chinese fir
and Masson pine. Species have drastically decreased in these artificial
forests. The structure and function of the ecosystem has been destroyed, land
fertility has declined, biodiversity decreased and productivity reduced
everywhere.
(2) Reasons for the stress
a.
Over-logging
According
to the forest resource inventory and statistics for the three periods 1973£1976,1977£1981 and 1984£1988, the overall loss of
forest resources was always more than the growth in China, and the differences
between them show an increasing trend. Based on statistics for 1977£1981, the forest resource loss
was about 294 million m3 during this period, i. e., a rate of 3.19%.
Comparing the statistics for 1977£1981 and 1984£1988, the mature forest
resource was astonishingly reduced by one-third, from 3,845.93 million m3
to 2,621.63 million m3, with an average annual reduction of 170.66
million m3 and a loss rate of 4.44%. During the 4th inventory period
(1990£1993),
although the rate of forest resources loss slowed, forest over-logging still
continued. In 1993, the national forest resource loss exceeded a reasonable
limit by 34 million m3. Through over-logging and slower
reforestation, as compared to the rate of deforestation, more and more open
forests, cut-over sites and bare mountain areas increased. Based on 1978
statistics, about one-third of the cut-over sites were converted into bare
mountain areas, with no immediate reforestation. During the 5 years of 1977£1981, the open forest area
increased by 10%, totaling 17.20 million ha, i. e., 14%15% of the forest area.
The main
reasons for this loss are£º(1) Deforestation for farming. About
one-third of the farmland has been exploited from primary forestland in China.
Especially in tropical China, more farmland was converted from forestland, for
shifting-cultivation and tropical economic plantations. For example, in Hainan
Island the agricultural exploitation rate of the land, i. e., the proportion of
farmland to total area, kept increasing annually along with the population
increase. Between 1950 to 1989, the accumulated area converted to farmland from
forest land was only 27,526 ha in all China, whereas in 1990, the area was
7,989 ha and in 1993 it was drastically increased to 440,000 ha, (2) Fuel
gathering. Fuel-wood was traditionally the main source of heating energy in
rural areas. Today, fuel-wood is still the only source of heating energy for
some mountainous rural communities and makes up about 68%¡«74% of their total energy
consumption. Especially in arid areas, there is still a serious energy shortage
for villagers. Based on statistics, the annual gap in energy resources for
rural communities in west China equals 6,590,000 t of standard coal, which is
translated into a fuel-wood shortage of between 3¡«6 months a year. This
situation again resulted in the increase in the intensity and scale of
fuel-wood gathering in this region. (3) Illegal cutting of forest. According to
statistics for 1987, the total number of illegal cutting of forest events was
74,600 cases, resulting in a timber area loss of 97,300 ha and forest volume of
1,402,900 m3. This threatens a biodiversity in two ways: (1)
reduction of forest types and (2) the destruction of forest habitats which, in
turn, results in the extinction or compulsory migration of animal species.
b. Forest
fires
Forest
fires occur at a high frequency and cause serious damage in China. Forest fires
not only result in the death of a large number of forest plants and animals,
but also the destruction of forest habitats, as well as causing changes in the
regional climate, and soil and vegetation composition and succession. Based on
statistics, the total area damaged by forest. Fires in China was 12,660 ha in
1990 and 22,200 ha in 1991 when forest-fire events increased by 3.8% and the
damaged forest area increased by 53.9%. In recent years, however, the rate of
damage due to forest fire in China has been decreasing year after year. The
worst forest fire since 1950 occurred in the northern part of Daxinganling
forest in 1987. It resulted in a total disaster area of 1,330,000 ha and in
which the burned forest and open forest area was 1,140,000 ha with a totally
damaged forest area of 870,000 ha. A large number of seed bearers, juvenile and
middle-aged trees were killed by the fire bringing about a serious problem of
natural forest regeneration in this region. The percentage forest cover
decreased from 76.0% to 61.5% after the fire. The fire also resulted in changes
to the ecological environment of the forest, such as the drying of slopes, the
degradation of shady hygrophytes, such as Rhododendron,
the luxuriant growth of xeromesophytes, such as Orostachys, Sedum and Artemesia, and the conversion of lowland into
swamp. The island like permafrost layer retreated. Pest damage by Ips subelongatus, occurred in larch
forests. The fauna of the forest soil was also drastically reduced, e. g.,
predatory animals with a bigger body-size decreased while saprotrophic animals
with smaller bodies, increased.
c. Forest
pest damage
It is documented
that more than 8,000 species of forest insects and diseases have been
discovered in China, and of which about 200 occur commonly on a large scale
throughout the country. Since the 1960s, the over-logging of natural forests
and the increase in man-made forests have become more and more frantic and such
activities have changed the composition and structure of forest vegetation and
the foodweb of the forest ecosystem. The self-resistant capability of the
forest to pest damage has decreased, resulting in a significant increase in
forest pest scale and frequency that has further harmfully influenced forest
growth and development. Based on data over the period from 1987 to 1991, during
this period, the area of forest diseases and insect pests was 214 times that
damaged by forest fire in the same period. The direct economic loss was
5,000,000,000 RMB. Along with the accelerating afforestation, the area of
artificial forests increased rapidly, and the forest diseases and insect pests
also entered a peak of occurrence, so that the task of prevention and control
will be much harder.
d.
Afforestation with mono-species
The most
profitable way to protect and to increase forest biodiversity is to close
hillsides and, second, to aerial sow. There are 33 million ha of man-made
forest which makes up about one-fourth of the total forest land in China,
ranking the country first in the world in terms of the scale of development and
the rate of increase. No attention has, however, been paid to closing hillsides
and aerial sowing for afforestation. The impacts of man-made forest development
on biodiversity are made up of two components: first, afforestation was a trade-off
for natural forests where a rich biodiversity had always existed, so that the
formerly, continuously distributed, natural forest ecosystems were either
broken up or partly substituted by the man-made forests; second, reforestation
used to be by mono-species with conifers in the majority creating a simplified
community structure.
e.
Environmental pollution
Acid rain
damage is a large problem in China. The main composition of acid rain in China
is sulfates. Based on statistics for 1994, the annual released amount of sulfur
dioxide was 18.25 million in China. Acid rain hazards to the forest are
widespread, and include 22 provinces/autonomous regions/municipalities directly
under the Central Government. It is especially common in regions south of the
Yangtze River, such as some areas in eastern, southern central and southern
China, as well as regions south of Qinling Mountain in southwestern China.
Preliminary investigations of four provinces or autonomous regions, i. e.,
Sichuan, Guizhou, Guangdong and Guangxi, show that more than 15,000 ha of
forests have died from acid rain damage, and 400 ha of forests are suffering
from acid rain. Acid rain also causes an increase in soil acidity and a
decrease in soil productivity, which indirectly results in the degradation of
forest growth and a decrease in forest resistance capability to pests and other
natural stresses, as well as an increase in the acidity of water bodies in
forest regions that have made some fish species unable to survive.
f. War
Wars
occurred frequently in China from the ancient to the present time. The nation
has suffered from numerous big and small wars during its long history of 5,000
years, resulting in the loss of a large number of forest and biodiversity
resources. During 1840 to 1949, forest resources were drastically reduced by
destruction of the forest vegetation and timber robbery during war years, which
resulted in the disappearance of 80% of the virgin forests in China during this
period. During the Anti-Japanese War (1937£1945), forest resources were
seriously destroyed, e. g., in northeastern China only about 6,421,780 m3
of forest was lost and the total loss to the country was more than one-tenth of
its stock.
g.
Disappearance and habitat fragmentation
On Hainan
Island, large areas of forest have been mostly transformed to rubber forest and
other artificial forests, and partly degraded into mountain grass vegetation,
as a result of the destruction of rain forest which, in turn, has resulted in
the substitution of Lonchura spp. and
Passer spp. for Psittacula alexandri fasciata and Gracula religiosa, and of
terrestrial beasts for arboreal ones. The primate Hylobates concolor hainanus is a typical arboreal species, and is
accompanied by Petaurista hainana, Pefinomys electilis and Ratufa spp.. The massive loss of
tropical rain forest has resulted in a drastic decrease in the populations of
these species and the sending of them to the verge of extinction. According to
statistics, there were 2,000 individuals of Cervus
eldi hainanus at the beginning of the 1950s but, after large scale rubber
planting, only 76 were left in the 1980s. At the same time, the number of Hylobates concolor hainanus was reduced
from 2,000 to about 30.
Habitat
fragmentation also has a direct impact on the survival of wildlife. Based on a
joint survey conducted by the Chinese Ministry of Forestry and WWF during 1986
to 1988, the habitat of the Giant Panda, Ailuropoda
melanoleuca, has been
continuously contracted. Compared with the 1970s, Giant Panda habitats have
decreased from 45 to 34 counties, and habitat loss is thought to be 11,000 km2
resulting in a discontinuous distribution. The population of the Giant Panda
has been divided into 24 sub-populations because of habitat fragmentation
resulting in inbreeding and loss of its genetic base, so that the species has
become highly endangered.
In
addition, illegal hunting of wildlife and over-gathering of medicinal plants
are important factors causing biodiversity stress to forest ecosystems.
5
Biodiversity preservation and its
sustainable use in China¡¯s forests
The forest plays
critical role in environmental protection and the sustainable use of forest
resources is the most important part of economic sustainable development.
During the last fifty years, China¡¯s government has done much to conserve and
expand forest resources, as well as preserving forest diversity. Up to now, in
addition to more than 500 forest ecosystem nature reserves and forest wildlife
types, more than 230 wildlife artificial breeding bases or breeding grounds
have been established, including those for the Giant Panda and Panthera tigris altais. As a result, these two and more than 10
other species of endangered animals, which were once on the verge of
extinction, have begun to restore their population numbers. At the same time,
more than 60 rare wild animals have been successfully and artificially bred.
Along with whole-people tree plantings, afforestation and various
forest-ecology engineering schemes (See section 4.4.4(4)), the quantity and
quality of forest resources in China is continuously increasing and improving,
and forest biodiversity may also be more efficiently protected.