Biodiversity Pressure
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Natural forest is a habitat with a high level of
wild biodiversity. The destruction of forest causes degradation of
biodiversity.
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Population of Vietnam is estimated to be about 76.3
million (1999) and it grows at the rate of 1.7%/year.
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The population is unevenly dense. About 76.5% of
the population lives in rural and mountainous areas. Mean density in 1999
was about 230.6
people/km2.
- The rapid growth of population poses a pressure on natural resources, leading to their over-exploitation. Normally the areas having high level of biodiversity are also areas with high rates of poverty.
Exploitation and unsustainable use of biodiversity
resources
Overexploitation
causes the loss of living habitat
Forest ecosystem is a habitat for most wild animals,
particularly vertebrates (mammals, birds, and reptiles). Loss of forest
leads to habitat loss and threatens the survival of many wild animals.
This is one of the main reasons of biodiversity degradation in Vietnam. In
the coastal zone, exploitation of marine biological resources is difficult
to control and manage. Mangroves, estuarine waters and littoral areas are
overexploited, and destructive methods are often employed for fishing such
as dynamite, toxic chemicals, electric shock, trawl nets with small mesh
size.
Overexploitation
causes the destruction of
bio-resources
Before 1970s, forest types were diverse with an
abundance of wild animals such as elephant, rhino, tiger, wild cows and
buffaloes, reptiles etc. and many amphibian species in the flat delta and
rice-field. But now it has become difficult to observe wild animals even
in the nature reserves and National parks. Some mammal species are
practically extinct such as: rhino (Dicerorhyncus sumatrensis), Tapia indicus, forest buffalo (Bubalus bubalis), white handed gibbon(Hylobates lar), and water mongoose
(Cynogale bennetti). Some
others are on the brink of extinction such as tigers, Rhinoceros
sondaicus, banteng, gaur, spotted deer, muntjac, Asian heron, white
crested pheasant, etc.
During the period 1991-1995, there were 8,964 animals belonging to 19 rare species listed in the Red Data Book of Vietnam, which were subjected to hunting pressure. The average number of rare wild animals being hunted annually is about 1,743 individuals
Number of rare species
hunted during 1991-1995
|
No. |
Species |
Number
of individual |
|
1 |
Serow |
820 |
|
2 |
Banteng-
Guar Bos |
413 |
|
3 |
Napa |
1,174 |
|
4 |
Horse
Bear |
194 |
|
5 |
Dog
Bear |
277 |
|
6 |
Tigers |
70 |
|
7 |
Leopard
|
54 |
|
8 |
Wolf
|
32 |
|
9 |
Gibbons |
851 |
|
10 |
Various
monkeys |
1,145 |
|
11 |
Red
faced monkeys |
227 |
|
12 |
Various
Languor |
608 |
|
13 |
Cha
Va monkey |
1,364 |
|
14 |
Pangolin |
963 |
|
15 |
Flied
squirrels |
451 |
|
16 |
Peafowl |
13 |
|
17 |
White
crest grey pheasant |
619 |
|
18 |
Horned
pheasant |
20 |
|
19 |
Python |
333 |
Sources : Do Tuoc - FIPI, 1997.
At present, the environmental quality of many places in Vietnam is alarming. Many environmental components are degraded by many waste sources (solid wastes, waste water and emissions), which also contribute to biodiversity degradation. The direct effects include death and decrease in numbers and indirect effects include the destruction of habitats and living environment of wild animals. Currently, results from studies show that the socio-economic activities in coastal zone of the Ha Long City has caused decrease of habitat and degradation of sensitive coastal ecosystems for example, mangrove, coral reef, seaweed and seagrass.
Introduction of Exotic
species
For years, the exchange and introduction of some
exotic species has brought about significant economic benefits. 35 species
of ornamental fish and 11 species of fish for consumption were introduced
from various countries, which considerably increased the production of
in-land fishery. In some
places, new exotic species introduced into Vietnam comprised 70-80 percent
of cultivated plants with high productivity (Nguyen Dang Khoi,
1995).
However, the introduction of exotic species has
also caused considerable damage to some indigenous species. Some exotic
species such as the snail Pila
sinensis were introduced into Vietnam without adequate scientific
studies. The species multiplied rapidly causing serious damage to rice
production.
In practice, it becomes necessary to exchange genetic
materials between countries and areas. However, the introduction and use
of exotic species is complicated and can cause adverse impacts on
indigenous species and environment.