Environmental Science Forest

Protection forest divided into three types, watershed protection forests, forest protection against sand and forest protection of coastal waves • Special use forests are used for special

1 Overview of forest resources

- Forest is one of the most important part constituting the biosphere

- Important role in creating the landscape and have a strong impact to the climate factors, land Standpoint theory of ecosystems, the forest are seen as a typical ecosystems in the

biosphere (Temslay, 1935: Vili, 1957; Odum, 1966) In the other hand, Based on the theory of the forest of Morodov Sukasov, the forest are a Biogeocenose Two theories are not different in the nature They are recognized and used in research of the forest

- Forests are also of great significance in the development of economic, social, ecological and environmental

- The formation of forest types are closely related to the formation of natural vegetation with geographic and climatic conditions In each forest type is formed, the climate, soil,

moisture will determine the composition and structure of the potential development of

vegetation

The division of the forest types of forest vegetation types are mainly based on the

ecological advantages

Some flora is important in the world

• Temperate coniferous forests with a relatively homogenous, lower yields than the

tropics, they are mainly distributed in North America, Europe, North China and some tropical mountains The trees are mainly pine, spruce, fir

• Temperate deciduous forest is distributed at low and tropical regions, mainly in

northeast America, South America, Asia Europe, a part of China, Japan, Australia

• Tropical rain forests are distributed mainly in the equatorial region of the Amazon Basin (South America), the Congo River (Africa), India, Malaysia Because of the complexity of changing rainfall patterns, monsoon and temperature, the tropical forest are often very complex in both composition and structure of forest

Based on the nature and purpose, the forest is divided into three types

• Protection forests are used for the purpose of protecting water, soil, prevent erosion and mitigate natural disasters, climate regulation, protection of ecological environment Protection forest divided into three types, watershed protection forests, forest

protection against sand and forest protection of coastal waves

• Special use forests are used for special purposes such as nature conservation, genetic conservation of forest flora and fauna, in service of scientific research, protection of historical, cultural and scenic for tourism It includes national parks, nature reserves, cultural and historical sites

• Production forests, including forest type used for wood production, forest animals and associated ecological environment protection

Forest resources are plentiful and diverse, including biological resources, land, climate and landscape The exploitation and utilization of forest resources in the world depends on

technology, traditions and social customs of each region and each country

Wood used as fuel, construction materials and raw materials for different industries: paper, plastic, paint Wood is considered the first material of chemical industry

Forests is an important resource, forests provide raw materials for human and base

economic resources of many ethnic in the world Exploitation of forest resources has

contributed an important part in economic and social development of many countries around the world

2 The importance of forests for environment

- Forests are the most important component constituting Biosphere In addition to significant plant and animal resources , the forest is also a geographical factor which is essential in nature, it plays vitally important role in the landscape and have strong impact to the land climate factors Therefore,it is not only has the function of forests in economic development, social but also of special significance in environmental protection1 Forests are the obstacles to the transport of wind and affect speed and direction of wind In

general, if h is the height of the forest range, the incidence of forests to reduce wind

speed significantly within 50-10 h in direct side and 20 - 30h in indirect side

2.1) Forest not only blocks wind but also cleans the air and have a great influence on carbon cycle in nature

In fact, the forest is considered as a giant dust refinery

Annually 1 ha of forests absorbs 36.4 tons of dust from the air

- Several research also showed that, the radioactivity in water in the place where the are forest only equal a half in the place have no forest

Pic.Schematic diagram of carbon cycle in a forest The processes drawn with red arrows lead major isotopic fractionation

2.2) Forests also contribute significantly reduces noise

For example a 50 m wide strip of trees beside the road has the potential to reduce noise 20 -30 dB

2.4 Forest has special meaning to the importance of balance oxygen and carbon dioxide

in the atmosphere

Every year about 100 billion tons of CO2 fixed during photosynthesis by plants and a similar amount is returned to the atmosphere by various processes in nature

It is predicted that if the whole biomass of tropical rain forest were burned in the next 50 years, and the amount of CO2 generated is not replaced by other sources to absorb CO2 is released at a rate of twice the current today

if the rate of deforestation maintain by 2050, the atmospheric concentration of cacbon

dioxide will doubled compared with the current and temperature of the Earth will increase by about 2 degree At that moment the ice will melt make the sea level rise as high as 3m by the end of XXI century

2.5) Phenomenon of evaporation from plant biological effects of climate create rain clouds The amount of water released from the plant is huge and depending on soil moisture In Sweden, from 1 ha of spruce forests on dry land out of water about 2100m3 /year , equivalent

to a rainfall of 210 mm, while 1 ha of forest on soil moisture will exit near 4000m3/year ,

equivalent to 400mm Overall, the amount of water vapor from the coniferous forest plants average 2-3 tons / ha / year, also in evergreen forests may reach 4-6 tons / ha / year Material evaporation occurs under the forest canopy is much less than bare ground, usually only 100 tonnes / ha / year in European forests

.Forest created a sub-climate environment well to human health Forests reduces the

temperature and increases humidity Especially many species can secrete substances with bactericidal action phitoxin special pine (Pinus sp), camphor (camphora cinamonmun),

eucalyptus (Eucalyptus), cinnamon (cassia Cinnamonmun)

Forest with the role of watershed protection, soil protection against erosion Vegetation have

an important function in preventing a fall to the ground and rain water has a role in the

redistribution of this water

Studies show that plants retained 25% of the total rainfall.The canopy of forest can reduce the power of destruction of rain with topsoil Forests increase infiltration and water holding

capacity of soil, restricting the flow on the surface Litter of the forest floor can hold 100-900%

of its weight Therefore significantly reduce soil erosion

Many studies show that in our country humid tropics, where forest soil erosion each year only about 1 - 1.5 tons / ha in the forest where there is no up to 100-150 tons / ha and the surface flow increased 3-4 times

3.Common causes of deforestation

 Commercial logging companies cut down mature trees that have been selected for their timber The timber trade defends itself by saying that this method of 'selective' logging ensures that the forest regrows naturally and in time, is once again ready for their 'safe' logging practices (WWF)

 Removing a felled tree from the forest causes even further destruction, especially when

it is carried out carelessly It is believed that in many South East Asian countries

'between 45-74% of trees remaining after logging have been substantially damaged or destroyed

 The reason these people are referred to as 'shifted' cultivators is that most of them people have been forced off their own land For example, in Guatemala, rainforest land was cleared for coffee and sugar plantations The indigenous people had their land stolen by government and corporations They became 'shifted cultivators', moving into rainforest areas of which they had no previous knowledge in order to sustain themselves and their families (Colchester & Lohmann)

 The creation of national parks has undoubtedly helped to protect rainforests Yet, as national parks are open to the public, tourism is damaging some of these areas

 Often, national parks are advertised to tourists before adequate management plans have been developed and implemented Inadequate funding is allocated for

preservation of forests by government departments Governments see tourism as an easy way to make money, and therefore tourism is encouraged whilst strict

management strategies are given far less government support

4.Forest loss and management

 Anthropogenic factors that can affect forests include logging, urban sprawl, human-caused forest fires, acid rain, invasive species, and the slash and burn practices of

swidden agriculture or shiftin cultivation

 Expand the area of agricultural land to meet food production

 Demand for fuelwood

 Grazing

The loss and re-growth of forest leads to a distinction between two broad types of forest, primary or old-growth forest and secondary forest There are also many natural factors that can cause changes in forests over time including forest fires insects, diseases, weather, competition between species, etc In 1997, the World Resources Institute recorded that only 20% of the world's original forests remained in large intact tracts of undisturbed forest.More than 75% of these intact forests lie in three countries - the Boreal forests of Russia and Canada and the rainforest of Brazil In 2006 this information on intact forests was updated using latest available satellite imagery

Canada has about 4,020,000 square kilometres (1,550,000 sq mi) of forest land More than 90% of forest land is publicly owned and about 50% of the total forest area is allocated for harvesting These allocated areas are managed using the principles of sustainable forest

management, which includes extensive consultation with local stakeholders About eight

percent of Canada’s forest is legally protected from resource development (Global Forest

Watch Canada) (Natural Resources Canada) Much more forest land — about 40 percent of the total forest land base — is subject to varying degrees of protection through processes such as integrated land use planning or defined management areas such as certified forests (Natural Resources Canada)

5 The forest resources in Vietnam

Issues of exploitation and use forests in Vietnam

Table 1 Plantation area focused 1990-2000 In Area

Data source: Economic Situation - Vietnam Social 1991-2000

Greatest achievements in the forestry sector

achieved in recent years is the capital of forests has been maintained and developed Total forest area based on the inventory published in

2000 reached 10.9 million hectares, up 1.8 million hectares compared with

1990, the forest coverage rate has increased from 27.7% in 1990 to 32.2% in 2000 and 35.8% in

2002 The reason for such results, a work surface by new forest planting, forest regeneration, reforestation a top priority On the other hand, closed forest policy, forest protection and

development of forests have been seriously implementing the country Implement the policy of this State, the majority of forest enterprises units, households have moved from small-scale

years area(1000

ha)

Index (Previous year 100%)

missions to planting, forest protection and forestry services Logging tasks to reduce the

maximum level, the forest development From 1990 to 2000 the country had 1939 thousand hectares of planted forests to focus on average each year 176 thousand hectares are planted

In the period 1990-1995 was 743 thousand hectares planted, the average annual 149 thousand hectares in 1996-2000 planted 1096 hectares, planted 219 thousand hectares per year (see Figure 1)

The value of forestry production in 1991-2000 the average annual increase of 1.2% Despite lower growth rate compared to other economic activities, but the structure of the output value

of forestry sector over the years has changed in a positive way Production value due to

reforestation, regeneration, regeneration and protection is growing Value of forest products from planted forests has increased in recent years

In about 10 years (1990-2000) production of timber country reached 29.6 million m3, the

average annual exploitation of 2.68 million m3 Closed due to forest policy has been limited logging wood production forests should exploit recent years has fallen from 32 million in 1990

to 24 million in 2000 The exploitation of timber, firewood for necessities such as paper

materials, pit props (see Figure 2)

Table 2 Timber production 1990 - 2000

Data source: Economic Situation - Vietnam Social

1991-2000 forest use in Vietnam

• Improve the environment: climate control, reduce co2, forest protection, to avoid

erosion

years

In timber

production

(1000

tonnes

Index (Previous year 100%)

• As fuel for a number of industries such as forest product processing, paper production, furniture making

• Ecotourism development: national forests, ecological reserves, biological reserves

• For scientific research, conservation of rare plants and animals, ecosystem development

…

Causes of forest degradation in Vietnam

May yet be the main cause of deforestation and forest degradation in our country are:

- Burn shifting cultivation: nomadic life, the total area of forest lost each year is about 40 - 50%

is due to burn shifting cultivation In Dak Lac in the period from 1991 - 1996 average loss of 3000-3500 ha of forest per year, of which over half the forest area lost due to shifting

cultivation

- Land under the land to produce crops business, especially deforestation for the cultivation of industrial crops such as coffee in the Central Highlands make up 40 - 50% forest loss in the region

- Overexploitation beyond the natural resilience of the forest

- Due to the impact of bombs and toxic chemicals during the war, particularly in the south have destroyed about 2 million ha of natural forests

- Do not plan mining, fishing techniques obsolete waste of forest resources

- Due to forest fires, especially mangrove forests, pine forests, deciduous dipterocarp forest

6.Issues of exploitation and use forests in Vietnam.

1 Forest and forest lands

Statistics in Vietnam show that 19.2 million hectares are forest land of which 9.3 million hectares are forested area, and 10 million hectares are denuded hillsides and barren lands Total standing volume is reported to reach 584 million cu.m of wood and 6.3 billion of bamboo calms Out of 9.3 hectares of existing forests5, there are 8.3 million hectares of natural forests and 1.05 million hectares of man-made ones, details of which follow:

Figures assumed to apply around 1995 (Editor).

Besides, there exist over 1-2 billion scattered trees planted in and around home gardens, along roadsides, canals That asset of scattered trees is going to increase by some 300 million trees established every year When converted into full plantation area, scattered trees now being established are reported to reach over 1-2 million hectares These "outside forest"

resources are of much relevance to local farmers who can find in these plantation belts (or patches) a lot of ready fuelwood and small timber for daily uses in the countryside These resources too can contribute to the lessening of the destruction of natural forests in many areas/regions of Vietnam

2 Forest cover in various areas/regions of Vietnam

The differences in climatic conditions from sub-equatorial areas to sub-tropical ones as noticed in Vietnam and its elevations from sea level to mountains of over 3,000 m high, have caused the indigenous plant and forest resources to differ in terms of tree composition, forest types and forest cover There are the dominance of pine forests, broad-leaved forests, mixed coniferous stands, and even dipterocarp forests in the uplands; and the occurrence of lowland dipterocarp forests, mangroves, bamboos, and mixed stands of hardwoods and bamboos in lower areas, flats and wetlands Forest resourses in Vietnam are not evenly distributed, covering

in different areas different percentage of local