Unit 4 : Forest

Seminar
Group 4:
Đỗ Văn Tình
Võ Minh Tiến
Châu Vũ Linh
Nguyễn Thị Ngọc Dung
FORESTS 9.5 đ
Topic
Instructor: DOCTORATE NGUYỄN VĂN MINH
Vacabulary
Forests cover a third of our planet`s land.
They provide raw materials, maintain biodiversity, protect land and water resources, and play a role in climate change mitigation.
I. The Context
II. Some of the main ecological benefit of forests
1. Forests reduce erosion
The roots of rainforest trees and vegetation help anchor the soil. When trees are cut down there is no longer anything to protect the ground, and soils are quickly washed away with rain. The process of washing away of soil is known as erosion. 
As soil is washed down into rivers it causes problems for fish and people.



The roots of rainforest trees and vegetation help anchor the soil
On steep hillsides, loss of forest can trigger landslides.
Forests also play an important role in reducing damage from flooding by reducing the rate of water runoff. 
In areas where bare soil, rain water falling water flow in soil erosion
2. Influence of forests on climate
Forests have a direct impact on the local wind regime.
Wind regime change will lead to changes about moisture and temperature regimes.
Forests are obstacles on the movement of the wind, the wind speed and wind direction changes
Forest changes in wind speed around the forest in a certain range in the catch wind and lee.
sphere of influence of forest to the wind depends on the height of the forest.
The higher the incidence of forest of larger forest to the wind.
Effects of forest to wind depends on the structure of the forest. Forest has a layered structure, the greater the influence of the forest to wind.
Ành hưởng của rừng đến gió là cơ sở lý luận để xây dựng nên những giải rừng phòng hộ.
Effects of forest to wind is the theoretical basis to build the forest.
Windbreaks are single or multiple rows of trees planted on windward field boundaries. Windbreaks slow wind, reducing physical damage to crop`s and fruit trees. Placed on the windward side of atolls, they can also prevent salt-spray from reaching the interior and reduce coastal erosion.
Chắn gió là một hoặc nhiều các hàng cây trồng trên ranh giới lĩnh vực đầu gió. Chắn gió chậm gió, giảm thiệt hại vật chất của cây trồng và cây ăn quả.Được đặt ở phía bên gió các đảo san hô, họ cũng có thể ngăn chặn muối phun đến nội thất và giảm xói mòn bờ biển.
Ứng dụng trong nông nghiệp
Applications in agriculture
Chắn gió là trồng tuyến tính của cây và bụi cây được thiết kế để tăng cường sản xuất cây trồng, bảo vệ con người và vật nuôi, và mang lại lợi ích bảo tồn đất và nước. Có nhiều loại khác nhau của chắn gió. Lĩnh vực chắn gió bảo vệ một loạt các loại cây trồng nhạy cảm với gió, gió kiểm soát xói mòn, và thụ phấn của ong gia tăng và hiệu quả thuốc bảo vệ thực vật. Chăn nuôi chắn gió giúp giảm căng thẳng động vật và tỷ lệ tử vong, giảm mức tiêu thụ thức ăn chăn nuôi, và giúp giảm tác động thị giác và mùi hôi. Snowfences sống tiếp tục con đường sạch trôi tuyết và tăng lái xe an toàn. Họ cũng có thể lây lan tuyết đều qua một cánh đồng, tăng độ ẩm của đất mùa xuân.
Windbreaks are linear plantings of trees and shrubs designed to enhance crop production, protect people and livestock, and benefit soil and water conservation. There are several types of windbreaks. Field windbreaks protect a variety of wind-sensitive crops, control wind erosion, and increase bee pollination and pesticide effectiveness. Livestock windbreaks help reduce animal stress and mortality, reduce feed consumption, and help reduce visual impacts and odors. Living snowfences keep roads clean of drifting snow and increase driving safety. They can also spread snow evenly across a field, increasing spring soil moisture.
3. Forests help maintain the water cycle

The role of forests in the water cycle is to add water to the atmosphere through the process of transpiration (in which plants release water from their leaves during photosynthesis). This moisture contributes to the formation of rain clouds, which release the water back onto the forest.
When forests are cut down, less moisture goes into the atmosphere and rainfall declines, sometimes leading to drought. 
4. Forests regulate the amount of water on the ground
The litter layer under the canopy play a role as insulation porous, forest ground cover to reduce evaporation and increase soil moisture.
Rainwater falling on the forest tree canopy and litter to keep the rate at which water flows more slowly. Therefore, Forest restricts flooding.
5. Forests for the atmosphere
Forests involved in the concentration of oxygen and carbon dioxide balance of the atmosphere.
Forests affect water evaporation intensity of the surrounding environment, effective climate control, beneficial to plants.
Forests against wind storm, dust filter of the atmosphere.
Forests filter for fresh air, prevent dust, limited bacteria, pathogenic viruses.
There is an important role in the formation of soil protection: erosion control soil, especially erosion on slopes slopes ...
6. The role of forests for land
7. Forests are valuable genetic resources.
There are approximately 10,000 species of higher plants (1000 species of large trees, 280 species of mammals, over 1020 species of birds, 259 species of reptiles, 82 species of amphibians, thousands of species of insects and other creatures).
Forests are valuable genetic resource bank of humanity.

III. The status of exploitation of forest resources in the world
Previously forests occupy about 60 million km ², and in 1958 only 44.05 million km ² in 1973 to 37.37 million km ². Current forest area is declining due to human impact and only about 29 million km
Since 1950 approximately 50% of tropical forests,
By the early `80s tropical forest loss in speed of 113,000 km ² / year
The rate of forest loss in recent years as increasing strength, predicted by 2020 about 40% of the remaining forest is destroyed seriously.
IV. The current situation of forest resources in Vietnam
For many reasons such as the long-lasted war, shifting cultivation and over-exploitation, the forest area reduced at alarming rate.
The reasons for forest lost
shifting cualtivation
Fosrest fire
over-exploitation
long-lasted war
A
B
C
D
The War: From 1961 to 1975, 13 million tons of bombs and 72 million liters of toxic chemicals sprayed mainly in the south have destroyed about 4.5 million hectares of forest
The expansion of agricultural land: shifting cultivation has turned 13 million hectares of former forest land barren.
In 1943, forest area of ​​Vietnam is estimated at 14 million ha, with a coverage rate of 43%. By 1976 the area dropped to 11 million hectares of forest cover rate 34% in 1985 to 9.3 million ha with coverage of 28%, in 1995 only 8 million hectares forest area ratio coverage of 24.2% (Khoa hoc moi truong, Le Van Khoa).
Chart: Changes in forest area of ​​Vietnam over the period
(millions of hectares)
V. How can forest area be preserved?
To protect and develop forest resources in Vietnam, the State should apply the following policies:


- Afforestation and greening of barren hills.
- Protected forests, national parks and nature reserves.
- Rational exploitation of forest production, limited clearing of forests to agricultural land, limiting migration.
- Natural closed forests.

Forest protection measures
Propaganda protect of forest
Currently, Vietnam has 27 national parks; 3 Sanctuaries species / habitats; 18 landscape protection area; 27 nature reserves; 12 Nature Conservation

Examples:

CUC PHUONG National Park
BACH MA National Park
NAM CAT TIEN National Park
……………..and Et cetera
CUC PHUONG National Park

VI. How Can They Be Increased?
Exploitation of natural resources, but still maintain the inherent ecological processes of the forest.
Prevent deforestation, especially primary forests, tropical forests.
Positive afforestation, intensive afforestation so that more forest exploitation
Strengthen propaganda about the role of forests.
Build a system to protect natural

Forest will be increased by activity people
The afforestation



In addition

Putting content protection and natural resources on education and the mass media

Mobilization of ethnic minorities living sedentary, development of agro-forestry or forestry-fishery combination of eco-sustainable exploitation of forests.

Focusing on planning and management of protected forest

The question:

Do you like the afforestation? Why or why not?

Tell me some forest protection measures in your country you know?
THANK FOR LISTENING