What are forest resources?
A forest is a large area covered mainly by trees. Forests cover about 4 billion hectares, roughly 31% of Earth's land.
Main types of forest
- Tropical rainforests (Amazon, Congo, South-East Asia, Western Ghats): hot and wet all year, tall evergreen trees, the most species.
- Tropical deciduous (monsoon) forests: trees drop leaves in the dry season; teak and sal are valuable timber trees.
- Temperate forests: oak, beech and maple that lose leaves in winter.
- Boreal (coniferous) forests or taiga (Canada, Scandinavia, Russia): pine, spruce and fir; softwood for paper and building.
- Mangroves: salt-tolerant trees on tropical coasts, such as the Sundarbans; they protect coasts from storms.
Uses of forests
Products (goods):
- Timber for buildings and furniture; hardwood (teak, mahogany) and softwood (pine).
- Fuelwood and charcoal: still the main cooking fuel for over 2 billion people.
- Pulp for paper and card.
- Non-timber forest products: fruit, nuts, honey, rubber, bamboo, cane, lac, gum, tendu leaves, and medicines (quinine from cinchona bark, many cancer drugs from plants).
Services (things forests do for free): make oxygen and store carbon (fighting climate change), hold soil with roots, soak up rain and feed rivers and groundwater, reduce floods, cool the local climate, and give a home to about 80% of land animals and plants. Forests also support tourism and the lives and cultures of forest communities and indigenous peoples.
Forestry as an economic activity
Forestry means growing, managing and harvesting trees. It belongs to the primary sector, because it takes a raw material straight from nature. Logs then go to the secondary sector (sawmills, paper mills, furniture factories).
- Logging of natural forest: clear-felling cuts every tree in an area; selective felling cuts only mature trees and leaves the rest.
- Plantations: fast-growing trees such as eucalyptus, pine or poplar planted in rows and harvested every 7 to 30 years. They give lots of wood but few species live in them.
- Agroforestry: farmers grow trees together with crops or animals, getting fruit, fodder and shade.
Big wood producers include the USA, Russia, Canada, Brazil and China. Many poorer countries depend on fuelwood.
Deforestation: causes and effects
Deforestation is the permanent clearing of forest for another land use. The world loses around 10 million hectares of forest a year, mostly in the tropics.
Causes: clearing for farms and cattle ranches (the biggest cause), oil palm and soya plantations, mining, dams, roads, growing towns, illegal logging, fuelwood collection and forest fires.
Effects:
- Soil erosion and landslides; rivers fill with silt.
- More floods and droughts, as less rain is soaked up.
- More carbon dioxide in the air → faster climate change.
- Loss of habitat and extinction of species.
- Forest people lose their homes, food and income.
Sustainable management and conservation
Sustainable yield means harvesting no more wood each year than the forest grows in a year, so the forest never shrinks.
- Selective felling and replanting (afforestation on new land, reforestation on cleared land).
- Protected areas: national parks and reserves where cutting is limited.
- Community forestry: local people protect and share forests. Examples: the Chipko movement and Joint Forest Management in India, community forests in Nepal.
- Certification: labels like FSC show wood from well-managed forests.
- Using less: recycling paper, efficient cookstoves, solar or gas instead of fuelwood.
- International action: programmes that pay countries to keep forests standing because of the carbon they store (such as REDD+).
Try it: count the trees
Count the trees on your street or in your school ground. Ask an adult how many were there ten years ago. Then go to the free-play step: set cutting to 20% and replanting to 0%. What happens after 20 years? Now find the highest cutting rate that still keeps more than 40 trees. That rate is the sustainable yield for this forest.
Key formulas and definitions
- Key term: forestry = growing, managing and harvesting trees (primary sector)
- Key term: sustainable yield = harvest per year ≤ growth per year
- Key term: deforestation = permanent removal of forest
- Key term: afforestation = planting trees where there was no forest; reforestation = replanting cleared forest
- Key term: non-timber forest products (NTFP) = honey, fruit, rubber, bamboo, medicines, etc.
Worked examples
1. A forest grows 2,000 m³ of new wood each year. A company wants to cut 3,500 m³ every year. Is this sustainable?
No. Harvest (3,500 m³) is bigger than growth (2,000 m³), so the forest shrinks by 1,500 m³ every year. A sustainable yield is at most 2,000 m³ per year.
2. Give two goods and two services of a mangrove forest.
Goods: wood for fuel and poles; fish, crabs and honey. Services: protects coasts from storm waves and cyclones; a nursery for young fish; stores a lot of carbon in its mud.
3. Why does deforestation on a hill cause floods in the valley below?
Tree roots hold soil and the leaf litter soaks up rain. Without trees, rain runs off fast and carries soil into rivers. The rivers rise quickly and their beds fill with silt, so they overflow.
Common mistakes
- Thinking a plantation is the same as a natural forest. Plantations give wood but have far fewer species.
- Saying forests are renewable so cutting is never a problem. They are renewable only if harvest stays below growth.
- Counting only timber as a forest resource. Honey, medicines, clean water, carbon storage and soil protection are resources too.
- Mixing up afforestation (new forest on land that had none) and reforestation (replanting a cleared forest).