Forest and their Uses

General Use

Maintaining the water supply

Maintaining the water supply

Forest:

• Enable water to be collected and stored within a water catchment

• Eg: Bukit Timah Nature Reserve

• Consists of 4 reservoirs surrounded by forests

Maintaining the water supply

• Forest forms part of the water cycle:– Process of evapo-transpiration– Water released into the atmosphere– Encouraging Cloud formation, condensation

and rain– Rain falls replenishes the water in rivers and

reservoirs– Leaves/branches intercept water and water

seeps into the ground as groundwater– Reducing surface-runoffs

Maintaining water quality

• Supports natural filteration

• Makes its possible for drinking and supporting life

• As the water flows seeps into the ground, soil particles trap impurities and filters the water

• Less run-offs reduce erosion of soil and deposited in reservoirs and rivers

• Keeps the soil fertile

Maintains the Nutrient cycle

Replenishing Oxygen and Removing Carbon Dioxide

• Forest as Green Lungs of the Earth:– During photosynthesis,

trees and plants give off oxygen and take in carbon dioxide to make food

– Reduction in carbon dioxide content prevents rising global temperatures

Nutrients on the forest floor

Form of Habitat for People

Form of habitat for plants and animal species

As a Resource

• For timber: – For industries

Recreation and eco-tourism

Camping and hiking

Education and

Research

Education and Research

Deforestation in Kalimantan, Borneo

Causes

Effects

Measures to Control Deforestation

Word Splash Area

Kalimantan

Farming

Lungs of the Earth

Amazon

Loss of nutrient cycle

Soil erosion

Loss of biodiversity

Commercial logging

Effects

Deforestation

Overpopulation

transport

Cattle ranching

settlements

Infertile soil

Mineral Ores

Decrease in evapotranspiration

Causes

Human Activities

• World deforestation rates and forest cover statistics, 2000-2005

• Borneo

• deforestation word splash.doc

• (Use the word splash to get students to categorise and develop a mind-map on the causes and effects of deforestation)

Rainforest clearance

YouTube - Saving the Rainforests in Indonesia - 24 Sep 07

• Location

Causes of Deforestation in Borneo

Increase in population

Increasing Demand for Resources

More land for farming

Land for Settlement

Land for Industrialisation

Timber

Fuelwood

Commercial Logging

Most intensive in the 1980s and 1990s:– with 60-240 cubic metres of wood harvested per ha– Logs for paper products mainly

majority of land-clearing for timber plantations:- large landholders:

- 1985 - 1997 cleared nearly 1.7 million ha

- small landholders cleared 467,000 ha

Mining

• Gold, silver and copper found under the forest

• Vegetation cleared to extract the minerals

• Leading to soil erosion and contamination of river (excess of cyanide killing animals)

Farming• Clearing forest for oil palm plantations

• Carried out by commercial profit making companies• Small-scale farmers clear forest by slash and burn

method for subsistence farming and cash-crop farming

• The 1997-1998 fires: – burned some 9.7 million hectares of forest and non-forest land in

Borneo– caused estimated economic damage of more than 9 billion

dollars– released 0.8-2.5 gigatons of carbon into the atmosphere. – In Kalimantan, more than 6.5 million hectares burned and the

smoke over the island "covered an area measuring 2,000 by 4,000 km.

Poaching of Animals

Transport

• Construction of roads and railway tracks link many settlements– Eg: Trans-Kalimantan Highway (230 km) cuts

through the rainforest– Links the 2 cities of Balikpapan and

Banjarmasin

Settlements

• Resettlement programmes: internal migration of people from islands such as Java and Sumatra to unpopulated Kalimantan

• Cleared forests to build settlements

• Population adding pressure to land: – Expansion of towns and cities (urbanisation)– More forest is cleared

Effects

• Lack of vegetation to hold the soil• Soil Erosion and soil leaching leading to

infertility of land • Soil washed into the nearby rivers causing

water pollution, raising of river bed and swelling of rivers

• Land slides due to lack of vegetation• Disruption to the nutrient cycle and

infertility of soil

Effects

• Increasing amount of carbon dioxide content in the atmosphere and contributing to global warming

• Loss of flora and fauna

• Reduce evapo-transpiration and decrease amount of rainfall

Solutions

• Conservation:– Afforestation such as practice of forest

plantation– Conserve some parts of the forest as nature

reserves or national parks– Impose fines on those illegal loggers,

corrupted forest rangers and those who do not abide by the rules

Solutions

• Conservation:– Protected Areas: Setting

aside land as National Parks or Forest Reserves

– Protected from cultivation, logging and construction of roads

– Practice of selective cutting where certain trees are felled to prevent soil erosion

Solutions

• Conservation:– Reforestation

(replanting trees in abandoned farming areas or areas that were once covered by forest)

– Afforestation (planting of trees in areas that were not originally covered by forest)

Solutions

• Demand Reduction– Practice of the 3Rs of Reduce, Reuse and

recycle– Public Awareness through education and

campaigns

Solutions

• Stewardship:– Our responsibility towards taking care of the

environment and the resources: – Who?

• by govt, special organisations such as the FSC (forest stewardship council) or individuals

– How?• Recycling• Conservation• Restoration• Regeneration

Sustainable Management (Development)

• Is careful use of resources so that the needs of the future generation are not compromised

• Use of environmentally-friendly strategies:– Economic devt approaches at the same time

not damaging the environment

• Egs: – Afforestation and reforestation– Controlled Logging

Question 1) How far do you agree that clearing the forest only brings

about environmental problems? Explain your answer.

2) The following measures have been taken by the Indonesian government to reduce the problems of deforestation.

• Reforestation and Afforestation • Controlled Logging • Control of Forest Fires

Are all the measures taken by the Indonesian government effective?