The factors affected the timber land

The causes of deforestation (Grainger, 1992
A. Immediate causes- land use
1. shifting agriculture
I i. traditional long-rotation shifting cultivation
ii.short rotation shifting cultivation
iii. encroaching cultivation
iv. pasturalism
2. Permanent agriculture
i. permanent staple crop cultivation
ii. fish farming
iii. government sponsored resettlement schemes
iv. cattle ranching
v. tree crop and other cash crop plantation

3. Mining
4. Hydro-electric schemes
5. cultivation of illegal narcotics

B Underlying causes
1. Socio-economic mechanisms
i. population growth
ii. economic development
2.Physical factors
i.distribution of forest
ii.proximity of rivers
iii.proximinty of road
iv.distances from urban centres
v. topography
vi. soil fertility
3. Government policy
i. agriculture policies
ii.forestry policies
iii. other policies

The mechanisms of Human impacts on biodiversity

Human impact on biodiversity become global in two main ways
First by affecting a globally dynamic systems such as the atmosphere, world climate or sea level and
Second by occurring in a localized or patchwork fashion in enough places to lead a globally significant impact (Turner et al 1990)



Type of global environmental change (affecting biodiversity)

Systematic
Direct impact on globally functioning system
Example:
a. Industrial and land-use emisions of greenhouse gases.
b. B. Industrial and consumer emissions of ozone-depleting gases
c. C. land cover changes in albedo


Cumulative
Impact through world wide distribution of change
Example
a. Ground water pollution and depletion
b. species depleting / genetic alteration

Impact through magnitude of change (share of global resource)
Example:
a. deforestation
b. desertification
c. industrial pollutants
d. reduction of population of certain species

Exploitation of wild living resources

Wild resources ore harvested by rural people throughout the world for food, shelter, traditional medicines, dyes, olis, intoxicants, fuel, beverages, fibres, tools. Religious purposes and cash income
Such harvests are motivated by cultural traditional, survival needs and to greater extent today for cash income to supplement earnings from other resources such as the people get the meat of Rusa, Kijang, Pelanduk from the forest