Deforestation

by

Dr.Shagufta ShahjahanDirector General (Rtd.)EPA, Punjab, Lahore

Deforestation

The Term deforestation refers to permanent clearing of forest land for all forms of agriculture and for other uses.

n Presently about 27% of the earth’s total land area is covered with forest

n Human cleared forest for centuries to use tress and land

n Most of the deforestation is done in temperate forests for following purposes:

� Housing

� Agriculture and

� Fuel wood

n Trend was halted for some times but again rose in Canada and Siberia.

n Tropical rain forest (occupy 6% of earth land)and dry forest are being cut an accelerated rate

n Tropical rain forest are found in Central and South America, Africa, South-East Asia.

n But half of these are found in Brazil, Zaire and Indonesia.

n At present about 50% of Indonesia, 40% Brazil, 18% India and 13% China is forest

n Tropical rain forest have been reduced to half their original area as being cut at alarming rate and may vanish within next 30-50 years (Raven et al., 1993)

n During 18th Century World lost about 8% of its tropical forest i.e. a decline from 1910 million hac. in 1980 to 1756 million ha in 1990.

n Dry forest are found in India, Kenya, Zimbabwe and Egypt.

Sr. No. Region Loss of original Forest Area

1. Central America Two third

2. Central Africa � Half

3. South- East Asia � > one-third

4. Latin America � > one-third

(Boktin and Keller, 1995)

n Ten countries which accounts for 76% of tropicaldeforestation include Brazil, Indonesia, Zair, Burma,Colombia, India, Malasia, Maxico, Nigeria and Thailand

n Rain forest being reduced 4.6 million hectares annually

Wide spread deforestation is driving

� Countless species extinction

� Threatening Indigenous Culture

� Threatening livelihood of million of people

i) Source of Medicines

n Active ingredients for 25% of the world’s prescription drugs are obtained form the plants in topical rain forest

n Around 2100 plants have been identified as source of cancer fighting chemicals (Middleton, 1994)

ii) Support Biodiversity

n Tropical rain forests support incredible diversity of species &

Provide habitat to

� More than 60% of all known species of plants

� 40% of birds of prey and

� 80 % of insects

n Forest also provide habitats for more wildlife species than any other biome.

Importance of Forests

iii) Source of timber for housing and commercial

n Tropical forests supply almost half of the wolrd’s annualhard wood and

n Also provide biomass for fuel wood and pulp for papermanufacturing

iv) Source of food

Tropical forests supply hundreds of the food products e.g.coffee, tea, cocoa, spices, nuts, chocolate and fruits

v) Control Soil Erosion and Regulate floods

n Forestry play major role in

� regulating flow of river (by increasing water retainingcapacity),

� Recycling of nutrients

� Absorbing and holding water to recharge springs, streamsand ground water

� Helping to control soil erosion,

� Reducing flooding

� Reducing amount of sediments washing into streams, lakesand reservoirs

n Forest influence local,regional and global climate

n About 50 – 80% of themoisture in air abovetropics comes viaevapotranspiration

n Clearing of forest results indrop of annual rainfall, dryof hotter climate (Miller,1994).

n Forest store 20-50 timesmore than carbon thancrops and pastures, i.e.deforestation constitutes ahuge net release of carboninto atmosphere and thuscontributes to globalwarming (Brown, et al.,1996)

• Through the process ofphotosynthesis trees remove anduse carbon dioxide to create roots,branches, trunks and leaves.

vi) Influence / Regulate Climate

Causes of Deforestation

n Primary causes of deforestation vary

n Asian Forests are being threatened by:

� Commercial Logging

� Agricultural Expansion

n Pressure on African Forests include:

� Fuel wood Collection

� Overgrazing of Cattle

� Logging

n Forest clearance in Latin America is associated with:

� Cattle ranching

� Populastion Settlement Schemes

� Major Development Projects

� Commercial Logging (Brown, et al., 1996)

Causes of Deforestation

Major causes of Deforestation are summarized below

i) Subsistence Agriculture

n Most Importance cause of deforestation amongst all &accounting to 60% if tropical deforestation

� Rapid population combine with poverty force subsistencefarmers and landless poors to tropical forest

� In efforts to grow enough food they use unsustainableagricultural practices

� Poor consume small tract of forest on one time basis andmove to have shelter and food

n Unequitable Land Distribution intensifies the situation

� e.g. in Barzil 5% farmers own 70% land. Mostsubsistence farmers were displaced from farmlandbecause of inequitable land distribution and forced intocutting of forest for food and shelter (Raven et al., 1993)

� In Brazil and other countries the process of cutting of treesbegins with construction of logging roads which are laterused by homeless, subsistence farmers and those in searchof food and shelter.

� About 5 million hectares of the tropical forests are beingdestroyed every year by poor landless peasant (Brown, etal., 1996)

ii) Commercial Logging

n Important cause of deforestation is use of timber for lumber(sawn timber) and paper products

� Consumption of tropical lumber has risen 14 folds since1950.

� Japan accounting for 60% export followed by USA andU.K (Middleton, 1995)

� Old forests of Oregon, Washington, Alaska and Siberiaare being lost due to commercial logging

� The cut trees are converted into cash and funds are invested onother development projects

� Developing countries borrow huge loans for economic growthfrom developed countries and are often forced to sell off theirforests at low prices dictated by international market.

� Globally 5.9 million hectares are logged annually in tropics andthese forests supply about 30% of the world’s log exports and60% of plywood an d veneer export (Brown et al., 1995)

� In south east Barzil, native forest are being cleared to plantEucalyptus trees to fuel wood (steel Industries).

� In Africa and Brazil’s Atlantic forest, on e the World’s rarest andmost diverse forest types, are being cleared for planation ofEucalyptus trees for pulp and fuel wood (Brown et al., 1996)

� Dense road network constructed for timber harvesting, exposesforest to exotic pests and diseases, increases soil erosion andopens forest to miners, ranchers and poor farmers.

iii) Cattle Ranching and Agriculture expansion

n Accounts for 12% deforestation

n In Latin America, cattle ranchers have replaced 20 million hectares.

n Forest are cleared for grazing of cattle for 6 – 10 years, after whichsavannas take over the land.

n In many tropical countries, (e.g. Brazil), Governments offer subsidiesto make ranching profitable.

n Tropical forest, due to demand in industrialized world, are cut andconverted into plantation for food and other products (beef, banana,coffee, tea, medicines and hard wood.

n More than 80% of deforestation in Viet Nam is for cultivation ofbanana, coffee and rubber plantation.

n In Philippines since 1940, logging and agriculture expansion havebeen primary cause of deforestation from 70%-25%

n In Brazil, agriculture expansion for coffee and soybeans is one of themajor cause of deforestation.

n In Nepal from 1950 to 1980,more than half of the forest cover waslost due to agriculture expansion and

n Thailand about 45 % b/w 1961 – 1986 (Bokton and Keller, 1995)

iv) Fuel Wood Collection

n Tropical forest are being destroyed at alarming rate primarilyfor fuel.

n Wood cut is often converted to charcoal for industries

n Nearly half of the world’s population including 1.5 billion indeveloping countries depends on wood for cooking.

n Pakistan lost its world’s single forest of juniper Trees in Ziaratdue to fuel wood collection. Only few trees have left(Carwardine, 1986)

n Mangroves forest in Pakistan, West Africa, Central America,India have been cleared for fuel wood collection.

v) Acid Rain

n More Subtle (delicate/clever) cause ofdeath of tress due to pollution

n Have caused 1/3rd of the forests inGermany.

n Problem extends to central Europe andis especially acute in Polan (Bokton andKeller, 1995)

vi) Forest Fires

Forest (Negligence or ill will havebeen cause of deforestation inPakistan (Carwardine)

Forest Fire on Murree Hills

Consequences of Deforestation

i) Soil Degradation

n Cutting of trees results in soil degradation due leaching of nutrients by water

n Erosion thus has limited use of many tropical for which they were cleared

n Unsustainable cultivation quickly deplete soil and rapidly reduce yield thus encourages settlers to move for further clearance of forests

ii) Increased Sediments Load

n Sediments load in the rivers increase

n Increased sediments load shortens the life of dams & reservoirs due to silting

n Deforestation in Nepal and Himalayas is increasing flooding in Indian rivers Ganges and Brahmaputra.

n Flooding resulted in property damages of US$ 2 billion (Boktinand Keller, 1995)

iii) Climate Change

n Effects of deforestation on climate are evident in Amazonia

n Deforestation resulted in reduced rate of evapotranspirationwhich further restricted survival of forest and agriculture

n Large scale deforestation enhances Global Warming

n Cutting of forest is releasing 1.5 billion tons of carbon storedin biomass and surrounding soil (Brown et al., 1996)

ii) Loss of Biodiversity

n Deforestation in tropics has resulted in loss of many speciesof plants and Animals

n In tropical forest many species are highly localized thus canbe destroyed with clearing much forest area.

n Due to deforestation population of migratory birds form NorthAmerica to Central America has been declined

n Scientists believe that deforestation can diminish around60,000 to 240,000 species of plants within period of 30 years

n Loss biodiversity results in lost of opportunities and lostsolution to future problems.

n Great extent deforestation is irreversible as deforested landcan not regenerate forests with its previous original diversity

iv) Loss of Native People

n Native people are another common causality ofdeforestation in tropics

n Deforestation threatens cultural and physical survival ofnative people by

� Forcing them out of their lands by developers

� Deaths due to diseases and

� clashes with foreign developers

n Indigenous Indian population of was about 1.0 million in1900 but has reduced to 200,000 due to deforestation

n Population of Africa’s last rain forest people “ Pygmies” isthreatened due to rapidly shrinking forests

n Deforestation (logging activities) has endangered thelivelihood of “ Penans” in Sarawak State of Malaysia’s

(Brown et al.,1995)

Context of Pakistan

n In Pak Forests occupy 5.2 % of the land area

n 37.6% are used for timber extraction

n Remaining are protected forests with no commercial value

n Main functions are to protect water and soil resources

n Categories include

� Coniferous,

� Scrub,

� Riverine,

� Mangroves and

� Irrigated forest

n Forest are Shrinking 1% per year

n Potential for sustainable forest yield has been reduced due to

� Widespread cutting of trees for fuel wood,

� Encroachments into forest lands (Agriculture & Settlements)

n Timber production has failed to meet national needs

n Fire wood consumption is expected to cross 30 million cubic meters

n Scrub forest are heavily utilized for cattle grazing

n Irrigation plantations are threatened by reduced water allocations.

n Economic viability of 50% of riverine forests has been deteriorated

nReduced dilutory effects has increased salinity in mangroves forests. Now these only have single salt tolerant tree species.

nBrowsing (i.e. surfing) by herds of camel have caused sever damage to mangroves in Sind Coast (ODA, 1992)

nNational Conservation Strategy emphasis on protectingwater sheds, riverine and mangrove forests and sustainable use of forest resources. It further emphasises the need of afforestation of critical waster sheds and extensive tree plantation in country to meet timber production (GOP-IUCN, 1995)

Measure to Reduce Deforestation

Forest Conservation is difficult in developing nations duedependency on fire wood and increased population.Nevertheless following measures for sustainable managementmay help reduce tropical deforestation

1) Reforestation

n So far only 1% of world’s tropical forests are managed sustainably

n For sustainability

� logging contracts should charge more for timber-cutting

� Logging Companies must enter into agreement / bond for reforestation

n Reforestation is necessary as need for timber is increasing. Reforestation rate is slow worldwide

� Latin America: Only one tree is planted for every 10 cut trees

� Africa: Only one tree is planted for every 29 cut

n Only few nations have developed forestry plans & no international coordination on forestry policies

2) Managed forest are often monoculture and low diversityforest.

� These become more prone to pest attack and variousdiseases.

� Need comprehensive pest and disease controlprogramme

3) Forest having old growth trees may e saved by haltingdevelopment like crop plantation, ranches and roads etc.

4) Trees farming, ranching and crop plantation be encouragedon degraded tropical forest lands

5) Large tropical areas should be set aside for indigenouspeople

6) Adaptation of adequate measures to alleviate poverty andstop flow of landless poors to tropical forest

7) Financial aid / assistance to tropical countries for protectingselected forest areas

8) Pakistan has taken appropriate steps to reducedeforestation.

� Tree plantation campaign in public sectors every year.

� Tree plantation of fast growing trees outside forestareas.

� Poplar, Eucalyptus and bamboo saplings are madeavailable for plantation

(Carwadine, 1986)

9) Fuel wood collection is major cause of deforestion whichmust be discouraged but its implementation by poordeveloping is doubtful

10) In cleared forests plantation of low intensity harvestingfruits, nuts, rubber ad other may result in minimum ofgenetic erosion and maximum conservation.

References

Boktin, D and Keller, E (1995) Environmental Science, Earth as a Living Planet. John

Wiley and Sons. Inc .New York

Brown,L R.et al (1997) State of the World, W.W. Norton and Co. London

GOP & IUCN (1992) The Pakistan National Conservation Strategy, GOP/JRC-IUCN,

Karachi

Kemp.D.D.(1994) Global Environmental Issues, A Climaological Approach.

Routledge, London

Middleton, N.(1995) The Global casino, An Introduction to Environmental Issues.

Edward Arnold London.

Miller, G.T. Jr.(1994) Environment: Problems and Solutions Wadsworth Publishing

CO., California.

ODA Environmental Synopsis of Pakistan, The INTERNATIONAL

Institute of Environment and Development Overseas

Development Administration, London

Raven, P.H.et al (1993) Environmental Saunders College Publishing London