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close this bookBasic Concepts in Environment, Agriculture and Natural Resources Management: An Information Kit (IIRR, 1993, 151 p.)
close this folderEcological basics
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Ecosystem degradation

Wheel of interacting forces affecting any ecosystem

The above is an illustration of the different factors involved in ecosystems degradation. The biggest responsibility involves the policy planners and implementors at the national, regional, provincial and municipal levels. The community (townsfolks, students, public officials, media and private entities) should play an important roles in the local use of the resources within each ecosystem. The role each one should play could be policing, reporting, organizing and taking hands-on-action to abate further loss of a tree, orchid, medicinal plants, bird and other animal species in an ecosystem. All of these are part of our national heritage. The conservation of which can be as joyful as the successful captive breeding of the Philippine Eagle or as sad as the plight of the Tamaraw. Much of the future of Philippine ecosystems depends on how we develop the social system which affects the ecological system.

If left alone and not irreversibly damaged, an ecosystem has the capacity to regenerate itself.

Impact of human activities on different ecosystems




1. Forest Ecosystem 6.7 million ha

Clear-cut logging

Continuous loss of forest cover


Rate of extraction at 100,000 ha/yr

Slash-and-burn activities

Loss of soil nutrient

Forest slopes soil exposed to onslaught of varying climatic conditions

Forest harvesting of wood/non wood products

Loss of soil fertility

Varied activities of forest dwellers

Loss of plant/animal resources

2. Grassland Ecosystem 10.6 million ha

Forest tires

Grassland areas further degrades

Kaingin practices

Soil erosion rate (an average

Harvesting of non-timber products

of 73 ha per year)

Mining activities

Increased surface run-off

Herbivore production

Loss of plant/animal resources

Human activities aggravating conditions of watershed areas

3. Freshwater Ecosystem 0.90 million ha


Loss of critical watersheds (19 out of 58)

Operations of mini-hydro power plants


Establishment of swimming resorts using natural springs

Increased silt-load

sedimentation of freshwater

Ecotourism activities

bodies and adjoining zones

Domestic agro-residential industrial sites of water

Affects water quality


Affects yield regulation service for diminishing water agro-industrial-domestic uses; power generation capability


Loss of ecotourism value

Open fisheries

Encroachement of exotic species

Drainage and conversion to agriculture

Loss of native plants/animals

Eutrophication of lakes

Biologically dead rivers; drainage channels

High level of organic and other polluants

4. Rural-urban Ecosystems11.8 million ha

Rural-urban community activities

Affecting life support system

Domestic; agro-industrial production



Lack of quality water


No water

Navigation traffic

Loss of lives, properties and industries

Decreased agricultural and industrial production

5. Mangrove Ecosystems

Mangrove harvesting

Affect mangrove productivity

Remnant 310,375 ha


Decreasing yield of fishery resources,

Land conversion for human settlement areas

Loss of habitat

Loss of nutrients

Conversion of mangrove areas into impoundments for fishy shrimp 210,456 ha

Loss of biodiversity

Conversion of 100,000 ha mangrove swamps into salt beds industrial and agricultural area for coconut and rice production


6. Coral Reef Ecosystems Remnant 2,245 kms

Open fisheries

Affect coral reef productivity

Dynamite fishing

Depletion of economically important fishing grounds

Coral reef harvesting


Muro-ami activities

Loss of biodiversity

Scuba diving