FORESTRY ACTIVITY

POTENTIAL IMPACTS

Logging: clear-cutting and selective

Landforms and Soils:

- slope, bank or shore instability

- rill, gully or shoes erosion

- loss of nutrients and organic matter

- decrease or alteration of microflora and fauna

- decrease in cation-exchange capacity

- soil compaction

- laterization

- rutting and swamping of soils

- burial of downslope soils as a result of excessive erosion and sedimentation

Water Resources:

- decreased infiltration and groundwater recharge

- increased storm runoff

- decreased baseflow; lose dependable year- round discharge

- local pending of water

- increased turbidity

- accelerated eutrophication

- contamination of waters with hydrocarbons, biocides and wood preservatives

- increased sediment loads, with detrimental effects on channel stability, aquatic life, useful reservoir life, navigation.

Climate and Air Quality:

- higher ground temperatures

- local and regional desiccation of the climate

- release of duet and fumes

- release of CO₂

Vegetation:

- high forest may not regenerate itself

- whole species may become extinct

- genetic erosion as a result of selective cutting of superior trees

- reduction of the total population of one species

- undesirable secondary forest growth

- influx of persistent weeds

- seed trees may not survive mechanical damage and "isolation shock"

- adjacent uncut forest may be damaged by machinery, windthrow, fires, illegal felling, sedimentation, hydrologic changes and intensified shifting cultivation

- regeneration may be affected by changes in the populations of animals that act as pollinators or seed vectors

- regeneration of useful species may be aided by the culling of over- age or defective trees.

Wildlife and Fisheries:

- some animals may be killed outright

- nesting sites, including hollow trees, may be eliminated or damaged

- feeding and breeding grounds may be eliminated

- spawning and nursery areas and bottom organisms (benthos) may be damaged or destroyed by sediment or logging debris

- animals may be displaced by noise and human presence

- displaced animals can induce reproductive and other stress in existing animal populations in uncut forest

- entire rare and endemic species can be eliminated

- some animals can be favoured by new browse and habitats created by logging; however, some of these animals can become pests or disease vectors

- some herbivores can be displaced and made dependent on agricultural crops

Traditional Cultures and Subsistence Economy:

- traditional shelter, food and other resources of forest dwellers could be reduced or eliminated

- in remote areas, "culture shock, and attendant social unrest could occur

- damage to or destruction of sites of religious or other heritage value

- disruption of local non-cash economy (assuming that preservation of a subsistence economy is the desired goal of local residents)

- temporary increase in fuelwood supply

- long- term decrease in fuelwood supply

- conflict over job opportunities or lack thereof in the forestry sector

- increase in shifting cultivation

Epidemiology:

- higher incidence of malaria (exposure of stagnant water) and other diseases

- more contact between vectors of arbovirus diseases and man

- creation of habitats for potential animal vectors of diseases (mainly grasslands invaded by rodents)

- introduction of diseases by forestry workers

- reduction of incidence of certain diseases through selective clearing (eg., trypanosomisais)

Conservation:

- damage to existing conservation areas (parks, game reserves, protection forests, etc.) either directly or indirectly by affecting the buffer zones around these areas

- damage to conservation areas that have vague legal statue or that are poorly demarcated on the ground

- disruption of conservation plane by affecting areas that have not yet bean sat aside loyally or administratively

- reduction in the amenity value of a region through adverse visual effects (as perceived from roads, settlements, navigable rivers, vistas inside parks), increased turbidity of streams, debris in streams, heavy road traffic and displacement of fauna

Forest Clearing with Fire

- may damage or injure soils, adjacent vegetation, aquatic life and wildlife

- may cause severe air pollution locally and temporarily

Forest Roads, Skid Trails and Yarding Areas (construction and use)

- usually main sources of sediment

- may be areas of high storm runoff because of bare or compacted soils

- may cause damage to adjacent uncut vegetation (mechanical injury, runoff, sedimentation, duet, fumes)

- may be sources of hydrocarbon contamination of waters

- may serve as new access routes, thereby increasing hunting pressure, poaching, illegal felling and shifting cultivation

- may, on the other hand, facilitate wild life management and enforcement of conservation laws

- may serve as axis for new unplanned settlements

- may facilitate the marketing of produce and other items

- may serve the aims of tourism by improving access to scenic or other valuable areas

- may be unsightly if poorly maintained or abandoned without proper clean-up

Log Hauling by Road

- source of accidents

- source of duet and fumes

- may interfere with local traffic

- may destroy wildlife

- may displace wildlife indirectly through noise

- may require upgrading of local road net work, including bridges

Logging Camps

- may require additional forest removal

- generate solid and liquid wastes

- harassment or illegal hunting of local wildlife

- can be source of friction with local residents

- can be eyesores if improperly built, maintained or abandoned

- can serve as temporary local housing once vacated and rehabilitated

Log Floating

- stray logs may interfere with navigation or with fisheries

- bark and other organic debris may accelerate the eutrophication of waters

- bottom scraping may damage benthos

- wood preservatives may contaminate waters

- may detract from the amenity value of bodice of water

- associated increases boat traffic may interfere with local boat movements, scare off fauna and be a source of hydrocarbon pollution

Sawmilling, Charcoal Making and other Wood Transformation

- may cause dust or other particulate emissions

- generate solid waste

- may damage aquatic habitats with improper disposal of sawdust and other wastes

- noise

- fire hazards

Demographic and Economic Expansions associated with Forestry

- may significantly improve living standards through job creation and stimulation of local economy

- may improve living standards through the establishment of health, educational and other facilities

- creates housing, road and other infrastructure needs

- generates liquid and solid wastes

- may lead to overall decline in environmental quality

- creates health and recreational needs

- may increase hunting pressure and inroads into animal habitats

- may increase shifting cultivation

- may cause land use conflicts

- may accelerate the erosion of traditional cultural values

- may create new social costs such as grime, crowding, higher cost of living, reduced amenity values and disease which offset socio- economic benefits

Reforestation, Afforestation and Shelterbelt Planting

- increased infiltration and lower storm runoff (except under some plantations such as teak and during extreme rainfall events)

- increased groundwater recharge with related increase in spring discharges and baseflow, or at least more even year round flow

- greater transpirational losses of water

- reduced soil erosion and sedimentation

- lower ground temperatures

- greater atmospheric humidity

- reduced atmospheric dust

- greater soil organic content and related water- holding and cation- exchange capacity

- greater slope and bank stability

- improved soil structure

- under some plantations, possible detrimental changes in soil pH, nutrient status and micro-organismic life

- some plantations, notably of conifers may adversely affect water quality and aquatic life, including fisheries

- greater fire hazard, especially with coniferous plantations

- new habitat for wildlife

- plantations may eliminate food and shelter of some species of animals

- some plantations may harbour new pests and pathogens

- large- scale re- or afforestation may eliminate some plant species not adapted to forest environments

- if plantations are fertilized, the lose of excess fertilizer may accelerate the eutrophication of waters

- return water from irrigated plantations may be saline

- tree roots from shelterbelts may invade adjacent cropland, clog drainage tiles and withdraw water from irrigation ditches

- may improve the appearance of the landscape

- monotonous plantations may detract from the appearance of the landscape

- may increase the supply of food, browse, fuel, construction materials and other forest products, even while protecting soil and water resources.