CHECKLIST OF POTENTIAL ENVIRONMENTAL IMPACTS OF INDIVIDUAL FORESTRY ACTIVITIES
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. |