Forestry Flashcards
(13 cards)
Discuss how commercial forestry may be managed to reduce the impacts on the
local environment.
[9 marks]
Indicative mark scheme:
* harvest at or below MSY
* managed by replanting
* calculated by growth rate and natural mortality
* maintains tree populations
* maintains forest ecosystem resources and services
* mixed species plantations (rather than monoculture)
* increased number of niches/food resources/breeding sites
* indigenous species (rather than non-indigenous)
* greater number of interdependent relationships – higher
biodiversity
* reduced risk of introduction of invasive species
* mixed age structure (rather than single age monoculture)
* managed by planting and harvesting plan
* greater number of interdependent relationships – higher
biodiversity
* selective logging (rather than clear felling)/coppicing/pollarding
* maintains canopy to increase interception and reduce soil
erosion
* avoids forest fragmentation
Explain how the canopy layer affects the survival of plants growing on the woodland
floor. (3 marks)
Controlled abiotic factors
* Low light levels/shaded
beneath canopy
* More humid beneath
canopy
* Reduced wind velocity
beneath canopy
* Canopy protects from rain
* Dead organic matter from
the canopy provides
nutrients
Explain why the reduction in light levels caused by the dense canopy may affect the biodiversity of invertebrates.
[3 marks]
fewer ground plants
reduced food/egg laying sites/DOM food
reduction in population/diversity
reduced temperature
beyond range of tolerance
reduction in population/diversity
What ecosystem services do forests provide?
1) Atmospheric regulation
2) Regulation of the hydrological cycle
3) Forest Microclimate
4) Habitat and Wildlife refuge
4) Soil conservation
coppicing
cutting trees to ground level on a cycle of 1-20 years depending on wood use. The branches that regrow can be used for baskets, fencing etc
pollarding
trees cut above ground level so the regrowing branches can’t be eaten by livestock
Advantages and disadvantages of cultivating non-indigenous species
Advantages:
-may be better adapted to the environmental conditions
- less likely to suffer damage caused by pests or disease
Disadvantages:
- less likely to support indigenous wildlife species as cant provide food etc
Single-species plantations
aka a monoculture
- makes plantation management easier as activities such as planting and felling can be carried out over large areas at the same time.
Close planting
planting all the seedlings close together makes the trees compete with each other for light so they grow tall and straight.
- results in a dense canopy which reduces biodiversity on forest floor
Simple age structure
- makes management easy
- reduces variety of abiotic factors
- reducing biodiversity
Causes of forest loss
1) Agriculture
2) Mineral extraction
3) Reservoirs
4) Urbanisation
5) Transport infrastructure
Effects of deforestation
1) Loss of forest resources
2) Ecological impacts
3) Changes to hydrology
4) Impact on soil
5) Climate impacts
Features of sustainably managed forests
1) Harvesting rates- rate of removal must not succeed MSY.
2) Mixed species plantations- increase in food choices etc
3) Indigenous species
4) Mixed age structure- provides a greater variety of abiotic factors
5) Selective logging- more labour intensive but better for wildlife and ensures maximum benefit over longer time
