Forest Resources Flashcards
Why is timber a desired material?
High strength:weight ratio, flexibility, require little processing for use and is often readily available
Mahogany and teak (tropical rainforest)
Oak and beech (temperate deciduous forests)
Conifer timber (northern coniferous forests)
How are forests exploited for fibres?
Most paper is made form flattened sheets of interwoven cellulose fibres from pulped wood, cotton is made from the fibres that surround the seeds of the the cotton bush and viscose textiles are made by the chemical treatment of cellulose fibres extracted from wood
How do forests act as food sources?
Trees- fodder for livestock
Fruits and nuts- food for many species and those species can be food
Forest plant species important in agriculture include: coffee, cacao, bananas, papayas and Brazil nuts, pigs and chickens were originally forest animals
How do forests act as fuel source?
Wood is still the fuel that is used by most people in the world for cooking (especially LEDCs)
How do forests regulate the atmosphere?
Photosynthesis and respiration, carbons sinks, carbon sequestration, maintains ozone layer via oxygen and carbon store in soils
How do forests regulate the hydrological cycle?
Highest transpiration rates increases rainfall downwind, increased interception by foliage (increased evaporation and decreased infiltration), soil formation and reduced erosion allows retaining water
How do forests impact the microclimate?
Low albedo increases absorption of sunlight, much of which is radiated as heat at night, this reduces temperature extremes
How do forests impact light levels?
Canopy absorbs a lot of solar insulation (particularly blue and red), plants below the canopy have less access to light, so these plants have special adaptations e.g. denser chlorophyll, additional pigments or different growth periods
How is wind velocity impacted by forests?
Significantly reduces me and plants rely on animals for pollination and seed dispersal
How is humidity impacted by forests?
High humidity means amphibians can habitat there as their skin won’t dry out
How do forests help conserve soil?
Roots cause aggregation, humus binds soil, humus and nutrients encourage detritivores and decomposers and interception and wind velocity reduced
What are some of the ecosystems services of forests?
Atmospheric regulation, habitat and wildlife refuge, regulation of the hydrological cycle, climate regulation, soil conservation and recreation/amenity uses
What have oak, beech, holly, hazel and ash traditionally used for?
Oak- timber framed buildings and ship building
Beech- tools handles and furniture
Holly- walking sticks and maths instruments
Hazel- wall and fencing panels
Ash- roof timber and furniture
What is pollarding?
Management method where trees are cut above ground level so the regrowing branches cannot be eaten by wildlife
What is coppicing?
Trees cut to the ground every 1-20 years depending on the growth rate of the species and the demand, the branches that regrow were used for baskets, fencing, charcoal, wall panels and roof rafters
What are some management methods for modern day commercial forestry?
Single species plantations, close planting, cultivation of non-indigenous species and single age structure
How do single species plantations benefit forests?
Mono cultures can make management easier, activities e.g. planting, thinning and felling can be carried out over large areas at the same time
What is close planting and how does it benefit?
Planting all the seedlings close together makes the trees compete with each other for light so they grow tall and straight, the low light levels at the ground level inhibits the growth of other plants that may compete with the trees for water or nutrients, the loss of these species that depend upon them reduces the forest wildlife diversity
What’s the benefit fo growing non-indigenous species for commercial forestry?
May be better adapted to the environmental conditions, and are less likely to sufferer damage from pests or disease, however inter-species relationships may be reduced leading to reduced diversity
What is single age structure?
Planting trees at the same time so they are the same age, size and require same management techniques, leading to lack of habitat e.g. old dead wood is for invertebrates and woodpeckers
What are the causes of deforestation?
Agriculture, reservoirs, mineral extractio, urbanisation and infrastructure for transport
How does agriculture contribute to deforestation?
- Increasing local population increases demand so more clearing
2.commercial cash crop agriculture where the produce may be taken to cities or exported
e.g. Rainforest clearance in se Asia to grow palm oil
Rainforest clearance in South America to grow sugar cane and soya or to rear cattle
How does infrastructure for transport increase deforestation?
Easier access to take out resources, they can create barriers also and cause population fragmentation
What are some resources that are exploited unsustainably?
Fuel, feeding livestock and timber
What is softwood?
Produced by confers e.g. Pine, spruce, and fir trees are often produced sustainably with replanting to replace harvested areas in areas e.g. Scandinavia and Canada
What is hardwood?
Tear and mahogany grow more slowly than congers so it is more difficult to commercially manage hardwood plantations as it may take longer to produce a saleable crop. a lot of harvested hardwood comes from mixed forests that are completely felled and may not be replanted.
What are the ecological impacts of deforestation?
Reduced biodiversity, loss of species and fragmentation of remaining forest areas
How does deforestation change hydrology?
Reduced interception/transpiration and increased rungs
How is soil impacted by deforestation?
Reduced soil formation, reduced dead organic matter, less protection, increased erosion, reduced root binding and reduced organic matter
What are the curate impacts of deforestation?
Increased albedo, reduced carbon sequestration and carbon reservoir and reduced rainfall downwind
How are forests sustainably managed?
Mixed species plantations, harvesting rate, selective logging, indigenous species and mixed age structure
How do mixed species plantations lead to sustainability?
Wildlife biodiversity increased by growing multiple species because there is increase in food choices, inter-species relationships and niches
What are the cons of selective logging?
More expensive, labour intensive
How is selective logging beneficial?
Maximum benefit from the timber and good for wildlife as smaller clearing
How does indigenous species plantations benefit wildlife?
More likely other indigenous species will benefit
How does mixed-age structure benefit?
Greater diversity of abiotic factors, increase biodiversity of other species living in the forest
What are the importances of forests?
Resources (timber, food, fuel, fibres, medicines), ecosystem services (atmospheric regulation, hydrosphere regulation, microclimate, habitat and wildlife refuge, soil conservation and recreation and amenity uses)
What are the effects of deforestation?
Loss of forest resources, ecological impacts, changes to hydrology, impact on soil and climate impacts
