Forest resources Flashcards
What are the resources timber provides?
Timber- Furniture, tools, buildings
Fibres- paper made from flattened sheeters of interwoven cellulose, wool
Fuel- Mainly used in LEDCs
Food- Fodder for livestock, food for humans (cacao,coffee), bushmeat in LEDCs
Medicines- Tress produces chemicals that have medicinal uses, quinine extracted treats malaria
What is meant by ecosystem services?
The indirect and direct contributions of an ecosystem to human wellbeing
What ecosystem service do forests do?
The balance of photosynthesis and respiration to regulate lvls of CO2.
Trees are carbon stores, they store it in their cellulose. Cellulose is difficult to absorb so trees have a long residence time of storing carbon.
Describe the ecosystem service hydrological cycle relating to forests
Transpiration from forests is important in increasing precipitation downwind.
Interception by leaves increases evaporation into atmosphere
Forests help soil formation, reduce erosion so soils are deeper
Soils retain water stopping flooding/moderating the flow of rivers
Low albedo so sunlight stored as heat in the water of wood
Absorb sunlight during the day and release it as heat at night so reduces temp extremes
How do trees produce habitats
Each tree has its own unique species therefore larger forests have more biodiversity and niches
Trees create variations in abiotic factors like temp, wind, light and humidity which support different species
The high primary productivity of forests means they can support a bigger food chain
Explain soil conservation as an ecosystem service relating to forests
Forests aid sol formation and reduce soil erosion.
Dead vegetation contributes to humus and nutrients in the soil which provides food for detritvores/decomposers
Trees stop soil erosion by producing low wind velocities and by interception from leaves
Leaf litter on soils reduces the impact of wind
Tree roots help to hold soil together reducing erosion, humus also binds soil
Loads of DOM mean loads of detritivores like worms which increase aeration so more water can infiltrate, less soil is washed away.
What are some recreational uses of forests?
Walking, camping, cycling, educational activities
What are some traditional forest management methods to reduce exploitation?
Mixed species forests, different types of wood can be used for different types of things, e.g. oak for building, ash for furniture, hazel for fences
Coppicing- cutting trees to ground level on a cycle, wood used for baskets/fecning
Pollarding- trees cut above ground level so the growing branches can be eaten by livestock.
Standard trees- trees grown to maturity to produce large timber for buildings
What is the impact on forestry as society becomes industrialised?
Demand for timber and the way it is used changes.
Demand could fall as people use electricity from fossil fuels
Species specific uses of wood replaced by large scale uses for construction
Harvesting methods changing to more damaging ones like clear felling which reduces biodiversity.
What are the management methods of modern forestry and why are the good?
Cultivating non-indigenous species- often better adapted to environment and wont suffer from disease/pests, indigenous species will not be supported due to lack of food/habitats so when extracting wood habitats arent being destroyed.
Single species plantations, reduces biodiversity, growing monoculture means easier management as felling can be carried out in large areas
Name two drugs extracted from trees and what they treat
Taxol extracted from yew trees and it is used in medicine to treat breast cancer
Rosy periwinkle from Madagascar produces vinblastine which is used to treat Hodgkin’s and vincristine to treat childhood leukaemia
Why do boreal forests have more carbon in their soil?
Because the decomposition is slow so there is more carbon within the soil that hasnt been released
Describe the benefits of a forest microclimate beneath the canopy
Creates a wider range of conditions for more species.
Low wind velocity provides shelter, pollination, stops soil erosion
Canopy creates shade which creates cooler temperatures
High humidity which allows amphibians to survive without their skin drying out
Give 2 examples and explain why biodiversity is important to human society
Medicines- new drug exploration and treating sickness now, rosy periwinkle
Biomimetics- Bird splayed wing tips being copied in planes to reduce fuel consumption
How do forests aid soil formation and reduce soil erosion?
Deciduous trees drop leaves, this contributes to DOM and will decompose to form humus.
Humus releases nutrients
Trees create shade which moderates temp so decomposition is more constant, DOM is nutrition for soil biota which aid soil formation.
Tree roots and humus hold soil together stopping erosion.
Why is the yield from wild communities lower than plantations?
More competition in the wild because there are more species
No genetic modification so plants arent modified to their potential
Big variation in productivities and gene pool size
List some reasons for deforestation
Mineral extraction
Urbanisation
Agriculture
Transport infrastructure
What is subsidence farming?
Individuals who farm for themselves in order to live
Why is the reliance on charcoal instead of coal in LEDCs unsustainable?
Involves the partial burning of wood with a shortage of air, once partially burnt the wood looses its energy content so more forests are cleared for demand and supply
Why is it harder to manage hardwood species like teak?
They grow more slowly so it is more difficult to produce a sellable crop
Why is charcoal preferred in LEDCs instead of coal?
It produces less smoke when burnt and also heats up faster
What are some sustainable practices that can be used to remove trees?
Heli logging where helicopters are used so forests can stay remote as no roads are built
Low impact removal like using animals to move timber or cutting trees down near water and using the current to move them, this prevents the need for new roads
Selective logging where trees of value are taken or dead ones are cut down to encourage new growth.
How can forests be managed to make sure they’re healthy?
Monitor the health of the trees by tracking disease
Thinning of forests to promote healthier growth
Replanting for future resources, replant indigenous trees so indigenous species benefit
What are the advantages of selective logging?
Habitat destruction decreased
Ecosystem stays largely intact as only small parts are cut down
Variation is still high
There is still resistance to diseaseW
What are the disadvantages of selective logging?
Roots of other trees may be damaged when removed
Only the best/biggest more adapted trees are removed
Regrowth is slow, especially in boreal or fir forests bc of the cold climate
What are the disadvantages of forest plantations?
Less species diversity and a smaller gene pool because of genetic selection.
Limited natural recycling
No age structure/trees all the same age
No nesting environments/do not support communities of animals
Monoculture plantations have an even smaller biodiversity
What are the advantages of plantations?
Faster growth due to fertilisers
Less competition as crops are controlled for max yield and efficiency
Less stress on wild species for resources which gives them a chance to regrow/recover
What are the advantages of natural forest?
More species diversity and a bigger gene pool
Nutrients are recycled naturally and returned to the ecosystem
How is the population controlled in natural forests?
Competition like natural selection/survival of the fittest and climate
Why do plantations use close planting?
Planting trees close together encourages them to compete with each other for sunlight etc this causes them to grow tall and straight with less branches.
Higher quality wood is produced.
What is the impact of large scale harvesting and creation of plantations?
Reduces biodiversity of the forest
Loss of soil due to erosion
Desertification possible which leads to flooding and difficulty in growing crops
What could be used to measure abiotic factors in a forest?
Light meters
anemometer
Humidimeters
How can plantations be managed to be sustainable?
Mixed species plantations which increases wildlife biodiversity
Indigenous species indigenous animals will benefit
Mixed age structure produces diversity in abiotic factors
Selective logging
Harvesting should not be over MSY
What are the key principles of forestry?
Forests provide a wide range of renewable resources
Forests provide ecosystem services
Good decisions can be used to manage forests sustainably
What does species evenness mean?
Measure of the abundance of different species within an area
