Forest resources Flashcards
name the 3 types of forests and their biodiversity
- deciduous (High biodiversity)
- coniferous (low biodiversity)
- tropical rainforests (highest biodiversity)
what does LEDCs and MEDCs stand for?
LEDCs = least economically developed countries MEDCs= most economically developed countries
name the 6 resources gained from forests
- timber
- fuel
- food
- fibres
- medicines
- genetic resources
why is timber and fuel important resources? and why are they being overexploited?
- as pop. increases, increased demand for timber
fuel = burning wood biggest provider of energy for cooking, mainly in LEDCs
why is food important resources? give examples and why are they being overexploited?
i.e. trees fodder for livestock, Nuts/fruits for humans. Bushmeat in LEDCs.
- Many plant species from forests i.e. cacao/bananas
+ forests could provide new, future food resources
why is medicines (examples) important resources? give an example and why are they are being overexploited?
- some still extracted from trees.
- forests not been researched for medicinal properties.
i. e. Aspirin came from willow bark
name the 5 ecosystem services forests provide
- atmospheric regulation
- regulation of hydrological cycle
- habitat/wildlife refuge
- soil conservation
- climate regulation
explain the 3 ways how forests help to regulate atmosphere
- reservoirs of C: carbon sequestration (store in cellulose) and photo. takes in C
- Photo: produces O2 = respiration + maintenance of O3 layer
- These processes increase C in biomass reservoir = less C in atmo.
explain the 3 ways how forests help to regulate hydrological cycle
- transpiration greater in forests: increase evap. more H2O in atmo.= increase rain
- interception: increase evap. decrease infiltration
- leaf litter/deeper soils: increase infiltration (delayed runoff = river levels fluctuate less + aquifer recharge)
explain how forests provide habitat and wildlife refuge
- biodiverse terrestrial ecosystems: different varieties of trees/stratification = different ecological niches
- high primary productivity: lots of energy (support higher trophic levels)
- trees create variations in abiotic factors i.e. temp/light levels + humidity/wind velocity
explain the 3 ways how forests aid soil conservation
- DOM: humus + nutrients/food for biota. (Humus = binds soil)
- trees/vegetation: increase interception = reduce splash erosion + windbreaks = less wind erosion
- soil biota: aerate soil = increase O2 for aerobic processes + increased infiltration = less runoff/erosion
explain how forests regulate global climate
- Decrease temp: photo+ carbon sequestration
- Less IR being absorbed
name at least 4 out of the 6 factors that influence choice of species for forest plantations
- growth rates
- resistance to pests/disease
- demand for particular products
- ability to grow in certain soils
- ability survive in climate conditions
- properties of wood
differences between the abiotic and biotic factors in a plantation and a natural forest
abiotic: plantation lower light levels (denser canopy), less wind velocity
biotic: plantation less varieties of trees and more uniform = less ecological niches. pest outbreaks have higher impact
name the 4 forestry practices that increase productivity
- growth of non-indigenous species
- close planting
- monoculture
- simple age structure
explain how the growth of non-indigenous species increases productivity (2) Include examples
+ species better adapted to environmental conditions
+ less likely suffer damage from local pests/diseases
= eucalyptus to East Africa (originally from Australia)
explain why monoculture increases productivity + impact on biodiversity
+ management of plantation easier
+ activities i.e. planting/felling carried out at same time
- decreases microhabitats/ecological niches = less biodiverse
explain why close planting increases productivity (2)
+ trees compete for light so grow tall/straight (more marketable)
+ suppresses growth of weeds
explain why a simple age structure increases productivity + impact on biodiversity
+ trees of similar sizes = similar tree management at same time so easier management
- reduction in abiotic factors
+ trees felled when income at greatest and growth rates slow
- less dead wood = less DOM, less nutrients for plants, they die
how does mixed species plantations increase sustainable management? (3)
- increase variety of resources for other species i.e. food/habitats etc.
- increase range of interspecies relationships + niches
- increase biodiversity
what are the drawbacks of mixed species plantations? (2)
- less useful if there is a specific product that is in demand
- less commercially viable
how does the use of indigenous species increase sustainable management? (2)
- trees suited to local climate
- resources for indigenous species/interspecies relationships
what are the drawbacks for use of indigenous species? (3)
- less suited to local fungi/disease
- may not grow as fast
- produce less desirable wood
how does mixed age structure increase sustainable management?(3)
- range of microhabitats/niches = increase biodiversity
- no need to harvest at same time (not all be mature) = minimises wildlife disturbance + soil erosion
- range of abiotic factors present i.e. light, temp etc.
how does selective logging increase sustainable management? (5 points)
- certain species can be chosen i.e. if important to wildlife/sensitive areas left alone
- useful for mixed species (mature at different times)
- use narrow access pathways (horse drawn carts/heli -logging) = no need for heavy machinery
- overall yield increased = each tree meets maturity instead of using clear felling method
- less soil erosion = ground always has vegetation
what are the drawbacks of selective logging? (2)
- more labour intensive
- more overall time/effort
name the 3 activities that are considered for clearance for alternative land uses
- agriculture/cattle farming: as pop. increases so does demand for food = more land needed for crop/livestock
- urbanisation: as pop. increases needs more housing
- mineral extraction: mining/associated structure. Increased demand for metals/minerals
how do the loss of forests have an impact on soil conservation? (4)
- less DOM: less nutrients
- less roots: less soil stability, increase erosion. Increase turbidity in waterways (anaerobic conditions)
- less foliage: decrease interception = increase impact of raindrops. Also increase wind erosion
- less soil biota: less aeration = less infiltration = more runoff. Less aerobic processes
how do the loss of forests have an impact on hydrology? (3)
- less evapotranspiration: less H2O in atmo. = less rain
- less interception
- increase runoff: increase risks of flooding = money needed for defences. Increase river level fluctuations
the impact on climate regulation with loss of forests:
- less _________.
- Less carbon _________: increases CO2 in ________ = decreases carbon in _______ reservoir. increase _______ greenhouse effect
- less ______ being produced: ______ needed for ________ respiration. decrease in _____ layer = UVB and UVC may not be ______.
- photosynthesis
- sequestration, atmosphere, biomass, enhanced
- oxygen, oxygen, aerobic, ozone, absorbed
how does the loss of forests impact biodiversity? (4)
- decrease in biodiversity, decrease in niches/variety
- loss of habitats/inter relationships: less seed dispersal, loss of food
- less variations in abiotic factors
- increased fragmentation: isolating groups of species and increased chance of inbreeding
how does loss of forests change abiotic factors?
- increased wind velocity
- less humidity
- higher light intensity
- increased temp
why are fibres important resources? give 2 examples of fibres and why are they being overexploited?
i.e. paper (flattened sheets of interwoven cellulose), cotton (fibres that surround seeds on cotton bush)
+ growing fashion/textile industries
why genetic resources important resources? give examples and why are they are being overexploited?
CWR new genes = new characteristics for selective breeding.
+ increase demand/importance as biotech associated with agriculture improve crops due changes in climate
i.e. Cacao + CWR in amazon: drought resistant
explain 3 ways how forests regulate a microclimate
- Trees windbreaks: lower wind velocity = plants below canopy rely on animals for pollination/seed dispersal
- high humidity from evapotranspiration = amphibians can survive
- light levels: canopy absorbs solar insolation = plants living below less light adaptations i.e. additional pigments/denser chlorophyll
explain how the growth of non-indigenous species impacts on biodiversity (2)
- less likely to support indigenous species
- less interspecies relationships needed for: food/ pollination/dispersal not present
explain how close planting impacts biodiversity
- decrease light levels (inhibits growth of other plants)
- decrease in those plants and species that rely on them = reduce biodiversity
