Forestry (yr 2) Flashcards
Biodiversity
a variety of plant/animal life in a particular habitat or in the world
(a high level is good)
Carbon Sequestration
A natural/artificial process by which carbon dioxide is removed from the atmosphere and held in a solid/liquid form
Fibres
a thread of filament from which a vegetable tissue/mineral substance/textile is formed
Fragmentation
the process or state of breaking or being broken into fragments
hydrology
the study of water
interception
precipitation that does not reach the soil and is stopped by things such as leaves, branches, etc
maximum sustainable yield
the maximum level at which a natural resource can be routinely exploited without long term depletion
monoculture
a cultivation of a single crop in a given area
non-indigenous
not naturally occurring in a particular region or environment
selective logging
practice of cutting down a few tree species while leaving the rest intact and unarmed
transpiration
the exhalation of water vapour through the stomata
What is medicine as a resource? Where is it found? Examples?
Chemicals extracted from trees and then (normally) artificially synthesised.
Most forests contain trees that hold these properties but they haven’t been fully exploited.
Quinine - for malaria
Curare - muscle relaxant
Timber as a resource
- Strong, light, flexible, little processing, readily available
- Uses -> construction, telegraph poles, furniture, tools, shuttering for concrete
- Mahogany/teak - tropical
- Oak/Beech - deciduous
- Conifer - coniferous
Timber used as fuel for a resource
- Used by most LEDCs still for heating/cooking
- In most MEDCs oil/coal/gas are used instead
Food from forests as a resource
- Cacao/coffee/bananas/papayas/brazil nuts/fodder for livestock/animals (pigs and chickens)
- Forest food gene possible used for genetically engineering/selective breeding of other plants in the future
Fibres from wood as a resource
- Paper made from flattened and interwoven cellulose fibres (pulped wood)
- Cotton from cotton bush seeds
- Viscose (rayon) textiles made by chemical treatment of cellulose fibres extracted from wood
How does the atmospheric regulation of a forest support life?
- balance of photosynthesis and respiration, co2 and o2 levels
- carbon sequestration in the cellulose
- growing trees reduces co2 levels - counteracts greenhouse effect
- Aerobic respiration releases o2 which reacts with NOx to produce o3 and restore the ozone layer
- forest soils = carbon reservoir and nitrogen reservoir
- total carbon in soil = more than double than atmosphere
How does the forest support life with its habitat and wildlife refuge?
- most biodiverse terrestrial ecosystem, microclimate/niches supported by each tree species
- Niches created by stratification - seen when there’s higher primary productivity
- Higher primary productivity = high energy levels to support higher trophic levels
Why might energy take a long time to be release from trees?
They take a long time to die and decompose as they live for a long time so store a lot of energy.
How does the forest regulate the water cycle?
- Evapotranspiration
- Interception - reduces surface runoff, and splash erosion
- Shading - reduces evaporation from soil
How does the forest help climate regulation?
- Stabilises climate
- Carbon and nitrogen cycle -> photosynthesis/aerobic respiration/carbon sequestration/ decomposition etc
- O2 released reacts with NOx to form O3 and repair ozone layer
- Microclimates and varying abiotic factors keeps a dynamic equilibrium in the cycles
How does the forest help climate regulation?
- Stabilises climate
- Carbon and nitrogen cycle -> photosynthesis/aerobic respiration/carbon sequestration/ decomposition etc
- O2 released reacts with NOx to form O3 and repair ozone layer
- Microclimates and varying abiotic factors keeps a dynamic equilibrium in the cycles
How does the forest help soil conservation?
- Root binding reduces soil loss by erosion
- DOM increases soil fertility/humus/depth
- creates platy or crumbly peds
- reduces erosion (water(splash)/wind)
- reduces nutrient leaching
How does the forest affect light?
The canopy absorbs most the light (favourable red/blue wavelengths) through its chlorophyll. Lower level plants absorb green wavelengths by having denser chlorophyll, additional pigments or growth periods for when canopy trees don’t have leaves.
What do forests do to wind velocity and humidity?
- Lower wind velocity by shelter of the trees so animals are used by plants for seed dispersal.
- Humidity is higher (transpiration) so it is easier for animals such as amphibians to survive as their skin doesn’t dry out.
How does it affect the microclimate?
Trees change abiotic conditions under the canopy layer creating a wider range or conditions that species may be better adapted to (inside range of tolerance)
Recreation and amenity?
How humans use the forest.
Holidays/walking/cycling/activity centre/educational activities/orienteering/camping.
Purpose of growing non-indigenous species?
Better adapted to survive certain conditions, less likely to suffer pests and disease.
GROW FASTER (easy marks for any question regarding non-native species.
Conifers - paper - sell - increased economic growth
Furniture/furnishings/desirable products - Oak/Teak/Mahogany
How does growing non-indigenous species impact biodiversity?
DECREASES
- outcompetes native species
- don’t support indigenous wildlife (food, nesting sites, shelter etc)
The purpose of a monoculture?
- Easier management of plantations
- Planting/thinning/felling can all happen simultaneously
How does a monoculture effect biodiversity?
DECREASE
- Reduces local plant species
- Food sources for animals/insects reduced
- Strips soil of nutrients when mass felled
What is the purpose of close planting?
- Trees compete with each other for light so grow tall and straight
- Grow quicker
- Wood will have less knots (less lateral growth) == More profitable
How does close planting decrease biodiversity?
- Low light levels inhibits the growth of other plants
- Lack of nutrients because of the quantity of trees in one area
- Less food sources for animals due to lack of low level plants
What is the purpose of a simple age structure?
- Management is easier as they will all be similar sizes and need similar management
- Felled when income is greatest, when approaching full size and the growth rate begins to slow
How does a simple age structure affect biodiversity?
- Reduces variety of abiotic factors that support wildlife
- Wood felled before it falls so there is a loss of habitat for invertebrates that live in the wood and therefore less food for bird species like the woodpecker.
Causes of deforestation?
- > Fuel including oil and gas
- > Minerals/ mining
- > Agriculture - crop and animals
- > Infrastructure
- > Plantations
- > Economic growth - items for trading
Impact on soil when forests are lost?
- Loss of soil fertility as there is no DOM returning to the soil to be decomposed so no nitrogen/phosphorus returns
- Nutrient leaching due to increased water erosion
- Increased erosion (both water and wind) as there is no root binding
- Soil becomes more compacted or can become toxic if there are spoil heaps leaking nearby
- Loss of soil structure
How does the loss of forests affect hydrology?
- Less interception
- Less evapotranspiration
- More surface runoff so more nutrient leaching
- More atmospheric water as there is increased evaporation from the soil
How does the loss of forests affect the climate
- Loss of micro climates and niches
- Reduced range of abiotic factors
- Increased atmospheric levels of the biogeochemical cycles
- Increased atmospheric H2O
How does the loss of forests impact the biodiversity?
- Lack of habitat, nesting grounds, food sources
- Abiotic factors pushed outside the range of tolerances of animals
- Decreased biodiversity due to change in biotic factors
Pros of mixed species plantations
+range of species increases = more resources for other species
+food sources/pollen sources/ habitat
+greater range of interspecies relationships and niches so higher biodiversity
Cons of mixed species plantations
- may be less useful if there is a demand for a specific product provided for by a particular tree
- other species may be less commercially viable
Pros of using indigenous species
+food/nesting sites for other indigenous species
+well suited for growth in local climate
+less impacted by local pests/fungi/disease
Cons of using indigenous species
-may not grow as fast or produce such as desirable type of wood
Pros of mixed age structure
+Range of abiotic factors present that vary across the forest which will be suited to a various range of species
+Microhabitats/niches to support a wide range of species
+Mixed species reduces need to harvest all trees at once as they won’t all be mature, therefore minimising overall wildlife/soil disturbance
Pros of mixed age structure
+Range of abiotic factors present that vary across the forest which will be suited to a various range of species
+Microhabitats/niches to support a wide range of species
+Mixed species reduces need to harvest all trees at once as they won’t all be mature, therefore minimising overall wildlife/soil disturbance
Pros of selective logging
+ trees will mature in mixed points and therefore will be able to be harvested at different times
+certain trees chosen whilst those that support wildlife/are in more sensitive areas can be avoided
+narrow access pathways and methods such as heli-logging or horse drawn sledges can reduce the amount of and that needs to be cleared
+allows for a higher yield- each tree reaches maturity compared to mass felling
+less soil erosion as land is not completely bare
+animals don’t need to move as far to find a suitable habitat when only a few trees are removed at a time.
Cons of selective logging
- more labour intensive
- requires more overall time/effort
Cons of selective logging
- more labour intensive
- requires more overall time/effort
