Forest Resources And The Importance Of Forests Flashcards
What % of the earths land area is covered by forests?
30%
Forests are often the climax community in ecological succession if the conditions are suitable. What are the conditions needed?
Presence of soil
Climate that doesn’t involve prolonged dry periods or serious fires
What determines the type of forest that is found in an area?
The temperature
3 topic links to forest resources
Biomes
Temperate broadleaf woodland
Tropical rainforests
Give 2 reasons forests are important
They provide resources and ecosystem services
What resources are gained from forests?
Timber
Fibres
Fuel
Food
Medicines
What ecosystem services do forests provide?
Atmospheric regulation
Regulation of the hydrological cycle
Forest microclimate
Habitat and wildlife refuge
Soil conservation
Recreation and amenity uses
Most resources from forests are now provided by cultivated plantations of species discovered in natural forests. What does the loss of wild forests result in?
A loss of valuable species, some of which become extinct before their importance is understood or discovered
Why is timber a useful resource?
Wood has a high strength: weight ratio
Flexibility
It requires little processing for use
Is often readily available
What tree species is timber gained from in tropical rainforests?
Mahogany and teak
what tree species is timber gained from in temperate deciduous forests?
Oak and beech
What tree species is timber gained from in northern coniferous forests?
Conifers
Why is wood from different species different?
They have different properties and uses
Name 4 uses of timber?
Structural uses: building construction
Telegraph poles
Furniture
Tools
What fibres that are gained from forests are important ?
Flattened sheets of cellulose fibres from pulped wood is used for paper
The fibres surrounding seeds on a cotton plant is used for paper
The chemical treatment of cells.ose fibres extracted from wood is used to make viscose (rayon) textiles
Explain the importance of wood as fuel
It is still the most used fuel in the world for cooking
Used as an energy resource by everyone before Industrial Revolution
It still provides energy for people in LEDCs who cant afford oil,gas or coal
How are forests important for food resources?
They provide food for livestock and fruit and nuts for human food
The animals in the forests can also be food for humans
Wild varieties of cultivate species may contain genes important in selective breeding programmes
May have more species that could be cultivated or domesticated
Name some of the forest plant species that are important to agriculture
Coffee
Cacao (chocolate)
Bananas
Papayas
Brazil nuts
Name 2 forest animals that are now important to agriculture
Pigs
Chickens
How are forests medicinally important?
They produce chemicals that have medicinal uses
Some are still extracted from tree tissues, but some are now synthesised artificially
Most forest species haven’t been researched for medicinal compounds
Name one compound that was indentified in trees and then synthesised artificially for medicinal uses
Quinine
Originally extracted from the cinchona tree
How are forests important in the regulation of the atmosphere?
The balance of photosynthesis and respiration is important in regulating atmospheric levels of co2 and oxygen
Forests are huge carbon stores, and their systems can be deliberately used to counteract climate change
The processes that remove co2 from atmosphere also release oxygen, these are essential for aerobic organisms and the maintenance of the ozone layer
Why does the carbon that is stored in forests, stay there for so long?
Cellulose is difficult to digest so wood is a carbon reservoir with a relatively long residence time
Explain carbon sequestration in forests
The process during which growing trees take more CO2 out of the atmosphere in photosynthesis and store it as wood
How effective are forests as a carbon store?
The total mass of carbon in forest soils is greater than in vegetation
The total mass of carbon in forests is roughly double the mass in the atmosphere
CO2 absorption by photosynthesis and the the storage of wood in carbon increases the amount of carbon in biomass reservoir, helps minimise climate change
Summarise the ways in which forests help to regulate the hydrological cycle
Greater transpiration rates
Interception by foliage
Soil formation and reducing soil erosion
Low albedo
Absorption of sunlight during the day
How do the greater transpiration rates in forests help to regulate the hydrological cycle?
They are greater in forests than any other terrestrial ecosystem
Transpiration is important in increasing precipitation rates downwind
How does interception by foliage in forests regulate the hydrological cycle?
It increases evaporation but decreases infiltration
How does the role of forests in soil formation and reducing soil erosion help to regulate the hydrological cycle?
Soil depth is greater than in other ecosystems
Soil will retain water after it has rained and moderate the flow of it into rivers
How is the low albedo of forests important in regulating the hydrological cycle?
It increases the absorption of sunlight and the storage of heat and water in wood
How does the fact forests absorb sunlight during the day regulate the hydrological cycle?
Convert most of the sunlight absorbed into heat which is radiated at night
This reduces temperature extremes between day and night
How are trees important to the forest microclimate?
They change the abiotic conditions beneath the canopy and create a wider range of conditions that different species may be adapted to
What factors of the forest microclimate can trees alter?
Light
Wind velocity
Humidity
How can trees alter the light in forest microclimates?
Canopy vegetation absorbs solar insolation, especially red and blue wavelengths which are absorbed in chlorophyll
Plants below the canopy have less access to light- what is available is green which cant be absorbed effectively
Plants need to have adaptations
Give 3 examples of plant adaptations because of trees changing access to light in forests
Denser chlorophyll
Additional pigments
Different growth periods- grow when trees have lost their leaves
How do trees change the wind velocity in forest microclimates?
They lower the wind velocity because of the shelter produced by the trees
How are plants adapted to the lower wind velocities that trees create?
Plants below the canopy layer use animals for seed dispersals instead of wind, which is actually the better system of dispersal anyway
How is humidity in forest microclimates altered by trees?
Higher humidity levels
This means more animals like amphibians can survive easily because their skin doesnt dry out
How are forests important for habitats and wildlife refuge?
They are the most biodiverse terrestrial ecosystem
Each tree species supports its own unique community
Greater variety of tree species, greater overall biodiversity
They create diverse habitats with large variety of possible ecological niches
High primary productivity of forests provides a lot of energy to support higher trophies levels in the food chain
How are forests important to soil conservation?
- dead vegetation contributes hums and nutrients to the soil
-trees intercept rainfall and reduce wind velocity- prevents soil erosion
-Leave leaf litter on surface,reduces impact of raindrops
-Tree roots hold soil together
-Lots of organic matter means lots of living organisms in soil like worms
What recreational uses are forests important for?
Walking, orienteering, cycling, camping
Also for educational activities
