Living world Flashcards
What is an ecosystem ?
A community of plants and animals that interact with each other and their physical environment
What is a primary producer ?
An organism that is able to create energy from the sun through photosynthesis
- It needs water, carbon dioxide and nutrients from soil to produce what it needs for itself
What is a primary consumer ?
Herbivore
- Eats plant matter
What is a secondary consumer ?
A creature that eats the herbivores
What is a decomposer ?
An organism such as bacteria or fungi that breaks down dead tissue, effectively recycling its nutrients back to the environment in the form of humus
What are natural factors that change the balance of an ecosystem ?
- Drought
- Disease
- Flood
- Fire
What are human factors that change the balance of an ecosystem ?
- Altering the drainage of the land may influence the amount of water
- Changing the pH levels of the water
- Altering the nutrient levels of the water - if fertilisers are leached into the water it can cause eutrophication
What is the impact of changing a component of an ecosystem ?
- Population numbers of producers and consumers may increase or decrease
- Some ecosystems with fewer producers or primary consumers may collapse
What is leaching ?
The removal of dissolved nutrients from within the soil caused by surplus water
What is surface run off ?
When water cannot filtrate the soil it may wash across the surface and take with it dissolved nutrients and partially decomposed nutrients
What are the characteristics of a tropical rainforest ?
- Located largely between the Tropics where warm air rises
- Hot and wet climate - humid all year round
- Most biodiverse terrestrial biome
- Infertile soils
What factors define biomes ?
- Climate
- Relief
- Geology
- Soils
- Vegetation
What are the characteristics of a temperate desiduous forest ?
- Temperate climate - not too hot or too cold
- Frequent storms with lots of rain
- Trees that grow here such as oak and elm lose their leaves during colder weather
- Found mainly in the northern hemisphere, north of the Tropic of Cancer and south of the Arctic Circle - found at higher latitudes with less insolation
What are the characteristics of grasslands ?
- Located between temperate forests at high latitudes and deserts at subtropical latitudes
- Open, continuous, flat areas of grass
Where are tropical rainforests found ?
Between 15° north and 15° south of the equator within the equatorial climate zone
What are the 5 layers in TRFs
Ground layer
Shrub layer
Under canopy
Canopy
Emergents
What adaptations do animals in TRFs have ?
- Sloth: Algae grow in the fur of the sloth helping to camouflage it
- Toucan: They have a large bill to reach and cut fruit from the branches of trees. They are also strong allowing them to crack nuts open
-Geckos: They have large, flattened toe pads with sticky scales which allow them to grip the smooth tree trunks
What adaptations do the plants in TRFs have ?
- Waxy leaves with drip tips: These ensure that rainwater runs off the leaf and does not remain which would encourage mould growth or break the leaf
- Buttress roots: These large roots above the ground which help to support the very tall trees because the roots below the surface are shallow
- Lianas: Vines which use the tall trees as support to reach the sunlight
- Epiphytes: These are plants which grow on trunks and branches of trees getting nutrients from air, rain or debris accumulating around the plant
What are the 6 main causes of deforestation ?
Hydropower
Agriculture
Road building
Logging
Settelments
Minning
What are the effects of deforestation
- Loss of biodiversity
- Increased overland flow
- Reduced interception and infiltration
- Increased CO2 in the atmosphere
- Increased leaching of nurients
- Increased risk of landslides
What is the impact of deforestation in the nutrient cycle
- Very few trees offering protection for the soil
- Few leaves dropped as litter
- Less nutrient rich soil is produced
- Rapid loss of nutrients by leaching results in acidic soil
- Change in composition (mineral content/ph) leads to soil in infertility
- Infertile soil results in very little vegetative growth
What are the social impacts of deforestation ?
- Indigenous communities have less land to sustain their traditional way of life
- Land does not get the opportunity to recover
- Less food available
- Improved quality of life for some people due to increased income and jobs
- Indigenous communities may give up their way of life leading to a loss of culture and traditions
- Increased risk of landslides which can destroy homes and block roads
- Loss of potential medicines
- Increased risk of flooding settlements
What resources do TRFs provide ?
- Building materials
- Existing food crops
- Wild meat and fish
- Water
- Medicines
- Energy
What are the economic impacts of deforestation ?
- More jobs available in mining, forestry, agriculture and HEP
- Increased income for the country through the export of goods from the forest - minerals, timber, crops
- Almost a quarter of Brazil’s GDP comes from activities in the deforested areas of the Amazon
