Living world

• ecosystem

  a natural system, made up of plants, animals and their surrounding physical environment
• biotic

  living features of an ecosystem
• abiotic

  non-living features of an ecosystem
• food chain components in order

  - producer

  - primary consumer

  - secondary consumer

  - tertiary consumer

  - decomposer (restart cycle)
• trophic levels

  show the amounts of biomass in each level of an ecosystem

  
• how to tell if an organism is living

  MRSGREN

  - movement

  - respiration

  - sensitivity

  - growth

  - reproduction

  - excretion

  - nutrition
• why is biomass lost as it moves up the trophic levels

  energy is lost of growth, movement etc (MRSGREN)
• food chain

  shows the direct links between producers and consumers in a simple line
• food web

  shows all the connections between producers and consumers in a complex way
• case study: epping forest

  - found in Essex, north east of London

  - small scale woodland

  - has a wide range of food chains and webs
• nutrients

  foods used by plants and animals to grow
• decomposers

  - bacteria and fungi

  - break down dead remains of plants and animals and release the nutrients for plants to use again
• changes to ecosystems

  - trees cut down ~ destroys habitats, effects nutrient cycle

  - hedgerows removed to increase size of farming fields ~ destroys habitats, alters plant/animal balance

  - ponds drained to use in farming ~ aquatic plants and fish die

  - agricultural fertilisers ~ causes eutrophication, increases growth of algae, depletes oxygen more fish die
• biome

  a large scale ecosystem, defined mainly by the dominant type of vegetation found in the region
• the worlds biomes

  - polar

  - tundra

  - temperate grassland

  - coniferous forest

  - deciduous forest

  - desert

  - tropical rainforest

  - savanna
• location of tropical rainforests

  - mostly found along the equator

  - between tropics of cancer and capricorn

  - found in central and southern America, central Africa, south east Asia, and northern Australia
• climate of tropical rainforests

  - temperature is consistently above 27°

  - temperature ranges from around 27.5°- 28.5°

  - average rainfall per month is 150mm

  - average rainfall a year is 2000mm

  - overall, climate is very hot and very wet
• soil characteristics in tropical rainforests

  - shallow of layer of organic material on the top called the humus layer (only fertile part of the soil)

  - the soil underneath the humus layer is called latosol and is full of iron and aluminium oxides (infertile part of the soil)
• why is the soil in tropical rainforests poor

  - there is a lot of water from rainfall

  - means most of the nutrients are washed away

  - this means any nutrients comes from the humus layer which is made up of dead plants (has decomposed)
• plant adaptations in a tropical rainforest

  - wide buttress base ~ greater stability as it covers more ground, allows trees to grow taller

  - drip tips ~ remove the mass of water, improve the stability of the trees and allowing them to grow taller

  - epiphytes ~ plants that live on other plants, gets them closer to the sunlight

  - lianas ~ vines that use the tree for stability to grow up to reach the sun

  - leaves with flexible bases ~ turn with the sun the maximise light intake for photosynthesis

  - emergents ~ grow rapidly to reach the sun as quick as possible, maximises photosynthesis
• layers of a tropical rainforest

  - forest floor

  - understory

  - canopy

  - emergent layer
• causes of deforestation in tropical rainforests

  - cattle ranches

  - small subsistence farming

  - large scale farming

  - logging

  - mining
• pros vs cons of deforestation (more related to impacts of mining specifically)

  pros

  - development of land mining creates jobs

  - companies pay taxes to the government, helps with development

  cons

  - fires can cause harmful pollution or spread widely in valuable areas of the forest

  - plants with medical benefits could become extinct
• impacts of deforestation ~ global and local

  global

  - loss of biodiversity

  - global warming

  local

  - decline of indigenous tribes

  - soil erosion

  - river pollution
• goods vs services

  - goods ~ a physical resource that can be taken, can hold it

  - service ~ provided, enables life to exist, can't hold it
• goods and services that tropical rainforests provide

  goods

  - native food crops

  - wild meat and fish

  - building materials

  - energy for HEP

  - water

  - medicines

  services

  - air purification

  - water and nutrient recycling

  - protection against soil erosion

  - biodiversity

  - wildlife habitats
• case study : Yachana lodges, Brazil

  - found in the amazon rainforest in Brazil

  - example of ecotourism

  - relies on fewer numbers but a more exclusive experience

  - tourists pay to see the unique ecosystems surrounding the lodge

  - travel by boats ~ roads aren't built, don't destroy the environment

  - solar panels used to provide electricity ~ renewable, doesn't emit carbon dioxide

  - lodges are made of local wood ~ aren't imported, blend in with the environment

  - provides jobs for locals and brings in money for the local area to ensure socio-economic development

  - lodges can also be used for education

  - this is sustainable as it provides the 'best of both worlds' ~ economic benefits whilst environment remains protected
• global tropical rainforest management strategies

  reduce debt

  - HICs cut down debt on LICs and NEEs (where most tropical rainforests are located

  - is a nice idea but is difficult to guarantee it will work

  - TRFs could easily still be exploited by HICs

  - mostly, HICs won't agree to this

  international agreements

  - international agreements to protect TRFs

  - have a lot more power as it is from governments

  - not everyone will agree to take part

  biosphere reserves

  - ensuring TRF are leaved untouched a part from for research and scientific purposes

  - allows development in a sustainable way

  - needs governments permission

  education by NGOs

  - increases awareness and spreads message of importance

  - no real power behind it

  - people may choose to not listen
• local tropical rainforest management strategies

  selective logging

  - only involves cutting down wolf trees and continuing to allow younger trees to grow

  - provides balance of economic and environmental benefits

  - clears canopy so younger trees can get sunlight

  agroforestry

  - a farming technique where crops and trees are combined

  - makes people become co-dependent

  - will only work on a small scale

  - doesn't necessarily tackle areas that have already been deforested

  ecotourism

  - type of sustainable action

  - provides balance of economic and environmental benefits

  - good by only on a small scale

  - educates visitors
• examples of cold environment biomes

  - polar

  - tundra
• location of cold environments

  - high latitude locations

  - very far from the equator

  - polar is inside the artic circle, tundra is just outside the artic circle
• why is it cold in polar and tundra locations

  - locates at the poles

  - means heat from sun is distributed over wider areas

  - results in colder temperatures

  - also, heat passes through the atmosphere at an angle

  - means more heat is lost as it spends a longer time period in the atmosphere
• plant adaptations to cold environments

  bearberry plant

  - is low growing to allow it to survive in the strong winds

  - small leathery leaves retain water in the dry conditions

  - hairy stems retain heat in the cold conditions

  - red berries grow quickly due to the short growing season

  artic poppy

  - hairy stem to retain heat

  - tracks the sun to maximise its sunlight for photosynthesis

  lichen

  - does not need soil to grow

  - can withstand cold temperatures

  - can survive beneath snow
• animal adaptations to cold environments

  artic foxes and artic hares

  - thick fur to retain heat

  - fur is white to allow them to blend in with the snow to help them avoid predators

  musk ox

  - 2 layers of fur for insulation

  - wide hooves so they can run in the snow

  walrus

  - thick layer of blubber fat that keeps them warm

  - tusks can break ice, allowing access to land and water
• why are cold environments important for our wildlife

  - are homes to many species of both plants and animals

  - increase global biodiversity