The Living World

The Living World

1. Ecosystems

   • Ecosystem - a unit that includes all the living parts, like plants and animals, and the non-living parts, like the soil and climate, in an area
   • Producer - an organism tat uses sunlight energy to produce food, like plants
   • Consumer - an organism that gets its energy by eating other organisms - it eats producers and other organisms, like a lion
   • Decomposer - an organism that gets its energy by breaking down dead material, like bacteria
   • Tropical Rainforests
     • Location
       • Central America
       • Amazon
       • Central Africa
       • South East Asia
     • Climate
       • Hot and wet with no definite season
     • Soil
       • Infertile
       • Leaching occurs often
     • Vegetation Structure
       • 1. Forest Floor - consists of mostly dead leaves, no sunlight
       • 2. Shrub Layer - consists of short plants at around 10m high, very little light
       • 3. Under Canopy - consists of 15m - 25m high plants, some light
       • 4. Canopy - consists of a continuous layer of tress at around 25m - 40m high, a lot of light
       • 5. Emergents - consists of the tallest trees at around 40m - 50m, the most sunlight
     • Plant Adaptations
       • Plants are adapted to heavy rainfall as they have a thick waxy leaves that have drip tips, so the water slides off, so it doesn't damage the plant with its weight
       • Tall trees have large buttress roots which support their trunks in the very shallow soil
       • Climbing plants, like lianas, use tree trucks to climb up to the light
       • The trees are deciduous - they drop their leaves in drier periods to reduce water loss
     • Case Study - Amazon
       • Causes (Between 2000 and 2005)
         • Farming - 360,000km2 destroyed by cattle ranching, 200,000km2 destroyed by small scale subsistence farming and 6,000km2 destroyed by large scale subsistence farming
         • Logging - 18,000km2 destroyed
         • 18,000km2 destroyed by mining, urbanisation, road constructions, dams and fires
       • Effects
         • Environmental
           • Habitats destroyed and loss of biodiversity
           • Amazon stores around 100 billion tonnes of carbon, deforestation will release some of this as carbon dioxide, causing global warming
         • Economic
           • Farming makes a lot of money for counties in the rainforest, in 2008, Brazil made $9.6 billion from trading cattle
           • Mining industry creates jobs for loads of people, the Buenaventura Mining Company in Peru employs over 3100 people
         • Social
           • Local ways of life have been affected, Brazilian rubber tappers have lost their livelihood as rubber trees have been cut down
           • Natives tribes have been forced to move, Guarant tribe moved because land was taken for cattle ranching and sugar plantations
           • Conflict between large landowners, subsistence farmers and native people, in 2009 there were riots in Peru over rainforest destruction and hundreds of native Indians were killed or injured
       • Sustainable Management
         • Replanting - some deforested areas are being replanted with new trees, Peru plans to replant more than 100,000km2 of forest before 2018
         • Reducing demand for tropical hardwoods - some countries reducing number of hardwood trees felled, Brazil banned mahogany logging in 2001
         • Education - by teaching people how to sustain the rainforest, it will last longer
         • Laws and Protection - most countries have laws to help protect the rainforest, Brazilian Forest Code says landowners have to keep 50-80% of land as forest
         • Reducing Debt - helped countries conserve rainforest, in 2008, the USA reduced Peru's debt by $25 million in exchange for conserving its rainforest
         • Ecotourism - becoming more popular, in Peru, there's about 70 lodges for ecotourists
   • Deciduous Forests
     • Location
       • Across Europe
       • East Asia
       • West of North America
       • New Zealand
     • Climate
       • Temperate maritime
     • Soil
       • Very fertile
     • Plant Adaptations
       • Broad leaves capture sunlight for the trees
       • Many trees have thick bark to protect against the cold winters
       • In the autumn, deciduous trees drop their leaves to minimize water loss
     • Case Study - Bramingham Woods
       • Used for...
         • Timber and Timber Products - some timber cut and sold, while other is used to make furniture and fencing
         • Recreation - forests used for walking, cycling and other outdoor activities
         • Conservation - building and maintaining entrances, keeping path open, carrying out improvements where needed
       • Management
         • Controlled Felling - when only some trees are cut down for a specific reason, like trees over a certain age or just one species
         • Replanting - where trees have felled, they are replaced by new trees
         • Planning For Recreational Use - paving footpaths to avoid erosion and provide plenty of bins to reduce litter
   • Hot Deserts
     • Location
       • Mainly between the north and south equator
       • South America
       • Australia
     • Climate
       • Warm all year
       • Extremely hot in summer
     • Plant adaptations
       • Cacti are well adapted for survival in the desert. They have: Stems that can store water. Widespread root systems that can collect water from a large area. In addition, cacti have spines instead of leaves. These minimise the surface area and so reduce water loss by transpiration. The spines also protect the cacti from animals that might eat them.