The living world

The living world

1. Ecosystems

   • Ecosystems = all of the biotic and abiotic components in an environment and the interactions between them
     • Biotic = living Aboitic = non-living

2. Food chains

   • A food chain is the passing on of energy
     • It shows how plants and animals interact within an ecosystem
   • It starts at the beginning with vegetation - known as the producer
     • It is referred to as the producer because it makes its own food through photosynthesis.
     • The first animal in the food chain is called the primary consumer and it can either be a herbivore or an omnivore
       • Herbivore = an animal which only eats vegetation Omnivore = an animal that eats meat and vegetation Carnivore = an animal that only eats meat
       • The second animal in the chain is called a secondary consumer
         • The animal at the end which is not preyed upon by other animals is called the ultimate predator

3. Major biomes of the world

   • Tropical rainforest
     • Characteristics
       • High temperatures and heavy rainfall all year
         • Mean monthly temperatures range from 26 to 28C
       • A third of the worlds trees grow here
         • There are over 1000 different types of trees
       • Lots of animals too
     • Adaptaions
       • Animals
         • Need to be able to keep cool - large ears + little body fat
         • Keep safe from predators - ability to change colour
         • Always wet - webbed feet
       • Plants
         • Large leaves - collect rainfall and direct it to the tree's root system
         • Ability to grow tall for photosynthesis
         • Plants grow thick leaves with drip tips and waxy surfaces to allow water to drain quickly to prevent rotting.
         • Rainforest soils are poor and most nutrients are in the top layers, so roots are generally shallow.
           • Wide buttress roots join the tree far up and help to support it. They also allow it to gather more nutrients.
         • Carnivorous plants are meat-eating plants that attract insects using smelly nectar and then trap them.
       • Most don't live on the forest floor
     • Found in Southeast Asia and the Pacific islands and West Africa
   • Hot desert
     • Characteristics
       • 2 seasons - summers are very hot and winters are cooler
         • Average summer temperature = 35C
       • Very little rainfall all year
       • Only a few plants can survive in the conditions - plants like cacti and thorn bushes dominate here
     • Adaptations
       • Plants
         • Draught resistant
           • Ephemeral plants
             • They are born only after rainfall and have a short life cycle so they die before the next drought arrives
         • Grow close to the ground
         • Ability to retain water
         • Cacti
           • Rapid life cycle
           • Thick waxy skin to reduce water loss
           • Cacti have spikes instead of leaves to minimise the surface area and therefore water loss due to transpiration
           • Ridges mean it can expand so can store more water
           • Spikes prevent them fro being eaten
       • Animals
         • Need to be able to keep cool - large ears, little body fat, white skin
         • Dull colours to blend in
         • Ability to go for a long time without water
         • Camels
           • Camels lose little water through urination and sweating
           • They have big eyelashes to protect their eyes from the sand that is blown around by the wind
           • Large feet to spread the load on the sand
           • Humps containing fat so it has a store of energy without insulating the whole body
       • The Bedouin people
         • Extremes of temperature
           • Wear white to keep cool and only go outside to do their jobs in the evening when it is cooler
           • Shelter made from dark material so the heat from the sun during the day will ensure they are warm when in their shelter when it is cold at night
         • Transport
           • They use camels for transporting their things, stay at each location for a few weeks at a time and have light-weight shelters which are easier to transport.
         • Drought/ lack of water
           • They collect water at water sources and stay within close to them and they drink the animal milk
           • They wear loose fitting clothes to allow air to circulate around the body which prevents sweat from evaporating too quickly and so slows down the rate of evaporation
         • Famine
           • Keep animals
         • Mainly live in the Arabian and Syrian deserts
         • Changes facing desert dwellers
           • They are involved with tourism which provides them with an income but is threatening their nomadic culture as they stay in that one place for a longer amount of time
     • Why hot deserts are hot and dry
       • The Hadley cell
         • Hot deserts are hot because the sun is in contacts with the central band of earth (the equator up to the tropics all year round)
         • They are dry because air rises and condenses at the equator causing heavy rainfall
           • The 'empty' air then sinks , and this tends to be around 30 degrees north and south which is where hot deserts are found - sinking causes high pressure and cloudless conditions
     • The hot deserts of the world are located between 15° and 30° north or south of the equator
   • Tropical grassland
     • Found between the tropical rainforests and the deserts (in South America, India and Australia)
     • Characteristics
       • Alternating wet and dry season
         • 90% of annual rainfall falls in the dry season (as much as 240 mm in a month)
         • Temperatures can reach 30C in the dry season
       • Grasses dominate the landscape but there can be a few trees
     • Also known as the savannah
     • Adaptations
       • Plants
         • Draught resistant
           • Trees have long roots
           • Grass and shrubs die in the dry season and grow rapidly in the wet season
         • Ability to grow tall to avoid being eaten
           • One tree sets off scent to stop themselves being eaten by animals e.g. giraffes
       • Animals
         • Dull colours
         • Lond legs / tall (long necks - giraffes) to reach tall trees
         • Migrate/ hibernate
         • Lions
           • Camouflage to grass
         • Kangaroos
           • Can freeze development of embryo during drought
   • Polar/ Tundra
     • Characteristics
       • Very cold all year round and the ground remains permanently frozen
       • Summers have lengthy periods of continuous daylight, winters are cold, dark and severe
     • Adaptations
       • Animals
         • Lots of body fat
         • Small ears
         • Thick fur
         • Short legs to conserve heat - arctic fox
       • Plants
         • Must have a high resilience to the cold and moisture deficient conditions
         • Arctic moss - slow growth, sheltered underwater
         • Caribon moss - can grow after periods of dormancy and can survive for long times without water
         • Bearberry - low to stay out of wind
     • Located at the North pole!

4. Desertification

   • Responses
     • Grow trees, hedgerows or fences around crops to protects the soil from being swept away
       • Great green wall - Sahara and the Sahel (Africa)
     • Farming without ploughing as ploughing leads to a moisture loss
     • Agroecology - sustainable farming
   • Causes
     • Caused by population growth and climate change
       • They lead to soil being exposed to wind and rain which increases the risk of soil erosion as the wind and rain carries the soil away
   • Effects
     • The non-natural process of land turning into desert
       • The Sahel (an area of fertile land south of the Sahara) is in danger of desertification
         • Latitude = 15 degrees north Runs the whole width of Africa Runs through Sudan, Chad, Mali and Nigeria

5. Masdar city

   • Near Abu Dhabi - UAE (United Arab Emirates)
   • Abu Dhabi and Dubai have developed very quickly (due to the discovery of oil)
     • Islands are owned by different Royal families After the discovery of oil the UAE became very wealthy and so wanted to attract people there (by building shopping centres, homes, creating jobs and entertainment (mainly indoor)
     • This has caused many problems which the development of Masdar city aims to address
       • As they were developed so quickly, little thought was put into sustainability
         • In Abu Dhabi, public transport is scarce and so there is heavy traffic
           • Masdar city will have everything close by so you can walk everywhere and there will be driverless electric pods underneath the city so it will be emissions free
         • There is lots indoors which requires air conditioning as it is very hot but this is not sustainable - they have to desalinise the sea water but the leftover salt is then put back into the sea which makes the sea hyper saline
           • They have to take salt out of the sea water because it is n the desert so there is not much water  but this uses a lot of energy and uses fossil fuels
           • Masdar city will not use fossil fuels and instead will use solar power
           • Instead they will keep Masdar city cool by planning streets and buildings to create shade and breezes
         • They will minimise waste by using waste water to water trees and plants

6. Flora

   • Plants + vegetation

7. Fauna

   • Animals

Imagens e arquivos do mapa