Topic 7- People And The Biosphere Flashcards
Global distribution and characteristics of major biomes are influenced by the climate
Biomes are large-scale ecosystems with distinctive vegetation and animals. There are many different biomes aceoss the world e.g Tundra in the North / Desert mainly within the equator and tropics/ TRF mainly on the Equator / Boreal forest in the North / Temperate forest above the tropic of Cancer
Characteristics:
TRF climate : hot all hear round no definite seasons / 20-28°c / 12 hours sunlight all year / 2000mm oer year lots of rainfall
This causes many evergreen trees adapted to gain sunlight / dense vegetation attracts a large variety of species / plant growth rapidly causing nutrients in the soil to be used up however there is a lot of leaf litter and decomposition
Temperate forest climate: 4 distinct seasons / high rainfall all year round / shorter winter days , longer summer days
This causes a mild,wet climate supports few plant species made up of broad-leaved trees. Thr mild climate and plants provide food for a variety of animals. Soil is relatively thick and nutrient rich due to seasons (leaf litter in Autumn)
Boreal forest climate: short summer and long winter / -20°c winter lowest/ low rainfall >500mm yearly/ lots of daylight in Summer
This causes many evergreen plants along with coniferous trees such as pine and fir and moss. There are few animaks due to the conditions and little food. The cool dry climate means that needles from trees decompose slowly, soil is thin , nutrient-poor and acidic.
Deserts climate:low rainfall 250mm yearly/ desert temp range from very hot during the day to cold at night / lots of daylight in summer
This causes sparse plant growth and variety due to lacking rainfall. A few animal soecies due to harsh conditions and availability of food. The sparse vegetation results in little leaf litter and dry climate means decomposition is slow.
Tundra climate: low temp 5-10°c / low rainfall/ lots of daylight in summer and none in winter
This causes barely any tree variety and most plants include moss,grass,shrubs. Lacking variety of animals in the Tundra. The sparse vegetation produces little leaf litter and decomposition is slow.
How does local factors alter biome distribution
Climate (ie temp,rainfall,sunshine hours) main factors however some other factors may taken into account:
Altitude-high latitudes are colder so fewer plants grow there which limit the number of animal species. This causes soil to be thin.
Rock type- rocks can be easily weathered into the soil and contain minerals. Additionally, some rock are impermeable and permeable.
Soil type- nutrient-rich soil benefits plants. The acidity and drainage of soils also vary which affects plant growth.
Drainage- poor drainage can lead to waterlogging and drowning. Although areas may be adapted to an aquatic environment.
How does biotic and abiotic factors interact
Biotic components- living parts of the environment (plants,animals)
Abiotic components- non-living parts of an environment (temp,water,sunlight,soil)
1) water availability can affect plant growth. Additionally, plants can take in water and release it into the atmosphere which lead to rainfall.
2) type and density of plant can affect the soil type which then affect the plant which grow on it e.g dense vegetation means a nutrient-rich soil due to leaf litter which support plant growth.
3) organisms cause biological weathering. When rocks are broken by organisms e.g tree roots. This releases minerals from within the rocks onto the soil.
How does the biosphere provide resources for indigenous and local people
Biosphere- all parts of the Earth that are occupied by living organisms
Food-indigenous people get their food directky from plants and animals e.g foraging for fruits wnd vegetables or hunting fish and animals. Others may also implement agriculture for food.
Medicine-plants have medicinal properties that are used to cure illnesses. Many plant species used for medicine elg quinine from the cinchona tree treats malaria
Building material- many plants used to make furniture e,g pine. Additionslly, sap from trees are used to make glue or to make buikdings waterproof.
Fuel- indigenous people rely on animals and plants for fuel for cooking and warmth,. Wood,dung,dired grass can be burnt for fuel. Additionslly, animal fat e.g blubber from seals are used to keep warm in colder regions.
How is the biosphere exploited commercially
Energy: demand for energy increasing as population increase more people have more electronic devices which are extracted from forests and the Earth.
-large areas of forestry cut down to clear land for growing crops used to make biofuels, power stations or hydroelectric dams
-drilling for oil and gas in tundra damage biosphere as pipelines melt the permafrost.
Water: used widely as population increases e.g washing,irrigation,cleaning. Natural water sources are exploited which damage the biosphere as plant and animals lose water to survive.
Minerals- demand for resources increase to create products. Minerals are often extracted by mining,quarrying,surface mining which work to destroy the natural landscape and release toxic chemicals and greenhouse gas emissions.
How does the biosphere regulates the composition of the atmosphere, maintain soil and regulate water
Regulating gases in the atmosphere:
Plant take in Co2 and give out oxygen during photosynthesis and animals take in oxygen and release co2 when they breathe.
The maintenance of gases help keep organisms to survive, reduce global warming, decrease acidity of oceans
Soil health:
Plants roots and animals e.g worms spread nutrients in the soil to maintain the soil structure and fertility. The roots of the poant hold the soil to prevent erosions. The vegetation intercepts rainfall to prevent leaching (where nutrients are washed downwards instead of going to plants)
Water cycle:
Movement of water between the land, bodies of water and the atmosphere. When rainfall occurs rain is taken by plants so river recieves less. This prevent soil erosion and flooding in rivers. The water is then stored and released into the atmosphere slowly by plants. This eventually forms into rainfall and the process repeats.
The global and regional trends increasing demand for food, energy and water resources?
Global:
World population is predicted to continue to be increasing. This is shown by population projections which estimate the population size through past and present values. However, there is always uncertainty.
-Demand for resources can also increase demand for another. This is seen through the increase in people requiring food will result in more people to want water. As a result energy need to be release to transport water from areas with a plentiful supply
Regional:
Increasing wealth- economic development means peopel are getting wealthier. This means more people have disposable incomes which affect resource consumption. More money spent on food which is wasted , products which are manufactured and running out, water consumption increases from more water use
Urbanisation- cities tend to be more resource-intensive than rural areas e.g fountaij in park use water
Food and water also have to be transported by rural areas to fit the demand within cities, and waste is barely recycled and is removed which uses energy
Industrialisation:
Manufacturing goods such as cars, chemicals and electricsl appliances use a lot of energy.
Manufacturing also uses a lot of water e.g for cooling and washing components. As a result demand for energy and water increase,
Indsutrialisation can also lead ro an increase in the production of processed goods e.g margarine. This increases ingredients such as palm oil which are grown on plantations replaced many trees which were deforested.
Theories between population and resources
Malthus’s theory:
He thought that population was increasing faster than the supply of resources so eventually the amount of people would be too great for the resources available. As a result he believed that people would be killed by famine,illness and war and the population would decrease to a elvel where the resources would be greater then the population. The point where the line crosses the population is the point of catastrophe.
Boserup’s theory:
Theorised that however big the population was the world’s population would produce enough resources to meet the demand of the world. She thought that if resources were limited people will search for different way to gain these supplies to avoid hardship. This is shown by how when the population begins to be equal with resource supply , the resource supply would increase to be available for the population
