People and the Biosphere

Question 1

Biosphere

Answer 1

> The layer of the Earth inhabited by living organism.

Question 2

Biome

Answer 2

> A large scale ecosystem.

Question 3

Ecosystem

Answer 3

> A self-sustaining system of interactions between living and non-living things.

Question 4

List of biomes

Answer 4

• Tropical rainforest.
• Tropical grassland (savanna)
• Temperate deciduous forest.
• Boreal forest (taiga)
• Tundra
• Temperate grassland
• Hot desert
• Mediterranean

Question 5

Influences on biome type

Answer 5

> Precipitation influenced by latitude:
-areas of low pressure = high rainfall.
-3 major convection currents (Hadley, ferel and polar), precipitation is high at the rising part of the cell as air pressure is low,
Latitude:
-temperature and sunshine intensity are controlled by latitude.
-near the equator, where sunshine is more intense, it is warmer.
-As latitude increases (towards poles), winter becomes longer and colder; climate more seasonal which limits growth.
In high pressure areas, lack of precipitation prevents tree growth so grassland, or in very dry areas, desert replaces them.

Question 6

Biomes - Biotic

Answer 6

> Living part, e.g plants and animals.

Question 7

Biomes - Abiotic

Answer 7

> Non-living part, e.g atmosphere, water, rock and soil.

Question 8

What does the biosphere do to the carbon cycle?

Answer 8

> It regulates it.

Question 9

Carbon Sinks

Answer 9

> Natural stores for carbon containing chemical compounds like C02 or methane.

Question 10

Carbon Sequestrian

Answer 10

> Removing carbon dioxide from the atmosphere and locking it up in biotic material.

Question 11

Biomass

Answer 11

> Percentage of living things.

Question 12

Nutrient Cycle

Answer 12

> Soil fertility - leaf litter decomposes returning nutrients to the soil, so depends on supply of leaf litter.
Biomass depends on soil fertility, as plants grow they take nutrients from the soil.
If the biomass is removed they would be no dead fauna so then there would be no leaf litter.
If trees don’t intercept rain there would be soil erosion. Less infiltration of water into soil so the ground water supplies are lower. Surface run-off increases soil erosion and water gets into rivers faster which causes floods more frequently.
No forest, drier soil, less evaporation, drier climate.

Question 13

Local Factors and Biomes

Answer 13

> Altitude
Rock Type
Soils
Drainage and Water Availiability

Question 14

Local Factors and Biomes - Altitude

Answer 14

> Altitudes:

• Minus 1 degrees C for every 100m up.
• Mountains are more exposed to wind and usually more precipitation.
• Trees don’t grow above treeline as it’s to cold.
• Altitudinal zonation = change in ecosystem at different altitudes, caused by alterations in temperature, precipitation, sunlight and soil type.
• Shorter days mean shorter growing period.

Question 15

Local Factors and Biomes - Rock Type

Answer 15

> Rock Type:

• Some are harder than others.
• Impermeable rocks don’t let water through = slate and marble.
• Permeable rocks = chalk and sandstone.
• When rocks undergo chemical weathering they release nutrients and chemicals into the soil.
• Limestone is very permeable so dry meaning no trees can grow… leads to lime stone pavements (Yorkshire).

Question 16

Local Factors and Biomes - Soils

Answer 16

> Soils:

• Mixture of tiny particles of rock, dead plants (animals), air and water.
• Different plants grow in different soils (neutral, acidic and alkaline, it depends on underlying rock.
• Sandy soils are dry with lots of gaps so water passes through quickly.
• Clay soils have very few air gaps so water doesn’t drain through easily.
• Peat soils are rich in dead matter.

Question 17

Local Factors and Biomes - Drainage and Water Avaliability

Answer 17

> Drainage and Water Availability:

• Where there’s impermeable rock, the ground may become frequently waterlogged as rain can’t drain away.
• Waterlogging can prevent trees growing and peats or marshland may form where only specially adapted plants like bulrushes can grow.
• Some plants can grow with roots in waterlogged areas.
• Soil wetness depends on precipitation, evaporation and how permeable a soil is.
• Sandy soil dry, clay wet.

Question 18

How we use the Biosphere

Answer 18

> We interact with the biosphere on a daily basis for:
-Goods: Physical materials e.g wood, fish.
-Services: Functions e.g. oxygen from trees, tree roots prevent floods.
-Food: Apples, nuts, berries, fish, crops, fruits etc…
-Medicines: Periwinkle - fights cancer, Quinine - malaria.
-Raw Materials: Fuelwood, oil, timber, coal, iron ore.
-Services: Spiritual well-being and happiness.
We call the goods and services that biomes provide ‘ecosystem services’.

Question 19

Ecosystem Services

Answer 19

> Provisioning Services (goods) = products obtained from the ecosystems, food.
Regulating Services = These services link to other physical systems and keep the whole planet healthy, storing carbon.
Supporting Services = Keep ecosystem healthy so it can provide the other services, nutrient cycling.
Cultural Services = Benefits people get from visiting or living in a healthy ecosystem, recreation and tourism.

Question 20

Efe Tribe

Answer 20

> Indigenous tribe of the Ituri tropical rainforest in the Congo Basin of Africa.
They use the provisioning services:
-Build small circular houses to live in, made from wood and leaves.
-Wood from forest for cooking fires.
-Efe hunt monkey and antelope for bushmeat + fish in rivers.
-Hunt the giant forest hog and sell its’ meat for items like pans + rice.
-Make medicines from plants and wild honey
Cultural services:
-Children and recreation.
Supporting services ensure their ecosystem’s maintained for their use.

Question 21

Asia’s Population and Impact on Resources

Answer 21

Water Consumption:
1975 = 1000 km cubed
2015 = 1700 km cubed
% increase = 70%
Oil Consumption:
1975 = 453 millions of tonnes
2015 = 1450 MoT
% increase = 220%
Coal Consumption:
1975 = 388 MoT
2015 = 2910 MoT
% increase = 624%
Meat Consumption:
1975 = 22
2015 = 135
% increase = 513%

Question 22

Malthus Theory

Answer 22

> Writing at a very pessimistic time during the revolutionary wars.
Limits to population and how many people the world can support.
Population increases in a different and faster way than food.
Population increases geometrically (1,2,4,8).
Food supply only increases arithmetically (1,2,3,4)
Eventually there will be a population verses food crisis.
Only natural checks (war, famine) would reduce population.
Prevention: having fewer kids.

Question 23

Boserup Theory

Answer 23

> Danish economist writing in 1960’s - full of optimism.
Human race will always invent new ways of coping with demand, population determines agricultural methods.
‘Necessity is the mother of innovation.’
As population grows, innovative humans will invent new ways of producing more food.
Some say we invented farming as we started to run out of food to hunt.
Today we are creating GM crops.

Question 24

Commercial Use

Answer 24

> Modern technologies have reduced day to day dependence on the biosphere, increasing in their exploitation.
Once a biome has been cleared for commercial exploitation, it won’t grow back, done for profit.
Slash and burning farming is still used by 500 million people worldwide.
Farmers clear small areas by cutting and burning, ash from burning adds nutrients to the soil, land farmed for 5-6 years before it becomes infertile.

Question 25

Resources

Answer 25

> Resources are found in the natural and we need them to survive.
Richest 20% consume over 85% of all resources, most in Europe, USA and Japan.
Poorest 20% consume only 1.3% of all resources.
Europe’s population is increasing slowly and demand for resources is staying the same.
Asia’s population is huge and growing slowly and straining the world’s resources.
Africa’s population is growing fast and its’ growth rate is accelerating.
China is ‘The World’s Factory’ and is a big strain.

Question 26

Type of Resources

Answer 26

> Non-renewable resources = cannot be remade, fossil fuels.
Sustainable resources = deliberately renewed by managing them, trees.
Renewable resources = renew themselves without being manages, solar, wind, wave.