biomes and forests

Question 1

what is meant by the term biome

Answer 1

global scale ecosystem

Question 2

state two resources people might obtain from the biosphere

Answer 2

food 
traditional medicines 
building materials 
wood fuels 
water

Question 3

three features of a rainforest

Answer 3

• very tall trees
• canopy layer
• layered or stratified forest structure
• buttress roots

Question 4

define the term abiotic

Answer 4

non-living component of an ecosystem

Question 5

state two good or services provided by the tropical rainforests

Answer 5

medicines
timber/wood
food

Question 6

describe one benefit of deforestation

Answer 6

many of the goods are exported - eg. timber - stronger currency

crops grown on deforested land

Question 7

outline one reason for the distribution of tropical rainforests

Answer 7

• areas of high rainfall - supporting rapid growth - dense vegetation
• close to equator - high temp - allowing high NET PRIMARY PRODUCTIVITY

Question 8

explain one way the biosphere can maintain soil health

Answer 8

leaf fall leads to litter which decays into humus - which provides nutrients for plant growth

source of organisms, such as earthworms, which improve soil quality and structure

Question 9

explain why Peru has high levels of biodiversity

Answer 9

• hot / wet tropical climate = ideal for growth of tropical forests which have high biodiversity = the complex stratification of the rainforest ensures a wide range of ecological niches

Question 10

explain two ways in which plants have adapted to living in tropical climates

Answer 10

• drip tips = remove excellent water in conditions of over 2000 mm of precipitation
• buttress roots = stabilises the trees as they increase in height
• waxy leaves = to stop excess water infiltrating into leaf and rotting

Question 11

explain why there are differences in the nutrient cycles in deciduous temperate forest and TRF

Answer 11

BIOMASS STORE - bigger in TRF = as more nutrients are held in the vegetation store because of high biodiversity in the ecosystem = so there is more available nutrients = as there is more photosynthesis, meaning a greater amount of productivity

SOIL STORE - smaller in TRF = as the nutrient uptake is higher in TRF and there is a greater amount of leaching due to more rainfall in TRF 2000 mm

LITTER STORE - smaller in TRF = as rate of decomposition s much greater because of the hight humidity

Question 12

explain why there are differences in the climate between deciduous woodland and tropical rainforest

Answer 12

SEASONAL VARIATIONS = deciduous woodlands are exposed to both warm and cold air masses during a year = which results in a greater seasonal variation / four distinct seasons

TEMP = higher in the TRF because they are located near the equator = where there is more direct sunlight hitting the land and sea = however deciduous woodlands have lower temps because they are found at higher altitudes further away from the equator = where the sing light is more dispersed

RAINFALL = higher in TRFs because there are higher temps = increases evaporation rates = warmer air can hold more water vapour

Question 13

explain one reason why tropical rainforests have a high biodiversity

Answer 13

oldest biome on earth planet = and has had more time to develop a greater species diversity

high rainfall/ temperature = produces good conditions for growth

Question 14

explain two causes of deforestation in tropical forests

Answer 14

• trees are cleared to grow crops / cattle ranching = as population increases or to export
• trees are cleared for fuel / firewood = as demand rises due to population growth
• trees are cleared for timber = as rates of urbanisation grow

Question 15

suggest one reason why the annual rate of deforestation has fallen since early 2000s

Answer 15

• the rate of deforestation has fallen because of increased protection of the forests by the government = this means that clear felling has been banned in some areas = and loggers will face significant fines or imprisonment if they dont follow this
• the rate of deforestation has fallen because of increased importance of ecotourism = this means job can be created without damaging the forest = which brings money into local economy and means fewer trees need to be cut down

Question 16

describe one way of conserving threatened environment

Answer 16

National parks = legal status given to designated regions to protect habitats and wildlife

Trade agreements = CITES ( convention of international trade in endangered species ) signed by 166 countries. purposed to prevent trade of items made from endangered species eg. ivory or crocodile skin footwear

Question 17

describe one way in which the biosphere acts as a life support system for the planet

Answer 17

• help balance the atmosphere = by acting as a carbon sinks = vegetation removes and stores CO2 and gives out O2

Question 18

describe one way a named biome has been damaged by human activity

Answer 18

• deforestation = leads to soil erosion
• expanding farmland = destroys habitats
• pollution from mining + industry = water and atmospheric

Question 19

describe how climate controls the distribution of biomes such as tropical rainforests

Answer 19

role of temp = high temp = more plant growth = location case study

told of rainfall

Question 20

explain how human activity is causing the destruction of tropical rainforests

Answer 20

• deforestation for timber - eg. mahogany = causes soil erosion = habitats destruction = and food chain collapse
• mining = stripping off forest cover
• man made climate change = is leading to higher sea levels = changes in temp and rainfall = drought becoming more common

Question 21

explain two ways in which the biosphere regulates the composition of the atmosphere

Answer 21

• vegetation takes in carbon dioxide = during photosynthesis = and releases oxygen = this carbon dioxide is stored within the vegetation forming a CARBON SINK
• animals release methane = during digestion = methane also released from wetlands = when organic matter breaks down anaerobically

Question 22

explain why altitude effects biome location

Answer 22

= temp decreases with height = approx 1 degree per 100m = eg. snows of Kilimanjaro

= rainfall changes with altitude - impact biome development because plant growth is affected by water supply = eg. temperate forest in Bolivia

Question 23

how does temp affect biome distribution

Answer 23

• temp effected by latitude
• sunlight arriving at the equator is highly concentrated
• this concentration of solar energy leads to a higher temp and a longer growing season

Question 24

how can soil affect biome distribution

Answer 24

• drainage = poor drainage can change soil conditions eg. poor drainage in Scotland has led to peat bogs rather than forest
• fertility - soils with higher nutrient content can support a greater diversity of vegetation
• frozen soil = impermeable = preventing root penetration

Question 25

explain how the biosphere effects the hydrological cycle

Answer 25

= vegetation transfers water to air through transpiration = plants are a major water store = vegetation slows surface runoff = rainfall can be intercepted by vegetation

Question 26

what is percolation

Answer 26

-downward movement of water through soil and bedrock.

Question 27

asses this - climate change presents a greater threat to tropical rainforests than it does deciduous woodlands

Answer 27

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