Population and the Environment

Stroud is one of the ? least deprived district authorities in England

20%

what % of children live in low-income families?

10%

in year 6 what % of children are classified as obese?

15% (better than England avg)

what is the male life expectancy?

80.1

what is the female life expectancy?

83.2

July avg temp

23 degrees

January avg temp

7 degrees

December avg rainfall

80 mm

April avg rainfall

50 mm

who manages Minch and Rodborough common?

National Trust

how many hospital stays for self harm per year?

222 (worse than England avg)

% of physically active adults

65.5%

England avg % of physically active adults

57%

deprivation score

10.9

England avg deprivation score

21.8

admission episodes for alcohol-specific conditions per year

62.5

England avg admission episodes for alcohol-specific conditions per year

37.4

England avg male life expectancy

79.5

England avg female life expectancy

83.1

what is there in Stroud that encourages physical activity?

no direct access to high street by car so people park outside & walk

the largest proportion of residents are classified as what?

Affluent Achievers (financially successful)

what is the life expectancy range between the least and most deprived areas?

6 years

what is demographic dividend?

economic growth as a result of a change in the population structure i.e. low dependency ratio

what are population growth dynamics?

study of how and why population size and structures change over time

what are the three scenarios of population balance?

optimum population

overpopulation

underpopulation

what does optimum population mean?

all resources are used to give the highest economic return per person and therefore the highest standard of living

what two things can lead to a higher ooptimum population?

low dependency ratio

improvements in technology

what is environmental resistance?

group of factors that control mortality rates

what is environmental resistance also known as?

limiting factors

what does it mean for a limiting factor to be ‘density independent’?

not influenced by the population size and density e.g. natural hazards will increase the death rate no matter what the population size is

example of density dependent limiting factor

food supply

what is biotic potential?

natural reproductive potential of the species

what happens when biotic potential > environmental resistance?

rapid population growth during log phase

what does underpopulation mean?

too few people to use resources efficiently for a given level of technology

what is ecological footprint?

measure of the demand placed by humans on Earth’s natural ecosystems

what unit is ecological footprint in?

gha (global hectares) per person

what is overshoot?

point when the population and its consumption of resources exceed the long-term carrying capacity

what is total productive bio-capacity?

all food, water and energy resources produced by the Earth’s natural systems annually to sustain us

how does Rees calculate carrying capacity?

(total productive bio-capacity) / (total population)

what does a gha represent?

unit of measurement representing the average productivity of all biologically productive areas on earth in a given year

what is the USA’s avg ecological footprint?

8.1 gha per person

what is Zambia’s avg ecological footprint?

less than 1 gha per person

how much ecological footprint does each person have available?

2 gha

how long does it take for Earth to replenish what we consume in a year?

1.6 years

what is Earth Overshoot Day?

the day it is thought we have used the productive bio-capacity

when was Earth Overshoot Day in 2000?

1st Nov

when was Earth Overshoot Day in 2014?

19th Aug

what is the logistic model of population growth?

as population size increases, the rate of increase declines as more environmental resistance is encountered

what shape is the curve of the logistic model?

sigmoidal - S

through what 3 agencies does the UN act?

1. World Health Organisation

2. World Bank

3. UNICEF

how does the World Bank reduce disease?

provides loans to less developed countries for health programmes

how does UNICEF reduce disease?

helps mothers and children access food, clean water and vaccinations

what is the broad aim of WHO?

improving health on a global scale

4 ways in which the WHO improves health

1. advising governments

2. working with other NGOs to limit outbreaks

3. promoting research and providing training

4. monitoring death and disease

example of a successful WHO project

response to Ebola outbreak in west Africa

what 3 things did the WHO do to reduce Ebola?

1. increasing number of treatment centres

2. helping find a vaccine

3. implementing travel measures

what is the classification system for soil types?

zonal

what are the three categories of the zonal system?

zonal, intrazonal, azonal

what is zonal soil?

mature soils, reflecting climatic conditions and associated vegetation

what is intrazonal soil?

soil reflecting the dominance of other factors, e.g. characteristics of the parent rock

what is azonal soil?

immature and skeletal soil, with poorly developed profiles

what state is zonal soil in?

dynamic equilibrium

what 3 things is zonal soil in dynamic equilibrium with?

climate, vegetation, parent matter

what two things make up soil?

1. minerals from weathered bedrock

2. organic matter from vegetation

what are the 5 soil horizons in order?

O, A, E, B, C (and then bedrock)

what is the O horizon?

loose, partially decayed organic matter

what is the A horizon?

topsoil with high humus content

what is the E horizon?

pale layer of silt and sand, from which clay, iron, and other materials have been leached

what is the B horizon?

zone in which the minerals leached from E accumulate

what is the C horizon?

mainly broken bedrock

what is leaching?

when water moves minerals and nutrients down through the soil profile

where are latosols found?

TRFs

how does the TRF climate impact bedrock weathering?

high temp and humidity → fast chemical weathering

how deep can latosols get?

30 to 40 m

why is the latosol O horizon thick?

year-round plant growth

why is the latosol A horizon thin?

as soon as leaf litter decomposes, the nutrients are absorbed by vegetation - so don’t stay in the soil

why does latosol have a lot of leaching?

rainfall higher than evapotranspiration → soil moisture surplus

what mineral is leached in latosols? Which horizon?

silicate from B horizon

why is the latosol B horizon red?

iron and aluminium are less soluble so don’t get leached

why are latosols poor for agriculture?

low nutrient content

why are latosols even worse for agriculture when the trees are removed?

soil has no protection from heavy rainfall, increasing leaching

what is slash and burn?

clearing one small area at a time for growing crops → after one season, it is allowed to recover

why does slash and burn improve agriculture in latosols?

burning adds nutrients to the soil

why are latosols useful for building?

the laterite horizon is soft when moist, but hard when dry

how is a laterite horizon formed?

build-up of minerals in the soil

where do podzols occur?

cool temperate climates in the northern hemisphere

what is higher in podzol areas, precipitation or evapotranspiration?

precipitation

under which 2 biomes are podzols usually found?

1. coniferous woodland

2. heather moorland

(both are taiga)

what is the O horizon in podzols?

layer of coniferous needles/heather leaf litter

what is the A horizon like in podzols? (3 details)

1. narrow

2. acidic

3. nutrients leached from it by water

how does acidity impact leaching in podzols?

water in soil is more able to dissolve minerals e.g. iron and aluminium

what layer does podzol leaching create?

pale E horizon of quartz sand and silt

where do minerals accumulate in podzols? What colour does this make it?

B horizon, making it reddish-brown

what is a hard pan/iron pan?

hard, continuous layer of iron in the B horizon of very well-developed podzols

why is arable farming difficult in podzols? (3 reasons)

1. acidity

2. lack of nutrients

3. iron pan causes waterlogging, damaging crops

what two things are needed for arable farming on podzols?

1. treatment with lime to reduce acidity

2. artificial fertilisation

why do podzols have a poor nutrient cycle?

coniferous trees do not take up certain elements → these are not added to the soil from falling needles

what 3 elements are not taken up by conifers?

1. calcium

2. magnesium

3. potassium

what two human activities are associated with podzol areas in the UK?

1. sheep farming

2. grouse breeding and shooting (patches of heather are burnt for this)

how much money does the UK get from grouse shooting annually?

£150 million