IB ESS paper 1

Biomes

Major zones on the earths surface characterised by different natural vegetation caused by different climates

Freshwater aquatic

Ponds, lakes, river

Marine aquatic

Oceans

Forest

a large area of land covered with trees eg tropical (hot, humid) or temperate (mild temperatures)

Types of forest, their location and vegetation

1. Boreal forest, subarctic, evergreen&coniferous

2. Temperate, warm, mid latitudes, mixed woodlands

3. Tropical and subtropical, between tropics of cancer and capricorn (hot and humid), subtropical broadleaf evergreen trees

- high precip

- high levels of humidity

- rich soils

- warm summers, cool winters - in winter, temps drop, stopping photosynthesis, vegetation goes dormant and NPP is very low

- longer daylight hours during spring and summer

- produces 75% of worlds NPP - large dense layer of vegetation

Grassland

A biome where grasses are the main plant life eg Savanna or temperate (mild temperatures)

Types of grassland, their location

1. Tropical savanna grassland, located between tropic rainforests and deserts eg Africa, india

2. Temperate grassland, between tropical deserts and temperate forests

Desert

An extremely dry area with little water and few plants

Types of desert and qualities (air, temp, precip, productivity, vegetation, soil)

- Hot, coastal and cold

- Dry air

- high temps

- low precipitation

- low primary productivity (NPP)

- vegetation scarce

- soil rich in nutrients so can support plants surviving there

Tundra

An extremely cold, dry biome. eg arctic or alpine

Types of tundra and qualities (air, temp, precip, productivity, vegetation, soil)

- Arctic and alpine

- low temps

- low photosynthesis rates and productivity - high for 1-2 months when there's sunlight

- nutrients in soil are limited as soil is frozen

Tundra vs tropical rainforest

Tundra:

- Low mean annual temp

- very low precip - as low as deserts

TRF:

- constant warm temp

- has the largest annual precip compared to any biome

This is because tundra is found at the poles, whereas TFRs at the tropics

Demographic transition model: stage 1 pre industrial society

Low growth; high birth and death rates with a natural increase close to 0.

death caused by:

- disease

- famine

high birth rates due to:

- lack of awareness of family planning

- children contributed to income through chores

stage 2: industrialising

CBR rates high, death rates drop quickly causing significant increase in NIR (rapidly expanding population)

falling death rates due to:

- improved food production and storage - green revolution

- doctors became aware of the link between disease, water supply and poor sanitation - greater understand of disease

- discovery of vaccination to treat infection

- access to basic healthcare and education

Stage 3: Industrial

population growth slows as both birth and death rates drop because of improved food production, health, and education - highest NIR of all stages

falling birth rates due to:

- availability of contraceptives

- understanding of family planning

- education of women

- ban of child labour - parents began to invest in childs education

Stage 4: Post industrial

Birth rates, death rates and NIR are all low.

- population is large having gone through a period of high growth

Stage 5: Post Industrial

Death rates exceed birth rates due to factors such as low exercise and obesity.

large numbers caused by high BR in stage 1 and 2 are now into old age.

- falling BR in stage 3 means theres fewer workers to support the aging population

Crude Birth rate

the number of births per year for every 1,000 people in a population

births/total population x1000

Crude Death rate

the number of deaths per year for every 1,000 people in a population

deaths/total population x1000

Natural increase rate (NIR)

fertility and mortality combine to determine population size, expressed in %

(CBR-CDR)/10

Doubling time

The number of years needed to double a population, assuming a constant rate of natural increase.

70/NIR

Cons of DTM

- doesn't take into account natural disasters or epidemics, eg AIDS/war

- MEDC based, the relationship between - relationship between economic development and pop. growth isn't the same as LEDCS.

- doesn't take into account government policies to manage population size

Role of the IUCN red list

to provide information and analysis on the status, trends and threats to species in order to inform and catalyse action for biodiversity conservation

IUCN red list categories include

1. Extinct

2. Extinct in the wild

3. Critically endangered

4. Endangered

5. Vulnerable

6. Near threatened

7. Least concern

Criteria used to determine conservation status

- Pop. size - no. of mature individuals

- Pop size reduction

- Geographical range - extent of occurence

- Quality of habitat

Flagship species

large and charismatic species used as spearheads for biodiversity conservation

Umbrella species

often large species requiring large habitat areas.

- Protecting the habitat of this species also protects the habits of other species.

Keystone species

A species that influences the survival of many other species in an ecosystem

- species that interact through the food web with other species

The two ways to conserve species

- In situ

- Ex situ

In situ conservation

To prevent a species becoming extinct - the reason for species loss needs to be addressed

eg habitat restoration (difficult and lengthy)

OR if poaching is a main threat, stopping the poachers

-> hard as for those living in poverty, this may be their only source of income and for others, fines and imprisonment is not sufficient to compete with high potential profits.

eg following the commercial banning of humpback whales by the International Whaling Commission in 1966, species numbers in the wild have increased and are no longer considered at threat by the IUCN Red List.

CITES and pros and cons

aims to ensure international trade does not endanger threatened species. It is a tool that can be used to support conservation strategies.

pros:

- restricts trade which threatens species becoming extinct

- encourages education and increases awareness surrounding endangered species

- can stimulate funding into research and conservation

cons:

- participation is voluntary, not mandatory

- focuses on conservation when main threat to biodiversity is habitat loss

- enforcement can be difficult

- trade driven underground (black market)

Ex situ conservation

Preservation of species outside their natural habitats.

- can be long and expensive

Plants - botanical gardens

Animals - captivity (zoos, aquariums)

pros:

- increases numbers, decreases extinction

- Opportunity to learn more about species biology and behaviour

- educates the public on species - gain financial/political support

- provides a temporary safe space to live while habitats are being restored

cons:

- requires resources and finance

- doesn't address cause of habitat loss

- may not be able to survive in wild when reintroduced, hunting skills difficult to learn in captivity

- detrimental to health - leads to aggressive behaviour

- susceptible to disease in small area

- ethical concerns

Factors which can lead to high numbers of endemic species

- a diverse range of ecosystems eg forests, reefs which will increase biodiversity

- the larger the place/island, the more biodiversity

- geographical isolation will cause speciation

- variation in altitude provides a range of habitats

Biocapacity

biological capacity of an area/region/country to generate the resources and absorb the wastes of a given population.

increases due to:

- renewable energy sources

- reduced vehicle use

declines due to:

- degradation

- soil erosion

Mitigation

Addresses the causes of climate change by reducing GHG emissions

- reducing NOx emissions through catalytic converters

- reducing energy consumption through cap and trade

Adaptation

Focused on dealing with the effects of climate change

Adaptation strategies to:

reduce risk of water shortages

- reducing demand, water conservation

- improving water supplies, desalination to use seawater

to reduce risk of flooding

- ban building on river flood plains

- use of flood barriers

- modify infastructure

to reduce climate change impacts of agriculture and fisheries

- use crops which reflect changing conditions eg pest resistant or grow at higher temperatures

- altering time of planting/harvesting to match conditions and optimise yields

- reduce soil erosion via winter crops and wind breaks

- reduction in fishing intensity

to reduce climate change impacts on ecosystems

- connecting protecting areas with corridors - movement

- increase protection of vulnerable species eg coral reefs

- develop forest fire management techniques

How the protection of forests contributes to conservation of aquatic environment

- Lack of deforestation reduces soil erosion

- increased tourism increases funds for conservation

- reduces agricultural activity which contributes to run off - stops nutrients entering water bodies preventing algal blooms and therefore eutrophication

Pros and cons of tourism on wildlife

Pros:

- increased revenues to invest back into conservation

- raises awareness = greater support, makes public appreciate wildlife

cons:

- growth in tourist sites lead to loss of habitat

- noise from tourism disrupts habitats

- can alter animal behaviour

- litter can degrade environment and damage habitats

- great access to wildlife areas can lead to increased poaching

Human activity and soil erosion

1. Urbanization

- growth of cities leads to loss of soil cover

- suffers compaction and pollution from leaded petrol and rubbish

2. Livestock grazing (overgrazing)

- leads to removal of vegetation, leaving soil exposed to water/wind erosion

3. Deforestation

- leaves soil exposed through removal of trees

- lack of vegetation = lack of rainfall interception, decreasing infiltration and increasing run off

4. Farming

- exposes soil to water/ wind erosion

- enhances chemical/physical degradation

eg tillage (ploughing land) - leaves land bare and vulnerable to water/wind erosion

- growing multiple crops per year - removing nutrients from soil faster than they're replaced

- excessive irrigation with poor drainage leads to water erosion/salinisation

5. climate change = higher temps, melts ice and increases floods

Threats to the soil: processes

1. wind erosion - wind carries soil particles through the air, increasing over flat areas - open areas are more vulnerable

2. chemical degradation - reduces fertility as leads to:

- salinization (water evaporates leaving salt so plants cant grow)

- acidification - increase in hydrogen ion conc lowering pH - caused by acid deposition, leaching, removal of nutrients from soil, ammonium based fertilizer use

- nutrient depletion from overexploitation - constant cropping without replacing nutrients

Impacts of climate change

pros:

- increase in heat can lower heating costs of a country

- melting ice can increase available land for agriculture

- provides favorable conditions for species, increasing biodiversity

cons:

- reduction in pop as species might not be able to adapt

- loss in biodiversity and tourism as a result

- increased precip. = increased leaching

- melting of permafrost will release greenhouse gases

- melting ice leads to albedo effect causing further warming

*depends on country - for iceland

Overall, will have positive effect as temps allow greater growth of trees which conserve the soil - producing greater yields which is important as already minimal life there

Impact of beaver dams on biodiversity

- reduce stream velocity

- cause loss of trees

- reduce fish species

- create habitats for new aquatic plants

Biotic factors

The living components of an ecosystem which directly affect another organism

eg a change in species diversity/ plant diversity

increase/decrease in species adapting to new ecosystem

Abiotic factors

Non living components of environment which influence organisms and ecosystems

eg

- temp

- sunlight

- pH

- salinity also soil reduction (due to beaver dams)

- pollutants

Measuring abiotic factors

temp - thermometer

Turbidity - secchi disk/litmus paper

Flow velocity - flow meter

Wind speed - anemometer

soil - hand identification chart for soil analysis

Quadrats and method

A frame of specific size, which can be divided up into subsections to study plants/ non-motile animals. They are usually square or rectangular.

they asses:

- no. of individuals

- % frequency

1. take a minimum no. of quadrat samples

2. calculate mean

3. extrapolate for whole study area

pros:

- easy method

- accurate with large species

cons:

- inaccurate with small species - species might be hiding under grass

- hard to count every blade of grass

Transect

A sample path in which you record the distribution of plants and animals in a particular study area

Types of transects:

Line sampling

- a line is placed and vegetation touching the line can be recorded at intervals

random sampling

- if line has no discernable patterns, this can be used.

- generate a random number and mark on the map, generate a second random number and draw a line between these two points

stratified:

if known subsets - lines should reflect proportions seen in whole area

systematic:

- if an environmental gradient, line should be placed along here

Belt transects:

- once the line is determined, quadrat is used to create belt of sampling, recordings may be continuous or interrupted

1. The ecologist could decide on a regular interval that he will use

2. He would record the temp (for example) and record results with a data collection table

3. he should repeat readings to obtain averages and increase reliability.

Bioaccumulation

The gradual build up of non biodegradable substances in an organism - build up in fatty tissues and occurs over lifespan

Biomagnification

The increase in concentration of non biodegradable substances in the tissues of organisms higher up in the food chain.

Succession

The process of change overtime in an ecosystem involving pioneer (don't need soil to grow eg moss, lichens break up rock to create soil), intermediate and climax communities. (the maximum possible development that a community can reach under environmental conditions)

primary:

- change that occurs in an area where no soil existed

- eg melting ice exposing rock that hasn't been built on yet

secondary:

- change occurs where soil already existed - eg previous ecosystems damaged by natural disasters or farming/logging

Zonation

A changing community along an environmental gradient due to factors such as altitude, latitude, temperature and depth of water

biotic factors include:

- predators

- human intervention

- competition

Sources of water pollution on land

1. Domestic sewage

- mainly organic

- main source of pathogens (eg bacteria) - illness if consumed

2. Industrial discharge

- organic matter

- toxic metals

- non biodegradable compounds

3. Agricultural run off

- pesticides, fertilizers (nitrates - soluble, easily leach causing growth of water plants), manure (contains pathogens)

4. Urban run off

- pollutants from catchment - organic waste, oil, toxic metals

5. Atmospheric input

- industrial plants, vehicle exhausts

Marine sources of pollution

1. Outfall pipes - directly from land to sea

2. Materials dumped at sea - sewage, radioactive waste etc

3. Shipping activities - litter, accidental discharges eg oil

Effects of water pollution: Organic pollutants

from sewage, farm run off

- food source for microorganisms -> they break it down using oxygen and creating nitrates, phosphates, sulphur and co2

- decrease in oxygen kills organisms

- anoxic conditions created - anaerobic bacteria break matter into methane, ammonia and hydrogen sulphide

Inorganic plant nutrients

nitrates and phosphates increase primary production causing eutrophication

- increased disease

- reduced commercial value

- water can be used or drinking or recreational activities

Toxic metals

- high levels interfere with essential cellular processes

- Bioaccumulation - levels build up over time through continual exposure

- Biomagnification - concentration of heavy metals increases in tissues through organisms higher up the food chain

eg mercury

Oil

- covers surfaces preventing gaseous exchange - blocks light causing oxygen depletion due to lack of photosynthesis

causing death, drowning - sticks to birds wings, ingestion causing intestinal disorders

Plastic debris

- entanglement

- Ingesting plastics blocks digestive system - suffocation, reduces feeding, reproductive problems

Noise pollution

Underwater harmful sound - causes beaching of whales

How to monitor impact of untreated sewage

1. pH - reflects local geology and soil, presence of certain plants are good indicators

*pH probe/litmus paper

2. Temperature - affects dissolved gases in the water - colder waters hold more O2 - warm waters can stress organisms and cause anoxic conditions

*thermometer

3. Biochemical Oxygen demand

- Measure of amount of oxygen used by organisms in a water sample

1.initial dissolved o2 reading of sample it taken

2. fill 1 litre bottle with sample and seal

3. incubate bottle in dark at 20* for 5 days

4. measure dissolved oxygen levels again

5. difference between initial and final = bod

2mg/1= great

20mg/1 = highly polluted

4. Biological monitoring

- biotic index:

high biodiversity - little pollution

low biodiversity - high pollution

use of indicator species:

stonefly larvae, mayfly nymph - highly sensitive to oxygen depletion

sludge worm, rat tailed maggot - little sensitivity to oxygen depletion

Simpsons diversity index

N(N-1) (total no. of organisms)/ change in n(n-1) (no. of induvidual species) - the higher the number, the more diversity there is

5. Secchi disk to monitor turbidity

6.measurements taken over time to observe water quality change

Water pollution management techniques from run off and eutrophication

Reduce pesticides by:

- using alternative approaches eg natural predators

- applying when and where needed, not blanket spraying

- use of biodegradable pesticides

Fertilizers by:

- when and where requires

- apply in dry weather to avoid being washed away

- dont use near aquatic systems

Eutrophication by:

- removing nitrates/phosphates from sewage effluent

- efficient use of fertilizer

- buffer zones

- restricting access of livestock to aquatic systems

4 ways in which solar energy reaching vegetation may be lost from an ecosystem before it contributes to biomass of herbivores (4 marks)

- reflected through leaf surface

- lost in faeces

- absorbed by herbivore but lost through respiration

- not eaten by consumer

- absorbed but not used in photosynthesis - not converted into chemical energy

Procedures to measure net productivity of insect population (7 marks)

- measure change of population size over year

- use Lincoln index by setting traps, capturing a sample, marking them and releasing them

- weigh a sample of insects to find wet weight

- use conversion factor to calculate dry weight

- calculate mean dry weight - use this and population sizes to calculate total weight change over the year

To what extent are the concepts of net productivity and natural income useful in managing the sustainable harvesting of named resources from natural ecosystems?

- Net productivity is the energy or biomass per unit area per unit time after allowing for respiratory losses (rate of growth of plants and animals)

- Natural income is the goods and services produced from the natural capital if its sustainably used. eg timber from trees, fish from fisheries

- The higher the net productivity, the higher the natural income will be - NP informs the speed of harvesting and the maximum sustainable yield (maximum yield that can be harvested while still allowing for natural regeneration)

- If resources are removed faster than they're produced, this will cause economic loss and therefore to avoid the risk, will promote sustainable harvesting

- this may lead to change of destructive harvesting methods, as if less fish are killed as bycatch or by destroying habitats then there will be a higher NP and therefore higher income

cons:

- NP limited to biotic resources and therefore may carry inaccuracies which can inaccurately inform natural income leading to unsustainable methods

- NP nor NI take into account damage caused by extraction there inaccurate

- difficult/complex to collect energy data

4 characteristics of ecosystems that contribute to their resilience (4 marks)

1. biodiversity

2. population size

3. climax community

4. steady state equilibrium

How positive feedback mechanisms may influence the equilibrium of an aquatic ecosystem during process of eutrophication (7 marks)

- promotes deviation away from equilibrium and drives it towards a tipping point

- excess of nitrates -> rapid algal growth-> reduces light penetration -> reduces O2 produces -> causes death of animals -> death increases decomposition -> this further reduces O2 -> causing anoxic conditions and further death of organisms

Pollution management strategies may be aimed at either preventing the production of pollutants or limiting their release into ecosystems.

with reference to eutrophication, evaluate relative efficiency of these two approaches to management.

- limiting release of pesticides - less pollutants which can wash into nearby aquatic ecosystems and as a result less pollutants which can bioaccumulate and biomagnify in ecosystems and therefore this will reduce the effect of pesticides on species over time and throughout the food chain eg death, disease

- limiting the release of fertilizer - reduce the amount washed into nearby water systems which could decrease nutrients entering water bodies, decreasing the production of algal blooms and therefore preventing or significantly reducing the effects of eutrophication eg disease, loss of water for drinking and recreational activities

- through restricting the access of livestock to aquatic ecosystems/ farmers reducing amount of livestock, this reduces the manure which might be washed into nearby ecosystems, therefore reducing release of pathogens, for example bacteria, which can cause disease, killing off fish stocks and also nutrients, again contributing to the formation of algal blooms and therefore eutrophication.

BUT

- manure of livestock can still be washed into the systems by rain despite efforts and farmers won't be willing to reduce livestock as they will still have to make money to live off. - have to meet demands eutrophication not their priority

- through limiting fertilizer used, although this may reduce eutrophication, this may be more time consuming for farmers, not cost effective as will have to purchase new machinery

Overall, both have significant effect - limitng the production would be less effective as nutrients entering an aquatic ecosystem will form algal blooms regardless of the quantity

- hard to get farmers to change attitudes to pesticide/fertilizer use - protection from pests, may reduce yield which would affect their income

Inputs into soil storages (2 marks)

- Organic matter from living organisms in the soil

- Minerals from weathering of parent material

- Gases - certain plants fix atmospheric nitrogen and change it into nitrates and ammonia compounds

- Water

- Decomposition

- Animal excretion

- Fertilizer

Outputs of out of soil storages (2 marks)

- leaching and evaporation

- denitrification

- soil erosion

- decomposition

Soil structure and texture

1. Sand, course, well drained (prone to leaching), subject to drought in low rainfall

2. Silt - medium

3. Clay, fine, poorly drained (prone to water logging), warm up slowly in summer

good soil - crumbles, breaks up easily

poor soil - course lumps that don't break apart

How waste management strategies can help preserve soil fertility (7 marks)

- recycling prevents release of non biodegradable material

- reductions helps to reduce quantity of non biodegradable material

- education/laws to promote disposal of hazardous domestic waste in appropriate collecting facilities

- sorting waste before landfill entry can remove toxic substances

- incineration may help to break down non biodegradable products

- landfills can limit release of non biodegradable materials

- composting doesn't break down non biodegradable compounds but can provide soil nutrients, increasing fertility

The provision of food resources and assimilation of wastes are two key factors of the environment that determine its carrying capacity for a given species.

to what extent does the human production of food and waste influence the carrying capacity for human populations?

- The carrying capacity is the maximum number of species sustainably supported by a given area

- food production = increase in CC due increase in food availability which can support larger populations and decreased competition, boosting health/nutrition

- waste can be reused, recycled so wont have as much effect on CC

BUT

- increases EF (is the area of land and water required to support a defined human population of a giving living standard)

- hard to counteract the impacts of landfill sites which will break down foods and waste into co2 and methane which are green house gases -> global warming = natural disasters, flooding, reduce resources

transport of food - increases carbon emissions again contributing to global warming

- mono cropping which will cause soil erosion through the depletion of nutrients, eventually leading to desertification meaning the land can no longer be used - reduces CC as less land to grow crops

- run off - pesticides, fertilizers -> eutrophication killing aquatic systems

- more waste (sewage) increasing BOD polluting waters, reducing water and fish supply

- irrigation (poor draining) = soil erosion, less land

- overgrazing - wind/water erosion

Mitigation strategies:

- reduction of pesticides/fertilizers

- alternative pesticides - natural predators

- polyculture/ crop rotation to use different nutrients - reduces nutrient depletion, can gain higher yields

Overall, despite mitigation strategies, leads to global warming and pollution and therefore although CC might increase short term... after using constant food production methods, CC will decrease long term due to effects of waste and lack of ability to produce food.

4 reasons why the genetic diversity of a population may change over time (4 marks)

- natural selection

- human activities eg pollution, hunting

- climate change may affect species, change surroundings and environment - reducing or increasing diversity

- farm animals might escape into the wild, introducing new genes

Explain how changes in the concentration of stratospheric and tropospheric ozone in the atmosphere can affect global biodiversity. (7)

- reduction in Stratospheric Ozone and production of Tropospheric Ozone has increased

- SO absorbs the most amount of harmful UV radiation, reducing the amount reaching Earths surface - further decreasing UV B and therefore skin cancer, burn and cataracts

- UV B will effect plant growth (damages chlorophyll) and populations in food chain, reducing diversity in food web

TO in urban areas increases photochemical smog - toxic to all species, highly reactive

- disrupts leaf cells, reducing photosynthesis and plant growth

- greenhouse gas -> global warming -> reduction in biodiversity

Environmental value systems differ in how they view the importance of biodiversity and this could influence a community's approach to conservation.

discuss how these different perspectives, including your own, influence approaches to conservation. (9 marks)

Ecocentric value systems:

- systems that believe that nature has an intrinsic value, supporting the biorights of species due to the value and vulnerability of nature and appreciating all the benefits that its provides us with

- believe animals have the same right to live as humans

- aim to minimize human intervention as this causes disruption and damage eg trampling

- insitu conservation - national parks - safe space from threats

Anthropocentric value systems:

- systems based around people and human needs disregarding the effects it may have on biodiversity.

- if pop increased, they would never take responsibility of depletion

- biodiversity will be important to them as it can benefit humans - conserve it for human benefit - it stabalises ecosystems for human benefit

- sustainable harvesting

- ecotourism which can boost their economy and generate profits which can be reinvested in education or healthcare - tourism might cause injury to wildlife (destroy habitats, seperate whale calfs from their mothers, stress)

Technocentric value systems:

- technology based and see technology as providing solutions for environmental problems, even if it may push natural systems past their normal boundaries in the first place.

- environmental issues are opportunities for science progress

- might use gene banks and technology to grow and rebuild populations.

- ex situ conservation if its useful to them, can research animals or it might be useful to preserve them

Overall, my own perspective lies between an ecocentric perspective and an anthropocentric perspective as I do believe that nature should be left untouched due to its inherent value and in the beauty and biodiversity that it provides, but I also believe that human needs have to be met

- we have to use conservation strategies which also allow us to harvest sustainably to meet demand, otherwise human populations will fall - compromise has to be made.

Types of systems

Open system:

exchanges both energy and matter with surroundings

inputs = rainfall, soil, organisms

outputs= evaporation, water

Closed system:

exchanges energy but not matter with its surroundings eg Earth

Isolated system:

exchanges neither energy nor matter with its surroundings

eg Universe

Transfers and Transformations

Transfer:

Processes involving a change of location but no change of state

eg water flows in rivers

Transformation:

Lead to formation of new product/change of state

eg water changing state

Positive/Negative feedback

Positive feedback:

- promoting deviation away from the equilibrium

eg climate change - increase in co2 increases temp, melting permafrost which releases methane, further increasing temp

Negative feedback:

- counteracts deviation from equilibrium and promotes stability

Tipping point

A critical threshold where small change can have dramatic affects on overall systems - new state of equilibrium

eg water cycle regulation could collapse

EIA

1. Scoping

- making sure EIA is focused on environmental impact

2. Baseline study

- flora and fauna

- abiotic factors

- human factors eg culture, heritage

3. Predicting and assessing affects

- temporary eg building = noise pollution

- permanent - as a result of finished product

4. Mitigation

- plan to prevent/ reduce negative impacts

5. The environmental statement

- report based on info gathered

- difficult to define extent of impact

- no standard between countries - thorough in some

Types of pollutants

1. Point source pollution

A single, identifiable point of pollution

2. Non point source pollution

Pollution from multiple diffused sources - hard to identify

3. Acute pollution

occurs suddenly and in high quantities over a short period of time

4. Chronic pollution

Persistant, long term release of pollutant

5. Primary pollution

Release of pollutant from direct source eg dust

6. Secondary pollution

formed when primary pollutants react with the environment or other pollutants eg acid decomposition

Ecosystem def

A community of organisms and the physical environment it interacts with

Species

A group of organisms with similar characteristics which can interbreed to produce fertile offspring

Habitat

The physical place within an ecosystem where an organism is found

Niche/fundamental/realised

Niche:

Describes the particular set of abiotic and biotic resources and conditions to which an organism responds

Fundamental:

Describes the full range of condition and resources in which a species can survive and reproduce

Realised:

Describes the actual conditions and resources in which a species exists due to biotic interactions

R and K strategists and growth curves

R strategist:

Species that tend to spread their reproduvtive investment among a large number of offspring so that they can colonize new habitats quickly and make opportunistic use of short lived resources.

- J curve, plenty of resources and limited competition until resistance takes place, causing a crash

- large number of offspring

- little parental investment

- unstable environments

- small

- early maturity

- short life expectancy

K strategist:

Species that tend to concentrate their reproductive investment in a small number of offspring to increase survival and adaption to living in long term climax communities

- S curve - limited resources, exponential growth, growth slows due to resource depletion, reaches its carrying capacity

- small number of offspring

- large parental investment

- stable environments

- large

- later maturity

- long life expectancy

Parasitism/Mutualism

Parasitism

- an organism takes nutrients from another organism - wouldn't be beneficial to kill its host as would lose its habitat

Mutualism:

- 2 organisms of different species in a mutually beneficial relationship eg oxpecker eating parasites on large mammals.

Pyramids

of numbers:

shows the numbers of organisms at each trophic level

of biomass:

shows the amount of biomass at each trophic level measured in dry weight

of productivity:

shows the turnover of biomass at each trophic level and the flow of energy over time

Path of solar radiation

- Reflected by Earth, clouds or atmosphere

- Absorbed by a surface or atmosphere

Carbon cycle: describe an animals role in the carbon cycle

- carbon store

- releases co2 into the atmosphere by respiration

- releases co2 into atmosphere as it decomposer

- provides carbon to consumers

- provides carbon to decomposers

Nitrogen cycle

Process by which nitrogen is converted into nitrogen compounds through the atmosphere, soil and organisms

Nitrogen fixation

This makes nitrogen available to plants through the fixation of nitrogen into nitrogen containing compounds eg ammonium ions

Nitrification

The conversion of ammonium into nitrites into nitrates by nitrifying bacteria in the soil

Denitrification

Converting ammonium ions, nitrite ions and nitrate ions into nitrogen gas by denitrifying bacteria.

Decomposition

The breakdown of biological matter into ammonium ions, nitrite ions and nitrate ions

Assimilation

When organisms take in nitrogen containing compounds and turn them into more complex molecules like amino acids for proteins