ESS IB EXAM PREP

Sun enters/exists with what wavelength?

Enters: short Exits: long

Greenhouse effect

Long wave radiation being trapped in the atmosphere

Latent heat

energy absorbed or released by a substance during a change in its physical state (liquid to gas) without changing its temperature

Productivity

energy used for new biomass / energy supplied

What are the trophic levels in order?

Solar insolation, producers, herbivores, carnivores, top carnivores (they all feed decomposers)

Solar insolation

The amount of solar radiation received by a planet (solar energy/specified area/time)

Tricellular model of global air circulation

Due to the laws of thermodynamics, the excess energy at the equator wants to move to areas of lower energy north and south. This energy is transported in the air (and water vapour) and causes the global winds and weather.

What are the cells for the Tricellular model?

Hadley Cell: Located between the equator and about 30° latitude, it is responsible for tropical weather patterns and trade winds.

Ferrel Cell: Found between 30° and 60° latitude, it operates in the mid-latitudes and is influenced by the Hadley and Polar cells, contributing to westerly winds.

Polar Cell: Extending from 60° latitude to the poles, it is characterized by cold air sinking and creating polar easterlies.

Transfers in the carbon cycle

consumption (feeding), death and decomposition, carbon dioxide from the atmosphere dissolving in rainwater and the ocean.

Transformations in the carbon cycle

photosynthesis (carbon fixation), respiration, combustion and fossilization

Storages in the carbon cycle

Organic: organisms and forests.

Inorganic: the atmosphere, soil, fossil fuels and oceans.

Transfers in the nitrogen cycle

absorption, consumption (feeding), death

Transformations in the nitrogen cycle

nitrogen fixation by bacteria and lightning, and denitrification by bacteria in water-logged soils; assimilation, decomposition

Storages in the nitrogen cycle

Organic: organisms.

Inorganic: the atmosphere, soil, fossil fuels and water bodies

What are biomes affected by?

Tricellular model, latitude, altitude, ocean currents, winds, solar energy received, precipitation, temperature

Forest

Tropical forest, Temperate deciduous forest, Coniferous Forest (boreal)

Location and climate: Within25°northandsouthoftheequator.Warmandwetwithlittleseasonalvariation.

Structure: Large species diversity in many niches. Tall emergent trees, canopy, under story of smaller trees, shrub layer. Nutrients are predominantly in the topsoil. With out the support of tree roots, these nutrients are quickly washed away.

Location and climate: Between40°-60° north and south of the equator. Mild climate.

Structure: Deciduous forests, often dominated by one species of tree. Below the trees is either a shrub layer or forest floor. Rich soils fed by the rapid breaking down of leaf litter.

Grassland

Savanna (tropical grassland) Temperate grassland Chaparral (Mediterranean)

Location and climate: Mostly located in Africa (below Sahara), Brazil and northern Australia. Warm with seasonal rainfall and fires.

Structure: Ample vegetation supports the largest terrestrial mammals (elephants, giraffes) and large herds of migrating herbivores (wildebeest, zebra). These intern support large predators (lions, cheetahs).

Location and climate: In centres of continents, between40°-60°

Structure: Large range of grasses supporting large numbers of herbivores and so carnivores. Food webs and ecosystems are simple.

Aquatic

Freshwater • swamps • lakes • ponds • streams • rivers • bogs

Marine

rock shore • mud flats • coral reef • mangrove swamp • continental shelf • deep ocean (Any water beyond the continental shelf; includes hydrothermal vents)

Location and climate:

65% of Earth's surface. Averaging 3.5miles deep

Structure:

0m-200m: phytoplankton, cyanobacteria and algae photosynthesis the available sunlight, supporting a range of zooplankton, fish and invertebrates. 200m-1000m: Larger generally carnivorous fish adapted to lower levels of light and higher pressures. 1000-bottom: Animals adapted to zero light and high pressure. Some create their own light through bioluminescence to attract prey or avoid predators. Bottom: Slow moving scavengers, survive on dead organic matter from above. Hydrothermal vents: volcanic heat and Sulphur support a wide range of organisms.

Tundra

• arctic • alpine

Location and climate: Tundra is found just south of the arctic ice cap. Alpine on high mountain tops. Cold with high winds. Structure: Permafrost prevents the growth of vegetation in the winter. In summer Low growing grasses, shrubs and mosses support a variety of small hibernating mammals. Simply ecosystems with slow rates of growth and decomposition. Possibly the most fragile biome and so the first to be effected by climate change.

Desert

Hot desert, Cold desert

Location and climate: 30°north and south of the equator. Structure:

Supports a small number of well adapted plant and animal (mainly reptile) species Water storage and collection are prime features.

Ecosystem

is a community and the physical environment with which it interacts, linked together by energy and matter f lows. A community is a group of populations living and interacting with each other in a common habitat.

1. Marine ecosystems: the sea, estuaries, salt marshes, and mangroves. Marine ecosystems all have a high concentration of salt in the water.

2. Freshwater ecosystems: rivers, lakes, and wetlands.

3. Terrestrial ecosystems: all land-based ecosystems.

Zonation

the clear change in ecosystems along an environmental gradient

Succession

the change of an ecosystem over time and is most clearly seen when an environment is low in species diversity and population:

1. either new rock formed after volcanic eruptions- lithosere, disposition of dry soils/sands- xerosere or drying of river deltas- hydrosere (primary succession);

2. or areas where the community is destroyed due to fire, flood or human activity (secondary succession)

Sub-climax community

A subclimax community is a stage in the succession of an ecological community preceding the attainment of a climax community. It is the penultimate stage in a succession. Reaching equilibrium

Plagioclimax

Plagioclimax refers to an area or habitat where succession is stopped or held at a particular stage due to human interference or intervention, such as farming, grazing, or burning.

r-selected strategists

• Examples: rabbits, weeds, bacteria

• Short lifespan with high mortality in early life

• Rapid growth and early maturity

• Many small offspring

• Little parental care or protection

• Highly adaptable

• Can colonise new habitats quickly and make use of short-lived resources

k-selected strategists

• Examples: elephants, people, whales

• Long lifespan with mortality in later stages

• Slow growth and late maturity

• Fewer large offspring

• High parental care or protection

• Specialists

• Enables them to survive in long-term climax communities

Species

a group of organisms that share common characteristics and that interbreed to produce fertile offspring.

Habitat

the environment in which a species normally lives.

Population

a group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.

Community

a group of populations living in the same area at the same time.

Niche

describes the particular set of abiotic and biotic conditions and resources to which an organism or population responds. The fundamental niche describes the full range of conditions and resources in which a species could survive and reproduce. The realized niche describes the actual conditions and resources in which a species exists due to biotic interactions

S curve

starts with exponential growth. No limiting factors affect the growth at first. However, above a certain population size, the growth rate slows down gradually, finally resulting in a population of constant size

1. Lag phase- population numbers are low and so birth rates are low.

2. Exponential growth phase population grows at an increasingly rapid rate unrestricted by limiting factors.

3. Transitional phase- population growth slows down considerably as limiting factors are reached.

4. Stationary phase- population growth stabilizes and then population fluctuates around a level that represents the carrying capacity.

J curve

J-curves show exponential growth in a population past the carrying capacity. These are followed by sudden population collapses known as diebacks.

1. Exponential growth- population grows at an increasingly rapid rate unrestricted by limiting factors.

2. Overshoot- population grows past its carrying capacity.

3. Dieback- population suddenly collapses usually due to a lack of food. The population declines below its original carrying capacity as the limiting factor is depleted.

4. Renewed growth- growth starts again once the depleted factor has recovered

Primary Producers

Green plants

Primary consumers

herbivores and omnivores

Secondary consumers

carnivores and omnivores

Decomposers

Obtain their energy from dead organisms, bacteria and fungi

Detritivores

snails, slugs, vultures

Bioaccumulation

Build up or increase in concentration of a pollutant in a specific species individual member

Entropy

A measure of the amount of disorder, chaos or randomness in a system; the greater the disorder, the higher the level of entropy.

BIomagnification

Build up or increase in concentration of a pollutant across trophic levels

DDT

DDTwasapopular insecticide introduced to the market in 1945. It was used in agriculture and to eradicate malaria by controlling mosquito populations. However the chemical passed in to aquatic environments and up the food chain and had serious impacts on many marine and bird species. A by-effect was the thinning of the eggshells of some of the effected bird species putting a further pressure on these species. These effects where highlighted in Rachel Carson's book Silent Spring (1962) leading to increased public opposition to the use of DDT. DDT was banned for agricultural use in most developed countries between 1970-80. A global ban came into effect in 2004 while still allowing for some use in malaria control.

Relationship between respiration and photosynthesis

Inverse

Photosynthesis: CO2 + water + energy = glucose + oxygen

Respiration: glucose + oxygen = CO2 + water + energy

Biodiversity

Biodiversity is a general term describing the variability in a community, ecosystem or biome. It can be defined as the combination of habitat, species, genetic

Speciation

Speciation is the formation of new species when populations of a species become isolated and evolve differently from other populations. Isolation of populations can be caused by environmental changes forming barriers, such as: mountain formation, changes in rivers, sea level change, climatic change or plate movements. The surface of the Earth is divided into crustal, tectonic plates that have moved throughout geological time. This has led to the creation of both land bridges and physical barriers with evolutionary consequences.

Types of sampling

Continuous- where every thing is measured: the entire line transect of the entire area.

Interrupted (transect)- points at regular intervals are measured.

Random-points are determined by random. A good practice is to draw a grid (at the size of your quadrat) over an area, giving a number to each square. A list of random numbers can then be generated by a computer or using a table. These should then be sampled.

Stratified random- where an area has two or more distinct areas, each area should be treated separately using the random method above.

Systematic- points/transects are placed at a set distant. Often the first is place randomly and then the rest by a systematic method

Types of traps

pitfall traps beakers or pots buried in the soil which animals walk into and cannot escape from

nets sweep, butterfly, seine, and purse

flight interception traps fine-meshed nets that intercept the flight of insects- the animals fall into trays where they can be collected

small mammal traps often baited, with a door that closes once an animal is inside

light traps a UV bulb against a white sheet attracts certain night flying insects

Tullgren funnels paired cloth funnels, with a light source at one end, a sample pot the other, and a wire mesh between: invertebrates in soil samples placed on the mesh move away from the heat of the lamp and fall into the collecting bottle at the bottom

Pooters sucks insects from vegetation

Kick sampling (water) disturbing a river bed and collecting the animals downstream in a net

Lincoln's Index

Lincoln index = n1× n2 / nm

where n1 is the number caught in the first sample, n2 is the number caught in the second sample and nm is the number caught in the second sample that were previously marked.

Simpson Index

This indication of diversity is only useful when comparing two similar habitats or the same habitat over time.

D= N(N−1) / sigma n(n −1)

where D is the Simpson diversity index, N is the total number of organisms of all species found and n is the number of individuals of a particular species. The sigma notation, means the denominator is the sum of n(n−1) for all the species that make up N. Using this formula, the higher the result, the greater the species diversity.

Gross Primary Productivity GPP

the amount of energy/biomass converted by producers per unit area per unit time. (g/m^2 year)

net primary productivity NPP

NPP = GPP - R

the gain (after respiration) by producers in energy/biomass per unit area per unit time. (g/m^2 year)

Gross secondary productivity GSP

GPP = food eaten - fecal loss

the total energy/biomass assimilated by consumers through feeding and absorption per unit area per unit time. (g/m^2 year)

net secondary productivity NSP

NSP = GSP - R

the gain (after respiration) by consumers in energy/biomass per unit area per unit time. (g/m^2 year)

Pyramid of numbers

record the number of individuals at each trophic level. They are a simple, easy method of giving an overview and are good at comparing changes in population numbers with time or season. However they do not account for size, so a tree is counted the same as an ant. This means pyramids of some ecosystems are inverted.

Pyramid of biomass

represents the biological mass of the standing stock at each trophic level at a particular point in time measured in units such as grams of biomass per square metre (g m= 2). Biomass may also be measured in units of energy, such as Jm= 2. However as organisms must be killed to measure dry mass, samples are made and extrapolated. Therefore results are not exact. Furthermore the measure is susceptible to seasonal differences in fast growing species (e.g., algae

Pyramid of productivity

Two organisms with the same mass do not have to have the same energy content. Pyramid of productivity shows the flow of energy (starting from solar radiation- optional) through each trophic level of a food chain over a period of time. Productivity is measured in units of flow (g m= 2yr= 1 or Jm= 2yr= 1). Unlike the first two, this type of pyramid allows for comparison between ecosystems but is limited in comparing seasonal differences. It is impossible for these pyramids to be inverted. However, they are also the most complicated to collect data for

Crude Birth rate CBR

Number of births per 1000 people, per year

Total fertility rate

Average number of births per 1000 women of childbearing age

Crude death rate

Numberofdeaths per 1000 people per year

Natural increase rate NIR

Natural Increase = Crude Birth Rate−Crude Death Rate

Doubling time

number of years for a population to double in size assuming the natural growth rate remains constant.

= 70/NIR

natural income

the yield obtained from natural resources

ex. wood coming from rainforests

Natural capital

natural resources that can produce a sustainable natural income of goods or services

ex. rainforests provide wood

Pollution

Pollution is the addition of a substance or an agent to an environment by human activity, at a rate greater than assimilation, and which has an appreciable effect on the organisms within it.

Pollutants may be in the form of organic/inorganic substances; light, sound, or heat energy; biological agents, or invasive species; and derive from a wide range of human activities including the combustion of fossil fuels.

primary pollutant

Pollutants that are emitted directly from a source into the atmosphere.

Ex. CO2, SO2, NOx, PM2.5, PM10

secondary pollutant

Pollutants that are not emitted directly, but form in the atmosphere through chemical reactions between primary pollutants and other components (like sunlight or water vapor).

Ex. Ozone (O₃) in tropospheric smog (formed from NOx + VOCs + sunlight)

Peroxyacetyl nitrate (PAN) in photochemical smog

Sulfuric acid (H₂SO₄) formed when SO₂ reacts with water vapor (acid rain)

Replace

Alter human activity to replace the pollutant- Promote alternative technologies, lifestyles and values through education and government legislation.

Release

Regulate to minimise the release of pollutant- Extract the pollutant from the waste and store securely.

Restore

Recover the pollutant and restore the natural environment

The Convention on International Trade in Endangered Species (CITES)

This very successful voluntary international convention aims to restrict the trade of species, where that trade threatens their survival. Species can be put into one of three groups:

• Appendix I: species cannot be traded internationally as they are threatened with extinction.

• Appendix II: species can be traded internationally but within strict regulations ensuring its sustainability.

• Appendix III: a species included at the request of a country which then needs the cooperation of other countries to help prevent illegal exploitation.

Storages in the hydrological cycle

organisms, soil and various water bodies, including oceans, groundwater (aquifers), lakes, rivers, atmosphere, glaciers and ice caps. Fresh water makes up only a small fraction (approximately 2.6% by volume) of the Earth's water storages. 68.7% of this is in ice. Only 0.3% of all water is accessible for us. The amount of time water is stored (the turnover time) varies greatly between a few days and tens of thousands of years. Therefore, depending on location water can be both renewable and nonrenewable capital.

Flows in the hydrological cycle

evapotranspiration, sublimation, evaporation, condensation, advection (wind-blown movement), precipitation, melting, freezing, flooding, surface runoff, infiltration, percolation, and stream- flow or currents.

urbanisation

Population shift from rural to urban areas

Expansion of infrastructure, housing, and services

Industrial development and economic opportunity in cities

Often results in land use change, habitat destruction, and increased pollution

indicator species of marine health

indicator species of terrestrial health

Lichens --> Air quality - sensitive to sulfur dioxide (SO₂) and acid rain

Amphibians (e.g. frogs) --> Soil and water pollution, pesticide levels --> Permeable skin = quick absorption of toxins

Earthworms --> Soil health and fertility --> Indicate presence of organic matter and proper pH

Butterflies --> Biodiversity and habitat quality --> Sensitive to changes in vegetation and temperature

Beetles (some species) --> Forest health and decomposition -> Depend on dead wood and specific habitat conditions

Eutrophication

excessive nutrient enrichment, often from leached agricultural fertilisers, leading to rapid growth in algae, plants and phytoplankton populations.

The biodegradation of nitrates and phosphates utilises oxygen. The increased BOD can lead to a lack of oxygen in the water (anoxic), which in severe cases leads to formation of methane, hydrogen sulfide and ammonia (toxic gases). Furthermore the algae blooms reduce light penetration to river beds, preventing aquatic plants from photosynthesising and replacing the lost oxygen. This kills the life in the water leaving 'dead zones'. Eventually the algae will die back and nothing is left. This effect is exaggerated in warmer waters, as the water can hold less oxygen and the rate of respiration is higher.

Management strategies

Altering human activity

• limiting fertilisers and detergents by encouraging better methods and legislation.

• educating people to care for the ocean. eg stopping plastic waste.

Controlling release of pollutant

• waste water treatment to remove nitrates and phosphates.

Clean-up and restoration of damaged systems

• precipitation of phosphates.

• removal of nutrient rich mud from eutrophic lake.

• reintroduction/management of plant and fish species.

Biochemical oxygen demand

measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity.

Inputs of soil system

organic material including leaf litter and inorganic matter from parent material, precipitation and energy

Outputs of soil system

uptake by plants and soil erosion

Storages of soil system

organic matter, organisms, nutrients, minerals, air and water

Flows of soil system

Transfers of material within the soil, including biological mixing and leaching (minerals dissolved in water moving through soil), contribute to the organization of the soil. Transformations include decomposition, weathering and nutrient cycling

Soil horizons

layers of soil structure

O leaf litter

A hummus layer

E leached

B iron and clay deposits

C rock

R bed rock

Sandy soil

low primary productivity due to poor water-holding capacity and low nutrient status.

Clay soil

quite low primary productivity due to poor aeration and poor water infiltration.

Loam soil

high primary productivity due to medium infiltration rate, water-holding capacity, nutrient status, aeration, and ease of working

Primary productivity

rate at which energy is converted by producers (like plants or algae) into organic matter (biomass) through photosynthesis.

It measures how much solar energy is captured and stored in an ecosystem.

Primary elements in the atmosphere

Nitrogen, Oxygen, CO2, water vapour

Ozone depleting substances

CFCs, chlorine, bromine

The Montreal Protocol

The Montreal Protocol on Substances that Deplete the Ozone Layer (1987) and subsequent updates is an international agreement for the reduction of use of ozone-depleting substances signed under the direction of UNEP. National governments complying with the agreement made national laws and regulations to decrease the consumption and production of halogenated organic gases such as chlorofluorocarbons (CFCs).

Ozone depletion management strategies

Altering human activity

• reducing the manufacture and release of ozone-depleting substances.

• developing alternatives to gas-blown plastics, halogenated pesticides, propellants and aerosols

• developing non-propellant alternatives.

Controlling release of pollutant

• recycling refrigerants

• UNEP has had a key role in providing information, and creating and evaluating international agreements, for the protection of stratospheric ozone.

• An illegal market for ozone-depleting substances persists and requires consistent monitoring.

Clean-up and restoration of damaged systems

• the holes in the ozone have been observed to be healing.

• atmospheric scrubbing methods have been proposed but are too costly to implement

acid deposition

Acid deposition occurs when sulfur dioxide and oxides of nitrogen are converted into secondary pollutants sulphuric acid and nitric acid. These fall as either dry deposition (such as ash and dry particles) or wet deposition (such as rain and snow).

The acid deposition acidifies the soil and water, which in turn kills organisms that cannot tolerate the change in pH. The acidic water increased solubility of aluminium turning lakes and streams toxic. The combination of acid and aluminium kills much of the aquatic ecosystems. The acid rain leaches nutrients from the soils such as calcium. The lack of calcium can lead to reductions in snail populations and so in turn affect bird populations. Plants can struggle to get the nutrients required to photosynthesise. Acid rain also directly damages the leaves of coniferous trees as it falls.

The impacts of acid deposition may be limited to areas downwind of major industrial regions but these areas may not be in the same country as the source of emissions. Therefore in certain cases, the pollution management of acid deposition often involves cross-border issues. For example Scandinavian forests were affected by the acid depositions of pollutants from British coal power stations

Photochemical smog

Photochemical smog is a complex mixture of primary and secondary pollutants, of which tropospheric ozone is the main pollutant. Now although, considering the last section, this would appear to be a good thing, Tropospheric ozone is highly reactive and has significant impacts on societies and living systems.

Primary pollutants react with chemicals in the atmosphere, under the presence of sunlight, to generate tropospheric ozone. Oxygen molecules react with oxygen atoms that are released from nitrogen oxides in the presence of sunlight. Deforestation and burning, may also contribute to smog.

Photochemical smog damages plants (crops and forests), irritates eyes, creates respiratory illnesses and damages fabrics and rubber materials. Economic losses caused by urban air pollution can be significant

Management strategies of photochemical smog and acid deposition

Management strategies

Altering human activity

• reducing use, or using alternatives to, fossil fuels — example activities include the purchase of energy-efficient technologies, the use of public or shared transit, and walking or cycling

• international agreements and national governments may work to reduce pollutant production through lobbying

Controlling release of pollutant

• regulating and reducing pollutants at the point of emission through government regulation or taxation

• use of scrubbers or catalytic converters to clean the exhaust of primary pollutants from coal-burning power plants and car exhausts. • regulating fuel quality by governments

Clean-up and restoration of damaged systems

• reforestation, regreening, and conservation of areas to sequester carbon dioxide.

• artificial sequestering

• spreading ground limestone in acidified lakes or recolonization of damaged systems — but the scope of these measures is limited

Climate

Climate describes how the atmosphere behaves over relatively long periods of time. Furthermore many of the negative and positive feedback mechanisms associated with climate change involve very long time lags and so can be difficult to identify.

Weather

Weather describes the conditions in the atmosphere over a short period of time and is therefore not an indicator of climate change.

Mitigation

Mitigation attempts to reduce the causes of climate change through the reduction and/or stabilization of greenhouse gas (GHG) emissions and their removal from the atmosphere.

Mitigation strategies to reduce GHGs in general may include:

• reduction of energy consumption- requires large societal changes.

• carbon taxes / carbon credits- by putting a price on emissions, cleaner alternatives are encouraged.

• reduction of emissions of nitrogen oxides and methane from agriculture

• use of alternatives to fossil fuel such as wind, solar and hydropower.

Mitigation strategies for carbon dioxide removal (CDR techniques) include:

• protecting and enhancing carbon sinks through land management.

• Reduction of Emissions from Deforestation and Forest Degradation in Developing Countries (UN-REDD programme)

• using biomass as fuel source

• using carbon capture and storage (CCS)

• enhancing carbon dioxide absorption by the oceans through either fertilizing oceans with nitrogen, phosphorus, iron (N/P/Fe) to encourage the biological pump, or increasing upwellings to release nutrients to the surface.

Adaptation

Adaptation attempts to manage the impacts of climate change by reducing adverse affects and maximizing any positive effects. This is necessary as, even with a large reduction in GHGs,historic emissions will still have an effect on the current climate.

Examples of adaptations include:

• flooddefences to protect against sea level rises;

• monitoring and control (vaccination programmes) of spreading tropical diseases;

• rainwater harvesting and desalination plants to provide water in drought regions;

• planting of crops in previously unsuitable climates to meet the gap in global food supply;

• adaptation of buildings and cities to their changing climate.

Rio Earth Summit UNFCCC

1992- Rio Earth Summit Countries developed a framework to address climate change and stabilize greenhouse gas concentrations. The United Nations Framework Convention on Climate Change (UNFCCC) went into effect 1994 but failed to slow down greenhouse gas emissions. It had little effect as there were no binding limits or enforcement.