IB ESS SL

system

An entity with at least two components (parts) that are linked and interact in some way.

open system

Allow energy or matter to enter or leave the boundaries of the system. A clear example is the human body.

closed system

allow energy to enter or leave but matter is contained within the boundaries. The Earth is an imperfect example of this. ( Some matter does enter the atmosphere, such as meteorites, or leaves, such as astronauts).

isolated system

do not allow matter or energy to enter or leave the system. This is a largely theoretical concept used in the laws of thermodynamics with the only possible example being the entire universe.

transformation of matter

A change in state of matter between solid, liquid or gas.

transfer of matter

A movement of matter from one location to another

matter

Anything that takes up space and has mass. It is normally made of atoms.

energy

the ability to do work and effect either the transformation (change) of matter or transfer (movement) of matter.

It lacks mass but can be found in stored chemical form. Other forms of energy relevant to environmental systems include heat, light and movement.

the first law of thermodynamics

States that the total energy of the universe or any isolated part of it will be the same before and after matter is moved or transformed.

"Energy can neither be created nor destroyed, merely changed from one form to another. For example, during the burning of coal, stored chemical energy is transformed to movement, heat, light and sound. The total amount of all energy transformed by combustion into (movement, heat, light and sound) is equal to the starting amount of chemical energy.

the second law of thermodynamics

This states that in an isolated system the total amount of entropy will tend to increase.

When energy is transformed there is a loss of order (complexity). This is seen practically by loss of heat energy during processes like combustion of coal. Chemical energy is more "ordered" than heat energy.

As energy transformations all involve the loss of heat the ultimate extension of the law is to predict that all other forms of energy will eventually transform into heat and cool down; the so called "heat death" of the universe.

constant energy input from the sun

Why does the earth not obey the 2nd law of thermodynamics?

If this were not the case, then complex living structures of the planet would start to breakdown the ordered chemical structure through death and decay.

the digestive system

Example of a system in the field of biology?

the global economy

Example of a system in the field of economics?

the ecosystem

Example of a system in nature?

a car

Example of a system in everyday life?

resilience

When the system has the capacity to return to the same state of equilibrium following a disturbance.

This type of stability is seen in negative feedback loops.

negative feedback

An initial change in the system leads to a cycle that returns to and reduces that change. Negative feedbacks are important in maintaining stable equilibrium in a system.

feedback mechanisms

These produce an effect on the equilibrium of a system. Flows in feedbacks are circular cycles, returning to produce an effect on the initial change. Both natural and human systems are influenced by them.

positive feedback

This is produced by initial change in the system triggering a cycle that returns to and amplifies a change. Positive feedbacks produce change in a system; they move away from equilibrium to a new state.

global warming

example of a positive feedback loop (concerned with temperature)

the gaia hypothesis

Suggests that feedback mechanisms are important in regulating conditions on a planetary scale. He modelled this through the temperature regulation through "Daisyworld"

daisyworld

Populations of white and black daisies regulate temperature on an otherwise barren planet.

-White daisies keep cool when it is hot, therefore they survive and reproduce

-Their population grows and the planets albedo increases

-following the population boom of the white daisies, the temperatures cool down

Black daisies gain advantage as they absorb more heat and keep warm, therefore they survive and reproduce.

ecology

the science of the relationship between living things and the non-living environment. This includes the study of ecosystems and their communities.

ecosystem

a complex system involving the interaction between the living and non living components of a defined unit. They vary in scale, from the whole world to soil systems.

recycle

Ecosystems are functional units in ecology, that transform energy and _______ matter.

species

a group of organisms that interbreed and produce fertile offspring. ( Indochinese Tiger)

population

a group of organisms from the same species living in the same area at the same time, which are capable of interbreeding. (The amount of Indochinese Tiger in Southeast Asia has been estimated around 1,000)

habitat

the environment in which a species normally lives.( Indochinese Tiger lives in a variety of forest types, mostly on the forest floor)

Niche

A species habitat and the resources in it. The "role" of the species in the ecosystem. Does not only depend on where it lives but on what it does. (Indochinese Tiger is the top carnivore, a major predator on animals such as : the wild pig. It thus regulates the competition between herbivores. It requires plenty of freshwater and prefers forest along side a river. A tiger requires a big enough population to find a breeding partner.

community

A group of populations living and interacting with each other in a common habitat. (In the community of Southeast Asia the Indochinese Tiger interact with other species through predation and competition. They might prey on Mouse Deer and compete with the clouded leopard.)

Ecosystem

A community of interdependent organisms and the physical environment they inhabit. (Rainforest biomes have a large biomass of trees with a canopy of over 50m in height. They have a high productivity despite often thin and infertile soils. The high productivity is largely due to good growing conditions all year round)

trophic level

The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains.

producers

In most ecosystems these are green plants or algae, photosynthetic organisms that form the base of the food chain. They are also known as autotrophs, meaning self feeding.

consumers

Any organism that eats or gains nutrition from another. They are also heterotrophs, which mean they feed on other organisms.

Herbivores

Heterotrophs that only eat primary producers. Literally "eats grass"

Carnivores

Heterotrophs, that are secondary consumers or greater. They divide into first order, second order , third order carnivores and so on up to a top carnivore at the end of the food chain. Literally "eats meat"

Omnivores

These are heterotrophs that feed at any trophic level. They often have a varied diet. Literally "eats all"

Detritivores

Heterotrophic organisms that consume dead organic matter by ingestion. Literally "eats detritus"

Decomposers

These organisms are fungi and bacteria that break food down outside their bodies, by secreting enzymes into the environment. As this process is inefficient they are important in recycling nutrients. Note they do not ingest (eat) as animals do.

Asia forest food chain

Strangling Fig -> Wild Boar -> Leopard Cat ->Indochinese Tiger

(4 trophic levels)

food chain

These show the sequence of organisms in successive trophic levels within a community. They are flow diagrams that show feeding relations and therefore movement of matter and energy.

food web

show more complex and complete feeding patterns than food chains.

pyramids

They show how ecosystems handle transfers of energy and matter between trophic levels. They are graphical models of communities, drawn like bar graphs on their side, with a central y-axis about which the pyramid is symmetrical. They show the total quantity in terms of numbers.

pyramid of numbers

shows the data count of populations in each trophic level

The 10% rule

States that approximately 10% of the energy in one trophic level will pass to the next.

parasites

Pyramids of numbers can be inverted due to ________

pyramid of biomass

The total number of organisms is counted and weighed.

energy calculation

Energy can be calculated per gram by controlled combustion of biomass to heat water. The energy change can be measured by the temperature change of the water. Total energy in the trophic level can then be estimated.

pyramid of productivity

The rate of change in biomass or energy within a community, trophic level or individual. The unit of energy must be put against time, normally combined with a unit of area or volume.

It is never inverted.

competition

biotic factor :

Occurs when resources such as space, light, mates, food, or nutrients are finite. If they are used there is less available to others and they may become limiting factors.

interspecific

biotic factor :

Competition between species

intraspecific

biotic factor :

Competition within species

parasitism

biotic factor :

When species live closely together, but one of the species gain at the other's expense. They may consume body parts or fluids, or capture the host organism's own nutrients from the gut.

mutualism

biotic factor :

relationships between species, where both benefit

herbivory

biotic factor :

the consumption of autotrophs by a primary consumer

predation

biotic factor :

the consumption of a primary consumer by a secondary consumer or higher.

light

abiotic factor:

Wavelengths are selectively absorbed in forest canopies and in water at depth. This may lead to a change in species such as red algae on the rocks of a shaded woodland stream or deeper in the ocean.

temperature

abiotic factor:

varies due to geographical locations and seasons

soil

abiotic factor:

Varies with local geology, successional stage and climate. Includes pH, % water content and organic matter

slope

abiotic factor:

angle and direction of it influences microclimate and drainage

pH

abiotic factor:

varies according to local geology or acidification due to pollution

turbidity

abiotic factor:

cloudiness of the water caused by suspended sediment or phytoplankton

dissolved oxygen

abiotic factor:

varies with depth, temperature and BOD

thermometer, °C

how is temperature measured?

light meter, lux

how is light intensity measured?

baking oven until all water evaporates, percentage of dry soil mass

how is soil % moisture measured?

baking oven until all organic matter is burned, percentage of original soil mass

how is soil % organic matter measured?

using a turbidity meter, meters

how is turbidity measured?

using a compass, measured using a clinometer

how is slope measured: direction, gradient?

using an oxygen probe, mg/l

how dissolved oxygen measured?

measured using universal indicator or pH probe

how is pH measured?

quadrating

estimating abundance of organisms

dry weight per unit area

estimating biomass of organisms

direct measure of estimating abundance in animals

-Freshwater nets for lake and stream

-Sweep nets for grassland and scrub

-Pit trapping and baited traps for terrestrial invertebrates

-Beating trays for invertebrates on trees

Lincoln index

indirect measure of estimating abundance in animals

capture, mark, release recapture

N = (Total population)

M= number caught in first sample

n= number caught in second sample

r= total recaptured (marked) in second sample

N = M x n

_______

r

Assumptions of the index:

-Animals are as likely to be trapped in both sample periods

-The marks do not harm the animals

-There is no change in population during sampling

-Animals mix freely back into the population after sampling

-Second sample has at least 10% recapture

Simpson's diversity index

indirect measure of estimating diversity (variety in systems)

1) It measures the number of species (by creating a species list)

2) It measures the relative proportions of species in the community

D= Diversity

N= is the total number of organisms in the community

n= is the total number of organisms of an individual species

Σ= the sum of

D= N(N-1)

________

Σn(n-1)

Interpreting the index:

The lower the value of D the less species diversity there is. The lowest value possible is 1.

-Can be a useful tool for comparing diversities of different habitats to see if there is a significant difference in diversity.

-If similar communities are very different in diversity it might be caused by human impact, for example the impact of pollution on freshwater invertebrates.

The stage of succession also influences diversity with typical patterns showing a general increase, which may fall slightly at climax.

carbon dioxide + water -> glucose + oxygen

photosynthesis

glucose + oxygen -> carbon dioxide + water + heat

respiration

isolation

the total radiation energy arriving at the Earth's surface from the sun

biome

A large community of plants and animals that occupies a distinct region. Terrestrial biomes, typically defined by their climate and dominant vegetation.

Tundra

Vegetation in :

Very little plant life. No trees as the soil water is permanently frozen; a permafrost. Lichens survive furthest north.

NPP 10-400 g/m2 per year

Climate:

Polar continental has the driest climate as the cold conditions lower humidity. Very low rainfall.

Latitude:

Only found in the highest latitudes, mostly in the Northern Hemisphere. North is ice cap and south is coniferous forest.

Temperate deciduous forest

Vegetation in ________

Trees grow well, although not as tall as in the tropics. Leaf fall occurs in the autumn as the cold conditions lower the rate of photosynthesis.

NPP 600-2500 g/m2 per year

Climate:

Temperate maritime (coastal) have the wetter conditions needed for tree growth. Mean annual rainfall 1000-2000mm.

Latitude:

Found in the mid-latitudes, along the coasts

deserts

Vegetation in ________

Specialised plants exist in the desert, which can cope with the extreme lack of water.

NPP 10-250 g/m2 per year

climate:

Arid climate is found where dry falling air naturally occurs. They are also found inland or in rain shadows. Mean annual rainforest less than 250mm.

latitude:

The desert belt is found at 20-30 degrees north or south of the equator.

tropical rainforest

Vegetation in ________

A tall, thick canopy at around 40m, with emergent trees up to 80m. Animals abundant but well hidden

NPP 1000-3500 g/m2 per year

climate:

Tropical equatorial. Grows where it rains every day, no dry season. Rainfall greater than transpiration. Mean annual rainfall over 2,500 mm.

latitude:

At the equator, from sea level up to 1000m and mostly between 10 degrees north and south.

biome distribution

_______ _____________ is influenced by latitude (variations in insolation) and by patterns of atmospheric circulation.

Productivity

The rate of growth of an organism, population, community or trophic level. It is the production of the defined group, over time. It can be measured with a variety of units, but biomass is quite common.

primary productivity

the rate of the change in producers, secondary the rate of change in consumers.

GP-R=NP

NP equation?

gross primary productivity

the amount of photosynthesis carried out by the producers; it indicates the total conversion of light to chemical energy during photosynthesis.

net primary productivity

the actual growth of the producer, the part of GPP that is available after the producer has carried out by respiration.

population

the number of organisms (individuals) of a species in a defined area.

rate of population growth

(BR-I) -(DR-E) = ______ __ __________ _____ equation

carrying capacity

The population that can be sustainably be supported in a given area over a extended period of time.

density-dependent limiting factors

ex. intraspecific competition for space, water, food. Disease, predation.

Change in relation to population density

density-independent limiting factors

ex. environmental or abiotic: flooding, drought, earthquake

S curve

A growth pattern, where at he start there are few limiting factors and the population increases exponentially. This continues until the population size approaches carrying capacity. Here it may fluctuate, but negative feedback mechanisms regulate it close to the carrying capacity.

(Fewer number of offspring, slow development of young, heavy investment in individuals)

J curve

Growth pattern shows no change in relation to carrying capacity, the population continues exponential growth well beyond carrying capacity before crashing back to a lower level.

(Large numbers of offspring, fast development of young, little investment in the individuals)

K-strategist

Produce small numbers of offspring, into which a large amount of energy is invested from parental care. Population growth is generally S-curve style. Population is strongly regulated by density dependent factors. They are typical of the climax community in succession and are strong intraspecific competitors.

R-strategist

Large number of offspring are normally produced by r-strategists. These offspring have little parental care and survive by themselves immediately. Population growth is more likely to be a J-curve style and the organisms are rapid colonizers whose populations don't stabilise once carrying capacity is reached. They are often pioneer species in a succession.

succession

Communities go through changes over time as they alter the environment, and in turn make conditions right for other plants. Positive feedbacks drive change forward. The process of community change over time is called ___________.