IB ESS SL

IB environmental systems and societies- terms and vocab from topic 1-8

Ecological footprint

a model that can be used to estimate the demands that a human population places on the environment. It is a measure of the amount of land that is needed to support a population.

The EF considers two aspects:

* **Biocapacity**: this is the earth’s bioproductive land and sea. Ex: includes forests, cropland, pastures and fisheries.
* **Demand**: considers the amount of bioproductive land we need to provide our resources and space for infrastructure and absorb the waste.

transfers

move energy or matter from one place to another without changing it in any way.

transformations

move energy and matter and change it’s state or form. Ex:

* Water changes state from solid, to liquid to gas (matter).
* Incoming light is transformed into heat as it is re-radiated from the earth’s surface (energy).
* Energy is converted into matter during photosynthesis.

open system

**exchanges matter and energy** with its surroundings.

closed system

**exchanges energy** __**but not**__ **matter** with its surroundings. 

Isolated system

**exchanges neither energy nor matter** with its surroundings. 

maximum sustainable yield

the optimum harvest that can be obtained yearly without affecting the standing stock and its ability to replenish itself

Bioaccumulation

the increase in the concentration of a pollutant in an organism as it absorbs or it ingests it from its environment.

takes place in a single organism over the span of its life, resulting in a higher concentration in older individuals.

Biomagnification

the increase in the concentration of a pollutant as it moves up through the food chain. (think consumption of DDT in fish)

takes place as chemicals transfer from lower trophic levels to higher trophic levels within a food web, resulting in a higher concentration in apex predators.

Biocapacity

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

Biodiversity

the variety of all life on earth. It includes genetic diversity, species diversity and habitat diversity. 

NPP

represents the amount of usable biomass in an ecosystem.

Takes into account respiratory losses (R) and is shown as the following equation:

NPP = GPP – R

GPP

all the biomass produced by primary producers in a given amount of time (before any of it is used for respiration)

GPP = NPP + R

NSP

Leftover energy after respiration

NSP = GSP – R

GSP

represents the total amount of energy or biomass used by consumers.

natural capital

natural resources that produce sustainable natural income of goods and services. Ex: forests, fisheries, fertile lands etc

natural income

the yield from natural capital. Ex: timber, fruit produce, etc.

k strategist

Have less offspring, but spend more time caring for them. Quality > quantity. Offspring grow up slower. More common in climax communities. Ex: horses, elephants, whales, etc.

Think “K” for “Kare”. Because they care for their offspring.

r strategist

Quantity > quality of offspring. Lots of offspring, grow up fast. Most of these animals are prey, or have some threat that makes it hard for their young to survive. Ex: rabbits, mice, insects, etc

climax community

The final stage of succession. This is a steady state equilibrium with the climate and/or the soil. Won’t change unless there is a disaster.

zonation

The change in a vegetation community along an environmental slope. The change may be caused by changes in altitude, depth of water, tidal level, distance from the shore etc. These types of changes are spatial and are determined by changes in the abiotic factors. 

succession

The predictable change in a vegetation community over time. It starts with a pioneer community. During this stage, the ecological community will change in composition.

BOD (Biochemical oxygen demand)

the measure of the amount of dissolved oxygen used to breakdown the organic material in a body of water. It’s an indirect measure of the amount organic material in the water.

Biotic index

determine water quality by observing the organisms living there. high biodiversity = likely clean water

Photochemical smog

occurs when sunlight activates reactions between (NOx) and volatile organic compounds (VOCs) resulting in the formation of ozone and peroxyacyl nitrates (PAN).

mostly likely to be formed under the following conditions:

* High emissions of pollutants
* Cities
* traffic
* High levels of sunlight
* Calm or light winds
* Dry weather conditions
* Hills/mountains
* thermal inversion

Limiting factors

the resources in the environment that limit the growth, abundance and distribution of organisms/populations in an ecosystem. Ex: water, food, sunlight, temperature, etc.

point source pollution

a single identifiable source of pollution. Ex: a specific factory, smokestacks, water treatment plant, etc.

non-point source pollution

pollution from diffuse sources. Difficult to monitor and control. Ex: polluted water from runoff, acid rain, road salt, fertilizer, etc.