IB ESS Topic 2

Biotic factors

the living organisms in an ecosystem

abiotic factors

the non-living factors in an ecosystem

trophic level

the position an organism occupies in a food chain as a result of its feeding habits

food chain

a simple linear relationship which shows how energy is transferred between organisms as each consumes an organism from a lower trophic level

food web

a group of interconnected food chains

biomass

the mass of organic material in an organism or ecosystem

producers

convert light energy and water, CO2 and minerals into new materials

consumers

cannot make their own food and much eat other organisms to obtain energy

Ecological pyramids

allow you to examine easily energy transfers and losses. they give an idea of what feeds on what and what organisms exist at the different trophic levels. they also help demonstrate that ecosystems are unified systems, and they are in balance

pyramid of numbers

represents the number of organisms at each trophic level

pyramid of biomass

represents the standing stock of each trophic level

pyramid of productivity

represents the flow of energy through a trophic level

species

a particular type of organism that can be interbreed and produce fertile offspring

population

a group of one species living in a given area at the same time

habitat

the environment where a species normally lives

niche

how an organism makes a living

community

a group of populations in a given area

ecosystem

a community of interdependent organisms and the abiotic environment in which they live

competition

any time there are limited resources the organisms much compete for them

parasitism

one organism lives in or on the other host gaining food from it

ex: nematodes

mutualism

both organisms benefit and none suffer

ex: lichen

predation

when one animal eats another

ex: felius catus eating field mouse

herbivory

an animal eating a plant

ex: white tailed deer eating oak leaves

System

assemblage of parts and the relationships between them which enable them to work together

Open system

Exchanges matter and energy

Closed system

Exchanges energy but not matter

Isolated system

Exchanges neither matter nor energy

1st law of thermodynamics

Energy cannot be created nor destroyed

2nd law of thermodynamics

Entropy of a system will increase over time

Entropy

The measure of the evenness of energy distribution in a system

Equilibrium

A state if balance which exists between the different parts of any system

Steady state equilibrium (dynamic)

Constantly changing to maintain equilibrium

Static equilibrium

No change over time (non living )

Stable equilibrium

The system tends to return the same equilibrium after a disturbance

Unstable equilibrium

The system returns to a new equilibrium after a disturbance

Negative feedback

Works to counteract any deviation from the stable state of equilibrium

Positive feedback

Enhances the change in the system and it is destabilized to a new state if equilibrium

Transfer

When energy or matter moves through an ecosystem without a change of form or state

Transformation

When energy or matter move through an ecosystem and it changes form or state

Flow

involves the movement if matter and energy through ecosystems

Primary productivity

Production if energy by autotrophs

Secondary productivity

Biomass Gained by the heterotrophs as they feed

Gross productivity

Total energy gained

Net productivity

The gain in energy or biomass after the deduction of losses through respiration

Carrying capacity

The number if individuals in a population that the resources in the environment can support for an extended period of time

Limiting factors

A resource that has a greater demand than supply can limit the size of the population

Intraspecific competition

Competition for resources between members of the same species

Density dependent limiting factors

Regulate the population and are due to the size or density of a population and create negative feedback (competition, predation, disease)

Density independent limiting factors

Are not dependent on the size of the population usually abiotic (forest fires, droughts, hurricanes)

Internal factors

Limiting factors that act within a species (limited food, limited territories)

External factors

Limiting factors act between different species (predation, disease)

K-strategists organisms

Few offspring, long time to mature, care for youngins, (apes, elephants)

R-strategists organisms

Many offspring, low parental care, mature quickly, utilize limited sources (insects, fish, frogs, and plants)

Type I survivorship

Survivorship high, mortality late (k-strategists, humans, big cats)

Type II survivorship

Constant mortality, can die at any age (mice, coral, reptiles)

Type III survivorship

High mortality early in life, low survivorship (r-strategists, plants, frogs)

Succession

Change in species composition over time long term

Climax community

The stable end result of the succession at a particular location

Seral stages

Lithosphere, hydrosphere, plagiosere

Primary succession

Colonization if newly created land by organisms

Secondary succession

Occurs after an area of a previously established land has been cleared (fire, landslide,plowing )

Resource

Any aspect of the environment which can be used to meet human needs

Natural capital

Source of supply of resources and services that are derived from nature (forests, mineral deposits, fertile soil, fishing grounds)

Provisional services of natural capital

Food, fresh water, fiber

Regulating services of natural capital

Climate regulation, disease

Cultural services of natural capital

Ecotourism, recreational

Supporting services of natural capital

Soil formation, nutrient recycling

Renewable capital

Composition and structure of natural, self-organizing ecological systems that yield a flow of goods and services

Replenishable capital

Non- living natural resources that depend on the suns energy for replenishment (ground water)

Non-renewable capital

Resources that take years to form, cannot be renewed

Non-renewable energy sources

Fossil fuels and nuclear fuels

Renewable energy sources

Hydroelectricity, biomass, wind, solar, geothermal, tidal, and wave power

Soil profile

The vertical succession down through a soil

Soil texture

The size of the solid particles in a soil

Soil depredation

Global process that involves both erosion and the reduction in quality of top soil associated with nutrient decline and contamination

Deforestation

Clearing of land for agricultural use

Overgrazing

Grazing if natural pastures at stockings intensities above the livestock carrying capacity

Desertification

Climate change and or destructive use of land, rev oval of vegetation

Soil conditioning

Adding materials to soil to improve soil fertility

No-till farming

Turning soil before planting a new crop, leading cause of soil degradation which minimizes soil distribution

Optimum population

The size of population that is the best out of several outcomes

Optimum rhythm of growth

Population growth responds to substantial technological advances

Reuse

use to repurpose materials that once we're thought of as useless

Recycling

The concentration of used or waste materials

Waste hierarchy

Reduce disposal in landfills by addressing the issue at the time of manufacture and all steps possible before disposal

Product stewardship

An approach to environmental protection in which manufactures retailers and consumers are encouraged and required to assume responsibility for reducing a products impact on the society

Ecological footprint

Sustainability indicator that expresses the relationship between population and the natural environment

Global hectare

With a world average ability to produce sources and absorb wastes

Pollution

Contamination of air, water or soil by substances that are harmful to living organisms in the form of gases liquids solids or energy

Na

...

Biochemical oxygen demand

The amount of oxygen required by aerobic microorganisms to decompose the organic matter

Photochemical smog

Air pollution caused by 100 pollutants in the presence of sunlight