ecology

Ecosystem

A self supporting environment including the living organisms and their interactions and their physical and chemical environment

Habitat

Place where organism lives

Microhabitat

Small place within habitat

Microclimate

A small area of distinct climate which is seperate to surrounding climate

Community

All of the populations of all the species living in a habitat at any one time

Biome

A major ecosystem, distinguished from one another by their climate

Abiotic factor

A non living element of a habitat

Biotic factor

A living element of a habitat

Trophic level

The position of an organism in a food chain describes its feeding relationship w other organisms

Decomposer

Microorganisms such as bacteria or fungi what break down animal or plant remains and return the mineral nutrients to the soil

Nitrifying bacteria

Oxidises ammonium compounds to form nitrites and nitrates

Nitrogen fixing

N2 gas to ammonia

Denitifying bacertia

Converts nitrates to n2, use nitrates to produce atp

Legume

Plants which have nodules on their roots which contain nitrogen fixing bacteria

Population

All of the organisms of the same species in the same habitat at the same time

Intraspecific competition

Competition between members of the same species for a limited resource

Interspecific competition

Competition between members of different specifies for a limited resource

Gross primary productivity

The rate at which plants absorb light and produce new plant material in photosynthesis, measured in mass or energy per area per unit of time eg g m-2 year -1

Net primary productivity

The new material produced by photosynthesis that is stored as new body tissue

The formula which shows relationship between GPP NPP and respiration

NPP = GPP - R

Describe the abiotic characteristics of ecosystems with a high NPP

Close to the equator so high light intensity and high water availability not excessively hot

Secondary production

The new material produced in animals

Density dependant factor

Different effect on denser pop than sparser eg disease

Density independent factors

A factor which has the same effect on population size irrespective of population size eg forest fires, tidal waves

Leaching

The loss of minerals from soil that occurs when water passes through it rapidly

Pyramid of numbers

Number of organisms at each tropic level

Pyramid of biomass

The biomass of these organisms

Pyramid of energy

Total energy stores - difficult and only if dead but most accurate

Efficenicy of energy transfer between graphic levels formula

Energy as a higher trophc level / at lower x100

Not always 10% pass its an oversimplification, depends on abiotic factors and physiology

Succession

The process by which the communities of organisms living in an area change overtime

Primary succession

A succession that starts w an empty inorganic surface such as bare rock

Secondary succession

A succession that develops on existing soil that has been cleared of vegetation

Colonisation

The spread of a species to a new area

Pioneer

The first organism to colonies a barren environment, start succession by breaking down rock to start the production of soil eg lichens and moss

Climax community

A self sustaining community w relatively stable biodiversity the most productive group of organisms an ecosystem can support long term

Climatic climax

The only climax community possible in a given climax

Plagioclimax

A climax community that is in part bc of human intervention not truely natural

Abundance vs distribution

The abundance of an organism refers to the number of that species in a defined area, distribution describes where it is found in the area and orrangement

3 ways of measuring abundance w quadrats

Individual count, percentage cover, acfor scale

Acfor scale

A simple method of measuring abundance by seconding if it is abundant, common freq occasional or rare

Line vs belt transect

Line transect tape between 2 points measuring what is on tape

Belt is 2 tapes and measuring area between

Cont transect- measurements all the way along

Interrupted transect- reg intervals

Peer review

Process in which scientific papers are assessed by expert scientist in the field before publification

Valid study

One which has been correctly designed so defo answers question which is being asked

Reliable study

Repeated by other scientists for similar result

IPCC

Intergovernmental panel on climate change

Analyse research from climate change scientists and produced an unbiased report for politicians and other decision makers

Anthropogenic

Produced by people

Dendrochronology

The dating of past events using tree ring grows can be used to give an indication of the temp and co2 con in the past

Ice cores

Ratio of diff isotopes of o2 in the ice indicates the temp at when it was formed. Thick so have proxy data going back years

Peat bogs

Anaerobic so preseve the bodies f organisms seeds and pollen grains, show the climatic conditions when the organisms were alive, the deeper the sample the longer ago the peat was formed

Greenhouse effect

The process by which greenhouse gases in the earths atmosphere absorb some of the suns IR radiation when it has been remitted from the earths surface as longer wavelength ir warms the earths surface

Importance of greenhouse effect

Maintains temp for human life

2 factors sustainability must balance

Human needs and conservation needs

IUCN

The international union for the conservation of mature produces the red list of threatened species

Cites

An international agreement to regulate trade in living organs and products made from them