EOTT population and ecosystems

What is a population?

total number of individuals of the same species in one area

what is an ecosystem?

environment where all biotic and abiotic factors interact with one another

what is a community?

total population of different species living in the same ecosystem at the same time

what is a niche?

role occupied by organism within community

What is the carrying capacity of an ecosystem?

number of particular species which a region cans support without environmental degredation

different population estimating techniques:

• random quadrat sampling

• Random systematic transect sampling

• Mark-capture-release

When would you use randomly placed quadrats:

• immobile species in different areas

when would you use belt transect:

• immobile species over a distance

mark-release-recapture assumptions:

• marks are not lost

• No mass death/ migration

• Marks don’t increase chance of being predated

• Marked individuals mix randomly

• Population is closed

what does a dynamic system mean:

constantly changing ecosystemp

describe primary succession:

how the environment of an ecosystem changes due to a change in abiotic factors/ environmental factors over a long period of time

How do new species develop in an area

• pioneering species colonise barren land

• Species can break down rock to produce soil

• Species dies out, decomposes

• Increases nutrition in soil/ changes the environment

• New species are able to live in environment

• New species may have adaptations so they outcompete previous species

• As organisms die, soil fertility increases, change in biotic/ abiotic factors

what is secondary succession?

process started by an event that reduces an already established ecosystem

define climax community:

• ecological community in which populations of plants/ animals remain stable and exist in balance with each other and their environment

define pioneer species:

• species that colonise barren environments

• Tolerant to harsh conditions

• Breaks down rock into soil

Mark-release-recapture formula:

Estimated population size: (number of marked organisms first released x total number of organism in recapture) / number of marked organisms recaptured