Succession and conservation Flashcards
defintion of biosphere
The part if the planet earthh where life occurrs
Definition of ecosystem
A reasonably self contained area together with all its living organisms
Definition of habitat
The physical or abiotic part of an ecosystem
Definition of microhabitat
A localised specific habitat within a larger habitat
Definition of terrestrial
An ecosystem on dry land
Definition of aquatic
An ecosystem in water
Definition of community
The living or biotic part of an ecosystem
Definition of biotic
Any living or biological factor
Defintion of abiotic
Any non living or physical factor
Definition of population
The members of the same species living in one habitat
Definition of species
A group of organisms that can sucessfully interbreed
Examples of abiotic factors
Climatic factors : temperature, humidity
Soil factors : PH, mineral supply
Human factors : pollution
Topographic factors: altitude, slope, aspect
Definition of density-independent factors
The size of the effect is independent to the size of the population
What is INTERspecific competition
Competition for resources where one species will out compete another one
What is INTRAspecific competition
Competition for resources between members of the same species
Why is intraspecific competition more significant than interspecific?
Members of the same species have the same niche and so compete for the same resources. It has a stabilising effect on populations
What relationship do parasites and their hosts have?
Symbioitic
What does an organisms ‘niche’ mean?
The abiotic and biotic factors that the organism needs in its habitat
What is the competitive exclusion principle ?
Two species cannot coexist in the same habitat if they have the same niche, they will compete and one species will win the competition.
What is a specialist?
Species with a narrow niche.
Why can many specialists exist in the same habitat?
They are not competing.
Where are specialists usually found?
Abundant, stable habitats
What is sucession?
Ecosystems are not fixed, but constantly change with time
What is the climax community
Species colonise a habitat in predictable order until a stable order is reached.
What is the pioneer species?
The organisms colonising in early sucession
What is a sere
The whole succession
What does primary sucession start with?
Rock or sand, an inorganic base
What does secondary succession start with?
Soil, but no organisms present
What is a xerosere?
Succession where there is no water
What is a lithosere?
Primary succession from bare rock.
What is a plagioclimax?
Deflected succession, caused by human intervention such as deforestation or clearing land for farming.
What is conservation?
Management of our environment to maintain biodioversity
What does conservation involve?
Active intervention to manage sucession and maintain a wide variety of different plagioclimaxes.
What is the capture-mark recapture technique?
Estimates population size by capturing a sample of animals, counting them and marking them, releasing them, capture second sample, count number of marked and non marked
What conditions need to be met for capture, recapture formula to be correct?
Marking not affecting survival.
Marked animals must have time to randomly mix with population
Population must stay constant between first and second sampling.
