7C- POPULATIONS IN ECOSYSTEMS Flashcards
DEFINTION OF HABITAT
THE PLACE WHERE AN ORGANISM LIVES
Definition of population
All the organisms of one species in a habitat
Definition of community
Populations of different species in a habitat make up a community
Definition of ecosystem
a community plus all the non living (abiotic) condition in the area in whihc it lives
Definition of abiotic
The nonliving features of the ecosystem
Definition of biotic conditions
The living features of an ecosystem
Definition of niche
The role of the species within its habitat
Definition of adaptation
Feature that members of the species have that increases the chance of survival and reproduction
how many species can be in a niche
one
what happens if two speceics try to occupy the same niche
They compete with each other until one species is more successful than the other
what are the different types of adaptations
physilogical, behavioural, anatomical
what is physilogical adaptations
processes inside there body
what is behavioural adaptaion
the way an organism acts
what is anatomical adaptation
structural feature of the body
why are organisms with better adaptations more likely to survive
more likely to survive and reproduce and pass on allele for the more advantageous allele
what is population size
total number of organisms of species in a habitat
what is maximum stable population size that an ecosystem can support called
carrying capacity
why does carrying capacity varrie
as its a result of both abiotic and biotic factors
what happens when abiotic factors are ideal
organisms can grow fast and reproduce successfully
what is interspecific competition
competition between different speices for the same resources
what is intraspecific competition
competition within a species for the same resources
how can interspecific competition lead to overall population reduction
as they compete for same resource it can lead to an overall resource decrease this means both populations limited by reduced food so have less energy for growth and reproduction therefore resulting in population decrease
how does out competition occur
when one species in the competition is better adapted it will out compete the less adapted
what is predation
where an organism kills and eats another organism
what is the relationship between predator and prey
interlinked
why do we take population samples
as too time consuming to actually measure accurately the number of individuals in a species
why are samples bias and example
to avoid bias
random- divide feild into grid and use random number generator to get coordinates which are random
what are quadrats used to measure
species frequency
number of individuals
whats a transect
lines which can be used to measure how plants are distributed across an area
formula for measuring abudence of a very motile speceis like fish
mark release recapture
number of species caught in first species x number caught for 2nd sample
/
number marked in 2nd sample
what are three assumption you make whilst using the mark release recapture method
1- marked sample has had enough time and oppertuinuty to mix back in with population
2- the marking process didnt effect the individuals chance of survival
3- there are no changes to population size during the study
how to measure ph of landd
ph probe
what happens to ph as you move inland
it decreases as nearer the shore there are lots of shell fragments which are made of calcium carbonate -an alkaline compund
further inland more rotting vegatation which is more acidic
why are ecosystems said to be dynamic
as they are constantly changing
what is succession
the process in which an ecosystem changes over time
what is primary succession
this happens on land that’s been newly formed or expose - like volcano
what is secondary succession
happens on land which has been cleared of all plants but soil remians - like when forrests cut down
what is the pioneer speceis
first species to conolise area
how does primary succession develope
1- abiotic conditions are hostile so only pioneer speceis can grow as they are specially adapted to these conditions
2- pioneer speceis change the abiotic conditions as they die and decompose forming basic soil
3-this makes abiotic conditions less hostile so new organisms with different adaptations can survive
4-some new species may change the new conditions to make it less suitable for the previous species
final stage of succcession is climax community what does this mean
Ecosystem is supporting the largest and most complex community of plants and animals it can it won’t change much more it’s in a steady state
describe a temperate climate
plenty of available water mild temperatures and not much change between seasons
has large trees as deep soils
describe polar climate
not much available water temperautures are low and massive changes between seasons
large trees can grow
what is a plagioclimax
when succession is stopped artificially
two ways of managing succession in moorland
1- animals can graze on the land stopping stages of succession being able to establsih
2- managed fires can be lit to cause secondary succession
what does sustainable mean
Enough resources are taken to meet the needs of people today without reducing the ability of people in the future to meet their own needs
four examples of conservation techniques
plants conserved using seedbanks
fishing quotas puts limits on the type fish u can catch
protected such as national parks
endangered species bred in captivity
