Populations in ecosystems

?
  • Created by: Hindleyc
  • Created on: 01-01-19 16:38
What do populations of different species form?
A community
1 of 51
What does a community and the non-living components of its environment together form
an ecosystem
2 of 51
What can ecosystems range in?
Size- from v small to the very large
3 of 51
Within a habitat what does a species occupy
A niche
4 of 51
What is this governed by?
Adaptation of both abiotic and biotic conditions
5 of 51
What can an ecosystem support?
A certain size of population of a species
6 of 51
What is this called?
Carrying capacity
7 of 51
What can population size vary as a result of?
-Effect of abiotic factors -interactions between organisms: interspecific and infraspecific competition and predation. availability of resources
8 of 51
Hybrid?
Viable offspring but infertile (mule) odd number of chromosomes
9 of 51
Species
Group of closely related organisms which are potentially capable of breeding together (interbreeding) to produce viable, fertile offspring
10 of 51
Population
A group of organisms, all of the same species that have the opportunity to breed with one other because they live in the same habitat - same ecosystem at same time
11 of 51
What can populations become?
Fragmented and isolated geographically and possibly, over many years, genetically
12 of 51
What happens if this becomes so pronounced?
that Interbreeding no longer possible, they are no longer the same species
13 of 51
Community
A number of populations - They are all the plants and animals which occupy a particular area in any one time
14 of 51
other definition
- collection of populations present in an ecosystem in an ecosystem at given time that interact with each other
15 of 51
Whats a Niche
A role an organism plays-organism has a food niche and a habitat niche- how an organism relates to its physical and biological environment
16 of 51
What happens if 2 species occupy the same niche
Interactions between them will eventually lead to the extinction of one of the species (interspecific competition)- describes how an organism fits into its environment
17 of 51
What is this process
Continual- more adapted species push other out eg red squirrels
18 of 51
Other definition niche
Describes what a species is like, where it occurs, how it behaves, its interactions with other species and how it responds to its environment
19 of 51
What is competitive exclusion principle
Diff niches persist but lower population. 1 organism outcompetes other species out of niche- if can't compete as successfully
20 of 51
Ecosystem
This is the inter relationship between the living (biotic) and non-living (abiotic) components of the ecosystem (particular area)
21 of 51
Carrying capacity?
An ecosystem can support a certain size of population this is called the carrying capacity (max size at any one time unless conditions change)
22 of 51
What is it
Sustained over long period determined by limiting factors
23 of 51
Abiotic
Ecological factor that makes up part of the non-biological environment of an organism eg PH temp, rainfall and humidity
24 of 51
Biotic
Ecological factor that makes up part of the living environment of an organism- food availability competition predation
25 of 51
What is an environment influenced by?
both these factors -abiotic and biotic
26 of 51
Biotic factor?
Living elements of a habitat which affect the ability of a group of organisms to survive there eg predators, competition, parasitism and disease - regulate size of a population more intensely than abiotic one
27 of 51
Abiotic factor?
non-living part of an organisms habitat. they can determine the ability of an organism to survive in the habitat. abiotic factors include temperature wind waves ph minerals light water shock pollutants currents
28 of 51
What are the biotic and abiotic factors often?
Linked with the ecosystem
29 of 51
Interspecific competition?
b/w diff species eg competitive exclusion principle- could remove 1 species
30 of 51
Intra specific
Within members of same species
31 of 51
Biomes
Group of ecosystems with the same conditions and animals and plants
32 of 51
Habitat
Place where organism normally lies - characterised by physical conditions and other types of organisms present
33 of 51
Microhabitats
Smaller units within each habitat
34 of 51
Why does no population continue to grow indefinitely
bc certain factors limit growth
35 of 51
Competition
Resources eg food water breeding sites light- greater availability = larger the population= affects degree of completion resulting in smaller populations
36 of 51
What can 1 organism successfully occupy
Ecological niche at 1 time
37 of 51
When does predation occur?
When 1 organism is consumed by another
38 of 51
How can populations only be estimated?
sampling and surveys
39 of 51
How does it work (effects pp relationship on population size)
-Predators eat their prey, there by reducing the population of prey
40 of 51
Then?
With fewer prey available, the predators are in greater competition with each other for the prey that are left
41 of 51
Then
Predator population reduced as some individuals are unable to obtain enough prey for their survival or to reproduce
42 of 51
Then
With fewer predators left fewer prey are eat and so more survive and are able to reproduce
43 of 51
What happens as a result
prey population therefore increases
44 of 51
What happens with more prey available as food?
Predator population in turn increase
45 of 51
What happens in natural ecosystems ? why?
Fluctuation of population size less severe bc organisms eat a range of foods
46 of 51
What is this a significant reason for?
cyclic fluctuations in populations
47 of 51
What is another reason
Disease and climate factors -also play a part
48 of 51
What are periodic population crashes important in
evolution as there is selection pressure- means that those individuals who are able to escape predators or withstand disease/diverse climate are more likely to survive and reproduce
49 of 51
What does population therefore evolve to be
Better adapted to the prevailing conditions
50 of 51
Within an ecosystem what are the 2 main things to consider
flow of energy through the system . cycling of elements within the system
51 of 51

Other cards in this set

Card 2

Front

What does a community and the non-living components of its environment together form

Back

an ecosystem

Card 3

Front

What can ecosystems range in?

Back

Preview of the front of card 3

Card 4

Front

Within a habitat what does a species occupy

Back

Preview of the front of card 4

Card 5

Front

What is this governed by?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Ecology, ecosystems and environmental biology resources »