Succession Flashcards
What is a climax community?
A stable community in which no further succession can occur
What is the 1st step of succession?
Colonisation by a pioneer species
What is the second step of succession
The environment becomes less hostile as hummus is formed
What is the 3rd stage of succession
The environment becoming less harsh allows other species to colonize it and compete for resources
What is the 4th stage of succession
The species diversity increases
What is the 5th stage of succession
Increased stability less hostile environment
What do the 6th stage of succession
The formation of a climax community
what is a niche?
a species role and position within an ecosystem
what are predator prey relationships?
They are cyclic relationships
name one reason for cyclic fluctuations in predator prey relationships
diesase, climactic factors
what do the crashes in predator prey relationships create
-selection pressures
which are important for evolution
why are the selection pressures created by crashes important
as the population evolves to become better adapted to the prevailing conditions
what is predation
where one organism the predator eats another the prey
what is uniformly distributed
there are the same number of organisms in each region
what assumptions are made in proportional sampling and not mark and relase methods
- organsims are uniformly distributed
- size of total area is required
give an assumption made in both propotional sampling and mark and release methods
animals are all from the same population
give one disadvantage of a line transcet
it may avoid certain areas
suggest one reason for habitat conservation
- protects niches
- protects endagerd species
Describe how percentage cover could be measured
- count how many squares of the quadrat by the plant
- by counting a square if it’s more than half covered
- the number of squares can be converted into a %
what is an ecosystem
all the organisms living in a community
plus all the abiotic conditions in the area in which they live
what is population size
total number of organisms of one species in a habitat
what is carrying capacity
the maximum stable population size of a species that an ecosystem can support
what is a population
all the organisms of one species in a habitat
