ecosystems Flashcards
what is an ecosystem
all living organisms that interact in a defined area, and the physical factors present - can vary in size and are dynamic
what is meant by ‘ecosystems are dynamic’
they are constantly changing
what is a biotic factor + eg.
living factors
- eg. predators, competition, disease
what is an abiotic factors + eg.
non-living factors
- eg. temperature, water, humidity, pH, wind, Co2
what are edaphic factors + 3 eg
soil factors
- clay - fine particles, easily waterlogged + forms clumps when wet
- loam - different-sized particles, retains water but no waterlogging
- sand - coarse, well separated particles to allow free draining, not easily eroded
why do abiotic factors often have a larger effect on plants than animals?
- plants are unable to hide / shelter / migrate in extreme conditions
- plants are more reliant on light/water in order to photosynthesise
- animals can regulate internal body temp
define species
organisms with similar features which reproduce to produce fertile offspring
define population
group of individuals of the same species that occupy the same habitat at the same time
define community
all populations of different species living in the same place at the same time
what is a biome?
a large scale ecosystem defined by abiotic factors (eg. weather)
what is a biosphere?
an area of the planet where organisms live (eg. ground, water, air)
why are ecosystems dynamic, but stable?
- population sizes rise and fall
- due to interactions between organisms and environment
- any small change can affect the other in predator/prey relationships
define niche
the role of an organism in its ecosystem
define habitat
the place where an organism/community lives
define keystone species
- organisms that have significant effect of ecosystem
- could be relied on by other organisms
