Comparing Abiotic and Biotic Factors
An ecosystem consists of any given area with organisms interacting with each
other and with the abiotic parts of their environment.
It consists of biotic factors eg plants, animals, micro-organisms, etc
and abiotic factors eg air temperature, humidity, water, soil particles
Comparing some abiotic and biotic factors in different environments
Abiotic factor
Temperature variation
(daily and seasonal)
Aquatic environments
Small, unless a very small
body of water
Terrestrial environments
big
Availability of gases
Low, and diffusion slow in
water
High and diffusion fast in
air
Good, but saltiness can
affect this
Varies, can be a big
problem eg deserts
Eg ……………..
Availability of water
Energy in Ecosystems
 Biomass pyramids – mass gets smaller and smaller with higher levels of
consumers; only about 10% energy passed to next level, 90% “lost” as heat
1st level consumers
Producers (or autotrophs) – largest mass


Energy transformations:
Light energy  chemical energy (eg glucose)  mechanical energy. etc
 Food chains: energy is passed along
producerconsumer next consumer next consumer
eg sea weedblack fishsharkhuman
Niche = the role or part an organism plays in the ecosystem, resources it uses and
how it is a resource
Resource = anything an organism needs to survive and reproduce