Download Chp 19 Ecosystem structure

V.C.E. Biology Unit 2
Living in an Ecosystem
Living Together
• Environment – organisms interact with the
biotic and abiotic characteristics of their
environment.
• Within any particular environment there is
a community of living things – that is many
populations of different species.
• A population is the members of one
species in the same place at the same
time.
Ecosystems
• An ecosystem is all the populations of
living things at a given place at a given
time interacting with their abiotic
surroundings and each other.
• The largest ecosystem is the Earth – we
call this a biosphere.
• The Earth has many smaller ecosystem
types – each of these is self-sustaining.
Places to Live
• Within an ecosystem, each species has a
niche – a part of the ecosystem which
gives it most (or all) the things it needs to
survive.
• A habitat is the term given to the space
within the ecosystem that a single
organism lives in – some organisms have
very specific habitat requirements, others
can exist within a broader range of
habitats.
Naming Ecosystems
• Ecosystems are described in general
terms as freshwater, marine or terrestrial.
• Then to be more specific we name them
either by their dominant species and/or
structural characteristics, eg;
Eucalypt Woodland
Basalt plains grassland
Warm Temperate Rainforest
Studying Ecosystems
• To study an ecosystem one must work
systematically – we use transects and quadrats
to collect information about the distribution,
abundance and diversity of abiotic and biotic
characteristics.
• Transect – a straight line through an ecosystem,
usually on a compass bearing.
• Quadrat – a square (10m x 10m) along one side
of the transect from which information is
collected.