Ecological Succession
Succession is a result of changing
conditions in an ecosystem.
Succession regenerates or creates
a new community.
• a sequence of biotic changes
• damaged communities are regenerated
• new communities arise in previously
uninhabited areas
2 types of succession:
Primary and Secondary
• primary succession — started by pioneer
species, such as lichens and mosses
• occurs in previously uninhabited area
• example: when bare rock is exposed by
receding glacier
Secondary succession is started by
remaining species
• occurs after fires or natural disasters
Primary or Secondary?
• Early settlers cleared forests and
replanted with crops.
• An abandoned parking lot cracks and
weeds begin to grow.
• A volcano erupts, but within years plants
begin to inhabit the barren lava.
• A farmer stops growing crops in a field and
lets it return to nature.
• Sand dunes develop due to wind. Soon
pioneer species begin living on the dunes.
A small group of people are
stranded on a barren desert island.
They have 500 bushels of wheat
and one cow. What should they do
to survive for the greatest length of
time?
A small group of people are stranded on a
barren desert island. They have 500
bushels of wheat and one cow. What
should they do to survive for the greatest
length of time?
A. Eat the wheat and then eat the cow
B. Eat the cow and then eat the wheat
C. Feed the wheat to the cow, drink the
milk, and then eat the cow.
Only ___ % of the energy from one
trophic level passes to the next.
What happens to the remaining 90%?
It is used by the organisms or
converted to heat
A small group of people are stranded on a
barren desert island. They have 500
bushels of wheat and one cow. What
should they do to survive for the greatest
length of time?
A. Eat the wheat and then eat the cow
B. Eat the cow and then eat the wheat
C. Feed the wheat to the cow, drink the
milk, and then eat the cow.