Transcript Species interactions - Learning on the Loop

Species interactions
Symbiosis
Symbiosis
•Symbiosis
is the term used to
describe close
interactions between
two or more different
species
Species interactions can be described
as either
• Interspecific • Intraspecific
Eg.Competition between
members of different
species for resources such as
food,etc.
• This is usually less intense
• Remember Gause’s
competitive exclusion
principle!
eg. competition between
members of the same
species for resources such
as food, breeding sites ,
territories etc.
• This is usually intense.
Exploitation
• One species benefits at the expense of
another
• it can be divided into:• Predation- predators and prey
• Herbivory- animals eat or graze on plants
• ParasitismEcto parasites live outside the hosts body.
Endo parasites live inside the hosts body.
Predator / Prey interactions
predators and prey
often regulate each
others populations.
They often mirror
each other when
there is not much
prey swapping.
When there are lots
of hares , there are
lots of lynx.
Herbivory
• Animals eat plants as
primary
consumers
• The cows benefit
and the grass
suffers harm.
Parasitism
• One organism
benefits and the
other one suffers
The body louse gets
food protection,
warmth and the
human suffers with
itchy bites blood loss
and feeling lousy!
competition
• Two species
compete for the
same resources.
Both organisms
suffer.
• Hyena and lions both
compete for the
wildebeast
Mutualism
• Both organisms
benefit
The zebra gets
ticks eaten off it
skin and the
Oxpecker gets a
free ride and
dinner!
Commensalism
• One organism
benefits whilst the
other is not effected
• The cattle churn up
the mud and the
egret benefits
because it uncovers
insects which it can
eat.
Amensalism
• One organism suffers
harm and the other
organism is not
affected
• Water birds trample
and kill vegetation
around the ponds
edge
Antibiosis – a special type of
amensalism
• One organism is
unaffected but the
other is killed or
harmed by
chemical
secretions
A food chain shown which way the
energy flows
Food webs and food chains are
arranged in trophic levels
the amount of Energy decreases with
each tropic level so there are always
less predators than prey