Transcript interacting

Ecosystem Interactions
Among Species
organism
population
community
ecosystem
biosphere
https://youtu.be/GxE1SSqbSn4
What Affects Populations of Species?
Interactions and Populations
 All populations of species in an ecosystem
strive for survival
 What do you think populations of species
need in order to survive?
Resources: food, water, safe
shelter, mates, space,
materials
But there are many factors
that affect a population’s
survival
Is there a difference
between a population and
a community?
Yes. A population is made up of
members of one species (who
breed) and live in a specific
area, more or less isolated
from other members of their
species.
A community is made up of a
collection of populations of
different species interacting
within a specific area,
functioning more or less as a
unit with certain identifiable
characteristics.
Biotic and Abiotic Interactions
 Biotic Interactions: Interactions
between living things.
 Example: How would a flower and a bee
interact? How would a moose and a
parasite interact?
 Abiotic Interactions: Interactions
between living and non-living things
 Example: How would a deer be affected
by a dry and hot weather?
Abiotic Interactions
 Terrestrial: temperature, water, light and
nutrient availability
 Aquatic: same as above plus light
availability, acidity, and salt concentration
 Tolerance range:
 The range in which a species can survive
 Optimal range:
 The range of abiotic factors a species is best
adapted to
Ecological Niche
 An organism’s niche is its ecological role
habitat = address vs. niche = job
•Spot in food
web
•Habitat
•Breeding area
•Time of day
that its active
Owl
SpeciesHawk
Interactions
Food
mice / small rodents
mice / small rodents
 Competitive
Exclusion trees (forest)
trees (fields)
Habitat
No
Time of 
Day
Daylight species can occupy
Nighttimethe same
two similar
Long at
wings
forsame
soaring timeShort wings for weaving
Adaptations
niche
the
Great distance vision
Great night vision
Amazing hearing
Biotic Interactions
 There are three main ways in which
species in populations interact with each
other:
1. Predator-Prey interactions
2. Competition
3. Symbiosis
1) Predator-Prey
Interactions
 the act of one organism eating another
organism in order to obtain food. Prey
animals adapt in order to avoid being
eaten.
 Ex. Camouflage or the ability to run very
fast.
- Mimicracy: one species that looks like
another species.
Predation
 When one organism consumes another
organism
 Examples:
 Wolf hunting a deer
 Lady bugs eating aphids
 Owl hunting a mouse
2) Competition
 interactions between two or more organisms
competing for the same resource in a given
habitat.
Competition
 Organisms might compete for resources
such as food and materials, mates or
territory/habitat
 Interspecific: competition between species
 Intraspecific: competition within organisms of the
same species
 Examples:
 Interspecific: cheetahs and lions both compete
for antelope; spruce and ash trees compete for
sunlight
 Intraspecific : two male deer competing for a
female
Competition
 Neither species benefits
 For example, by the early 1950s
the American chestnut (
Castanea dentata) had been
eliminated as a dominant canopy
species in deciduous forests of
eastern North America by the
accidental introduction of a
fungal pathogen known as
chestnut blight (Endothia
parasitica). Other tree species
took advantage of their sudden
release from competition with
the chestnut by opportunistically
filling in the canopy gaps that
were left by the mature chestnut
trees.
3) Symbiosis
 a close interaction between two different
species where one species lives in, on,
or near another species.
Three types of Symbiosis:
a) Mutualism
b) Commensalism
c) Parasitism
What do you think each of these mean?
Mutualism
• A relationship between two
species where both benefit. The
yucca moth both pollinates and
feeds on the yucca plant;
• acacia ants live in the thorns of,
defend, and are fed by the acacia
tree in which they live;
• Butterfly-weed provides food for
and is pollinated by butterflies
like Pipevine Swallowtails.
• Many plants and their pollinators
have evolved mutualistic
relationships.
Clown fish and sea
anemone
The clownfish have a
protected territory and
the sea anemone
needs the mucus
from the clown fish to
make their venom
Parasitism
 When two organisms coexist and one
organism benefits while the other is
harmed
 Examples:
 Dogs and Cats + Fleas, ticks, intestinal worms
 Lampreys and salmon
 Leeches
 Bed bugs
 mosquitoes
Parasitism
http://www.micro.utexas.edu/courses/levin/bio304/com&pop/communities.html
Zombie Ants
 A parasitic fungus can infect an ant.
 The fungus then takes over the control center
of the ant and manipulates it forcing it to
climb to the highest point available and then
latch on to the vegetation.
 The fungus then pushes through
the ants head releasing spores
and uses the ants body for
nutrition.
Commensalism
 When two organisms coexist and one
organism benefits while the other remains
unharmed
 Examples:
 Cattle and the egret: the egret consumes insects that
have been disturbed while the cattle forage
 Barnacles and scallops: the barnicles have a place to
live and the scallop is unaffected
arks: Remora
endowed with an
sk on the dorsal
heir heads. They
hesive disk to
e” on larger
ually whales,
to be sloppy
en food floats
he whale’s
remora can
lf and collect the
od floating by.
Commensalism
http://www.nearctica.com/ecology/pops/commens.htm
Other Examples of Biotic
Interactions
 Mutualism –Ex: the boxer crab carries around
anemones in its claws. The anemone protects the
boxer crab from predators, and the anemone eats
scraps of food that the boxer crab drops.
 Commensalism –Ex. A bird building a nest in a tree
(tree doesn’t suffer)
 Parasitism –Ex. Leach or a tick sucking blood from
an animal.
 SEE PAGE 62-63 for MORE EXAMPLES
Which type of Symbiosis?
1
2
3
Which type of Symbiosis?
 Image 1 – parasitic tick on a dog
 Image 2 - As buffalo eats grass, the
egrets (birds) eat the insects that they stir
up. The buffalo is unaffected.
 Image 3 – The bee feeds from the
flower’s nectar, but it also helps crosspollenate the flower so it can reproduce.
What relationship is
this?
More examples
mutualism
commensalism
+/0
predation
+/- competition
+/+
-/-
Comparing Relationships
type of interaction
sign effects
mutualism
+/+
both species benefit from
interaction
commensalism
+/0
one species benefits, one
unaffected
competition
-/-
each species affected
negatively
predation, parasitism,
herbivory
+/-
one species benefits, one is
disadvantaged
0/0
Neither species benefits or is
harmed
Neutralism
Species Interactions
competition (-/-)
 compete for limited resource
 competitive exclusion!
predation / parasitism (-/+)
 Parasite: an organism whose ecological niche is
closely linked to its host causing discomfort and
possibly death to host
mutualism (+/+) (symbiotic)
 lichens (algae & fungus)
commensalism (+/0)
 barnacles attached
to whale