Transcript Biodiversity in Ecosystems

1. Explain various relationships with respect to food chains, food
webs, and food pyramids, including:
producer
consumer (herbivore, carnivore, omnivore)
predation (predator‐prey cycle)
decomposers
symbiosis (mutualism, commensalism, parasitism)
2. Describe the relationships between abiotic and biotic elements
within an ecosystem, including air, water, soil, light,
temperature (abiotic) and bacteria, plants, animals (biotic)
3. Design and analyse experiments on the effects of altering
biotic or abiotic factors (e.g., nutrients in soil: compare two
plant types with the same nutrients, compare one plant type
with different nutrients)
Ecosystem
Habitat
Community
Species
Population
Symbiosis
Mutualism
Commensalism
Parasitism
Predation
Niche
Competition
Predator
Prey
Biodiversity
• By studying past and present ecosystems, we
can better understand what may happen in
the future.
– Historical ecology is the study of natural and
written materials to better understand the
ecology of a certain area.
– Many First Nations sources provide detailed
knowledge of plants, animals, and natural
occurrences of an area.
 An ecosystem has abiotic components that
interact with biotic components.
– Abiotic (non-living) factors include air, water, soil,
nutrients, and light.
– Biotic (living) factors include plants, animals, and
micro-organisms.
– Ecosystems can take up many hectares of land or can
be small, such as a tide pool or a rotting log.
A habitat is where an organism
lives.
The habitat of the red fox often includes
the edges of forests or marshlands.
HABITATS
There are all sorts of different
‘habitats’ that different species
occupy:
• The Blind Flatworm
shrimp
& the eyeless
Live in dark caves. They are
called “troglobites” (cavedwellers). They have adapted to
darkness - do not require eyes...
White-Spotted Puffer Fish
• Lives in coral reefs (in tropical waters)
Second most poisonous vertebrate in
the world...
It’s muscles, skin, liver and ovaries
contain toxin 3x deadlier than cyanide.
The Rattle Snake
Occupies different habitats depending on
the time of year...
SUMMER
WINTER
Open grassland (areas
with high rodent
density)
Hibernating dens (rock
fissures or caves)
• The abiotic components are what allow the
biotic components to survive in an ecosystem
– Abiotic factors include oxygen, water, nutrients,
light and soil.
• Oxygen is produced by the green plants and certain
micro-organisms and is used by animals and most other
micro-organisms.
– An example of a micro-organism that
produces oxygen is cyanobacteria. They
are found in oceans, rivers, bare rocks, and
soil. “Blue-green algae”
• Water is necessary for all life.
• Nutrients often enter the food chain with plants and
are very important for plant and animal growth.
• Light is required for photosynthesis, which is the
process in plants that converts and stores the Sun’s
energy into starches and sugars.
• Soil not only contains water and nutrients
but also is home to many plants and animals.
Earthworms in soil
– A species is a group of closely related organisms that
can reproduce with each other.
– A population refers to all of the members of a certain
species within an ecosystem.
– A community is all the populations of the different species
that interact within an ecosystem.
• Symbiotic relationships are the interactions
between members of two different species
that live together in a close association.
– Commensalism – one species benefits, one is not
affected
• Example: the barnacles on a whale
– Mutualism – both species benefit
• Example: a bee gathering nectar from a flower
– Parasitism – one species benefits, the other is
harmed
• Example: hookworm living in dogs
Mutualism Video
COMMENSALISM
(Biological hitch-hiking)
The Imperial shrimp hitches a ride
on a large sea cucumber. It rides
along through areas of potential
food, at no cost to the other
organism.
Anyone home?
The pearlfish is a small fish (5-10cm) that lives
inside a seacumber in the day and at night, exits
through the anus of the seacumber to feed.
MUTUALISM
• Leaf Cutter Ants
Cut the leaf..
These ants
cultivate (grow)
a fungus. They
feed the fungus
and the fungus
serves as their
food!
Teachers' Domain: Ancient Farmers of
the Amazon
Chew into a
pulp
Store the pulp
with ant feces
and fungus
spores
Fungus begins
to grow...
MUTUALISM
LICHEN = algae + fungus
The algae
provides food
(glucose) for the
fungus through
photosynthesis.
PARASITISM
HOOK WORMS
A parasitic worm that
lives inside the
intestines of its host
(mammal). These
worms such blood from
the host’s intestinal
walls ...this leads to
anemia (iron
deficiency).
M
O
U
T
H
The common way for hook worms to enter
is through the skin (walking barefoot)...
PARASITISM
• The Pine Beetle
The pine beetle has
infested lodgepole
pine trees in BC’s
Central Interior.
Burrows in the
tree, feeds on
trees phloem
(nutrients) and
lays its eggs.
The Pine Beetle’s Legacy....
• In B.C., the provincial government estimates the
beetle's spread will have economic implications for
30 communities and will impact 25,000 families
whose livelihood depends on the pulp and paper
industry.
• The environment is also affected: trees normally
capture CO2 (greenhouse gas) – but the death of
more trees has instead released carbon into the
atmosphere, according to a study published in April
2008 in the journal Nature.
A niche refers to the role an organism has
within an ecosystem, physically, chemically
and biologically.
– Within the niche, an organism interacts with other
individuals of the same species or with individuals
of other species
Competition is a harmful interaction that
occurs when a resource is needed by two or
more individuals.
– Competition usually means resources are limited.
– This limits the size and health of that individual
and perhaps that population.
– Resources include food, water, and mates.
 Predation is the relationship between predators
“the eaters” and their prey “the eaten”.
– Predators have adaptations to help them catch their
prey.
– Prey have adaptations to help avoid predators.
• Examples of adaptations include spines and shells,
camouflage and mimicry.
– The numbers of predators and prey influence each
other.
Biodiversity refers to the variety and number
of different individuals and species in an
ecosystem.
– Healthy ecosystems generally have high
biodiversity.
– Most biodiversity losses occur from the loss of
habitat.
• Humans often have a negative impact on
biodiversity.
– Many efforts are now made to lessen this impact
in order to maintain biodiversity.
• Ecological management programs try to balance human
progress with maintaining biodiversity.