Download 1.2 Ecosystems

1.2
Ecosystems
What is an ecosystem?
 Biomes
can be divided into many
different types of ecosystems.
 An ecosystem is made up of many parts.
abiotic components include oxygen,
water, nutrients, light, and soil.
 Biotic components include plants, animals
and microorganisms.
 Ecosystems
can be extremely large taking
up many hectares of land or small, such
as a tide pool or a rotting log.
 Within ecosystems are habitats. A habitat
is the place in which an organism lives.
Abiotic Interactions in Ecosystems
 The
abiotic components are just as
important as the biotic components to an
ecosystem.
 Abiotic factors include oxygen, water,
nutrients, light and soil.
 Oxygen
is produced by plants and
certain micro-organisms and is used by
animals and most other micro-organisms.
 Water is necessary for all life.
 Nutrients, (such as nitrogen, and
phosphorus) often enter the food chain
with plants and are very important for
growth.
 Light is required for photosynthesis, which
is the process in plants that converts and
stores the Sun’s energy into starches and
carbohydrates.
 C6H12O6 + O2  CO2 + H2O + Energy
 Soil not only contains water and nutrients
but also is home to many plants and
animals.
Biotic Interactions in
Ecosystems



A species is a group of closely related
organisms that can reproduce to create
offspring.
A population refers to all the members of a
particular species within an ecosystem.
A community is all the populations of the
different species that interact in a specific
area or ecosystem. These biotic interactions
are sometimes ordered in an ecological
hierarchy of organism, population,
community, and ecosystem.
Self checks: answer the following
with your partner and complete WB pg
10-12
 What
is an ecosystem?
 What is a habitat?
 What are 3 abiotic components of
ecosystems necessary for supporting life?
 Explain why soil is important to
ecosystems?
 What is a species?
 What is a population?
 What is a community?
Biotic Interactions in
Populations
 Within
an ecosystem, organisms interact
constantly within their species and with
other organisms. Three kinds of symbiotic
interactions in ecosystems are
Commensalism
2. Mutualism
3. Parasitism.
Symbiosis refers to the interaction between
members of two different species that live
together in a close association
1.
 Commensalism
is a symbiotic relationship
in which one species benefits and the
other species is neither helped nor
harmed.
Ex 1 the barnacles on a whale
 Ex 2crimson anemone
provides shelter and
protection for the
candy-striped shrimp

 Mutualism
is a symbiotic relationship in
which both organisms benefit.

Ex. A bee gathering nectar from a flower
 Parasitism
– one species benefits,
the other is harmed
Example: hookworm living in
dogs
Example: mosquito and human
Self Checks
 http://www.youtube.com/watch?v=zSmL
2F1t81Q&feature=related
 What
is symbiosis?
 What is commensalism?
 Give an example of mutualism.
 Give and example of parasitism
Niches
A
niche refers to the role an organism has
within an
ecosystem, physically, chemically and
biologically.
Competition
 Competition
is a
harmful interaction
between two or more
organisms that can
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.
Predation
 Predation
is the relationship between the
“eaters” (predators) and the “eaten”
(prey).


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.
Predator-prey relationship
between lynx and snowshoe
hare
The prey population grows when there are few predators, but as
the prey population grows, the predator population begins to
grow decreasing the pray population. As the prey population
shrinks, the predator population shrinks and the process repeats.
Biodiversity in Ecosystems

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.
Homework
 Textbook
page 51 #1-8, 12, 13