Transcript Ecology and the Environment - Mrs. Nicolai's Science Class

Ecology and the Environment
Many organisms have relationships
that are not understood until it is too late.
Dodo Bird
Calvaria tree
The dodo bird and the calvaria tree
is an example of how one species
interacts with another species.
Ecology is the study of
relationships among
organisms and between organisms
and their environment.
The dodo bird and the calvaria tree are
living in the part of the Earth called the
biosphere.
The biosphere is
the part of the
Earth that supports
living organisms.
Abiotic Factors in the Biosphere
All organisms depend on the
environment around them. Water, soil,
sunlight, temperature, and air are all
abiotic factors.
Abiotic factors are the non-living things
of the environment.
a = not
biotic = living
Abiotic Factors in the Biosphere
The abiotic factors in an area determine what
organisms are able to live in that
environment. Remember natural selection?
Desert fox
Arctic fox
Biotic Factors in the Biosphere
Abiotic factors do not provide everything
an organism needs to live. All organisms
also depend on other organisms for food,
shelter, protection, or reproduction.
Living organisms in the environment are
called biotic factors.
Biotic Factors in the Biosphere
Examples of biotic factors helping organisms
to live:
1. Mushrooms would not be able to grow
without the decaying bodies of other
organisms to feed on.
2. Bees could not live without
pollen from flowers.
Levels of Biological Organization
You have already learned that the living world
is highly organized (classification unit). The
biotic and abiotic factors are organized, too.
Ecosystem
Community
Population
Populations
Individual organisms of the same species that
live in the same place and can produce young
form a population.
Populations
Members of populations compete for food,
water, mates, and space. The resources of
the environment and how the organisms use
these resources determine how large a
population can be.
Communities
Groups of populations that interact with each
other in an area form a community.
Populations in a
community depend
on each other for
food, shelter, or for
other needs.
Ecosystems
An ecosystem is made up of a biotic
community and the abiotic factors that affect it.
Ecosystem = biotic factors + abiotic factors
Characteristics of Populations
1. Population Density: the size of a
population in an area of a specific size
Example: If there are 100 mice in an area of a
square kilometer, the population density is
100 mice per km2.
Characteristics of Populations
2. Limiting Factors: Any biotic or abiotic factor
that restricts (limits) the number of individuals
in a population.
Examples of limiting factors: amount of food,
water, living space, mates, and nesting sites.
Characteristics of Populations
3. Carrying Capacity: The largest number of
individuals an environment can support and
maintain for a long period of time.
Characteristics of Populations
If a population becomes bigger than the
environment’s carrying capacity, some
individuals will not have enough resources.
Interactions in Communities
Populations are regulated not only by the
supply of food, water, and sunlight, but also
by the actions of other populations.
Interactions in Communities
The most obvious way one population can
limit another is by predation. Predation is
when one organism eats another organism.
Interactions in Communities
Predators are more likely to kill old, sick, or
very young prey (organisms that get hunted
and eaten).
This helps keep the
population of prey
healthy and strong.
“Survival of the Fittest”
Interactions in Communities
Many species of organisms have close,
complex relationships with each other for
survival.
Symbiosis is any close relationship between
two (2) or more different species
Interactions in Communities
Mutualism: a symbiotic relationship that
benefits (helps) both species
Interactions in Communities
Commensalism: a symbiotic relationship that
benefits (helps) one partner but does not help
or hurt the other partner.
Interactions in Communities
Parasitism: a symbiotic relationship that
helps the parasite and hurts the parasite’s
partner, or host.
Habitats and Niches
In a community, every species has a job.
Each also has a certain place it lives.
Where an organism lives is called its habitat.
The job an organism has is called its niche.
Habitats and Niches
What a species eats, how it gets its food, and
how it interacts with other organisms are all
parts of its niche.
Part II
Matter and Energy
Energy moves through an ecosystem in the
form of food.
Producers are organisms that capture energy
from the sun and use it for photosynthesis.
Consumers are organisms that get their
energy when they eat producers or other
organisms.
Decomposers are organisms that get their
energy from breaking down the bodies of
dead organisms.
Food Chains
A food chain is a
simple way of
showing how energy
from food passes
from one organism
to another.
Food Webs
There are many food chains in any
ecosystem. A food web is a series of
overlapping food chains.
Ecological Pyramids
Energy is lost as it travels up a food chain.
Only a small part of the energy that comes
from the sun is captured by plants to make
food.
Ecological Pyramids
When an herbivore (an animal that eats only
plants) eats a plant, some of the energy in the
plant is transferred to the herbivore, but most
is given off into the atmosphere as heat.
Ecological Pyramids
The same thing happens when a carnivore
eats an herbivore.
Energy Pyramid
The energy pyramid shows how energy is lost
as it goes up the food chain.
The Cycles of Matter
Matter on Earth is never lost or gained, but
used over and over again. In other words, it is
recycled.
The carbon atoms in your body right now have
been on Earth since the planet was formed
billions of years ago.
The Cycles of Matter
Many important materials that make up your
body cycle through ecosystems.
These materials include:
Water
• Carbon
• Nitrogen
•
Part III
Ecosystems
Ecological Succession
Ecological succession is the process of
gradual change from one community of
organisms to another.
Primary Succession
Primary succession is ecological succession
that begins in a place that does not have soil.
Primary Succession
The first community of organisms to
move into a new environment is called
the pioneer community.
These are usually
organisms that can
survive in bad
conditions.
Primary Succession
Pioneer communities change the
conditions in their environment to make it
better for other organisms to start living
there. These new organisms gradually
take over.
Secondary Succession
Secondary succession is succession
that begins in a place that already has
soil and was once the home of living
organisms.
Climax Communities
A climax community is a community
that has reached the final stage of
ecological succession.
Climax Communities
As succession happens, the abiotic and
biotic factors change. The amount of
sunlight, nutrients, and water changes as
new species grow. In a climax
community, the abiotic and biotic factors
stay the same unless the trees are cut
down or there is a fire.
Comparing Pioneer and Climax
Communities
Pioneer
Climax
Simple
Only a few species
Simple food chains
Changing
Complex
Many species
Food webs
Stays the same