Transcript Chapter 13: Ecology

Ecology
What is it?



Definition: The study of interactions
between living and non-living things in the
environment in which they live
Abiotic = non-living
Biotic = living
Why study ecology?





The research provides us with information
that is necessary for understanding and
resolving many of the environmental and
ecological issues that confront us like:
Overpopulation
Species extinction
Global Warming
pollution
2 Ecological Truths:


Our planet does not only belong to humans
but also to many other forms of life.
The health of the human population
depends on the well-being of much of that
life.
Ecosystems


Definition: An ecosystem is a collection of
producers, consumers, an decomposers
interacting with one another and their
environment.
Example: Greenfield Park
Organization of Matter
6 levels
1.
Organism: an individual living thing
Organization
2. Species: a group of organisms that can
reproduce
Organization
3. Population: A group of organisms, of the same
species, living in the same area
Levels of Organization
4. Community: The
interaction of ALL
living things (plants
and animals) in a
given space.
Levels of Organization
5. Ecosystem: The interaction between a
community and its non-living parts (soil, air,
water, etc.)
Levels of Organization
6.
Biosphere: All the
living areas of the
Earth
Parts of An Ecosystem
Abiotic = non-living




Air
Water
Soil
Rocks
Biotic = living





Plants
Animals
Protists
Bacteria
Fungi
Organisms in an Ecosystem


3 Kinds of Organisms:
Primary Producer (autotroph): use
sun’s energy to make food
Chemotrophs (a group of bacteria)
harvest their energy from chemicals.
Organisms in an Ecosystem
2. Consumer (heterotroph): Obtain energy by eating
other organisms

Herbivore: eat only plants

Carnivore: eat only other animals

Omnivore: eats plants and animals
Organisms in an Ecosystem
3. Decomposer: Get
energy by breaking
down dead matter
Organisms together in an Ecosystem
Habitat



Each organism lives in a habitat
Definition: the natural physical
environment in which an organism or
population influences and utilizes in order
to live
Each organism has a “role” in their habitat
Niche


Definition: the specific activities and
relationships to other organisms a species has
while obtaining and using the resources needed
to survive and reproduce
Example: Lions and honey bees
Niche Cont’d

Niche Competition
 2 Species partially share a niche: both
compete in the overlapping parts of the
niche for resources, nesting sites, or
territory. If the overlap is minimal, both
species can coexist.
 Example: Lions and
hyenas
http://www.metacafe.com/watch/384580/rhino_a
ttack/
Niche Cont’d


2 Species have the same
niche: both compete head
to head in the niche for
resources, nesting sites, or
territory. One of the
species will be superior to
the other in utilizing the
niche. The 2nd species
disappears from the
ecosystem.
Example: Darwin’s Finches
Energy: Essential for Life


The sun is the source of energy for all life
Plants transfer the sun’s energy into the
building blocks of living tissue
Carbohydrates
 Fats
 Proteins
through a process called Photosynthesis.

Energy Flow in the Biosphere


Energy can’t be
recycled = 1 way
flow
Flows through
primary producers to
final consumers
Energy Flow in the Biosphere
Trophic Levels: Feeding
level
 Each level higher = less
energy
 Energy is lost through
usage and heat back to
the environment
 Omnivores, decomposers
and scavengers also
obtain energy from the
energy pyramid
Energy Cycle

Only 10% of the energy obtained gets passed on
from one organism to another
Carrying Capacity & Limiting Factor



Carrying Capacity: The limit
of individuals in a population
an ecosystem can support
Limiting Factor: The factor
that limits the carrying
capacity
Example: Carrying capacity of
elk is 21,000 in Yellowstone
National Park, two limiting
factors are food and space
Opportunist & Specialist Species
Opportunist Species: use the environment
in a number of ways
 Example: Raccoons
 Specialist Species: Can
feed on only one type of
Food
 Example: Anteaters

Food Chain
One path of energy from a
Producer to a tertiary consumer
 Example:
Plants-grasshopper-mouse-owl

Food Web

A collection of many food
chains that interact with one
another
http://video.google.com/videoplay?docid=-
4792608939520617017&q=Lion+King+Circle+of+Life&total=623&start
=0&num=10&so=0&type=search&plindex=0
Food Chain or Food Web?
Nutrient Cycles
Water Cycle
Water Cycle




a.k.a. Hydrologic cycle
This cycle describes how water flows from
the atmosphere to earth and back again
Precipitation- is water released from clouds
in the form of rain, freezing rain, sleet,
snow, or hail.
Run-off is the water that flows from land
back into a body of water
Water Cycle Cont’d
Condensation-is the process by which
water vapor in the air is changed into liquid
water
 Condensation forms clouds
and fog
 Produces rain (precipitation)

Water Cycle Cont’d
Transpiration- the release of water vapor from
plants and animals
 Evaporation-is the process
by which water changes
from a liquid to a gas
or vapor
 Evapotranspiration=
evaporation + transpiration

http://video.yahoo.com/video/play?vid=1077701735
Warner Brothers Anamaniacs
Nitrogen Cycle
Nitrogen Cycle




Nitrogen (N) is an element that is required
to make proteins
79% of the air is Nitrogen gas, but most
organisms can’t use it in this form
Plants must get (N) in a “fixed” form :
NO3- , NH3, (NH2)2CO
Animals must get (N) from plants
4 Process of the Nitrogen Cycle




Nitrogen-fixation-taking the (N) from the
atmosphere to make it usable
Decay-breaking down organic matter into
ammonium (NH4NO3)
Nitrification-Bacteria breaks down the
ammonium to nitrates
Denitrification-the process of changing
nitrates to the atmosphere
Phosphorus Cycle
Phosphorus Cycle




Phosphorus (P) can only be found in water,
soil, and rock sediments
It does not exist in the atmosphere as gas
It is the slowest cycle
This is often the limiting factor: b/c there
are so little amounts in soil (Fertilizer)
Phosphorus




Animals can only attain
(P) by consuming plants
or herbivores
Only released by
weathering of rocks
Your body needs this for
ATP (form of energy)
Your body also needs
this for its DNA
Carbon Cycle
Carbon Cycle



Carbon is needed to build our living tissue
It is the most abundant nutrient
It exists in the non-living environment as:
CO2 gas
 Carbonate rocks
 Deposits of coal, petroleum,
and natural gas
 Dead matter from once living things in the soil

Carbon Cont’d



Producers transfer Carbon from the atmosphere
from CO2 to organic matter
Living organisms eat the producers and pass the
Carbon from one to the next
Carbon returns as:




CO2 gas through respiration
Burning organic matter (plants/fuel)
Decay of organic matter, methane
http://youtube.com/watch?v=c40jebr9jbg
Carbon Cont’d

More burning of fossil fuels adds Carbon
into the air





Pollution from oil
Burning vegetation grazing or deforestation
Contributes to the “Greenhouse Effect”
CO2 in the atmosphere prevents heat from
escaping back into space, which makes
earth warmer!
http://video.google.com/videoplay?docid=5128613033824536021
&q=greenhouse+effect&total=411&start=0&num=10&so=0&type
=search&plindex=7