Transcript Ecology notes - Pierce Public Schools

Unit 2: Ecology
Chapters 2-5
What is Ecology?

A branch of __ that studies the
interactions that take place between
__ and their __
The Environment

Abiotic Factors – The __ parts of an
organism’s environment


Ex) air currents, __, moisture, __, and soil
Biotic Factors – All the __ organisms that
inhabit an environment

This includes an organisms relationships with
other organisms. They depend on each other for
__
Levels of Organization

1) Organism - __


2) __ – A group of organisms, all of one
species, which interbreed and live in the same
place at the same time


Ex) __
Ex) A __ of dogs in an area
3) __ – All the populations of different
species that live in the same place at the same
time

Ex) dogs, cats, mice, insects, dandelions, grass, etc…
Levels (cont.)

4) Ecosystem – Made up of interacting __ in a
given area and with the __ components of that
area

Two Types:



A) Terrestrial – located on __
B) Aquatic – __.
5) __ – The portion of the earth that supports
life.

Extends from high in the atmosphere to the bottom of
the __
Organisms in Ecosystems

Habitat – __



Ex) lawn, stream, forest
Can change or disappear
__ – all strategies and adaptations a species uses
in its environment


Ex) how it meets its specific needs for __ and __, how
and where it survives, and where it reproduces.
It is an __ for a species to occupy a niche different
from those of other species in the same habitat
Relationships in Ecosystems

A. __

Organisms may compete with each other for
food, water, mates, sunlight, space, etc…




Ex) cattle and sheep
Ex) plants for __
Competition also increases when resources are in
__
Affects the __ of a species

When a population increases to a point in which
demand of the resources exceeds the supply, the
population size __
Competition (cont.)

There is a competition within and between species.
 __ – Animals that feed on other living animals (by
killing them first)
 Ex) Owls, Hawks
 Prey – The animals that are killed or eaten
 Ex) __
 Hawks and Owls are in competition for the same prey
 __reduces the competition.
Relationships in Ecosystem (cont.)

B. __


Organisms that cooperate in their life activities
may __ each other’s survival
__ animals – members of the same species that
live together in colonies and help one another


Ex) __
Symbiosis – when two different types of
organisms (different species) __

These relationships help maintain survival in many
species
Three Kinds of Symbiosis

1) Mutualism – A relationship in which both species
__


2) Commensalism – A relationship in which one
species is __.


Ex) Ants and acacia trees
Ex) Spanish moss growing from limbs of trees
3) Parasitism – A relationship in which a member of
one species derives __ at the __ of another species

Ex) Ticks on a dog
How organisms obtain energy

The producers: __



Organisms that use __ energy or energy stored in
chemical compounds to make energy-rich
compounds.
Ex) __
Other organisms in the biosphere depend on
autotrophs for nutrients and energy (__)

The consumers: __


An organism that __ make its own food and feeds
on other organisms.
Types:

__- A heterotroph that feeds only on plants


__- Heterotrophs that eat other heterotrophs


Ex) rabbits, grasshoppers, elephants, etc…
Ex) lions
__- Organisms that eat a variety of foods that include
animal and plant materials

Ex) Humans, raccoons, opossums, bears

Types: (cont.)

__- Organisms that eat animals that have already died.
(They do __ kill for food)


Ex) Black vultures, buzzards, ants, beetles
__- Break down dead and decaying plants and animals
and release nutrients

Ex) Some protozoan’s, many bacteria, and most fungi
Food Chain





Model that shows how __ move through an
ecosystem.
Nutrients and energy move from autotrophs to __
and eventually to __
Most consists of two, three or four transfers
Only a __ portion of energy remains in the final
transfer as compared to what was in the original
A portion of the energy is given off as __
Example of a Food Chain

Berries (__)
 Field mouse (1st order __)
 Cat (2nd order __)
 Coyote (3rd order __)
 Crow (__)
 Bacteria (__)
Food Web


Shows __ the possible feeding relationships at
each level in a community
Better than a food chain because organisms
__
Ecological Pyramid




Shows how __ flows within an ecosystem
Base of the pyramid represents __
Higher levels are layered on top of one
another
The total energy transfer from one trophic
level to the next is only about __

Why? When an organism consumes food, it uses
some of the energy for __ and the rest is given off
as __
How fast do populations grow?

Resembles a “__” curve




Exponential growth – as the population gets
larger, it also grows at a __ rate
Initial increase is __ because the number of
reproducing individuals is small
Rate of population growth soon increases
because the total number of individuals that
are able to reproduce has increased.
Population growth does have__
What limits growth?





1) __
2) __
3) __
4) __, etc…(Table 3.1)
__– Any biotic or abiotic factor that restricts the
existence, numbers, reproduction, or distribution of
organisms


Ex) Timberline
Population growth will stabilize in an __-shaped
growth curve
Carrying capacity


The number of organisms of __ species that
an environment can support __
When a population rises above the carrying
capacity, more organisms __



Limiting factors become an issue
The population drops below the carrying capacity
The population will then __ below the
carrying capacity (Fluctuates)

Figure 4.4
Reproductive Patterns

Life-history pattern – __

1. Rapid life-history patterns




Common among organisms from __ environments
Characteristics: __ body, mature __, reproduce
early, __ life span
Populations increase __, then decline when
environmental conditions become unsuitable, then
rapidly increase again
Ex) mosquitoes, wild mustard plants
Reproductive Patterns (cont.)

2. Slow life- history patterns




Organisms live in more __ environments
Characteristics: __ species, reproduce and mature __,
and are __-lived
They __ population sizes at or near carrying capacity
Ex) Elephants, bears, whales, humans, trees
Reproductive Patterns (cont.)

3. Density factors – how organisms are __;
random (dandelions), clumped (mushrooms), and
uniform (evergreens) *is a __

a) Density-dependent factors – these factors have an
increasing effect as the __ increases



Includes disease, competition, predators, parasites, and food
Ex) corn crop, HIV/AIDS
b) Density-independent factors – affect populations,
regardless of their __ (usually __ factors)


Includes temp., pesticides, floods, drought, volcanoes, etc…
Ex) insects, earthworms
Predation and Population Size



Populations of predators and their prey
experience changes in their numbers over
periods of time
Is usually a predictable cycle
Ex) Canadian lynx and the Snowshoe hare


The two populations rise and fall close to a 10 year
cycle
In prey populations the young, old, or injured
members are caught.
Effects of crowding and stress

When populations become crowded
(overpopulated):


1. Environments cannot support increased
numbers
2. Animals exhibit various stress symptoms





a. aggression
b. decrease in parental care
c. decreased fertility
d. Resistance to disease
Can have a negative effect on a population
Human Population



Census taken every 10 years
Demography – study of human population size,
density and distribution movement, and its birth and
death rates
History:





Before 1800’s – growth was slow (1st billion reached in
1800
Since 1930 – population grew rapidly
1999 – reached 6 billion
2002 – population growing at a rate of 1.3 million people
per year
Estimate by 2050 – more than 9 billion people on Earth
Human Population (cont.)

Human population is different than other organisms
because humans can consciously change their
environment





Ex) Eliminated diseases like small pox
Ex) Developed methods for producing more food
Ex) Infant mortality rate has decreased
Ex) Improved the delivery of clean water
Results in people living longer and able to produce
offspring that live to produce offspring
Calculating Growth Rate

Four factors:





A. __
B. __
C. __
D. __
Formula:

(Birthrate +Immigration rate) – (Death rate +
Emigration rate) = Population Growth Rate (__)
Growth Rate (cont.)

Doubling time – the time needed for a __ to
double in size



Developed country – has a __ growth rate
Developing country – has a __ doubling time
__ – the proportions of the population that are
in different age levels


Rapidly growing countries have age structures
with a __ base (many children and teenagers)
Stable populations occur when the % of people in
each age category is fairly __
Natural Resources

Those parts of the environment that are useful
or necessary for __

Can be classified into two types:


A) __
B) __
Renewable Resources



Those resources that can be __ when they are
used
Examples: __, __, wildlife and fish, forests,
and air
A renewable resource is not necessarily __

Ex) Fresh water can become limited by drought
or overuse
Nonrenewable Resources



Resources that __ be replenished by natural
processes
Sometimes called “__” resources
Examples: coal, __, natural gas, and minerals
like iron, zinc, copper and lead

__ formed millions of years ago from deeply
buried organic materials. When they are depleted
they are gone forever
Sustainable Use



Is a way of using natural resources at a rate
that __
__ activities affect the supply and the quality
of renewable resources
These principles are applied to agriculture,
fisheries, land development etc…

Ex) Use of __ instead of pesticides
Pollution




The result of substances that __(becomes
unclean usually by contamination of manmade waste)
Air, water, soil, are damaged by pollution
Pollutants (materials that pollute) can be
serious such as __, __ released by nuclear
accidents, __, and __
Habitat Degradation – damage to a habitat by
__

Three types: water, land and air
Water Pollution


Degrades aquatic __ in streams, rivers, lakes and
oceans
Ex) Excess __ and animal __ are often carried by
rain into streams and lakes



These sudden nutrients cause __ blooms. When they die,
they sink and decay, removing needed __ from the water
Ex) __ form eroded soils can enter water and clog
the gills of fish
Ex) Detergents, heavy metals, industrial chemicals
in runoff cause death in aquatic organisms
Land Pollution





__: made up of cans, bottles, paper, plastic,
metals, dirt, and spoiled food that people
throw away each day
Average American produces about __ kg of
daily (657 kg of waste/person /year)
Some decomposes __
Most becomes buried in __ (meant to reduce
contamination of groundwater supplies)
Use of pesticides and other chemical can lead
to habitat degradation
Air Pollution


Causes __ problems and irritates membranes
in the eye and nose
Sources: Volcanic eruptions, forest fires,
burning of __


Ex) sulfur dioxide – from __ burning factories
and nitrogen oxide from __ exhaust combine to
form acid precipitation. This take __ from the soil
__ waves from the Sun can cause damage to
living organisms
Methods Used to Reduce Pollution

1. __ – large earthen pit for waste disposal



Either have a high __ content to keep wastes from
seeping into underground water or have large __ liners
About __ of waste in US is disposed of in landfills
2. __ – Act of recovering and reusing
materials


Ex) paper, aluminum, tin cans, glass, motor oil, auto
batteries, auto tires, old cars
Just about anything can be recycled some way
Methods (cont.)

3. __

Laws impose strict standards for what can be
released into the environment



Ex) __ required to have a catalytic converter
Ex) __ (1990) Requires power plants to install
scrubbers on all their smokestacks
4. International agreement to stop __
(chlorofluorocarbons) production


Used as __ in refrigerators and air conditioners,
as aerosol propellants etc…
Primary cause of __ hole
Methods (cont.)

5. Incinerating – __




They are equipped to prevent releasing harmful
__ into the air
Pollution control devices catch __ materials
Without this, smoke containing __ are released
into the air. They then settle to the earth and harm
plants, animal, and structure (paint on buildings)
Only __ of waste in the U.S. are incinerated