Transcript Ecology - Madison County Schools

Ecology—the study of the
interaction between organisms
and their environment
I. Feeding relationships
A.Autotrophs=producers
MAKE their own food
Ex: plants, algae, some bacteria
B.Heterotrophs=consumers
Eat other organisms; do NOT
make their own food
Types of Consumers:
1. Herbivore—only eat plants
2. Carnivore—kill and eat other
animals
3. Omnivore—eat both plants and
animals
4. Scavenger—eat dead animals
5. Decomposer—(also called saprobe/
saprophyte)—break down and absorb
nutrients from dead organisms
II. Survival relationships
A. Predation (Predator-prey)—
Predator hunts and eats prey.
B. Competition—occurs when 2
species fight for the same limited
resources
Predators
Competition
C. Symbiosis-2 species living
together; at least one
depends on the other
Types of Symbiosis:
1. Mutualism—BOTH species
benefit (mutually beneficial!)
Ex: clownfish & sea anemone
flower & bee
cattle & white birds
Mutualism
2. Commensalism—One species
benefits and the other is NOT
AFFECTED
Ex: orchid & tree
human & eyelash mites
Commensalism
3. Parasitism—One species
benefits and the other is
HARMED.
Ex: tick on a dog
mistletoe in a tree
mosquitoes on humans
Parasites
III. Matter and Energy
relationships
A. Food
Web—
expresses ALL possible
feeding relationships in
a community
Food Web example
B. Food chain— one path
in a food web
Food chain example
1. A food chain MUST start with
a producer.
2. Arrows are used to show the
direction of energy transfer.
3. A food chain does NOT
typically have more than 5
levels.
Why are food chains this short?
• Only about 10% of the energy
at each level is passed to the
next level.
C. Trophic level—represents a
feeding step in a food web
1. First trophic level—producer
2. Second—herbivore/omnivore
3. Third—carnivore/omnivore
4. Fourth—carnivore/omnivore
5. Fifth—carnivore/
omnivore/decomposer
D. Ecological or energy pyramids—
describe energy conversion in an
ecosystem
1. The SOURCE of energy for all
pyramids is the SUN.
2. The BASE of the pyramid is
PRODUCERS.
3. The TOP is the top
CARNIVORE or omnivore.
4. Biomass—the total mass
of all organisms at any one
level in the pyramid
5. Biological Magnification—
the concentration of toxic
substances increases as it moves
up the food chain
*Will be highest in top level
IV. The Organization of Life
A. Organism—3 Things that
affect organisms:
1. habitat—where it lives
2. niche—its way of life
3. trophic level—its feeding
level in the food chain
Niche
B. Population—all members of
the same species that live in a
certain area
--Animal population is also
called a breeding group.
Populations
A group of individuals
of one species usually
Aoccupying
group of
individuals
of
one
species
a defined
usually
occupying a defined area.
area.
C. Community—All
populations in a
certain area
D. Ecosystem—the biotic and
abiotic factors interacting in an
area
1. biotic—living things
2. abiotic—nonliving things
Ex: water, soil, temperature,
precipitation
Ecosystem
E. Biome—A large area
defined by the presence
of certain plants and
animals
Biomes
Permafrost
F. Biosphere—
the area on Earth where
life exists (the SURFACE)
Biosphere
V. Geochemical Cycles
Water Cycle
Nitrogen Cycle
Carbon Cycle
Carbon Cycle
Oxygen Cycle
Types of Lakes
Oligotrophic
Eutrophic
Estuary
• Place where
freshwater,
such as a
river, meets
the sea
• Ex:
bay, swamp,
marsh, bayou
VI. Homeostasis in Communities
A. Carrying capacity—the
largest number of organisms
from a species that can be
supported by the environment
Ex: There is only enough food for
a certain number of deer.
Why Hunting is Legal
B. Limiting Factor—any living or
nonliving thing that restricts the
existence, numbers,
reproduction, or distribution of
organisms
Ex: food available,
temperature
Why These Animals Live Only in
Certain Places
C. Tolerance—the ability to
withstand fluctuations
(changes) in environmental
factors
--There is a range of
conditions (temp., amt. of food,
etc.) in which organisms can
survive.
D. Succession—orderly, natural
changes that take place in a
community
*climax community—a stable,
mature community that
undergoes little to no succession
2 Types of Succession:
1. Primary—establishment &
development of an ecosystem in an area
that was previously UNINHABITED
Lichens and algae on bare rock
Succession of plant species on abandoned fields in North Carolina.
Pioneer species consist of a variety of annual plants. This successional
stage is then followed by communities of perennials and grasses, shrubs,
softwood trees and shrubs, and finally hardwood trees and shrubs. This
succession takes about 120 years to go from the pioneer stage to the
climax community. From http://www.physicalgeography.net/fundamentals/9i.html on 10-6-10
2. Secondary-REESTABLISHMENT
of a damaged ecosystem in an area
where the soil was left intact
Secondary Succession—Illustration of (1) a climax forest (2) destroyed by wildfire and (3) and
(4) its eventual recovery. Secondary succession occurs in an area where life once existed but has then
been destroyed. (Reproduced by permission of The Gale Group)