Transcript Lorem Ipsum - Tri-County Technical College

Ecosystem Organization
Chapters 18, 19, and 20
Bio 100
Tri-County Tech. College
Pendleton, S. C. 29670
Ecology
• The study of the interactions that living
things have with each other and with the
environment around them
• Biotic components are “living”
• Abiotic components are “nonliving”
Levels of Classification
• Ecology is studied by first looking at
populations;
–
–
–
–
Then communities
Then ecosystems
Then biomes
Then the biosphere
Hierarchy of Interactions
• Organism (adaptations that enable
individual organisms to meet challenges
posed by their abiotic environments
• Organismpopulationcommunity
ecosystem
Populations
• the smallest unit of group organization
• all the members of a single species that live
together in a specified geographic region
• Examples
– all the frogs of one species in a specific pond
– all the bacteria of one type in a test tube
– all the deer in Pickens county
Communities
• More inclusive than the population.
• All the populations of all the species living
in a single region.
• Examples
– all the deer and all the mountain lions in
Oconee County
– all the species of fish in a farm pond
The Ecosystem
• All the living and nonliving elements in a
specific geographic area
• May be large or may be small
• Example
– A farm pond ecosystem includes all the
communities of living things as well as the
rainfall, chemical nutrients, inflow and outflow
of water.
Biomes
• Very large ecosystems
• May be the size of a continent
• Some examples of biomes
–
–
–
–
tundra
temperate forest
desert
tropical rain forest
Community Interactions
• At the base of all communities are the
producers.
– green plants and other photosynthetic
organisms
• The next level up are the primary
consumers
– they feed on the producers
– also called herbivores
More Interactions
• Secondary consumers
– feed on the herbivores
– also called carnivores or omnivores
• Tertiary consumers
– feed on the secondary consumers
• One way to summarize these relationships
is the food chain.
– who eats who
Food chains
• Food chain is straight line or sequence of
who eats what
– No branching and fairly simplistic
• Seldom show the detritivores (the
decomposers; bacterial or fungal)
• Producerprimary (herbivore), secondary,
tertiary, and quaternary consumers
Food Webs
• Natural communities rarely contain well-defined
groups of primary, secondary, and tertiary
consumers. (see text)
• What actually exists is a “food web”.
– the many interconnecting food chains in an
ecosystem
– describes the actual feeding relationships within
a given community more accurately than does a
food chain
Energy Flow
• From one level to the next the energy flow
is inefficient.
• Studies have shown that energy flow
between trophic levels is approx. 10%
efficient.
• Energy pyramid
– great amount of energy at the base and steadily
decreasing amounts at higher levels
Human Eating
• Humans eat on several trophic levels.
• Possible Meal
–
–
–
–
–
Steak -Baked Potato
Tossed Salad
Bread
Iced Tea
Biomes
•
•
•
•
•
Large land areas
Similar environmental conditions
Characteristic plant communities
Light is usually not limited
Water is usually limited and unevenly
distributed
Temperate Deciduous Forest
• land based
• large trees that shed leaves in fall
(deciduous)
• considerable amount of rainfall
• worldwide distribution
• South Carolina, NC, Ga, etc
• Sometimes referred to as Temperate
Deciduous Forest
Deciduous Forest
Temperate Deciduous Forest
Grassland (prairie)
• west of temperate deciduous forest
• Eurasia, Africa, Australia, South America
• various spp. of grasses are dominant
vegetation
• not enough rainfall for tree growth
• prairie dog, pronghorn antelope, prairie
chicken, grasshopper, rattle snake
Savanna
•
•
•
•
•
similar to grassland
grasses and scattered trees
wet and dry seasons
fires during dry part of year
South America, Africa, Australia
Savanna
Savanna Locations
Desert
•
•
•
•
low and irregular rainfall
some are hot and some are cold
air cools very rapidly at night
scattered, thorny plants either w/o leaves or
with reduced leaves
• water storage in fleshy stems --- cacti
• burrowing animals, insects, and reptiles
Desert
Desert Areas
Taiga (Coniferous forest)
• Southern Canada
• dominated by evergreen trees
• long, cold winters with abundant
snowfall
• mice, bears, wolves, squirrels,
moose and flies
Taiga
Taiga Locations
Temperate Rainforest
• as opposed to tropical rainforest
• Northern California Coast, Oregon,
Washington, British Col., Southern Alaska
• 80+ inches of precipitation per year
• lush growth of plants
• Northern Spotted Owl
Tropical Rain Forest
•
•
•
•
•
near equator
Central and South America, Africa
high temperatures, rains nearly every day
thousands of plant species
tree frogs, bats, lizards, birds, monkeys,
insects
• forest floor is very dark
Tropical Rain Forest
Rainforest Locations
Chaparral
• Coastal areas with mild, rainy winters and
long, hot, dry summers
• Dense, spiny evergreen shrubs dominant
• Adapted to and dependent on periodic fire
• Southern California best example
Tundra
•
•
•
•
north of the taiga biome
extremely long, severe winters
short, cool summers
deeper soil layer is permanently frozen
– permafrost
• no trees
• very few animals
• easy to injure and slow to heal
Tundra
Tundra Locations
Community Interactions
• A community is all organisms interacting
with each other in a defined area.
• Therefore, the idea of interaction is inherent
in the concept of the community.
• Kinds of interactions-– predation, parasitism, commensalism,
mutualism, and symbiosis
Predation
• One animal, the
predator,
captures, kills,
and eats another
animal, the prey.
• Example
– hawks preying
on mice
Parasitism
• One organism, the parasite, lives on another
organism, the host, and obtains nourishment
from the host.
– the host is often damaged
• The tapeworm is a parasite
– a human is the host
Commensalism
• One organism
benefits and the other
is not affected
• Many bacteria live on
the skin and survive
on skin secretions but
the human is not
harmed
Mutualism
• two species live
with each other
and both benefit
• termites can’t
digest cellulose
• they have gut
protozoa that
digest the wood
Symbiosis
• general term for
“living together”
• parasitism,
commensalism,
and mutualism
can be thought of
as types of
symbiosis