Download Ecosystem - McArthur Media

The Nature of Ecology
How to make a food web.
1. Start with one producer on BOTTOM and draw arrows up
to the things that eat them (their predators). (** Hint: a
producer is something that photosynthesizes, it gets its
energy from the sun.)
2. Fill in all the predators that eat that producer (these are
primary consumers).
3. If there are other things those predators eat fill in those
organisms (one at a time). These are other producers, other
primary consumers or even sometimes secondary consumers.
Eagle
tertiary
consumer
Snake
Hawk secondary
consumer
4. Continue filling in each organism’s predators and prey placed
at the correct trophic level (with arrows going from prey to
predator).
Rabbit
5. Primary consumers eat producers. Secondary consumers eat
primary consumers. Tertiary consumers eat secondary
consumers. (some organisms will be at more than one level). If
the hawk ate grass and rabbits, it would be both a primary and
a secondary consumer and have arrows from both rabbit and
grass.
grass
primary
consumer
producer
The Nature of Ecology

Ecology- the study of how organisms interact with
their environment

Organisms- any life form

Species- groups of organisms that share similar DNA;
look similar, have similar behavior, can produce viable
offspring.
Populations

Population- all of the
organisms within a
species that interact in a
specific area and at a
specific time
Communities, Ecosystems & The Biosphere

Habitat- the place where a population or organism lives

Community- all of the organisms that occupy a specific area;
also called biological community

Ecosystem- a community of different species and their
interaction with each other and abiotic factors in environment
Ecosystem Concepts and Components
Fig. 4-9 p. 70

Biomes-areas
with a consistent
climate and with
similar
organisms

Aquatic life
zones- marine
and freshwater
portions of the
biosphere
Community Structure and Species Diversity
Fig. 8-2 p. 144
Biodiversity dependent on latitude
Fig. 8-3 p. 145
Fig. 8-2 p. 144
Ecosystem Boundaries: Ecotones

Ecotonetransitional
zones between
ecosystems
where there are
a mixture of
species not
found together
in adjacent
ecosystems
Fig. 4-10 p. 71
Principles of Ecological Factors

Abiotic Factors- all of the nonliving parts in an ecosystem

Biotic Factors-all of the living factors in an ecosystem

Range of Tolerance- any variation in the physical or chemical
environment that an organism can withstand before it is killed/harmed
Regulating Population Growth

Limiting Factors- a distinguishing chemical or
physical factor that regulates the population
growth of a species; more specific than any
other factor

Niche- an organisms functional role within an
ecosystem; everything that affects the survival
and reproduction
Abiotic Factors That Impact Populations
Aquatic Life Zones
Terrestrial Ecosystems
• Sunlight
• Temperature
• Precipitation
• Wind
• Latitude
• Altitude
• Fire frequency
• Soil
Light penetration
• Water currents
• Dissolved nutrient
concentrations
(especially N and P)
• Suspended solids
• Salinity
Figure 4-13 Page
•
73
The Biotic Components of Ecosystems
Producers
(autotrophs)
Consumers
(heterotrophs)
Decomposers
Fig. 4-16 p. 75
Food Chains
Fig. 4-18 p. 77; Refer to Fig. 4-19 p. 78
Food Webs
• Only 10% of
the energy
producers make
gets transferred
to the primary
consumer.
• The secondary
consumer only
gets 1%.
• The tertiary
level gets 0.1%.
Native Species
Species naturally evolved to live in the
area. Ex. douglas fir, western red
cedar, milkvetch, black squirrel
Native (indigenous) - naturally
evolved to live in the area Western Red
Cedar, Douglas Fir, Milkvetch, black squirrel
Non-native (invasive species)
Species introduced by
humans, by mistake or
intentionally. Also
called exotic species.
Kudzu - aka: foot a night vine, mile a
minute vine, or the vine that ate the
south!
Ironically introduced for soil conservation
purposes!
$500 million per year in lost crops and control
costs
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Special Roles of Some Species
Removal of keystone species will cause
collapse of ecosystem
Special Roles of Some Species
Keystone Species
Pollinators
Top Predators
Special Role of Some Species
Indicator species - ecosystem smoke alarms - abundance of
population indicator of overall health and viability of
ecosystem
Species Interactions: Competition
Interspecific competitioncompetition between two
or more species
As a result of competition,
the two species evolve to
gain separate, more
specialized niches (coevolution)
Species Interactions
Mutualism - benefits both species
Ex. pollination
Commensalism - benefits one species,
but has little effect on the other
Ex. Fern living in the shade of a tree
Species Interactions: Parasitism
Parasite - living on or in another
species (host)
Important ecological role of parasitesincrease biodiversity by keeping species that
may eliminate other species in check