Ecosystem Final Project
Matter and Energy in Organisms and
Ecosystems
The study of interactions among organisms and between
organisms and their environment, or surroundings
ECOLOGY
Species Populations Communities Ecosystem Biome
LEVELS OF ORGANIZATION
A group of organisms so similar to one another that they can breed
and produce fertile offspring
SPECIES
Groups of individuals that belong to the same species and live in
the same area
POPULATIONS
One Hungry Planet
THE JOB OR ROLE OF THE ORGANISM
• the type of food an organism eats
•the organism’s type of shelter
• the predators that eat it
•the time of day it is active
NICHES
A collection of all the organisms that live in a particular place,
together with their non-living, or physical environment.
ECOSYSTEM
Food Webs and Trophic Levels
Energy Transfer in Food Webs
About 10 percent of net energy production at
one trophic level is passed on to the next level.
Processes that reduce the energy transferred:
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Respiration
Growth and reproduction
Defecation
Non-predatory death
Nutritional quality
Producers
plants and other organisms capable of
carrying out photosynthesis.
Decomposers
organisms that convert dead matter into
gases such as carbon and nitrogen to be
released back into the air, soil or water
primarily bacteria and fungi
necessary for recycling nutrients to be used
again by producers
Consumers
organisms that eat something else
Primary Consumers: eat producers
Herbivores
Secondary Consumers: eat primary
consumers
Omnivores and Carnivores
Tertiary Consumers: eat secondary
consumers
Energy is “lost” of becomes “disorganized” as it is transferred to
heat.
ENTROPY
diagram which completely illustrates the transfer of chemical energy
within and ecosystem
FOOD WEB
Ecosystem models typically simplify the systems they are studying
to a limited number of components that are well understood, and
deemed relevant to the problem that the model is intended to
solve.
ECOLOGICAL MODELS
A sample of the population is taken, the animals are marked, released, and a second sample is
taken. After their initial release a proportion of the population will be marked. The proportion of
marked animals in the second sample should reflect the proportion of animals marked in the
entire population. For example, suppose that 10 animals were marked and released in the first
sample. If 50% of the animals in the second sample are marked, then you can assume that 50%
of the animals in the population are marked. The 10 animals in the first sample therefore
represent approximately 50% of the population, so the population = 20.
MARK & RECAPTURE
You could count every individual organism in an ecosystem, but you could imagine
how long this would take for small plants in a large area - just imagine trying to
count all of the individual blades of grass in a football field! When conducting
ecology research, scientists often select several smaller sample plots inside a larger
study area. The scientists thoroughly study the smaller areas, and use information
from these plots to make generalizations about the larger study area.
PLOTTING
Human population density vs global vegetation patterns
Carrying Capacity – Maximum population size an environment can
sustain.
Population Density =
People per km2
PLANTS AND PEOPLE
TYPES OF POPULATION
CURVES
Increasing the same amount at regular intervals
LINEAR CURVE
The number of intervals added to the population gets larger during each
time interval
EXPONENTIAL CURVE
When a species is introduced there is rapid growth due to ample
resources and few predators. Eventually the growth levels off when
the population reaches the carrying capacity.
S CURVE
Types of population curves
S- Curve
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When a species is
introduced there is rapid
growth due to ample
resources and few
predators
Eventually the growth
levels off when the
population reaches the
carrying capacity