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Chapters 2-4 EcologyMrs. Geist
Biology, Fall 2010-2011Swansboro High School
2.2 Nutrition & Energy Flow
How do organisms obtain energy?Energy: the ability to cause change or do workObtaining Energy
Producers: make their own food. A.k.a. autotrophs.Consumers: eat other organisms. A.k.a heterotrophs.
Herbivores: eat producers, such as plants and green algae (ex: cow)
Carnivores: eat other consumers (ex: wolf) Omnivores: eat both producers and consumer (ex: humans) Scavengers: eat animals that have already died (ex: vulture) Decomposers: break down dead or decaying organisms (ex:
fungi, some bacteria)
Flow of Matter and Energy in EcosystemsFood chain: a model that scientists use to
trace the flow of energy and matter (i.e. nutrients) in an ecosystem.Ex: sun grass cows human wolf bear
vulturesEnergy source producer primary consumer secondary consumer tertiary consumer scavenger
Food web: complex model of overlapping food chains
Energy pyramid: amount of available energy decreases as you go up in trophic levels
Food Web
www.tutorvista.com
Energy Pyramid
http://www.mesa.edu.au
Water CycleEvaporation: water from lakes and oceans
becomes water vapor in the airCondensation: water vapor condenses on dust
in the air and forms cloudsPrecipitation: further condensation results in
rain, ice, or snowNatural Processes recycle water
Plants and animals need water for survival. Plants lose water through transpiration. Animals breathe out water vapor and perspire or
urinate.
Water Cycle
Carbon CyclePhotosynthesis: autotrophs utilize sun and
CO2 gas to form sugarsHeterotrophs feed directly or indirectly on
autotrophs to obtain carbon.Cellular respiration releases energy from
glucose and releases CO2 back into the air.
Carbon Cycle
EcologyEcology: the study of the relationship
between living things and their environmentHabitat: where an organism livesNiche: strategies and adaptations a species
uses in its environmentObtaining food and shelterHow and where it survivesWhere it reproducesNo two species can occupy the same niche at
the same time
2.1
SymbiosisSymbiosis: close relationship between 2
organisms. 3 types:Mutualism: both organisms benefit.Commensalism: one organism benefits; the
other is neither harmed nor helped.Parasitism: one organism benefits; the other
is harmedTest your knowledge with the “Symbiosis
Worksheet”
Levels of Organization in an EcosystemOrganism: a living thingPopulation: a group of organisms of the same
species living in the same area at the same timeCommunity: all of the populations of a different
species in the same place at the same timeEcosystem: living organisms that interact with
each other and the abiotic factors in a given areaBiotic: living things. Ex: plants and animalsAbiotic: non-living things. Ex: temperature, climate,
soil, rocks.Biosphere: the life-supporting portion of Earth
Levels of Organization in an Ecosystem
Carrying CapacityCarrying capacity: the amount of organisms
an environment can supportLimiting factors: any biotic or abiotic factor
that restricts the existence, numbers, reproduction, or distribution of organisms.Ex: elevation, temperature, climate, soil
chemistry, space, water, nutrients/food, sunlight
Tolerance: an organism’s ability to withstand fluctuations in biotic and abiotic environmental factors
SuccessionPrimary succession: occurs on an area of newly
exposed rock or sand or lava or any area that has not been occupied previously by a living (biotic) community.First species to arrive are called pioneer species.
Ex: lichens (algae and fungus living together)
Secondary succession: takes place where a community has been removedex: in a plowed field or a cleared forest
Climax community: populations of plants or animals remain stable and exist in balance with each other and their environment.Final stage of succession
Primary Succession
Secondary Succession
Factors affecting Population sizeDensity-independent factors: affect the
population in the same proportion no matter the number of individuals (population size).
Density-dependent factors: affect the population more or less depending on the population size