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