ALL LIVING THINGSNEED ENERGYIn an ecosystem, anorganism’s role depends on: How it obtains energy & How it interacts with the other living things in the ecosystemOrganism’s energy role is: Producer Consumer Decomposer
Introducing PRODUCERSIt all begins with plants thatmake their own food…..
CONSUMERS CAN BE…Herbivores eat plantsCarnivores eat animalsOmnivores eat plants and animalsScavengers eat dead animals
ECOSYSTEMS DEPEND ON THE BALANCE OF THEIR FOOD WEBSThe loss of one organism may tip thedelicate balance of survival for manyother organisms within that food web
POPULATION SURVIVAL Limiting Factors Prevent population from increasing Can happen if too many predators or not enough food -- changes in food web Carrying Capacity Largest population that environment can support Can happen from changes in food web Population graph goes up & then flattens
“Carrying Capacity” of Ecosystem (Most of one species ecosystem can hold) Rabbit Growth Curve 30 25 Population Size 20 15 Population 10 5 0 0 2 4 6 8 10 12 YearPopulation Graph goes up as species multiplies, then flattens when there is no more food to continue reproducing. Population of species can no longer grow.
Series ofPredictable Changes That Happen in aCommunity Over Time
Changes Over Time Where No Ecosystem Existed Before New Growth Begins withLichen & Mosses
Mature Bushes & Grasses & Lichen &Hardwood Small Trees Small Plants MossesTrees after after 20- after 5-15 first few150+ years 100 years years years
Changes OverTime After aDisturbanceSuch as aForest Firein anEcosystem