Ecology: Parts of an Ecosystem Population Dynamics

Ecology What is it? Study of how organisms INTERACT with living and non-living thingsStudy of how organisms INTERACT with living and non-living things

What will we be looking at? Parts of an ecosystem Parts of an ecosystem Things that affect pop’n size Things that affect pop’n size Roles and relationships in an ecosystem Roles and relationships in an ecosystem Energy flow in an ecosystem Energy flow in an ecosystem Importance of biodiversity Importance of biodiversity Succession Succession Human impacts on the environment Human impacts on the environment

What makes up an ecosystem? ECOSYSTEMS – BRAIN POP!!ECOSYSTEMS – BRAIN POP!!ECOSYSTEMS – BRAIN POP!!ECOSYSTEMS – BRAIN POP!! BIOTIC FACTORS “Bio” means living Living things in an ecosystem Can you list the living things that live in this ecosystem? Frogs, insects, fish, hawks, grasses, bacteria, amoeba etc……..

What makes up an ecosystem? ABIOTIC FACTORSABIOTIC FACTORS When you put “a” in front of a word it negates itWhen you put “a” in front of a word it negates it Means “non-living” factorsMeans “non-living” factors Can you list some non-living factors that affect the pond ecosystem?Can you list some non-living factors that affect the pond ecosystem? Water, light, temp, acidity, oxygen and nitrogen levelsWater, light, temp, acidity, oxygen and nitrogen levels

Organization of Life BIOSPHEREBIOSPHERE HABITATHABITAT ECOSYSTEMECOSYSTEM COMMUNITYCOMMUNITY POPULATIONPOPULATION Decreasing amount of biotic and abiotic factors

Population Growth Brain Pop Video

What affects pop’n sizes in an ecosystem? COMPETITION!COMPETITION! Struggle for resources among organismsStruggle for resources among organisms If no competition, pop’ns would grow INFINITELY (no limit!)If no competition, pop’ns would grow INFINITELY (no limit!) Competition maintains FINITE (limited) pop’n sizesCompetition maintains FINITE (limited) pop’n sizes Finite popn’s limited by LIMITING FACTORSFinite popn’s limited by LIMITING FACTORS CAN BE ABIOTIC OR BIOTICCAN BE ABIOTIC OR BIOTIC

Comparing Finite and Infinite Pop’ns INFINTITE GROWTH FINITE GROWTH

What affects pop’n sizes in an ecosystem? ABIOTIC LIMITING FACTORSABIOTIC LIMITING FACTORS Amount and intensity of sunlight Amount and intensity of sunlight Amount of water Amount of water Amount of dissolved oxygen (lakes, rivers, etc) Amount of dissolved oxygen (lakes, rivers, etc) Acid level Acid level Temperature range Temperature range Minerals available Minerals available

What affects pop’n sizes in an ecosystem? BIOTIC LIMITING FACTORSBIOTIC LIMITING FACTORS Predator/Prey relationshipsPredator/Prey relationships Predators limit prey pop’n sizes by eating themPredators limit prey pop’n sizes by eating them Prey limit predator pop’n sizes by dying/being killedPrey limit predator pop’n sizes by dying/being killed If too many killed, predators starveIf too many killed, predators starve Adapting (survival of fittest)Adapting (survival of fittest)

What affects pop’n sizes in an ecosystem? Effects of Predator/Prey Relationship As you can see, AS PREY POP’N DECREASES, THE PREDATOR’S POP’N DECREASES

What do we call it when a species reaches its limit? EVERY pop’n in an ecosystem has a CARRYING CAPACITY (K)EVERY pop’n in an ecosystem has a CARRYING CAPACITY (K) The # of orgs of a single species an ecosystem can supportThe # of orgs of a single species an ecosystem can support Determined by biotic and abiotic factorsDetermined by biotic and abiotic factors EX: a fox pop’n is affected by how much it has to eat (biotic) and also temperature (abiotic)EX: a fox pop’n is affected by how much it has to eat (biotic) and also temperature (abiotic) Once K is reached, pop’n will remain stable unless major changes in biotic and abiotic factorsOnce K is reached, pop’n will remain stable unless major changes in biotic and abiotic factors

Carrying Capacity (K) of a Stable Pop’n This graph shows the Carrying Capacity (K) of an organismThis graph shows the Carrying Capacity (K) of an organism THIS SHOWS A STABLE POP’NTHIS SHOWS A STABLE POP’N SLOWLY INCREASING TO K AND THEN DECREASING ONCE IT HITS K AND BACK UP AGAINSLOWLY INCREASING TO K AND THEN DECREASING ONCE IT HITS K AND BACK UP AGAIN