1. Ecology Study of how organisms INTERACT with living and non-living things in their environmentStudy of how organisms INTERACT with living and non-living things in their environment

2. Ecology: Parts of an Ecosystem Population Dynamics Day 1 of Ecology

3. 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

4. What makes up an ecosystem? 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……..

5. 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

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

7. What affects pop’n sizes in an ecosystem? COMPETITION!COMPETITION! Struggle for resources among orgsStruggle for resources among orgs 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

8. Comparing Finite and Infinite Pop’ns INFINITE GROWTH FINITE GROWTH

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

10. 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 byPrey limit predator pop’n sizes by If too many killed, predators starveIf too many killed, predators starve Adapting (survival of fittest)Adapting (survival of fittest)

11. 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

12. 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 CC is reached, pop’n will remain stable unless major changes in biotic and abiotic factorsOnce CC is reached, pop’n will remain stable unless major changes in biotic and abiotic factors

13. 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