Environmental ScienceEnvironmental ScienceLiving Things in Living Things in

EcosystemsEcosystems

Chapter 2Chapter 2

Notes #2Notes #2

LaVigne

How species interact with each How species interact with each other other

►5 Major Interactions Among Biotic 5 Major Interactions Among Biotic Factors in an EcosystemFactors in an Ecosystem PredationPredation CompetitionCompetition ParasitismParasitism MutualismMutualism CommensalismCommensalism

How species interact with each How species interact with each other other

► PredationPredation► On organism kills& eats On organism kills& eats

another organismanother organism► Predator – the killer/eaterPredator – the killer/eater► Feed on the young & weak Feed on the young & weak ► Limits the size of prey Limits the size of prey

populationspopulations► Prey – gets eaten/killedPrey – gets eaten/killed► Prey declines the Prey declines the

predators must find other predators must find other preyprey

How species interact with each How species interact with each otherother

Predation Examples

How species interact with each How species interact with each other other

► CompetitionCompetition► 2 or more organisms 2 or more organisms

of the same or of the same or different species different species attempt to use the attempt to use the same limited same limited resourcesresources

► can occur evenly if can occur evenly if there’s no contact there’s no contact (indirect)(indirect)

► ex-2 insects, same ex-2 insects, same plant, one feeds plant, one feeds during the day, one during the day, one at nightat night

How species interact with each How species interact with each other other

► ParasitismParasitism► parasite- organisms that parasite- organisms that

live in or on another live in or on another organism & feed on it organism & feed on it w/o immediately killing w/o immediately killing itit

► host- organism the host- organism the parasite takes parasite takes nourishment from nourishment from

► organisms are organisms are negatively affected by negatively affected by parasitesparasites

Mistletoe on an apple tree

How species interact with each How species interact with each otherother

Hungry Tick Full Tick

Parasitism

How species interact with each How species interact with each otherother

►MutualismMutualism► a cooperative a cooperative

partnership between partnership between two species in which two species in which both species benefitboth species benefit

► Example you & Example you & intestinal bacteria, intestinal bacteria, bacteria aids you bacteria aids you w/digestion you give w/digestion you give bacteria warm bacteria warm home/foodhome/food

How species interact with each How species interact with each other other

CommensalismCommensalism► One species benefits, One species benefits,

the other is neither the other is neither harmed nor helpedharmed nor helped

► Remora & sharks Remora & sharks attach to sharks & attach to sharks & feed on scraps from feed on scraps from their meals the their meals the sharks aren’t affectedsharks aren’t affected

► Commensalism is Commensalism is very rarevery rare

How species interact with each How species interact with each otherother

► Commensalism or Mutualism?? Commensalism or Mutualism?? The sea anemone and the clown fish….The sea anemone and the clown fish….

Scientists tend to agree that it is commensalism, there is not sufficient documented proof that the anemone benefits in any way…

Do the fish scare away other fish/predators???

Finding Nemo….do they keep the anemone clean???

AssignmentsAssignments

►Complete and Hand in the Complete and Hand in the Transparency #2 worksheet with the Transparency #2 worksheet with the Section 2.1 on the back (you received Section 2.1 on the back (you received this on Friday)this on Friday)

►Complete the 2.2 Section review WSComplete the 2.2 Section review WS