ECOLOGY AND
ECOSYSTEMS
ECOLOGY
IS THE STUDY OF THE
INTERACTIONS BETWEEN
ORGANISMS AND THEIR
ENVIRONMENTS
ECOSYSTEM
• A LIMITED AREA IN WHICH LIVING
AND NONLIVING THINGS
INTERACT
• HAS 2 PARTS:
–ABIOTIC FACTORS (NONLIVING)
–BIOTIC FACTORS (LIVING)
HOW MANY ABIOTIC
(NONLIVING) COMPONENTS
CAN YOU FIND IN THE
FOLLOWING ECOSYSTEM?
MAKE A LIST ON YOUR
PAPER.
ABIOTIC FACTORS
•
•
•
•
•
LIGHT
TEMPERATURE
WATER/MOISTURE
SOIL
WIND OR CURRENT
(HOW MANY OF THESE DID YOU PICK
OUT OF THE PICTURE?)
BIOTIC FACTORS
THE BIOTIC FACTORS INCLUDE
ALL OF THE LIVING ORGANISMS
IN THE ECOSYSTEM
ALL OF THE MEMBERS OF ONE
KIND OF ORGANISM IN THE
ECOSYSTEM MAKE UP A
POPULATION
HOW MANY ABIOTIC
(NONLIVING) COMPONENTS
CAN YOU FIND IN THE
FOLLOWING ECOSYSTEM?
MAKE A LIST ON YOUR
PAPER.
• THE PRODUCERS MANUFACTURE
THEIR OWN FOOD USING A PROCESS
CALLED PHOTOSYNTHESIS. SOME
EXAMPLES OF PRODUCER
ORGANISMS ARE GREEN PLANTS AND
ALGAE.
• THE CONSUMERS CANNOT
MANUFACTURE THEIR OWN FOOD,
AND MUST OBTAIN THEIR ENERGY
FROM OTHER SOURCES.
TYPES OF CONSUMERS
• HERBIVORES ARE CONSUMERS
THAT EAT PLANT MATERIAL
• CARNIVORES ARE CONSUMERS
THAT EAT ANIMALS (MEAT
EATERS)
• OMNIVORES ARE CONSUMERS
THAT EAT BOTH PLANTS AND
ANIMALS
RELATIONSHIPS BETWEEN
ORGANISMS
1. PREDATOR-PREY: A PREDATOR IS AN
ANIMAL THAT FEEDS ON OTHER
ANIMALS. THE PREY IS THE ANIMAL
THAT THE PREDATOR EATS. THESE
RELATIONSHIPS ARE IMPORTANT
BECAUSE THEY KEEP THE
POPULATIONS IN AN ECOSYSTEM
BALANCED. AN EXAMPLE IS THE
LION AND THE ZEBRA. OTHERS:
2. PARASITE-HOST: A PARASITE, WHICH
IS USUALLY SMALLER THAN ITS
HOST, OBTAINS ITS MATERIALS AND
NUTRIENTS FROM A LARGER
ORGANISM CALLED THE HOST.
SOME PARASITES ARE VERY
SPECIFIC AND WILL ONLY LIVE WITH
ONE SPECIES OF ORGANISM.
EXAMPLES ARE FLEAS ON A DOG
AND FEATHER LICE ON BIRDS.
3. COMPETITION: THIS MAY OCCUR
BETWEEN MEMBERS OF THE SAME
POPULATION OR BETWEEN
DIFFERENT POPULATIONS. IT
HAPPENS BECAUSE THE
ORGANISMS HAVE THE SAME BASIC
REQUIREMENTS FOR SPACE, FOOD,
OR MATES. THESE ITEMS THAT
CAUSE COMPETITION WHEN THEY
ARE IN SHORT SUPPLY IN AN
ECOSYSTEM ARE CALLED LIMITING
FACTORS.
4. COMMENSALISM: A RELATONSHIP
BETWEEN 2 POPULATIONS
THATBENEFITS ONE AND DOES NOT
HELP OR HURT THE OTHER. A
EXAMPLE IS THE RELATIONSHIP
BETWEEN A LEOPARD AND CARRION
FEEDERS. IF THE LEOPARD KILLS AN
ANTELOPE AND EATS ALL IT WANTS,
SOON VULTURES, HYENAS AND
JACKALS WILL COME TO “CLEAN UP”
THE LEFTOVERS.
5. MUTUALISM:A RELATIONSHIP
BETWEEN TWO POPULATIONS THAT
IS BENEFICIAL TO BOTH. FOR
EXAMPLE, AS A HONEYBEE GATHERS
NECTAR AND POLLEN FROM A RED
CLOVER FLOWER, THE FLOWER IS
POLLINATED BY THE BEE. SINCE
BOTH THE BEE AND THE FLOWER
BENEFIT, THE RELATIONSHIP IS
MUTUALISTIC.
MANY MUTUALISMS ARE OBLIGATORY,
WHERE BOTH ORGANISMS MUST LIVE
TOGETHER OR THEY WILL DIE.
TERMITES, FOR EXAMPLE, HAVE A
TYPE OF MICROORGANISM IN THEIR
INTESTINES WHICH HELP DIGEST
WOOD. WITHOUT THE PROTOZOANS,
THE TERMITES WOULD DIE OF
STARVATION-NO MATTER HOW MUCH
WOOD THEY EAT! WHAT DO THE
MICROORGANISMS GET?
LAB ACTIVITY
SIMULATION OF
PREDATOR-PREY
INTERACTIONS IN
AN ECOSYSTEM
FOOD CHAINS
• ARE MODELS THAT SHOW HOW
MATTER AND ENERGY MOVE
THROUGH AN ECOSYSTEM
• NUTRIENTS FLOW FROM
AUTOTROPHS TO HETEROTROPHS,
AND FINALLY TO DECOMPOSERS
• EACH ORGANISM IN THE FOOD CHAIN
REPRESENTS A TROPHIC LEVEL
FOOD WEBS & ECOLOGICAL
PYRAMIDS
• FOOD WEBS REPRESENT ALL THE
POSSIBLE FEEDING RELATIONSHIPS
AT EACH TROPHIC LEVEL IN A
COMMUNITY
• ECOLOGICAL PYRAMIDS ARE
MODELS THAT SHOW THE ENERGY
CONVERSIONS IN AN ECOSYSTEM
MATTER CYCLES
• MATTER IN AN ECOSYSTEM IS
CONTINUOUSLY RECYCLED
• THERE ARE FOUR PRIMARY
MATTER CYCLES THAT WE WILL
STUDY
• WATER
• CARBON
• NITROGEN
THE WATER CYCLE
THE CARBON CYCLE
THE NITROGEN CYCLE
SUCCESSION
• IS A PREDICTABLE SERIES OF
CHANGES THAT OCCUR IN BIOTIC
COMMUNITIES AS THEY PROGRESS
TOWARD A CLIMAX COMMUNITY
• WHEN A CLIMAX COMMUNITY IS
DESTROYED (FIRE, WATER, MAN,…) IT
WILL GO THROUGH THE SERIES OF
CHANGES IN SUCCESSION
PIONEER ORGANISMS
• ARE THE 1ST ORGANISMS TO MOVE
INTO THE DESTROYED AREA
• THESE ORGANISMS ARE SMALL
• THERE ARE FEW POPULATIONS, BUT
THE POPULATIONS ARE LARGE
• THE ORGANISMS HAVE HIGH
METABOLIC RATES AND SHORT LIFE
SPANS
CLIMAX ORGANISMS
• ARE THE ORGANISMS TO MOVE INTO
THE AREA AFTER IT HAS BEEN
SETTLED BY THE PIONEERS
• THESE ORGANISMS ARE LARGE
• THERE ARE MANY SMALLER
POPULATIONS
• THE ORGANISMS HAVE LOW
METABOLIC RATES AND LONGER LIFE
SPANS