UNIT 2--F98: ECOLOGY
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ALPINE TUNDRA
CHAPTERS 46-50 IN TEXT
READ CHAPTERS 48, 49 FIRST
CHAPTERS 46, 47, 50
FOLLOW HAND-OUT NOTES
ALPINE BOREAL FOREST--CLINGMANS DOME
• WHAT IS IT???
• DEFINE DISCIPLINE
• INTERRELATIONSHIPS OF
“OLOGIES”
HISTORICAL PERSPECTIVE
• ARISTOTLE--4 th CENT B.C.
– ATTEMPTS TO EXPLAIN PLAGUES OF MICE &
LOCUSTS
– CYCLES OF POPULATIONS HIGH/LOWS TIED TO
WEATHER CONDITIONS
• NATURAL HISTORY APPROACH
– VARIOUS WORKERS: 17-1800’s TO PRESENT
ECOLOGY
• SCIENCE WHICH FORMULATES
AND TESTS HYPOTHESES ABOUT
ENVIRONMENTS
• NOT SYNONYMOUS WITH
ENVIRONMENTAL CONCERNS, I.E.,
CONSERVATION
– EARTH DAY--APRIL 22, 1970
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ECOLOGY: THE STUDY OF
RELATIONSHIPS
• ERNST HAECKEL--1870 (1866)
• THOREAU (1858)-USED WORDS IN
VARIOUS LETTERS, NOT
DEFINITION
• OTHER PUBLICAITONS RE: ISSUES
IN 1600’s, 1700’s
CHAS. KREBS
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THE SCIENTIFIC STUDY OF THE…
…ABUNDANCE
…DISTRIBUTION
…OF ORGANISMS
LEAVES OUT RELATIONSHIPS--…INTERACTIONS THAT DETERMINE
THE DIST/ABUND OF ORGANISMS
BASIC APPROACHES TO
ECOLOGICAL STUDY
• DESCRIPTIVE
– NATURAL HISTORY APPROACH
• FUNCTIONAL
– RELATIONSHIPS, IDENTIFICATION & ANALYSIS
OF PROBLEMS COMMON TO ALL AREAS
• POPULATION & COMMUNITY STUDY
– EVALUATE CAUSE/EFFECT RESPONSES OF
POPULATIONS/COMMUNITIES TO
ENVIRONMENTAL CHANGE
– ALLOWS US TO ASK--HOW DOES THE SYSTEM
OPERATE???
ECOLOGY: DEFINITION
• THE STUDY OF RELATIONSHIPS
OF ORGANISMS...
• ...TO THEIR ENVIRONMENT
• ODUM:
– THE STUDY OF THE STRUCTURE
AND FUNCTION OF NATURE
– THE SCIENCE OF THE LIVING
ENVIRONMENT
REAL ISSUES IN NATURE
• WHERE ARE THE
ORGANISMS???
• HOW MANY ARE THERE??
• WHY???
• WHAT ARE THE FACTORS
THAT AFFECT
DISTRIBUTION???
BASIC APPROACHES (CONT’D)
• EVOLUTIONARY
• ORGANSISMS ARE HISTORICAL PRODUCT
OF EVOLUTIONARY PORCESS &
INTERACTION
• ALLOWS FOR STUDY OF ULTIMATE CAUSES
– WHY NAT. SELECTION FAVORS A PARTICULAR
ADAPTATION
– WHY DOES NAT. SEL. FAVOR A PARTICULAR
ECOLOGICAL SOLUTION??
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PORTION OF
EARTH’S
SURFACE AND
ATMOSPHERE
WHICH CONTAIN
LIVING SYSTEMS
LIKENED TO
THE “SKIN”OF AN
APPLE TO TOTAL
VOLUME OF
EARTH
BIOLOGICAL HIERARCHY
• ECOLOGY PRIMARILY CONCRNED
WITH 3-4 LEVELS
• ECOSYSTEM
• COMMUNITY
• POPULATION
• GOOD ECOLOGISTS HAVE
FOUNDATIONAL
UNDERSTANDING OF ALL LEVELS
BIOLOGICAL HIERARCHY
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BIOSPHERE…
ECOSYSTEM
COMMUNITY
POPULATION
INDIVIDUAL….
ATOM
CONCEPT OF ECOSYSTEM
• AN AREA IN NATURE…
• ...WHERE THERE IS INTERACTION...
• ...AND EXCHANGE OF MATERIALS
– ENERGY & NUTRIENTS
• …BETWEEN BIOTIC (LIVING) AND
ABIOTIC (NON-LIVING) COMPONETS
ENERGY FLOW IN AN ECOSYSTEM
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ECOSYSTEMS:
STRUCTURE & FUNCTION
• EXCHANGE OF
MATERIALS
–ENERGY
–NUTRIENTS
TROPHIC STRUCTURE
• AUTOTROPHS
– PHOTOAUTOTROPHS--SUNLIGHT
ENERGY; GREEN PLANTS
– CHEMOAUTOTROPHS--CHEMICAL En;
CERTAIN BACTERIA
• HETEROTROPHS
– “ANIMALS”; GET ENERGY FROM
EXTERNAL (OTHER ORGANISM)
SOURCES
TROPHIC STRUCTURE
• AUTOTROPHS
– PRODUCERS
– PRIMARY PRODUCERS--CAPTURE ENERGY
FROM SUNLIGHT
– TRANSFORM SUNLIGHT En TO SOME OTHER
FORM OF CHEMICAL En
– USEFUL TO ORGANISMS
• SUGARS, STARCH, ATP
• HETEROTROPHS
– CONSUMERS
TROPHIC STRUCTURE
TROPHIC STRUCTURE
• HETEROTROPHS
• TERTIARY CONSUMERS
– PRIMARY CONSUMES
• HERBIVORES
• “SECONDARY PRODUCERS”
• En SOURCE: FROM PRIMARY PRODUCERS-GREEN PLANTS
– SECONDARY CONSUMERS
• CARNINVOIRS
• En SOURCE: PRIMARY CONSUMERS
– CARNIVORES
– En SOURCE: PRIMARY/SECONDARY
CARNIVORES, HERBIVORES
• DECOMPOSERS
– DETRITIVORES
– BACTERIA, FUNGI
– En SOURCE: DEAD ORGANISMS (DEAD
ORGANIC MATTER)
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TROPHIC STRUCTURE
• PRODUCERS
• CONSUMERS
• DECOMPOSERS
ENERGY FLOW
• LOWER TROPHIC LEVEL
• NEXT HIGHEST TROPHIC LEVEL
• CROSS-FEEDING BETWEEN
TROPHIC LEVELS BY CARNIVORES
• FOOD CHAIN
• FOOD WEB CONCEPT
ECOLOGICAL PYRAMIDS
• “TRIANGLE” CONCEPT
• ONE TROPHIC LEVEL, WITH GREATER
ENERGY, BELOW NEXT HIGHEST
TROPHIC LEVEL
• ENERGY PYRAMID:
– ALWAYS LARGEST AT BOTTOM
OLD FIELD FOOD WEB
ENERGY PYRAMID
ENERGY PYRMAMID
DECOMPOSERS
SECONDARY PRODUCERS
HERBIVORS
PRIMARY PRODUCERS
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ECOLOGICAL PYRAMIDS
• ENERGY
• BIOMASS
• NUMBERS
NUMBERS PYRAMIDS
• SIMILAR SHAPE TO ENERGY &
BIOMASS PYRAMIDS
• SHAPE DETERMINED BY SAME
LAWS THAT GOVERN ENERGY &
BIOMASS PYRAMIDS
• ALL BASED UPON ENERGY
TRANSFER & EFFICIENCY
BIOMASS PYRAMID
NUMBERS PYRAMID
• “TRIANGULAR SHAPE”
• LARGER BASE---WHY???
• BASED UPON LAWS OF
ENERGY TRANSFER,
UTILIZATION BY NEXT
HIGHEST TROPHIC LEVEL
BIOMASS PYRAMID
BIOMASS AND
(NUMBERS)
PYRAMID
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ENERGY TRANSFER EFFICIENCY
ENERGY BUDGET
• 10% EFFICIENT BETWEEN
TROPHIC LEVELS
• WHAT HAPPENS TO OTHER
90%???
–HOW IS IT DISPERSED
–IS IT LOST???
–ACCOUNT FOR IT
ENERGY PYRAMID
DECOMPOSERS
ENERGY FLOW:
10 % EFFICIENCY
SECONDARY PRODUCERS
HERBIVORS
PRIMARY PRODUCERS
NITROGEN CYCLE
NUTRIENT TRANSFER &
RECYCLING
• NUTRIENTS, SUCH AS NITROGEN,
PHOSPHORUS, ETC. FLOW
THROUGH ECOSYSTEM AS PART OF
BIOMASS
• FOLLOW FLOW OF ENERGY
• ARE RECYCLED (BACK INTO SOIL)
BY DECOMPOSERS
ECOSYSTEMS DYNAMICS
• ENERGY TRANSFERED BETWEEN
TROPHIC LEVELS
– 10% EFFICIENCY
– 90% DISPERSED (HEAT, DEAD ORGANIC
MATTER)
• NUTRIENTS TRANSFERED BETWEEN
TROPHIC LEVELS
– RECYCLED FROM DEAD ORGANIC
MATTER BY DECOMPOSERS
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NUTRIENT BUDGET & RECYCLING
GRAZING FOOD WEB
BIOACCUMULATION/
BIOCONCENTRATION
• ENVIRONMENTAL CONTAMINANTS
(CHEMICALS) CONCENTRATE IN
BIOLOGICAL TISSUES
– FATTY TISSUE OF ORGANISMS
• NOT BROKEN DOWN BY METABOLISM OF
ORGANISM
• TEND TO REMAIN IN BODY TISSUE FOR A
LONG TIME (BIOCONCENTRATE)
DETRITAL FOOD WEB
DDT (INSECTICIDE)
• APPLIED IN SMALL AMOUNTS TO SWAMPS FOR
CONTROL INSECTS (MOSQUITOES)
• CONCENTRATIONS OF 0.01 PPM
• ABSORBED BY GREEN ALGAE--PRIMARY
PRODUCES OF AQUATIC ECOSYSTEM
• EATEN BY “WATER BUGS”, WHO ARE FED UPON
BY SMALL FISH
• SMALL FISH EATEN BY LARGER FISH
• LARGE FISH EATEN BY MAN
• DDT BIOCONCENTRATES IN FATTY TISSUE
THROUGH OUT FOOD CHAIN
• HEALTH EFFECTS ON MAN???
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OSPREY:
POPULATIONS
HAVE SIGNIFICANTLY
INCREASED IN NUMBER
SINCE THE BANNING OF
CERTAIN PESTISIDES,
SUCH AS DDT & RELATED
CHLORINATED
HYDROCARBONS (I.E.,
PCBs)
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