Ecology

Ecology

• Study of the relationships between the living (biotic factors plants, animals, predators, microbes, etc) and the non-living (abiotic factors soil, temperature, pH, light, rainfall, wind, etc) that occur w/in a specific habitat

Ecosystem

• All the living and non-living factors that interact in some way w/in a well-defined area at a specific timeEx: desert, pond, grassland, forest, tundra

WHAT AFFECTS THE DISTRIBUTION OF THE TERRESTRIAL BIOMES? CLIMATE, ELEVATION, RAINFALL, DISTANCE FROM

EQUATOR – ALL OF THE THINGS THAT AFFECT CLIMATE!

Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2

Abiotic and Biotic Factors

BIOTIC & ABIOTIC FACTORS

Ecological Niche• The role or function of an organism w/in a given ecosystem

– Food chain path of energy through trophic levels of an ecosystem

– Food web complicated, interconnected path of energy (food chain)

FOOD WEB

Cont. Ecological Niche

1. Producers (Autotrophs)• Include plants, algae, and some kinds of bacteria• Carries out photosynthesis process that

synthesizes glucose (sugar) from CO2 and H2O in the presence of light

• Autotrophic cells produce ALL the food available to the ecosystem

light

6 CO2 + 6 H2O ------------------------ C6H12O6 + 6 O2

chlorophyll

Cont. Ecological Niche

2. Consumers (Heterotrophs)• Organisms which utilize nutrients synthesized by

autotrophs (dependent on producers!)Ex: birds, humans, bats, elephants, butterflies, giraffesa. Respiration– Aerobic (requires O2) breakdown of nutrients and

the production of energy (ATP) and wastes

6 O2 + C6H12O6 -------------------- ATP + 6 H2O + 6 CO2

Cont. Consumers

b. Fermentation– Anaerobic (does not require O2) breakdown of

nutrients and the production of energy and wastes

-------- ATP + 2 alcohol + 2 CO2 (yeasts)

C6H12O6 -------- ATP + 2 acetic acid + 2 CO2 (bacteria)

-------- ATP + lactic acid (bacteria)

Cont. Ecological Niche

3. Decomposers (Detritivores/ Saprophytes)• Includes bacteria and fungi• Heterotrophic organisms which break down

dead/ decayed organic matter and then recycle the nutrients (elements) back into the environment

* NOTE: Observe how the carbon is cycled between the various organisms that are carrying out theses basic life reactionsEx: how matter (non-living) is interacting w/ organisms (living things)

Pyramids of Trophic Levels

• Trophic level each step in a food chain/ “feeding” level that exists w/in an ecosystem

• 5 trophic levels typically recognized: 1. Primary producers = autotrophs/ usually photosynthetic2. Primary consumers = herbivores that consume primary producers (ex: plants and algae)

• 3. Secondary consumers = carnivores that eat herbivores 4. Tertiary consumers = carnivores that eat other carnivores 5. Decomposers = consumers that derive energy from detritus (organic wastes) and dead organisms from other trophic levels

Decomposers recycle matter

• Energy flow through an ecosystem is unidirectional (not returned to ecosystem)

Practice

Ecological Pyramid

• Ecological pyramid- diagram showing relationships between organisms making up an ecosystem

• Looks at trophic efficiency percentage of production (available energy) transferred from 1 trophic level to the next

3 Kinds of Ecological Pyramids • 1. Pyramid of Numbers

– Numbers of organisms in each trophic level

Cont. 3 Kinds of Ecological Pyramids2. Pyramid of Energy

o Measures the amount of energy available to higher trophic levels

o Greatest amount of energy is present in the “producer” level

o Only a small portion of this energy (10%) is passed on to primary consumers, and only a small portion of the energy (10%) in primary consumers is passed on to secondary consumers

o Used to show the LOSS of energy (10% LAW) at each level

o Considerable energy (in the form of heat/ 90%) is LOST to the environment at each successive feeding level

Cont. Pyramid of Energy

Producers 100%

10%

1%

.1%

.01% Respiration HeatWasteAssimilationMovement100%

SUNLIGHT

Energy lost:a. Sunlight is reflected off leaves instead of being used for

photosynthesis b. Through respiration as heat c. Excretion and defecation d. Energy used for movement and transport

Cont. Pyramid of Energy

Ex: a. Humans cellular respiration

6 O2 + glucose -------- 36 ATP (energy molecules)

(100%) --------- 55% lost as heat b. Cycles: C, O2, N2 ------- recycled through respiration and photosynthesis

Cont. Pyramids of Trophic Levels

3. Pyramid of Biomasso Total dry weight of ALL organisms

at EACH trophic levelo Low trophic efficiency a

decrease in available energy at higher feeding levels

o Therefore, less organic matter/ biomass can be supported at each higher level

a) Total mass of producers MUST be > total mass of primary consumers

b) Total mass of primary consumer MUST be > total mass of secondary consumers

Pyramid of Biomass

Ecological Pyramids

Pyramid of NumbersShows the relativenumber of individualorganisms at eachtrophic level

Biomass PyramidRepresents the amount ofliving organic matter at each trophic level/ typically, thegreatest biomass is at the base of the pyramid

Energy PyramidShows the relative amount of energy available at each trophic level/ organisms use about 10% of this energy for life processes and the rest is lost as heat

Competitive Relationship

• A change in the size of 1 population affects all other organisms w/in the ecosystem

• Predation (+/-) relationship in which 1 species kills and eats the preya. Predator animal that hunts, kills

and eats other animals for food -Need to be adapted for efficient

hunting if they are to catch enough food to survive

b. Prey organisms that predators kill for food

- Must be well adapted to escape their predators if enough of them are

to survive for the species to continue

Cont. Competitive Relationships

1. Niche how an organism lives/ how it does its jobs; affects the energy flow w/in ecosystem

2. Competition when 2 species uses the same resources/ when the resource is in limited supply

3. Character displacement response to competition; some changes may by physical or behavioral

4. Competitive exclusion species that is the better competitor may drive the other outa. No 2 species can occupy the same nicheb. Local elimination of 1 competing speciesc. Species using resource more efficiently eliminates the other

Cont. Competitive Relationships

5. Coevolution 2 species interacting w/in an ecosystem; some work in opposition to each other, others cooperate w/ each other

6. Coevelution “arms race”a. Selection pressure on each other- 1 must defend itself and the other must overcome the defenseb. Predator counter-attack measures Ex: stealth, camouflage, avoiding repellants

Bay-Breasted WarblerFeeds in the middlepart of the tree

Yellow-Rumped WarblerFeeds in the lower part of the tree andat the bases of the middle branches

Cape May WarblerFeeds at the tips of branchesnear the top of the tree

Spruce tree

Section 4-2

Figure 4-5 Three Species of Warblers and Their Niches3 SPECIES OF WARBLERS & THEIR NICHES

Camouflage/ Cryptic Coloration

Aposematic/Warning Coloration

Mimicry

Venomous Coral Snake Red Milk Snake

• The monarch (left) and viceroy (right) butterflies exhibiting Müllerian mimicry

Symbiosis

• 2 different species living together in some (unusual) way

• 3 Patterns1. Mutualism (+/+)o Both species benefit from each other

2. Commensalism (+/0)o 1 specie benefits while the other is neither helped

nor harmed3. Parasitism (+/-)o 1 specie benefits while the other is harmed o Parasite steals nourishment from host

Cont. Symbiosis

RELATIONSHIPS: WHO WINS? (+) WHO LOSES (-)

Interactions Effect on One Effect on Other

Competition

Parasitism

Predation

Mutualism

Commensalism

Neutral relationship

Guess the relationship?

Guess the relationship?Tick in a dog

Guess the relationship?Barnacles on whale

Condensation

Seepage

Runoff

Precipitation

TranspirationEvaporation

RootUptake

Section 3-3

The Water Cycle

THE WATER CYCLE

CARBON CYCLE

CO2 in Atmosphere

CO2 in Ocean

NITROGEN

• 79% OF ATMOSPHERIC GAS (N2) IS NITROGEN

• UNUSABLE AS GAS – PLANTS & ANIMALS MUST HAVE IT FOR THEIR PROTEINS

• ANIMALS EXCRETE NITROGEN COMPOUNDS AS METABOLIC WASTE (BREAKDOWN OF PROTEINS): URIC ACID, UREA, AND AMMONIA (LISTED FROM LEAST TO MOST TOXIC)

Nitrogen Cycle

Compound Converts To By (Which Bacteria)

N2 Ammonia/Protein N2 Fixing

NH3 Nitrites NO2- Nitrifying

NO2- Nitrates NO3

- Nitrifying

NO3- Nitrogen N2 Denitrifying

Nitrogen Cycle

Convert N2 to proteins in plants called legumes clover Nitrifying bacteria:

convert NH3 to nitrites & convert nitrites to nitrates

Nitrates (Usable: can be absorbed by roots)

Reduces nitrates to nitrogen, restoring N2 to atmosphere

N2 in Atmosphere

NH3

NO3-

and NO2-

PHOSPHOROUS CYCLE

WHICH THINGS CYCLE THROUGH THE BIOSPERE? WHICH ONES DO SO WITH THE ASSISTANCE OF THE

ATMOSPHERE?

WATERPHOSPHOROUS

SULFUR CARBON

NITROGENOXYGEN

PopulationGrowth

can be

represented bycharacterized by characterized by represented by

which cause a

Exponentialgrowth

Logisticgrowth

Fallinggrowth rate

S-shapedcurve

Limits ongrowth

No limits on growth

J-shapedcurve

Constantgrowth rate

Unlimitedresources

Section 5-1

Concept Map

POPULATION GROWTH

3 Factors that Affect Pop Size:

1. # of births2. #s of deaths3. #s of inds that enter or leave the pop (IMMIGRATION & EMIGRATION)

POPULATION ….• Grows when BIRTHRATE > DEATH RATE• Stays more/ less the same when BIRTHRATE = DEATH RATE• Shrinks when DEATH RATE > BIRTHRATE

EXPONENTIAL GROWTH• Occurs when inds in a pop reproduce at a constant rate

• Under ideal conditions with a UNLIMITED RESOURCE, a pop will grow exponentially

• J-shaped curve

Nu m

ber

of Y

east

Cel

l s

Time (hours)

Carrying capacity

Section 5-1

Figure 5-4 Logistic Growth of Yeast Population

LOGISTIC GROWTH• As resources become less available, growth of pop slows or stops• CARRYING CAPACITY # of inds that a given environment can support• S-shaped curve

LIMITING FACTORS (CAUSES POPULATIONS TO

DECREASE)• DENSITY-INDEPENDENT: AFFECT ALL POPULATIONS

REGARDLESS OF SIZE- UNUSUAL WEATHER, SEASONAL CYCLES, & CERTAIN HUMAN ACTIVITIES

• DENSITY-DEPENDENT: DEPENDS ON POP SIZE- (AFFECT LARGE & DENSE POPULATIONS, NOT SMALL & SCATTERED POPULATIONS)- COMPETITION, PREDATION, PREDATION, PARASITISM, & DISEASE

Growth of Aphids

Exponential growth

Steady populationsize

Peak populationsize

Rapid decline

Steady populationsize

Section 5-2

A Density-Dependent Limiting Factor A DENSITY-DEPENDENT LIMITING FACTOR

60

50

40

30

20

10

01955 1960 1965 1970 1975 1980 1985 1990 1995

2000

1600

1200

800

400

0

2400

Moose Wolves

Section 5-2

Figure 5-7 Wolf and Moose Populations on Isle RoyaleA DENSITY-DEPENDENT LIMITING

FACTOR

Agriculturebegins

Plowingand irrigation

Bubonicplague

IndustrialRevolutionbegins

Section 5-3

Human Population Growth

HUMAN GROWTH POPULATION

U.S. Population Rwandan PopulationMales MalesFemales Females

Section 5-3

Figure 5-13 Age DistributionHUMAN POPULATION GROWTH(AGE- STRUCTURE DIAGRAMS)

Protists

Insects

BacteriaFungi

Plants

Other Animals

54.4%

4.2%

18%

3.4%0.3%

19.7%

Section 6-3

Species Diversity

SPECIES DIVERSITY

Fish-Eating BirdsMagnification ofDDT Concentration

10,000,000

100,000

10,000

1,000,000

1

1000

LargeFish

Small Fish

Zooplankton

Producers

Water

Section 6-3

Figure 6-16 Biological Magnification of DDT

BIOLOGICAL MAGNIFICATION/AMPLIFICATION

•CONCENTRATIONS OF A HARMFUL SUBSTANCE INCREASE IN ORGS AT HIGHER TROPHIC LEVELS IN A FOOD CHAIN/ WEB

• TOP CARNIVORES AT HIGHEST RISK

ECOLOGICAL SUCCESIONSERIES OF PREDICTABLE CHANGES THAT OCCURS IN A COMM OVER TIME

A.PRIMARY SUCCESION- occurs on an area of newly exposed rock or sand or lava or any area that has not been occupied previously by a living (biotic) community

• Pioneer species LICHEN

B. SECONDARY SUCCESION-takes place where community has been removed ex: in a plowed field or a clear cut forest

PRIMARYSUCCESION

SECONDARYSUCCESION