chapter2.ppt

Chapter 2

Chapter 2

Fundamentals of Ecology Fundamentals of Ecology

Karleskint

Karleskint

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Small

Turner

Key Concepts

• Ecology is the study of relationships among

organisms and the interactions of organisms

with their environment.

• An organism’s environment consists of

biotic

(biological interactions)

and

abiotic

(non-living, physical)

factors.

Key Concepts

• All organisms expend energy to maintain

homeostasis, i.e., internal balance relative to

external changes.

• Physical factors of the environment, such as sunlight, temperature, salinity, exposure, and pressure, will determine where organisms can live.

• Species interactions that influence the

distribution of organisms in the marine

Key Concepts

• Marine ecosystems consist of interacting

communities and their physical

environments.

• Most

populations

initially grow at an

exponential rate, but as they approach the

carrying capacity of the environment, the

growth rate levels off.

• Energy in ecosystems flows from

Key Concepts

• The average amount of energy passed

from one

trophic level

to the next is

approximately 10%, limiting the number

and biomass of organisms at different

trophic levels.

• 10% rule

Vocab

• Biotic = alive

• Abiotic = not alive

• Habitat = anywhere a species can live • Niche = where a species actually lives

• Species = organisms that are so genetically similar, they can produce fertile offspring

• Population = group of a species that live in the same place at the same time (unit that

More vocab

• Homeostasis = maintaining a constant condition • Osmosis = movement of water across a

differentially permeable (semipermeable)

membrane from an area of low salt to an area of high salt concentration

– Salts sucks water

• Carrying capacity (K) = the maximum number of a species that an ecosystem can support

Study of Ecology

• Ecology

– from the Greek word oikos meaning “home”

• Environment

– biotic factors – abiotic factors

• Habitat: where an organisms lives

• Ecosystems

Study of Ecology

• The study of organisms interacting with

one another and their environment. This

entails:

– biological (biotic) factors

– environmental (abiotic) factors – the organism’s behavior

Species B Species A Larger Food size S al in it y Size of s

edim ent parti cles Coar ser H ig h er Zone of overlap _Niche Niche 0 Stepped Art

Homeostasis and Distribution

of Marine Organisms

• Maintaining homeostasis

– changes in external environment

– internal adjustments to maintain a stable internal environment

• optimal range

Characteristics of the Physical Environment

that Affect Organism Distribution

• Sunlight

– photosynthesis – vision

– desiccation • Temperature

• Salinity

–solutes –osmosis

–solutes in the body fluids of organisms –tolerance for variation ion environmental

salinity

–regulation of solutes in body fluids

No net water movement

(c) Hypotonic solution (b) Hypertonic solution

(a) Isotonic solution

Net water movement into the cell

Net water movement out of the cell

Inside the cell Outside the cell Cell membrane Outside the cell Inside the cell Cell membrane Outside the cell Inside the cell Cell membrane Stepped Art

• Pressure

–760 mm Hg or 1 atmosphere at sea level

–increases 1 atmosphere for every 10 meters below sea level

–This is why things exploded when they dredged them up!

Characteristics of the Physical

Environment that Affect Organism

• Metabolic requirements

–nutrients and limiting nutrients

–oxygen as a requirement for metabolism –anaerobic and aerobic organisms

–eutrophication and algal bloom

• Metabolic wastes

–carbon dioxide is a common byproduct of metabolism

– Eutrophication

Characteristics of the Physical

Environment that Affect Organism

• A group of the same species that

occupies a specified area at the same

time.

• Species: a group of organisms so genetically similar they can make fertile babies

• Geographic range

• Population size

• Population density (abundance)

• Dispersion

– Clumped

• Usually organisms that sexually reproduce – Uniform

• Often organisms that have territories – Random

• Neither of the above

• Can occur through:

– reproduction – immigration – death

– emigration

• Can be affected by:

– survivorship – life history

– opportunistic and equilibrium species

• Many ways a population can increase in

size, depending on the carrying capacity of

the environment

– exponential/logarithmic growth – logistic growth

• Carrying capacity

= the maximum number of

individuals of a species that an environment

can support

– Reached when a resource is limited.

• Density Dependent Factors

– have greater effect as population increases in size

– They’re resources (you can run out!)

• Density Independent Factors

– not related to population size

– Natural disasters

• kill regardless of population

• Composed of populations of different

species that occupy one habitat at the

same time

• Niche: what an organism does in its

environment

– fundamental niche – realized niche

Communities

• Biological environment

– competition

• may be interspecific or intraspecific • may result in competitive exclusion

• resource partitioning allows organisms to share a resource

– predator-prey relationships

Communities

• Symbiosis

: living together

– mutualism – both organisms benefit

– commensalism – one organism benefits, the

other is nether harmed nor benefited

– parasitism – one organism benefits, the other

Mutualism

Commensalism

Parasitism

Acacia Plant & Ants

acacia tree so they get a nice safe place for their eggs. The acacia

covers the infected area with brown flesh

(called a gall.) The plant has to use valuable resources to

create the gall.

What symbiotic relationship is this?

Anemone & Anemone Fish

mutualism

This fish lives its entire adult life among the tentacles of a bulb- tentacle sea anemone. Anemone

fish do not get stung by the

anemone as would most other fish so they get protection from

predators. The fish often drop

food scraps which the anemones

can eat.

Boxer Crab & Anemones

This Boxer Crab carries a pair of stinging anemones in its claws, which it uses

to defend itself from predators. The anemones get to move around which

increases their food supply.

mutualism

The remora attaches itself to the shark and saves energy since it doesn’t have to swim, and it gets to

snack on the sharks kills. The shark doesn’t get

anything.

Shark & Remora

commensalism

This tiny emperor shrimp is riding along on the back of a sea cucumber (a long worm-like starfish relative) while it crawls along a sandy bottom.

The shrimp gets to travel around under the protection of

its much larger partner, and the sea cucumber doesn't

seem to mind.

Emperor Shrimp & Sea Cucumber

commensalism

Moray Eel & Cleaner Fish

This moray eel has a small fish cleaning between its teeth. The eel gets a clean mouth while the

cleaner fish gets a nice meal.

What symbiotic relationship is this?

Cattle & Cattle Egrets

As these cattle walk around eating grass they

stir up lots of insects. The egrets hang around and get a yummy meal of

insects.

What symbiotic relationship is this?

Antelope & Ox Bird

This ox bird hangs out on the antelope and gets

a delicious meal of bugs living on the antelope. The antelope gets rid

of parasites.

What symbiotic

Loa Loa Worm & Human

This worm infects human blood stream and gets a

nice warm safe home there. The

human may go blind or have other

complications as a result.

What symbiotic

Goby and Alpheid Shrimp

What symbiotic relationship is this?

mutualism

This alpheid shrimp (on the right) uses its strong claws like a bulldozer to

create a burrow in the sand. The shrimp is nearly

blind. It relies upon its partner, the sharp-eyed goby, to warn of danger. When a potential predator

approaches, both animals disappear quickly into the

Wrasse & Batfish

Can you see the two cleaner wrasses are removing parasites from

a batfish? One of the wrasses has entered the gill slit of the batfish, and

may even enter its

mouth in search of food. The batfish gets a bath

and the wrasse gets a meal.

What symbiotic

Hummingbird Moth & Flower

This hummingbird moth is drinking the nectar of a flower. The flower gets pollinated (the moth brings

pollen from other flowers) and the moth gets a tasty

meal.

What symbiotic relationship is this?

Ecosystems: Basic Units of the Biosphere

• Energy flow through ecosystems

• Producers = Autotrophs

(auto = self, troph = grow)

Sunlight

Chlorophyll

6 Oxygen (O₂) +

Glucose (C₆H₁₂O₆) Produces

6 Water (H₂O) +

6 Carbon dioxide

(CO₂)

Stepped Art

Ecosystems: Basic Units of the Biosphere

• Measuring primary productivity

– rate at which energy-rich food molecules are being produced from inorganic matter

– measuring carbon in organic products of photosynthesis

• light-dark-bottle method • radioactive tracers

Ecosystems: Basic Units of the Biosphere

• Consumers = Heterotrophs (hetero = other, troph = grow)

– first-order consumers

– second- and third-order consumers – detrivores

– decomposers

• Food chains and food webs • Other energy pathways

Seaweed (producer) Sea urchin (first-order consumer, herbivore) Helmet snail (second-order consumer, carnivore) Fish (third-order consumer, carnivore) Stepped Art

Ecosystems: Basic Units of the Biosphere

• Trophic levels

– number of levels is limited because only a fraction of the energy at one level passes to the next level

– ecological efficiency • ten percent rule

– trophic pyramids

Biogeochemical Cycles

• Hydrologic cycle

– water is lost through evaporation

– carried north and south from equator

Ocean

Lakes Soil mois ture Land Precipitation Moist air Precipitation Sea spray

Salt _Runoff

Groundwater

Soak in and percolation Seepage Seepage

Evaporation from

rivers, soils, vegetation, lakes, falling precipitation

Evaporation from ocean

Stepped Art

Water Cycle

The Sun

Lake Fresh water Oceans

Salt water Run-off

Evaporation/ Transpiration

l  g (invisible)

Condensation

g  l

Precipitation (rain)

Biogeochemical Cycles

• Carbon cycle

– carbon released from organisms through respiration and decomposition

– recycled by photosynthetic producers

– carbon is used in shells, corals and skeletons as part of calcium carbonate

CO₂ in the atmosphere Plant residues Peat coal Limestone Decomposers Sediments Shells

CO₂ in atmosphere to plants for photosynthesis

Precipitation

Limestone CO2 is

taken up by phytoplankton for photosynthesis Dissolved CO₂ Respiration Dissolved CO₂ forms

HCO₃–

Decomposition

Stepped Art

Atmospheric Carbon

CO_{2 (g)}

The Sun

Carbon Cycle

Plants (producers) Photosynthesis

CO_{2 (g)}  CH₂O form

Primary Consumer

Detritivores

Respiration

CH₂O form  CO_{2 (g) CH form} Combustion_{ CO}

2 (g)

Biogeochemical Cycles

• Nitrogen cycle

– producers use nitrogen to synthesize protein forming amino acids

– bacteria recycle nitrogen from wastes and decomposing, dead organisms

Ground

Legume Plants

Nitrogen fixation N_{2 (g)}  NH_{3 (l)} legumes NO₂ or NO₃

Ammonification NH₃  NH₄+

Nitrification

NH4+  NO2 or NO3

Animals

Atmospheric Nitrogen N_{2 (g)}

Denitrification NO _form  N_{2 (g)}

Plants

Biosphere

• Includes all of earth’s communities and

ecosystems

• Examples of ecosystems:

– estuaries

– salt marshes

– mangrove swamps

– rocky and sandy shores – kelp forests

Distribution of Marine Communities

• Pelagic division

– neritic zone and pelagic zone

– photic zone, disphotic zone, and aphotic zone – plankton and nekton

• Benthic division

– shelf zone, bathyal zone, abyssal zone, and hadal zone