Ecology Basics

Everything you should have retained from

BIOLOGY!

What is Ecology?

Eco – from the Greek word for House (oikos)ology – from the Greek work (logos) for study of

Ecology = the study of interactions between organisms & their abiotic environment, interactions among organisms

Organization of Life Scheme

Organization of Life Scheme

All living matter can be organizedSMALLEST LARGEST

atom molecule cells tissues organs systems individuals

Ecology deals with the level above the individual organismOrganism Populations CommunitiesEcosystemsBiosphere

Organism

Organism: individual living thing, able to produce offspring

Scientists study daily movements, feeding, or breeding behaviors.

Ex:

A deer

A Parasite

Population

Population: members of same species that live together in the same place at the same time

Compete for food, water, mates, and other resourcesResources determine or limit how big/small a population is

Ecologists may study effects of populations of organisms on environmentAlso study growth rates of populations and predict future populationsEx

Many deerRabbitsEndangered species

Community

Community: populations of different species that live and interact together in a defined area at the same time

Study the # of species, kinds of species, relationships with one another

Ecologists are concerned with effects on community when a new species is added or removed.

Ex: Hawks go up then mice go down

EcosystemEcosystem: community + its nonliving surroundings/environment

Both biotic and abiotic interactions

Study HOW ecosystems function as regulators of water, nutrient cycles

Ex: Rain forest

Biome

Biome: A group of ecosystems that make up a specific region for species to live

Similar climate (not weather)Temperature

Elevation

Rainfall + precipitation amounts

BiosphereThe biosphere is the highest level of organization.

Biosphere: made up of entire planet & all its living & nonliving parts

Ecologists are concerned with all interactions within the biosphere.

Biotic = living components

plants/animals, disease, interactions

Biotic factors= all living organisms found on Earth

Abiotic: nonliving components

Air currents

Temperature

Rainfall

Light Exposure

Soil

pH

Dissolved oxygen levels

Species in land zoneSpecies in aquatic zone

Species in transition zone only

Land zone Transition zone Aquatic zone

Numberof species

AdjacentEcosystemsOverlap

Notice the lack of sharp Boundaries called ecotones

How Organisms interact

Key terms- Autotroph, heterotroph, scavenger, decomposer, symbiosis,

commensalisms, mutualism, parasitism, food chain, trophic levels,

and food web

Feeding Relationships

Producer/Autotroph: make their own food, photosyntheticEx: plant, tree, fern, algaeHeterotrophs= consume nutrients

"I MUST BE A HETEROTROPH I CAN'T MAKE THESE !!"

Herbivores

Herbivores: eat plants, Vegetarian!

Squirrel, rabbit, Ms. Chris

Omnivores and Decomposers

Omnivores- energy from meat & plantsExamples=me, mouse, bacteria

Decomposers: break down/ absorb nutrients from dead organismsEx: Fungus, mushrooms

"What shall I eat today...meat or veggies....."

Carnivores and Scavengers

Carnivore= meat eatersHeterotrophs which eat other heterotrophs

Example=lion

Scavenger: gets energy from dead organism (doesn’t kill-stealer)

They play a beneficial role in ecosystem.

Clean up dead animalsExample=vulture, dung beetle, maggots

Matter & Energy in Ecosystems

2 laws govern ecosystem function

1) 1st Law of Thermo - flow of energy, cycling of nutrients

2) 2nd Law of Thermo – energy tansfers

Food Chains

Food Chain: linear model used to show energy transfer

Nutrients and energy go from

autrotroph--> heterotroph-->decomposers.

Food chains consist of 3-5 linksNever 6, b/c amount of energy left by the 5th is only a small fraction from the 1st.

Algae Fish Heron Alligator

Trophic Levels

trophic level: feeding level for each organism in a food chain, energy lost between each step

A food chain represents only one possible route for transfer of matter/energy

Many other routes exist.

Food Webs

Food Web: complex web of interconnected food chains Many plants & animals involved. A food web gives all possible feeding relationships at a trophic level in a community.

More natural then food chains… why?

Pyramids of EnergyIllustrate that energy decreases at each trophic level

The total energy transfer from one trophic level to the next is only about 10%. What happens to the other 90%?

100010010

1

Pyramid of Energy

Top Carnivores

Carnivores

Herbivores

Producers

Pyramid of Energy FlowPyramid of Energy Flow Loss in energy b/n successive trophic levels Loss in energy b/n successive trophic levels 10% gets transferred10% gets transferred

Explains…Explains… Why there are few top carnivores (eagles, hawks, Why there are few top carnivores (eagles, hawks,

tigers, white sharks)tigers, white sharks) Why such species are first to suffer when the Why such species are first to suffer when the

ecosystems that support them are disrupted ecosystems that support them are disrupted Why these species are so vulnerable to extinctionWhy these species are so vulnerable to extinction

Heat

Heat

Heat

Heat

Heat

10

100

1,000

10,000Usable energy

Available atEach tropic level(in kilocalories)

Producers(phytoplankton)

Primaryconsumers

(zooplankton)

Secondaryconsumers

(perch)

Tertiaryconsumers

(human)

Decomposers

Fig. 4.23, p. 86

Grassland(summer)

Temperate Forest(summer)

Producers

Primary consumers

Secondary consumers

Tertiary consumers

PYRAMIDS OF NUMBERS - depicts numbers of organisms in the various trophic levels for ecosystems

Abandoned Field Ocean

Tertiary consumers

Secondary consumers

Primary consumers

Producers

PYRAMID OF BIOMASS – depicts biomass of organisms in the various trophic levels for ecosystem

The size of each square represents dry weight per square meter of all organisms at that trophic level.

Primary ProductivityPrimary Productivity An ecosystem’s gross primary productivity An ecosystem’s gross primary productivity

(GPP) = Rate at which an ecosystem’s (GPP) = Rate at which an ecosystem’s producers convert solar energy into chemical producers convert solar energy into chemical energy as biomass energy as biomass

Net primary productivity (NPP) =Net primary productivity (NPP) ={Rate at which producers store chemical {Rate at which producers store chemical energy as biomass <photosynthesis>} - {Rate energy as biomass <photosynthesis>} - {Rate at which producers use chemical energy at which producers use chemical energy stored as biomass <aerobic respiration>}stored as biomass <aerobic respiration>}

Fig. 4.24, p. 87

Variation in productivity on Earth Where are the most productive regions?

High productivity – green Low productivity -- yellow

Fig. 4.36, p. 99

SolarCapital

Airresources

andpurification

Climatecontrol

Recyclingvital

chemicalsRenewable

energyresources

Nonrenewableenergy

resources

Nonrenewablemineral

resourcesPotentiallyrenewable

matterresources

Biodiversityand gene

pool

Naturalpest anddiseasecontrol

Wasteremoval and

detoxification

Soilformation

andrenewal

Waterresources

andpurification

NaturalCapital

Ecosystem Services

MEMORIZE these!

You will always be asked to relatetopics/problems

tothese issues.

Habitat and NicheEvery species has a particular function in its community called it’s niche

Niche: role a species plays in a community

space, food, weather, & any other condition an organism needs to survive & reproduce are part of it’s niche

ExFungi break down of organic matter

Coyotes keep rodents down

You keep dishes clean & drive little sis around town

You read, outline, study as a student

HabitatHabitat: the place where organism lives

Ex bird in trees

Prairie dog in grassland burrows

Your house

Several species share habitats, the food, shelter and other resources of that habitat

Community Interactions

Symbiotic relationships= “Living Together”

Competition

Interaction between organisms trying to obtain the same source

Organism A: harmed

Organism B: :-(

Ex: Dogs fight over bone

Darwin Theory of natural selection1) populations have ability to increase size

2) Resources are limited

3) Competition will arise

4) Natural Selection: the strongest (fittest) will survive

5) Survivors traits passed on to offspring

6) There will be change over time-evolution

CommensalismOne species benefits & the other is neither helped nor harmed

Org A-helped :-) B-no effect :-|

EX: Barnacles on a whale

Do not harm or help whale

• Barnacles benefit because constant moving water source

Commensalism• Ex #2: Spanish moss• flowering plant that

drapes itself on branches of trees

• Orchids can grow on the moss

• The trees are not harmed or helped but the moss and the orchids have a place to live.

Predator vs prey “Predation”• One organism hunts another for food

– Predators- hunt for food– Prey- organism that predator eats– A(predator) benefit :-), B (prey) killed :-(– Ex: Fox hunts & kills rabbit

Predator vs prey• Ex #2: Praying Mantis

• Although praying mantis generally eats insects & small tree frogs, the female will devour part of her own mate

• Commonly found in tropical and warm temperate climates, the mantis was introduced into the United States to help control certain insect populations.

Mutualism: both species benefit

• Org A :-)• Org B :-)• Ex: whale shark &

tiny fish: has small fish that live in its mouth & clean debris from teeth.

• Shark gets a free cleaning & the fish get lunch

Mutualism

• Ex #2: Hippo & little birds: little birds live on its back which eat insects off hippo, hippo does not get bitten

Mutualism

• Lichens=mixture of algae & fungus

• Algae produces food lichen requires (by photosynthesis), fungus absorbs vital nutrients & water for algae.

Parasitism• one organism benefits at expense of another

– Org A :-)– Org B :-(

• Example:Tapeworm parasitic worm that infests intestinal lining

• no mouth or digestive tract, able to absorb partially digested material through their body surface.

Parasites• Ex 2: Sheep Tick • Carnivorous, feeding

on the blood of various species of birds, reptiles, and mammals, including human beings.

Parasites• Ex #3: chigger • Chiggers are

parasitic on warm-blooded animals. As larvae they cling to vegetation & attach themselves to any animal that brushes against them.

Parasite vs Host

• Feeding: Feeds on host

• Living:Lives on body of host

• Effect: grows, but depends on host for life processes

• Feeding: Is fed on• Living: larger host=

more parasites it can support

• Effect: Host may become ill or die from parasite

Summary of symbiotic relationships

Relationship Description Harmful vs helpful

Example

Predator & prey One animal eats another

One is helped one is killed

Cat eating a mouse

Parasitism One animals feeds off another

One is helped one is drained of resources or killed

Tick living off a deer

Commensalism One species benefits from another

One is helped one is not phased

Barnacles and a whale

Mutualism Both rely on each other

Both are helped Flower and insect

How can carbon move?

#1

#2

#3

#4

HEAT

PRESSURE

#5

#6

The Adventures of Carbon!

#1

#2

#4#3

#5

#6

Carbon of Life-formulas

How do humans influence the carbon cycle? • Besides breathing, we

• Combustion of fossil fuels

• *Combustion of fossil fuels in atmosphere creates ACID RAIN.

Ecology of Populations

Terms

• Population ecology: study of how & why populations change

• Demographics: study of human populations

Factors that determine population change• 1) Births

• 2) Deaths

• 3) Immigration: movement “in” a population “Im”-“I”-IN

• 4) Emigration: movement “out’ of a population “Em” “E” Exit

Increase or decrease?

• Births & immigration > deaths & emigration?

• Deaths & emigration > births & immigration

Populations DO NOT experience linear growth• They experience __?____ growth

– Bacteria: J-shaped curve

Bacterial cells divide every 20 minutes!!!Bacterial cells divide every 20 min!!!

Bacterial Growth

• Assumption for graph above:• 1) unlimited resources 2) no death• 3) all bacteria reproducing• If so, 1 cell=Earth in 7 ft in 48 hrs!

Beginning growth, pop established

Rapid growth: more bacteria & more offspring

exponential growth meets real world

• The leveling off of a population results in a “s” shaped curve

CARRYING CAPACITY (dotted line)

J vs. S

Fluctuations: inc & dec of pop

Limits on population growth

• Limiting factor: regulates size of a population (limit pop growth)

• 2 kinds of limiting factors– Density dependent factors– Density independent factors

2 Types of Limiting factors

• Density Dependant: factors that depend on density of a population

• EX food, shelter, water, mates.

• Density Independent: factors that do not depend on density of a population

• EX: Temp, Storms, Floods, Drought, Weather

Population Dynamics

• Population dynamics: study of composition, # of individuals, & factors that cause change

Purpose for pop dynamic study

• 1) observe effects of environmental change/impact on populations

• 2) Use pops as environmental quality indicator

• 3) Determine if threatened or endangered

• 4) Understand pop interactions

Two Factors which cause change• Density dependent: food, shelter, water

• Density Independent: weather, temperature

Birth Rate: Explain: # of young produced in a given time• Factors that affect population birth rate:

• 1) # of births

• 2) time between births

• 3) Age of 1st reproduction-sexual maturity

• 4) Amount & quality of food

Death Rate

• Death Rate: # of deaths in population in a given time

• AKA “mortality rate”

• Age & sex specific

Sex Ratio

• Sex ratio: distribution or # of males & females within population

• Typical sex ratio: 50/50, when uneven affects population

Mating systems effect

• Monogamy: 1 partner for a breeding season or multiple breeding seasons

• 90% of birds are monogomous

• Polygamy: 2+ mates each season

• Deer, lions

Age Structure

• Examining individuals at each age level

• Prereproductive 0-14

• Reproductive 14-44

• Postreproductive 45+

Age Structure Diagrams

Human Impact

Habitat Destruction

• Habitat destruction: process of damaging/destroying habitat; cannot support organism

• Biodiversity: variety of life on Earth

Habitat Destruction

• Urbanization: increasing population/ growth of city into rural areas

• Deforestation: clearance of naturally occurring forests (logging, burning).

• Invasive species: Non-native species of plants/animals that out-compete native species in a habitat.

Global Warming

• Definition: Global warming: theory that world's avg temp is increasing due to burning of fossil fuels

• Results in higher atmospheric concentrations of gases (CO2)

Global warming

• Greenhouse effect: warming that results when solar radiation is trapped by atm,

• outgoing thermal radiation blocked by atmosphere

• EX: your car in summer

Global Warming

• Greenhouse gases: vapors in lower atmosphere that reflect solar radiation back to earth

• Water, carbon dioxide (CO2), methane (CH4), nitrous oxide (N20), ozone

Global Warming Effects• *Polar icecaps melting, habitat loss

• so sea levels rise

• animals habitat changing (endangering, extinction?)

• *Weather changes (hurricanes from warm air)

– Migration

Ozone Depletion

• Dfn: reduction of protective layer in upper atm by chemical pollution.

• Pollutant: Chloroflurocarbons (CFCs)

• Effects: skin cancer, cataracts, plant disease, marine life disruption (phytoplankton reduced 6-8%)

Acid Deposition• Dfn: transfer of acids (or acid-forming

substances) from atm to Earth's surface

• AKA?

• Pollutant: fossil fuels, Acid rain

• Effects: slowly destroys plant life/habitats erodes buildings

Natural Resource Use

• How do we directly effect natural resources?

• Deforestation, housing

• How do we indirectly effect natural resources?

• Green yard creates green pond

Natural Resource Use

• Growing fruits/veggies? You may want some pesticides!

• Pesticide: chemical used to kill pests (rodent /insects)

• Bioaccumulation: accumulation of substances in an organism (pesticides, organic chemicals)

Bioaccumulation

• Chemical gathers in organism faster than it can be broken down

• DDT: dichloro diphenyl trichloroethane bug spray

• Bird: lays on egg & it cracks (b/c bioaccumulation)