Ecology

ECOLOGY

What is ecology?

The study of the interactions between organisms and the living and non-living parts of their environment

ECOSYSTEMSThe sum of all the organisms living within its boundaries(biotic factors) and all the abiotic factors with which they interact.

Involves two unique processes: energy flow and chemical cycling

Interdependence

The survival of all organisms depends on their interactions with living and non-living components

Example – we depend on plants for O2 and plants depend on us for CO2

Levels of Organization

Think back to the levels or organization

Try now… what are the levels of organization (of life) going from smallest to largest? Hint: it starts with

atom..

Ecological Organization

Define each level of ecological organization by looking at the picture and listening to your teacher Individual organism Population Community Ecosystem Biosphere

Biotic Factors

Living things that affect the environment, such as plants, animals, bacteria, fungi, etc.

Abiotic Factors Nonliving things that affect the environment,

such as water, wind, sunlight, soil, salinity, climate (temperature/rainfall

Ecosystem Components

Biotic Factors – living parts of the environment Plants Animals Bacteria Protists Fungi

Abiotic Factors – non-living parts of the environment Sunlight Soil Water Nutrients Climate (rainfall

and temperature)

Pick out the biotic and abiotic factors in this picture

Niche vs. Habitat

Niche – an organisms specific role in it’s habitat

Habitat – the place where an organism lives

Warbler niches

Generalist vs. Specialist

Generalist – species with very broad niches (can exist in many conditions) Think of examples

of generalists

Specialist – species with very narrow niches (can exist only in certain conditions) Think of examples

of specialists

STOP POWERPOINT – WATCH PLANET EARTH!!

DAY 2: COMMUNITY

What is a community?

All the populations in a given area interacting with each other and their surrounding environment.

Energy Transfer

Producers – called AUTOTROPHS – make their own food Plants Some protists Some bacteria

Consumers – called HETEROTROPHS – must obtain food Animals Most protists Fungi Many bacteria

Types of Consumers

Herbivore – eat producers Carnivore – eat other consumers Omnivore – eat both producers and

consumers Detrivore (scavengers) – eat “garbage”

or detritus of ecosystem Decomposer – break down dead

organisms into small molecules that can be used by autotrophs again

Your turn

Think of an example for each… Herbivore Carnivore Omnivore Detrivore Detritus Decomposer

Species interactions

The way species interact with each other is categorized by whether they cause each other benefit or harm

Interspecific Interactions: may be positive (+) for one species, negative (-), or neutral (0): competition between two different species

Intraspecific Interations: competition within same species

Interactions between species: Competition Symbiosis Predation

Predation

Predator – organism that kills/eat another organism

Prey – organism that is killed/eaten

Competition

Competition - two or more species use/need the same limited resource

Competition

Food, space, mates

From http://www.milosphotos.com/wildlife1/dallrams.jpg

SYMBIOTIC RELATIONSHIPS

Two organisms living together in a relationship

Parasitism – one organism benefits, the other is harmed Mutualism – both organisms benefit Commensalism – one organism benefits the other is neither helped nor harmed

Symbiosis

Symbiosis is a close, long-term relationship between two species of organisms

Parasitism/Predation – one organism benefits, the other is harmed

Mutualism – both organisms benefit

Commensalism – one organism benefits the other is neither helped nor harmed

Predation/parasitism-

“Good for me - Hurts you” One organism feeds

(predator) on another (prey)for food

One is benefited, one is harmed (+/-)

Defense for predators include:

From http://www.funkstownvet.com/HEARTWORM.jpg

Commensalism -“Good for me -Doesn’t bother you”

Two organisms live together, and one is helped while the other is not affected (+/0)

Ex. hermit crabs

From http://www.ukdivers.net/life/uk/hermit.jpg

Mutualism - “Good for me - Good

for you” Two organisms benefit

from living together (+/+)

Ex.: ladybugs eat aphids on rosebushes, ants make “sap”, aphids eat “sap”

From http://www.broward.org/naturescape/images/lady-bug-eating-aphids.gif

Herbivory Type of predation

done by herbivores

Herbivores preying on plants (+/-)

From http://oneidaswcd.org/grazing%20cow%203.jpg

Parasitism, Mutualism, or Commensalism???

WAYS TO AVOID PREDATION

Animals have adaptations to avoid being eaten.

Secondary Compounds in Plants

Plants can’t run away, so they produce toxins to deter herbivores

Ex. aspirin, clove oil

From http://www.worldfood.com/images/spices/cloves.jpg

MIMICRY

Some organisms mimic others in order to protect themselves

Batesian Mimicry A harmless or palatable species

mimics one that is neither harmless nor palatable

Example: When disturbed, the hawkmoth larva looks like a snake.

Mullerian Mimicry Two unpalatable species mimic

each other

Viceroy butterflies taste foul to birds and will make birds regurgitate them when

eaten.Monarch butterflies taste bad too so birds try to avoid them as well.

Example: Honey Bee and

Yellowjacket

From http://www.forestry.caf.wvu.edu/buttonsGood/pics/honeyBee.gifFrom http://www.eatonvillenews.net/images/Bob/TONY%20YELLOW%20JACKET%201%20SEPT.%2025,%2005%20135F1366b.jpg

Both species share similar coloring and have poisonous venom

STOP! DO NOTECARDS ON RELATIONSHIPS

Energy flow

When one organism eats another molecules are metabolized and energy is transferred.

As a result energy flows through an ecosystem Notice that energy is

lost as it is transferred up levels… WHY??

Producers Every organism at this

level is an autotroph (self-feeders) doing photosynthesis.

All plants, photosynthetic protists and blue-green bacteria are producers.

First-level consumers are HERBIVOROUS, meaning they eat only plants.

Secondary consumers- eat primary consumers.

Consumers/Heterotrophs: Organisms that cannot make their own food.

Tertiary consumers

Tertiary consumers eat secondary consumers

These are fewer in number in an ecosystem

Many are omnivores

Detritivores or Decomposers

Consumers that get their energy from detritus, which is nonliving organic material : remains of dead organisms, feces, dead leaves, and wood

Detrivore (scavengers) – eat “garbage” or detritus of ecosystem

Decomposer – break down dead organisms into small molecules that can be used by autotrophs again

MATTER- recycles and is reused over and over

ENERGY- moves one direction and is used up~ it escapes as HEAT

http://www.nelsonlakesshuttles.co.nz/One%20Way%20Arrow.jpg

http://mff.dsisd.net/Environment/Cycles.htm

Food chains

Remember these? Food chains show a single pathway for feeding relationships among organisms in an ecosystem

Food Chains

Cow eats corn, people eat cow Linear, simple Limited by available energy

Another food chain

By looking at the food chain, what is the difference between primary and secondary consumers?

Food webs

Food webs provide a more realistic and complex picture of the feeding relationships within an ecosystem

Pick out one food chain from this web (start with sun)

Define primary, secondary, and tertiary consumers…

Biomass and Energy Transfer

1 hawk10 snakes 100 mice feed1000 plants feed

********Rule of 10Rule of 10********

Only 10%Only 10% of the energy is transferred to the next organism

Trophic levels

A trophic level indicates an organims position in energy transfers (where they fall in a food chain)

Trophic levels

What can the pyramid shape tell you about trophic levels?

Ecosystem recylcing

Energy and matter flow through the living and non-living worlds and are constantly being reused and recycled – called the biogeochemical cycles

Water cycle Carbon cycle Nitrogen cycle Phosphorous

cycle

Carbon Cycle

Water cycle

Life could not occur without water

Carbon cycle

How have humans added more carbon to the atmosphere?

Nitrogen cycle

What role do bacteria play in the nitrogen cycle?

Phosphorus Cycle

STOP – DO 10% LAB

DAY 4:POPULATIONS &CARRYING CAPACITY

Animal populations

A population is a group of organisms that belong to the same species and live in a particular place at the same time

What is a population?

A group of the same species living in the same habitat, using the same resources

From http://www.uszanders.com/Photo%20Collection/slides/15PH%20Raccoons.jpg

Population Density

The number of organisms per unit area

http://www.wwt.org.uk/images/flamingo/press-images/DrinkingFlock.jpg

Density and dispersion

Density measures how crowded a population is

Dispersion is the spatial distribution of individuals

Dispersion

Three types of dispersion Random Uniform Clumped

Clumped Distribution

Organisms gather in clumps within an area

Can be beneficial for group

From http://cipm.ncsu.edu/ent/ncentsoc/haning2.jpg

Uniform Distribution

Organisms space themselves out uniformly.

From http://www.mkaz.com/photo/blog/images/2005_R41_04.jpg

Random Distribution

Organisms are randomly scattered within an area

What kind of distribution do HUMANS fit?

Age Structure

Age structure diagrams show the distribution of individuals among different ages in a population

Survivorship curves

Survivorship curves show the probability that members of a population will survive to a certain age

Survivorship Strategies: R strategistsOrganisms which reach sexual maturity at an early age, reproduce quickly

Many offspringLittle parental care

Survivorship Strategies: K strategists

Organisms which reach sexual maturity later in life

Have few offspringInvest time in parental care

STOP: DO DEER POPULATION LAB

Population Clock

http://www.worldometers.info/world-population/



Human Numbers Through Time: A.D. 0

Taken from Nova online

300 million

A.D. 1000

310 million

1800

1 billion65% Asia, 21% Europe, 1% North America

1927

2 billion

1960

3 billion

1974

4 billion

1987

5 billion

1999

6 billion62% Asia, 12 % Europe, 12% Africa, 9% Latin America, 5% N. America

2050

Population will more than likely will reach 9 billion peopleNearly all growth will take place in developing countries

In the past few decades…

Death rates have declined Living longer in both industrial and developing countries

immunization, health care, technology Avg life expectancy: 78

Birth rates have declined Parents are choosing to have less children Access to family planning More women starting families later in life

* PGR remain high though because birth rates have not fallen as much as death rates

Why so many children?

Fear their babies may die Need laborers to work Ensure that they themselves will be

cared for in their old age Lack access to education and to family

planning

To reduce fertility rates

1. Greater access to primary health care and family planning services

2. Receive a basic education (esp. girls and women)

3. Have government serviced that help protect them when sick, old, unemployed

Some say we have already exceeded the carrying capacity

Others say billions more can be sustained on earth

Consensus World population will continue to grow until

after the middle of this century Peak of some 9 billion Perhaps declining in the latter years

What controls population size?

Density-Independent Factors Weather, floods, fire Reduce population by the same

proportion regardless of size Density-Dependent Factors

Shortages of food, shelter Triggered by increasing population

density

In groups of 2 or 3, answer the following (in complete sentences)1. What do you think daily life might be in your town

in 2050 when there are 9.2 billion people on this planet?

2. What types of technological changes will be needed to accommodate the world’s growth?

3. What do you think will be the greatest environmental concerns at that time?

4. Do you see population growth becoming a major political issue by 2050? Why or why not? What types of population issues might people be talking about at that time?

Ecology

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