Review of the Ecology Unit

Post Falls High SchoolBiology

What is Ecology?

The

Ecology- the study of interactions between

– organisms and organisms– organisms and their environment

Where do we fit in?

(What is our environment?)

The Biosphere!

Factors that effect us:1. Abiotic Factors

Wind/Air currentsMoisture

Soil

Light

Temperature

A- stands for non Bio- stands for living

Abiotic Factors- nonliving factors

2. Biotic Factors:

Biotic- Living factors

What is the organization of Ecological Study?

Population

Community

Ecosystem

Biosphere

Organism

Levels of Organization Individual- one

organism (living)

Ex a moose

Levels of Organization Population- groups

of individuals that belong to the species and live in the same area. (living-living same species)

Ex many moose

Levels of Organization Community- groups of

different populations (more than one population or different groups of species)

Ex many groups of moose beavers, trees, grass (all living)

Levels of Organization Ecosystem- all

organisms in a particular area along with the nonliving. (living and nonliving)

Ex many groups of moose beavers, trees, grass, rocks, water, mountains

Levels of Organization Biome- group of

ecosystems that have the same climate and similar dominant communities

Biomes: tropical rain forest, tropical dry forest, tropical savannah, temperate grassland, desert, temperate woodland and shrubland, temperate forest, northwestern coniferous forest, boreal forest (taiga), tundra, mountains and ice caps

Levels of Organization Biosphere- all of

the planet where life exhists, includes land, water, and, air

Life extends 8 km up and 11 km below the surface

IN AN ECOSYSTEM:

Organisms live in a Habitat

Organisms fit into a Niche of the environment

Habitat vs. Niche Habitat- an area where an organism lives Niche- an organisms role in its environment

– The Long Version full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. Includes where in the food chain it is, where an organism feeds

Habitat is like an address in an ecosystem and a niche is like an occupation in an ecosystem.

Community Interactions

when organisms live together in an ecological community they interact constantly.

Three types of interactions– Competition– Predation– Symbiosis

Competition- competing for resources

occurs due to a limited number of resources

Resource- any necessity of life. water, nutrients, light, food.

Competitive exclusion principle- no two species can occupy the same niche in the same habitat at the same time

Predation Predation- when

an organism captures and feeds on another organism.

Predator- hunter Prey- hunted

Symbiosis Symbiosis- any relationship where

two species live closely together. (3 types)– Mutualism– Commensalism– Parasitism

Symbiosis Mutualism- both

species benefit from a relationship.

Lichens (fungus and Algae)

One example is the lichens, little non-descript patches of stuff you see growing on rocks and tree bark. This is a symbiosis, consisting of a fungus and an alga. The fungus provides a protective home for the algae, and gathers mineral nutrients from rainwater and from dissolving the rock underneath. The alga gathers energy from the sun. There are thousands of species of lichen in the world; actually thousands of species of fungi with just a few species of algae which can form a partnership with almost any of them.

Symbiosis Commensalism – One

member of a symbiotic relationship benefits and the other is neither helped or harmed

Ex. Holes used by bluebirds in a tree were chiseled out by woodpeckers after it has been abandoned .

Symbiosis Parasitism- One

creature benefits and one creature is harmed

Ex tapeworm. Feeds in a humans intestines absorbing his/her nutrients.

Relationships: Symbiosis = Living Togethera)

commensalism b) mutualism

c) parasitism

Identify these relationships

ENERGY FLOW

Autotrophs vs. Heterotrophs

Energy Flow (Trophic Levels)

Producers- make their own food

Consumers- get energy from consuming producers

Producers Producers- capture

energy from sunlight or chemicals and use the energy to produce food.

Producers are autotrophs- they make food from their environment

2 main types of autotrophs

One type gets energy from the sun-by photosynthesis

Another type gets energy without light- by chemosynthesis

Consumers Consumers are

heterotrophs- get energy from other organisms

Types of Consumers Herbivores- eat only plants Carnivores- eat animals Omnivores- eat both plants and

animals Detritivores- eat dead matter (plants

and animals)

Feeding Relationships Energy flows through an ecosystem in one direction

from:– 1. the sun or inorganic compounds– 2. To autotrophs (producers)– 3. To heterotrophs (consumers)– Decomposers get energy from decomposing dead

organisms

Food Web- A network of feeding relationships.

(More realistic that a food chain)

Food Chain- a series of steps in which organisms transfer energy by eating or being eaten.

Food Web

They can become very complex!

Trophic levels

Each step in a food chain or a food web is called a trophic level.– Producers are the first

trophic level– Consumers are the

second, third, or higher trophic level

Each trophic level depends on the one below for energy

Energy Pyramid Only part of the energy

stored in one level can be passed to the next- most energy is consumed for life processes (respiration, movement, etc., and heat is given off)

Only 10% of the energy available within one trophic level is transferred to organisms in the next trophic level

Biomass Pyramid Biomass- the total

amount of living tissue within a given trophic level.

A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

Energy Losses

Energy transfers are never 100 percent

efficient

Some energy is lost at each step

Limits the number of trophic levels in an

ecosystem

Energy flow is a one way path! (not a cycle)

All Heat in the End At each trophic level, the bulk of the

energy received from the previous level is used in metabolism

This energy is released as heat energy and lost to the ecosystem

Eventually, all energy is released as heat

All living organisms need certain elements/compounds for life processes– Ex: your cells need C,H,O,P,N & S in

order to live and reproduce (make more cell)

Cycles in nature keep these elements “moving” from organisms to organism (and sometimes into the atmosphere)

Biogeochemical Cycles(Matter moving through the environment)

Biogeochemical Cycles(Matter moving through the environment)

The flow of a nutrient from the environment to living

organisms and back to the environment

Main reservoir for the nutrient is in the environment

Transfer rates to and from reservoir are usually lower

than the rates of exchange between and among

organisms.

Matter is recycled through an ecosystem – not one way

flow

Three Categories

Hydrologic cycle

– Water

Atmospheric cycles

– Nitrogen and carbon

Sedimentary cycles

– Phosphorus and sulfur

CYCLES IN NATURE

Carbon Cycle

Carbon moves through the atmosphere

and food webs on its way to and from

the ocean, sediments, and rocks

Sediments and rocks are the main

reservoir

Carbon Cycle

photosynthesisTERRESTRIAL

ROCKS

volcanic action

weathering

diffusion

Bicarbonate, carbonate

Marine food webs

Marine Sediments

Atmosphere

TerrestrialRocks

Soil WaterPeat, Fossil

Fuels

Land Food Webs

Carbon in the Oceans Most carbon in the ocean is dissolved

carbonate and bicarbonate Ocean currents carry dissolved carbon

Carbon in Atmosphere Atmospheric carbon is mainly carbon

dioxide Carbon dioxide is added to

atmosphere– Aerobic respiration, volcanic action,

burning fossil fuels, decomposition of organic materials

Removed by photosynthesis

Nitrogen Cycle Nitrogen is used in amino acids and nucleic acids

(all living organism need nitrogen to make

proteins)

Main reservoir is nitrogen gas in the atmosphere

Decomposers are vital to convert ammonia into:

1. usable nitrites & nitrates for plants (nitrogen fixation)

2. nitrogen gas (denitrification = puts it back into the atmosphere)

Phosphorus Cycle Phosphorus is part of phospholipids and all

nucleotides

– What are these?

It is the most prevalent limiting factor in

ecosystems

Main reservoir is Earth’s crust; no gaseous

phase (it never enters the atmosphere – like

carbon and nitrogen)

Phosphorus Cycle

GUANO

FERTILIZER

ROCKS

LAND FOOD WEBS

DISSOLVED IN OCEAN

WATER

MARINE FOOD WEBS

MARINE SEDIMENTS

excretion

weathering

mining

agriculture

uptake by autotrophs

death, decomposition

sedimentation setting out leaching, runoff

weathering

uplifting over geolgic time

DISSOLVED IN SOILWATER,

LAKES, RIVERS

uptake by autotrophs

death, decomposition

Communities & Biomes Vocabulary to Know:

– Limiting Factor– Succession

Primary Secondary

– Climax Community

Community

All the populations that live together in a

habitat

Habitat is the type of place where

individuals of a species typically live

Type of habitat shapes a community’s

structure

Limiting Factors Definition?

What factors would limit these communities?

What is Succession & what causes it?

Changes to a community

Biotic Factor

Abiotic Factors

2 Types of succession Primary

– From nothing– Even the soil must be “created”

Secondary– From soil– Disaster can strike and make it start over

Primary Succession

Secondary Succession

Pioneer Species

Species that colonize barren habitats

Lichens, small plants with brief

life cycles

Improve conditions for other species

who then replace them

Climax Community

Stable array of species that persists

relatively unchanged over time

Succession does not always move

predictably toward a specific climax

community; other stable communities

may persist

Pioneer stage Climax Community

The trend of Succession

Biogeography

The study of the distribution of

organisms and the processes

that underlie distribution patterns

Factors that Affect Distribution

Geologic history

Topography

Climate

Species interactions

Climate

Average weather condition in a region

Affected by:

– amount of incoming solar radiation

– prevailing winds

– elevation

Rotation and Wind Direction

Earth rotates faster under the air at the equator than it does at the poles

Deflection east and west

Seasonal Variation Northern end of Earth’s axis tilts toward

sun in June and away in December

Difference in tilt causes differences in

sunlight intensity and day length

The greater the distance from the

equator, the more pronounced the

seasonal changes

Ocean Currents Upper waters move in currents that distribute

nutrients and affect regional climates

Rain Shadow

Air rises on the windward side, loses

moisture before passing over the mountain

Soil Characteristics

Amount of humus

pH

Degree of aeration

Ability to hold or drain water

Mineral content

Biogeographic Realms

Six areas in which plants and animals

are somewhat similar

Maintain their identity because of

climate and physical barriers that tend

to maintain isolation between species

Biomes

Regions of land characterized by

habitat conditions and community

structure

Distinctive biomes prevail at certain

latitudes and elevations

Biomes

Biome Chart (to fill in during presentations)Create a Biome Table with the Following Columns:1. Name of Biome2. Major Location(s)3. Avg. Temperature/climate4. Avg. Rainfall – convert to inches5. Major plant life6. Major animals7.Other – include things such as other major identifying factors of the biome, alternate names of the biome, limiting factors of the biome for plants/animals, etc. Note:

To convert rainfall from cm to in = 1cm X .39 = in

Biome Location Temp. Rainfall Plants Animals Other

Coral Reef

           

Savannah            

             

             

             

             

             

Population Biology What is a population? What is exponential population

growth? What happens to a population when it

reaches its carrying capacity?

How many mice are in the following population?

Estimate!

Ready

SETSET

Go!

How many did you count?

What is the best way to count them?

SAMPLING

Population Sampling Sometimes, the entire population to be

studied is small enough for the researcher to include the entire population in the study.– This type of research is called a census study

because data is gathered on every member of the population.

Usually, the population is too large for the researcher to attempt to survey all of its members.– A small, but carefully chosen sample can be

used to represent the population.– The sample reflects the characteristics of the

population from which it is drawn

Sampling Methods There are LOTS ways to sample a

population including:– Biased sampling, Systematic sampling, Stratified

sampling, Judgment sampling, Quota sampling, Snowball sampling, Counting method, Hit-or-miss method, etc…

HOWEVER, the most common methods are:

– Random and non-random sampling

– Each gives you a “best estimate” of the population size

Population Size Factors that affect:

– Natality– Mortality/Fatality– Immigration – Emigration

                                                    

Population Growth Curves Explain what is happening to the

populations below:

Population Growth Curves Explain what is happening to the

populations below:

Rate at which a population could grow if it had unlimited resources

If a population reached its biotic potential it would have exponential growth

Biotic Potential = Reproductive Potential

The “J” Curve

The “S” CurveThis graph shows a typical population growth curve. Under ideal conditions a population would have a growth with a slow start, then a very fast rate of increase and finally the growth slows down and stops.

Population Density

Environmental Limits on populations

Density-dependent– Disease– Food– Parasitism– Predation– Competition

Intraspecific Interspecific

Density-independent– Temperature– Storms– Floods– Drought– Habitat Disruption

Density Dependent Here is a dramatic

example of how competition among members of one species for a finite resource — in this case, food — caused a sharp drop in population.

The graph shows a population crash; in this case of reindeer on two islands in the Bering Sea. Inter or Intra?

Density Dependent This graph shows the effect of interspecific competition on the population

size of two species of paramecia, Paramecium aurelia and Paramecium caudatum.

When either species was cultured alone — with fresh food added regularly — the population grew exponentially at first and then leveled off.

However, when the two species were cultured together, P. caudatum proved to be the weaker competitor. After a brief phase of exponential growth, its population began to decline and ultimately it became extinct. The population of P. aurelia reached a plateau, but so long as P. caudatum remained, this was below the population density it achieved when grown alone.

Density Independent This graph shows the

decline in the population of one of Darwin's finches on Daphne Major, a tiny (100-acre) member of the Galapagos Islands. The decline (from 1400 to 200 individuals) occurred because of a severe drought that reduced the quantity of seeds on which this species feeds. The drought ended in 1978, but even with ample food once again available the finch population recovered only slowly.

Organism Interactions Limit Populations

Predation Competition

– Both types Parasitism Crowding/stress

The Human Population

Figure 4.10 pg 104

Demography Vocabulary Age Structure Immigration Emigration Birth/Death Rate

Age Structure Pyramids These pyramids compare the age structure of the populations of France

and India in 1984. The relative number (%) of males and females is shown in 5-year cohorts. Almost 20% of India's population were children — 15 years or less in age — who had yet to begin reproduction. When the members of a large cohort like this begin reproducing, they add greatly to birth rates. In France, in contrast, each cohort is about the size of the next until close to the top when old age begins to take its toll.

Age Structure Pyramids These population pyramids show the baby-boom

generation in 1970 and again in 1985 (green ovals). Profound changes (e.g. enrollments in schools and

colleges) have occurred — and continue to occur — in U.S. society as this bulge passes into ever-older age brackets.

Diversity & Conservation Importance to

nature

Importance to people– Oxygen– Diet– Medicines

Loss of Diversity

Threatened Species

Endangered Species

Extinction of Species

•Alabama -- 115 listings •Alaska -- 11 listings •Arizona -- 60 listings •Arkansas -- 29 listings •California -- 300 listings •Colorado -- 33 listings •Connecticut -- 19 listings •Delaware -- 20 listings •District of Columbia -- 3 listings •Florida -- 111 listings •Georgia -- 66 listings •Hawaii -- 317 listings •Idaho -- 25 listings •Illinois -- 28 listings •Indiana -- 29 listings •Iowa -- 14 listings •Kansas -- 15 listings •Kentucky -- 47 listings •Louisiana -- 26 listings

•Maine -- 15 listings •Maryland -- 26 listings •Massachusetts -- 24 listings •Michigan -- 21 listings •Minnesota -- 13 listings •Mississippi -- 38 listings •Missouri -- 25 listings •Montana -- 17 listings •Nebraska -- 13 listings •Nevada -- 38 listings •New Hampshire -- 12 listings •New Jersey -- 23 listings •New Mexico -- 42 listings •New York -- 26 listings •North Carolina -- 63 listings •North Dakota -- 8 listings •Ohio -- 26 listings •Oklahoma -- 20 listings •Oregon -- 54 listings

•Pennsylvania -- 17 listings •Rhode Island -- 17 listings •South Carolina -- 42 listings •South Dakota -- 12 listings •Tennessee -- 96 listings •Texas -- 91 listings •Utah -- 47 listings •Vermont -- 8 listings •Virginia -- 71 listings •Washington -- 41 listings •West Virginia -- 21 listings •Wisconsin -- 16 listings •Wyoming -- 18 listings •American Samoa -- 4 listings •Guam -- 12 listings •Northern Mariana Islands -- 13 listings •Puerto Rico -- 75 listings •Virgin Islands -- 13 listings •Outlying Caribbean Islands -- 0 listings •Outlying Pacific Islands -- 0 listings

Endangered Species/State

2004 Data

Threats to Biodiversity Habitat Loss Habitat Fragmentation

– Biotic Issues– Abiotic Issues

Habitat Degradation– Air Pollution– Water Pollution– Land Pollution

Exotic Species Non-native

organisms that “move-in” to a particular area

There can be a lack of competitors = exponential growth

Can take over the niches of native species

Example: Page 124

Conservation Sustainable use:

– Use what you need, but don’t damage the ecosystem

Is this a good example of sustainable use?

ConservationHabitat Corridors

Conservation Reintroduction Programs Captivity Breeding

Example:

The Ginkgo Tree would probably be extinct if it were not for Chinese monks keeping it in captivity around temples

Humans & The Environment

Pest Control– Benefits vs.

Problems– EX: DDT

Humans & The Environment

Ozone (O3) Depletion

– O3 forms a “good layer” around the Earth

– CFC release is breaking down the protective ozone layer

– UV rays increase skin cancers & other cell mutations to plants & animals!

Humans & The Environment Acid Precipitation

– In the form of rain, snow, dew or fog

– Created when gases such as nitrogen oxide (NOx) and sulfur oxide (SOx), generated in the burning of fossil fuels such as coal and oil, react in the atmosphere with sunlight to produce acids such as nitric and sulfuric acid. These acids dissolve in rain to become acid rain.

How is Acidity Measured? When we observe acid

rain, acidity is measured in units called pH.

The pH scale is from 0 to 14– pH 7 indicates neutral– higher pH numbers =

alkalinity (base)– smaller numbers = acid

We’ll do more on pH in the “Biochemistry” chapter

Natural Acid Precipitation CO2 combines with

water to form a weak acid H2CO3 (carbonic acid)

But we are adding to the problem…– by adding nitric and

sulfuric acids

Look at the “clean rain” – it’s already slightly acidic???

Effects of Acid Precipitation• In Japan, rain which registers pH 5.6 or less is considered acid rain;

some 80-90% of the rain that falls in Japan in a year is acid rain. • In Japan, acid rain with acidity equal to lemon juice has been

observed at Mount Tsukuba in 1984 (pH 2.5) and at Kagoshima in 1987 (pH 2.45). The problem is even more serious in North America and Europe. In those regions, forests are withering and lakes becoming uninhabitable to fish, and stone structures such as buildings and bronze statues are being damaged by corrosion.

1970 1985

Humans & The Environment

Global Warming– “The Greenhouse Effect”

– Fossil fuels give off lots of CO2

– This builds a blanket around the earth– It is predicted that the Earth temp. will

increase ~50C before 2050 = Ice age????

Carbon Dioxide Increase

Carbon dioxide levels fluctuate seasonally

The average level is steadily increasing

Burning of fossil fuels & deforestation are

contributing to the increase

Greenhouse Effect

Greenhouse gases impede the escape

of heat from Earth’s surface

Global Warming Long-term increase in the

temperature of Earth’s lower

atmosphere

Other Greenhouse Gases

CFCs - synthetic gases used in

plastics and in refrigeration

Methane - produced by termites and

bacteria

Nitrous oxide - released by bacteria,

fertilizers, and animal wastes

Hopefully, this is NOT the end!