review of the ecology unit
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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!
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