Download Organisms - Piscataway High School

Ecology and the Environment
(Ac Bio Chapters 3 - 6)
(Honors Bio – Unit 5)
Ecology: study of interactions among/between
organisms and their environment
LEVELS OF ORGANIZATION
Biosphere (AKA ecosphere):
All parts of planet in with life
11 km below surface of ocean to
8 km above Earth’s surface
Levels of Organization in Biosphere:
Individual
Species
Similar - can breed / Produce
fertile offspring
Groups of same Species, in same
area
Community Groups of different populations
together in same area
Population
Ecosystem
Biome
Communities & Abiotic factors
Ecosystems w/ same climate &
Similar dominant communities
FOOD CHAINS/WEBS
ENERGY FLOW
Autotrophs – make own food
photosynthetic – use light NRG + CO2 to make
carbs (glucose) + O2
chemosynthetic – use chem. NRG to make
carbs
Heterotrophs – rely on other orgs for NRG/food
Herbivores – eat only autotrophs
Carnivores – eat other heterotrophs
Omnivores – eat both autotrophs & heterotrophs
Detritivores – eat dead organisms
Decomposers – break down organic matter
What is the difference between a decomposer and a
Detritivore?
both get nutrition from dead organic matter
detritivores actually eat organic matter turning it into POOP
(earthworms eating their way through soil, vultures eating dead
deer)
decomposers secrete enzymes into the dead stuff to break down
organic matter then absorb resulting molecules (bacteria & fungi).
All detritivores are decomposers.
All decomposers are not detritivores.
Energy Flow:
One direction:
from sun (or inorganic compounds)
to
autotrophs
to
heterotrophs
Food Chain:
Series of steps in which organisms
Transfer energy by eating/being eaten
Food Web:
Links all food chains in ecosystem
Trophic Level: step in food chain
Decomposers/detritivores Break down dead organisms
Or organic waste for NRG
Top level carnivores =
(have no predators)
Second level carnivores =
eat other carnivores
First Level Carnivores =
eat herbivores
Herbivores =
second trophic level
Autotrophs =
first trophic level
Ecological Pyramid:
Compares amnts of
NRG or matter in trophic
Levels of food chains/webs
Energy Pyramid
10% of NRG available
170
Within 1 trophic
1,700
Level is passed to 17,000
Organisms in
170,000
Next level
Other 90%??
Used by organisms AT that
Level OR lost as heat
Biomass Pyramid
Compare amount of biomass
at Each level
Represents amount of food available for each level
Pyramid of Numbers
Shows numbers
Of Individuals at each
level
Pyramid of Numbers
Corresponding
BIOMASS PYRAMID!!
Cycling of Matter in the Biosphere
http://icue.nbcunifiles.com/icue/files/nbclearn/site/video/widget/NBC_Learn
_Video_Widget2.swf?CUECARD_ID=65227
Biogeochemical cycles:
Living organisms transform matter and
Recycle chemicals (atoms)
Water Cycle
Runoff & seepage
condensation
Root uptake
Water = solvent
Makes up 60 – 70 % of the weight in
living organisms
molecule w/ 1 oxygen
atom & 2 hydrogen atoms
Covalently bonded.
H2O neutral (10+ and 10-)
polar molecule: One end has a net – charge,
other end has a net + charge.
Hydrogen bond: weak (weaker than
ionic and covalent) attraction (bond)
between opposite ends of polar molecules
Cohesion: attraction of oppositely chgd.
ends of adjacent water molecules, causes
Water to “bead” on smooth surfaces
creates surface tension - allows small bugs/
animals to walk on water.
Adhesion: attraction between molecules of
Different substances
causes meniscus, capillary action
Water dissociates (separates) into two
Ions (charged particles):
Hydroxyl ion
OH-
Hydrogen
H+
If you apply electric voltage across two water-filled beakers and separate
them, The water stretches from beaker to beaker, creating a bridge that
defies gravity. Water bridges were discovered 120 years ago, but no one
has ever been sure why they do not collapse. One theory is that the voltage
makes water molecules line up, creating a “dielectric” tension that stops the
bridge from falling. Another argues that surface tension—the tendency of a
water’s surface to shrink inwards—keeps the bridge aloft. Now, researchers
believe that water bridges rely on both strategies. The results could help
engineers develop electrowetting, a method of using electricity to adjust
the adhesion of fluids to a screen that is expected to be used in the next
Generation of e-book readers.
pH scale –concentration of H+ ions in solution
Acid: more H+ ions than
OH- ions
pH less than 7
Neutral:
= amounts of OH- and H+ ions
pH exactly 7
(pure water)
Base: more OH- ions
than H+ ions
pH greater than 7
Carbon Cycle (gaseous cycle)
CO2 in
Atmosphere
CO2 in Ocean
Carbon released:
Respiration
Decomposition
Erosion
Volcanic activity
Mining
Cutting/burning
forests
Burning fossil fuels
Carbon removed:
photosynthesis
Storing Carbon Underground:
Burial/decomposition of dead organisms
Nitrogen Cycle (gaseous cycle)
needed by ALL organisms to Make
(amino acids) and nucleic acids
proteins
Nitrogen gas (N2) makes up 78% of atmosphere,
cannot be used directly by living organisms
Nitrogen fixation:
Bacteria living in roots of
Legumes convert N2 into
Ammonia – usable by
autotrophs
Decomposers return nitrogen to the soil as
ammonia
Denitrification: Soil bacteria convert nitrates
Into nitrogen gas
Nitrogen Cycle (Gaseous Cycle)
N2 in Atmosphere
NH3
Ammonia
NO3and NO2-
Nitrates/Nitrites
Phosphorus Cycle (sedimentary cycle)
needed to make DNA, ATP, phospholipids
(cell membranes), bones!
Doesn’t enter atmosphere like C, O, N
Stays in rock & soil minerals & ocean sediments
Plants pull phosphate from soil/water,
Combine into organic compounds – then cycle
Through food web
How do we get phosphorus into our bodies??
A Sedimentary Cycle
Fertilizers 3 numbers on label separated by dashes.
example: 5-10-5.
Numbers = percentage by weight of 3 major nutrients plants need:
N-P-K in that order.
10 pound bag of fertilizer labeled 5-10-5:
5% nitrogen
10% phosphorus
Other 80% comprised of other nutrients and filler.
Limiting Nutrient
Nutrient scarce or cycles slowly limits
primary productivity (rate at which
Organic matter is created by producers)
Algal Bloom
Too much nutrient (fertilizer, Phosphates in
detergents) –
Runs Off into water, algae grows fast,
Algae Dies off & decomposes (using oxygen),
fish die
BIOMES
Habitat:
where organism lives (address)
Includes biotic and abiotic factors
physical & biological Conditions where
Niche: organism lives ANDWay it uses those
conditions (job)
Place in food chain, physical conditions needed,
How & when it reproduces
Interactions in A Community
When organisms try to use same
Competition Resources at same time
Competition Exclusion Principle
No two species can occupy the same niche
In the same habitat at the same time
Predation
One captures and Feeds on another
Symbiosis Two species live closely together
Mutualism Both benefit
Commensalism
One benefits, other neither
Helped or harmed
Parasitism
parasite lives in or on host &
Causes harm to host
Ecological Succession:
Change in ecosystem over time
Primary Succession
No soil exists
Pioneer species (lichens) first
break down rock, make soil
Climax community: stable
Secondary Succession
Ecosystems return to original state
After disruption (forest fire, farming)
Ecosystems and Communities
Impact of Climate
Weather: Day to day condition of
Atmosphere at particular
Time and place
Climate:
Average, yr. after yr.
Conditions of temp. and
Precipitation for region
Climate zones
Determined by latitude (angle of heating)
Polar Zones Cold, sun’s rays strike at low angle
No. & So. Poles
Tropical Zones
Near the equator
Receive (nearly) direct sunlight year round
Always warm
Temperate Zones
Arctic Circle
Tropic of Cancer
Tropic of Capricorn
Antarctic Circle
Between polar zones & tropics
Affected by changing angle of sun
Ranges from hot to cold,
depending on season
Wind and Ocean Currents
-Caused by unequal heating of Earth’s surface
-Distribute/transport heat throughout biosphere
Prevailing Winds:
air near equator rises
Air near poles sinks
Upwelling
Water at poles sinks
Water at equator rises
Winds move surface water
Land Masses (microclimates)
Interfere with air masses / wind currents
Rain Shadow
-Air is cooled as it moves over mountain
-Drops moisture (rain) on one side
-Other side is dry (the rain shadow)
Biome
Complex communities, cover large
Area, specific soil & climate
Conditions, specific plant & animal
Life (with adaptations for survival)
Two main components of climate:
Temperature
Precipitation
Terrestrial BIOMES Only 30% of Earth is “land”
Polar
1) Taiga (Boreal Forest)
2) Tundra
(ice desert)
Coldest biome
Permafrost: permanently frozen subsoil
Freezing/thawing topsoil damages plant roots
Short scrubby plants
3) Mountains
(Alpine biomes)
Temperate Biomes
1) Taiga (Boreal Forest)
2) Northwest Coniferous Forest
pine trees (conifers), bears
3) Temperate Forest
4) Temperate Grassland
Deciduous trees:
Lose leaves in fall
5) Temperate Woodland/shrubland
6) Desert
Grassland distributions
Tropical Biomes
1) Tropical Rain Forest
Hot & wet year round
Most diverse biome
Canopy Dense covering of leaves 50-80 m above forest floor
Understory Shorter trees and vines in shade of canopy
2) Tropical Dry Forest
Deciduous trees: Drop leaves in dry season to Conserve water
3) Tropical Savanna
Grasslands, warm, less Rainfall than dry
forest, more Than desert
4) Desert Dry, hot during day – some colder at night
Evaporation is Greater than precipitation
Cover 30% of Earth’s land (all deserts
combined)
Aquatic Biomes
Freshwater Biomes 3% of Earth’s surface
Flowing Water Rivers, streams, creeks, brooks
Standing Water Lakes & Ponds
Plankton: microscope life forms
food for larger animals
zooplankton - heterotrophs
phytoplankton - autotrophs
Wetlands Water covers (or is near surface)
For part of year
Bogs Acidic water
Marshes Along rivers, no trees
Swamps -Water flows slowly
-Flooded forests
Estuary
-Where river meets ocean
-Tides rise & fall
-Food chains start w/ detritivores
(clam, worms, sponges)
-Incl. salt marsh, mangrove swamp
Marine Zones About 70% of earth covered by salt water
Photic Zone
Upper layer, enough light for photosynthesis
Aphotic Zone Permanently dark
Chemosynthetic organisms
Benthic Zone Ocean floor
Sea star, anemone, marine worms
Intertidal zone:
Area of shoreline between low and high tides
Organisms must be able to survive movement
Of tidal waters, changes in salt levels
Coral Reefs
Found in warm clear waters of tropics &
subtropics
Very diverse life forms
• Nearly 2/3 of the world’s population live along
the coast/within 100 miles of it
• Since 1990 the world has lost ~ ½ of its coastal
wetlands due to development
• in the past 200 yrs ~ 55% of the area of
estuaries and coastal wetland in US have been
destroyed/ damaged
Population Ecology
Populations
Identified by:
Range (geographic distribution)
River Otter Range
Density (number of individuals /unit of area
Growth Rate
Age Structure
River Otter Density in Montana
Factors affecting Population Size:
Birth Rate
Death Rate
Immigration Rate
Emigration Rate
Exponential Growth:
ideal conditions
Unlimited resources
reproduction occurs at constant rate
Logistic Growth:
growth slows or stops after a period of
exponential growth
why??
Resources become limited
Slows /levels off when
birth rate = death rate
immigration = emigration
ZPG:
Zero
Population
Growth
Carrying Capacity:
largest number of individuals a given
environment can support
http://www.census.gov/popclock/
if everyone on planet consumed only what’s
needed, 40 billion would be feasible
Earth’s carrying capacity
Limiting Factors:
cause population growth to decrease
Competition
Predation
Parasitism
Disease
Weather
Natural Disasters
Seasonal Cycles
Human Activities
Affects of Humans on the Biosphere
Tragedy of the commons:
Any resource that is free and accessible to
Everyone may eventually be destroyed
no one is responsible for
Protecting resources, no one benefits
From preserving resources
Renewable Resource
Ex: fresh water
plants
wind
Can regenerate (alive)
Can be replenished by
biochemical cycles
(nonliving)
Nonrenewable Resource
Ex: fossil fuels
Cannot be
Replenished by
Natural process
Sustainable Resource Utilization
Way of using resources without
Depleting them, without causing harm
To environment
Negative human impact on environment
Soil erosion – loss of topsoil by water/wind
-Desertification
Deforestation
Overfishing
Air Pollution / smog
Acid Rain:
Nitrogen and sulfur from
Burning fossil fuels combines
With water vapor to form
Nitric and sulfuric acids
Ecological Footprint
Land/water/Energy resources used and Needed to dispose of
generated wastes (in relation to time)
Biological Magnification
Concentrations of
harmful substances
Increase in organisms at
higher trophic
Levels in food chains &
food webs
Ozone Depletion
Ozone layer
Molecules of O3, absorbs
Harmful Ultraviolet (UV)
radiation
CFC’s (chlorofluorocarbons)
~propellants in Aerosol sprays
~coolants in Refrigerators,
freezers, AC,
~Used in production of plastic
Foams – can damage ozone
Global Warming increase in average temp. of
biosphere
Since the late 19th century, avg. atmospheric
Temperatures have risen about 0.6 oC
Since 1980, avg. temp have risen between
0.2 and 0.3 oC
Hypothesis: due to addition of CO2 from human activities
Burning of fossil fuels
Cutting and burning of forests
Concentrations of carbon dioxide in
Atmosphere have been rising for 200 years
Evidence
Greenhouse Effect: Natural & Necessary!
Build up of gases (carbon dioxide, methane)
Traps heat energy (like glass in a greenhouse)
Natural greenhouse effect is intensified
Possible Effects of Global Warming
Rising sea levels / flooding
Long term effects on ecosystems?
Invasive Species
Reproduce rapidly, lack parasites & predators
Nutria – native to So.
America – destroying
Shoreline habitats in
SE US
Biodiversity Diverse ecosystems are More stable
Threatened Biodiversity
Altering habitats
Hunting to extinction
Introduction of toxic compounds into food webs
Introduction of foreign species
Extinction: when species disappears from
All Or part of its range
Endangered species: in danger of extinction
Conservation
Wise management of natural resources
Preservation of habitats & wildlife
Endangered Species Act
National Parks
Earth Day
Earth Summit