ecology
TRANSCRIPT
ECOLOGY
Ecological Organization
• Abiotic factor: Non-living things in an ecosystem that affect the life of the organism. – Sunlight– Air– Water– Temperature
• Biotic factor: All living things in an ecosystem. – Animals– Plants– Bacteria– Fungi
FACTORS AFFECTING POPULATION SIZE
Biogeochemical Cycling
Competition• When 2 or more species live in the same
area and eat the same organisms they are said to be in competition for those resources.
• Examples:– Cheetas and lions have the same prey on the
savannah in Africa– Grass and weeds in your yard
Coexistence/Cooperation• When individuals of different species
work together to meet their needs they are said to be coexisting or cooperating.
• There are several strategies that species use to cooperate:– Mutualism– Parasitism– Commensalism
Mutualism• An interspecies relationship in which
both species benefit from the interaction.• Species 1 (+)• Species 2 (+)• Examples:
– A bee pollinating a flower– Fungus on plant roots– Clown fish and sea anemone
Parasitism• An interspecies relationship in which one
species benefits to the detriment (harm) of another.
• Host - Species 1 (-)• Parasite - Species 2 (+)• Examples:
– Fleas/ticks on a dog– Tape worm– Head lice
Commensalism• An interspecies relationship in which one
species benefits and the other is unaffected.
• Species 1 (+)• Species 2 (0)• Examples:
– Barnacles on a whale– Cattle egrets and livestock– Orchids on a tree
PRODUCERSEnergy mostly enters to the world as sunlight and producers capture it to turn it into food molecules in a process called photosynthesis.
They are: plants, algaes and bacteria.
Producers are the source of all the food in an ecosystem
A producer can make its own food
• Consumers cannot make their own food.• Consumers obtain energy by feeding on (consuming) other organisms.• They are classified by what they eat:
– Herbivores– Carnivores– Omnivores
CONSUMERS
HerbivoresDo they eat “ Potatoes ” ? ? ? ?
PRIMARY CONSUMERS• Also known as HERBIVORES • Ex: mice, deer, cows, and elephants• Herbivores eat ONLY PLANTS
• Are CARNIVORES or OMNIVORES• If the animal must be killed before it is
eaten, the secondary consumer is known as a predator.
SECONDARY CONSUMERS
ScavengersFeed on the bodies of dead organisms
DECOMPOSERSBreak down wastes and dead organisms, and so complete the cycle by: - returning nutrients to the soil & water - returning CO2 to the air & water
Food Chain
A food chain shows how each living thing gets food, and how nutrients and energy are passed from creature to creature.
Food Webs
A food web consists of all the food chains in a single ecosystem.
Trophic Levels An organism’s position in the food chain is
often referred to as its trophic level.
Energy Pyramids• 90% of energy at each level is used by the
organism for its day to day existence.• So only 10% transfers to the next level
There are as many as 25 elements found in ALL living organisms and just like energy they are cycled through the biosphere. Far and away the most abundant are CHNOPS.
Plants capture energy from Plants capture energy from sunlight for Photosynthesissunlight for Photosynthesis
6CO6CO22+ 6H+ 6H22O + Energy O + Energy C C66HH1212OO66+ + 6O6O22
Photosynthesis occurs in the Photosynthesis occurs in the chloroplasts in plant cellschloroplasts in plant cells
Cellular Respiration
O2 is converted to CO2 in the mitochondria of animal cells.
CC66HH1212OO66+ 6O+ 6O22 6CO 6CO22+ 6H+ 6H22O+ Energy O+ Energy ((infraredinfrared))
Combustion
Any chemical reaction in which one of the reactants is OXYGEN (aka fire) is a combustion reaction.
COMBUSTION OF CARBON• A combustion reaction in which one of the reactants is
CARBON always yields CO2 as a product.
• Burning Methane CH4 + O2 CO2 + 2H2O
• Burning Propane: C3H8+5O23CO2+4H2O • Examples:– Incinerating trash, yard waste– Forest fires– Combustion engines in cars– Burning coal to generate electricity
Just like tree rings can tell us about how old the tree is and whether it was a wet/dry or cold/hot year…
So can Ice Core Samples tell us about the paleoclimate…
Paleo = ancient
The Ice Core Drill
Layers of Ice
Like the growth rings on a tree…each layer represents a year (or in this case, season) of ice accumulation.
Volcanic Ash Layer
Cutting the Ice
Gases Dissolved in the Ice
Ice Core Storage Room
Climate Change• CO2 is a greenhouse gas, meaning that it
holds heat IN the atmosphere.• Atmospheric carbon has increased
dramatically since the beginning of the Industrial Revolution in 1850.
Effects of Climate Change• Melting Polar Sea Ice • Change in ocean salinity• Ocean Acidification• Rising global temperatures• Rising sea levels• Receding glaciers• ALL ecosystems are affected!
Melting Polar Sea Ice
Ocean Acidification• Ocean acidification is a reduction in
surface ocean pH levels due to the increasing absorption of carbon dioxide.
• When CO2 dissolves in water, carbonic acid is formed.
• The saturation of carbonic acid decreases the ability of many marine organisms to build and maintain their shells and skeletal structures.
Ocean Acidification
Results in habitat loss & breakdown of the marine food web
Mendenhall Glacier
The Meade Glacier is located:
Here he is from space (zoomed)
Here he is on approach when we helicoptered out to visit him last summer:
Receding Glaciers
Water Cycle• ALL living organisms MUST have water to survive!• The availability of water is determined by the water
cycle and weather patterns driven by it.• Water is a reactant in photosynthesis and a product
in cellular respiration!
The Nitrogen Cycle• Nitrogen-fixing bacteria – “Fix” nitrogen
from the atmosphere into a form that is ingestible by living organisms.
• Nitrogen moves through the food chain (trophic layers) in the same manner energy does.
• Denitrifying bacteria – break down decomposing organic material and release the nitrogen back into the atmosphere restarting the cycle.
PHOSPHORUS CYCLE
Field Study: Wild Horses of Shackleford Banks
This is my tent. It is upside down. The wind did it. What does that tell you about the wind on the island?
This young fella is standing in freshwater.