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.

Carbon Cycle

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

FOOD

You are what you eat!

Digestion

The digestive process breaks down consumed

food into molecules/nutrients which are needed to

carry out all of the body’s essential processes such as:• Carbohydrates• Fat• Proteins• Vitamins & Minerals• Water

A healthy diet satisfies three needs:

• fuel to power all of the bodies activities

• raw materials needed to build the bodies own molecules

• essential nutrients that the animal can't make for itself

Why Do We Eat?

Calories• A calorie is the unit of measure of the

amount of energy a food source contains.• Every consumer needs a given amount of

energy simply to exist from day to day and as a consumer that energy must come from the sun through consuming/eating another organism.

• The more active the organism, the more energy (in the form of calories from food) it requires.

Carbohydrates

• Carbohydrates are a major source of energy in the form of sugar.

• A type of sugar called glucose is needed for cellular respiration.

• Carbohydrates are either simple or complex.

• Simple carbohydrates are either already in the desired form (glucose) or they can easily and quickly be processed into the glucose form.

• They provide an instant energy boost.

• Complex carbohydrates require a lot of processing to get it into the glucose form.

• They provide longer lasting (sustained) energy than their simpler counterparts.

Fiber

• Fiber is a complex carbohydrate found in plants that cannot be made into sugar by the body for fuel.

• It is still an important component of the diet because it helps move food through the digestive process.

• Fiber passes through the digestive system and is eliminated.

• DNA codes for one of about 20 amino acids. Your body can make about half of those amino acids but the rest MUST come from your food!

• Collections of amino acids code for specific proteins.

• Collections of proteins become tissue.

• Collections of tissues become organs.

• Collections of organs become BODIES!

Amino Acids

• Meat food sources contain “complete proteins” meaning all 20 amino acids are present.

• Not every vegetable has all 20, and are therefore considered to contain “incomplete proteins.”

• Vegetarians must eat a variety of plants to get all 20 amino acids.

• The average American consumes DOUBLE the recommended daily amount of protein the long-term effects of which are not fully understood.

Fat

Fat is needed:• For energy• As a building and insulating material in various parts

of the body.• Saturated fat (from animal sources) is less desirable

and can clog up arteries.• Unsaturated fat (from plant sources) is the more

desirable and can actually help blood flow by “scrubbing” the undesirable fat and bringing it back to the liver where it can be properly disposed of.

Healthy EatingA healthy diet is:

• Low in fat

• Low in sugar (especially refined, simple carbs)

• High in fiber

• Variety of vitamins & minerals

• Caloric intake should not exceed energy output!

Extra calories will be stored as fat deposits!

Exercise

At least 20 minutes of exercise per day improves:

• Weight

• Digestion

• Respiration

• Blood flow

• Energy level

• Overall health!

• Insulin (produced by the pancreas) is a hormone needed to convert sugar into a usable form for cellular respiration.

• Diabetes is a disease in which insulin either cannot be produced or not properly utilized by the body.

• Some are born with diabetes (type 1); Type 2 is caused by a poor diet (i.e. high in sugar & fat and low in fiber) and lack of exercise.

• Overweight individuals are more likely to develop diabetes.

Diabetes

• 17 million Americans have diabetes already, 5.9 million don't even know they have it.

• It is the 5th leading cause of death in the United States.

• Diabetes is often linked to heart disease which is THE leading cause of death in the US.

• Diabetes diagnosis is up 49% from 1990 to 2000. Similar increases are expected.

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.