Unit 4: Ecology (4.1 Species, Communities, and Ecosystems)

We are going to pass.

What is Ecology?

The study of relationships between living organisms and between organisms and their environment.

What is a Species?

It is a group of organisms, which can interbreed and produce fertile offspring.

What is a population?

It is a group of organisms of the same species who live in the same area at the same time.

What is a community?

A group of populations living and interacting with each other.

What is a Habitat?

An environment in which a species lives.

What is an Ecosystem?

It is a community and its abiotic factors.

What are Autotrophs?

• Use an external energy source to produce organic materials from inorganic raw materials from abiotic environment.

• Known as producers and are the beginning of all food chains.

• A variety of energy sources is possible with the most frequent being light.

• It is also a method of Nutrition.

What are Heterotrophs?

• Use energy in organic materials obtained from other organisms, however sodium, calcium, and potassium are often obtained as inorganic nutrients from the abiotic environment.

What are the types of Heterotrophs?

• Consumers

• Detritivores

• Saprotrophs

What is a consumer?

• an organism that ingests other organic matter that is living or recently killed.

What are a Detritivores?

• an organism that ingests nonliving organic matter. Example: earthworm

What are Saprotrophs?

• an organism that lives on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion.

• Example: bacteria and fungi

Sustainability

What are the three requirements in ecosystems?

• Recycling of Nutrients

  • carbon & nitrogen cycles

  • decomposers such as saprotrophs break down organic matter to release nutrients.

• Detoxification of waste products

• Energy availability, most commonly from the sun

  mesocosms.

What is the method to comparing Estimated Population Size?

• Quadrat Method

• Chi-Squared Test

(KNOW HOW TO DO BOTH)

What the Quadrat Method?

• choose area of study

• mark areas with tape of set size (1m x 1m)

• randomly select sample quadrats using a table or random number generator

• count number of each organism in each sample quadrat

• calculate the average number of each of the two organisms.

• multiply the average by the total number of quadrats for each organism.

• average per quadrat x Total # of quadrats for each and compare results.

What is the Chi-squared method?

Determines if there is a statistical difference between what is expected and what is observed. Expected= row total x column total/ grand total

• Mode- stat diagnostics on

• 2nd and x-1

• Edit

• Enter

• 2 x 2 (enter after each)

• Type number and then enter for each

• Stat on calculator

• Tests

• χ2 test (c) then enter

• Down to calculate and enter

• GO PRACTICE AND STUDY!!

What are the Tropic Levels?

• An organism's position in a food chain/web.

• Chemical energy in carbon flows through a food chain by being eaten by other organisms.

Top of the food chain —— to ——- Producers

• Tertiary Consumers

• Secondary Consumers

• Primary Consumers

• Producers

ENERGY FLOW IN AN ECOSYSTEM

How much energy passes between levels?

• Only between 10-20% of energy is passed between levels.

• Only available if it stored as chemical energy used in growth of an organism.

How is the rest of energy loss? what are the 3 ways?

• Some organisms are not eaten.

• Some parts are eaten but not absorbed.

  • (eg. bones/ hair) so lost as waste.

• Much of what is eaten and absorbed is used in cellular respiration and lost as heat.

  • Heat cannot be converted to other forms of energy.

• Energy leaves ecosystems as heat but nutrients must be recycled (carbon & nitrogen cycles)

What does the loss of energy restrict?

Loss of energy restricts the length of food chains.

• This leads to Less energy, biomass, and fewer organisms at the top of the pyramid.

• There is not enough energy at lower levels to support large numbers.

What is carbon fixation?

• Carbon dioxide is produced by cellular respiration and diffuses out of organisms into the atmosphere and water.

  • Non-photosynthetic cells in producers, animal cells, and saprotrophs such as fungi

• Autotrophs absorb carbon dioxide from the atmosphere and water by diffusion and convert them to organic matter.

• This reduces the amount of CO2 in the atmosphere particularly in areas with a large number of plants.

• In aquatic habitats, CO2 can dissolve into water as a gas or combine with water to make carbonic acid (H2CO3). Carbonic acid can dissociate to hydrogen and hydrogen carbonate ions (H+ and HCO3-). This is how CO2 can make water acidic.

What Cycling of Nutrients?

Cycles are a good example of interactions between biotic and abiotic factors in an ecosystem.

What is Methanogenesis?

Three groups of anaerobic bacteria involved:

• Organic Material

  • First type of bacteria: Organic acid, alcohol, hydrogen, & carbon dioxide

  • Second type of bacteria: Acetate, hydrogen, & carbon dioxide.

  • Third type of bacteria: (Archaean Bacteria): Methane

Methane in the Atmosphere

• Methane (CH4) is produced by Archaean anaerobic bacteria in environments such as:

  • Mud along the shores

  • Swamps, mires, and other wetlands in which the soil or peat is waterlogged.

  • Guts of termites or ruminant mammals (cattle & sheep)

  • Waste buried in landfills.

• Even though large amounts are produced and diffuse into the atmosphere, methane concentration in the atmosphere is not very high because it is easily and naturally oxidized to carbon dioxide and water in the stratosphere.

What is Peat?

• In waterlogged areas, the water covers dead organic matter and becomes acidic and anaerobic, so aerobic decomposers such as saprotrophs are unable to fully breakdown organic matter.

• The partially decomposed organic matter accumulates and becomes compressed to form peat.

What is fossilization?

The process of remains or traces of living things becoming fossils.

What is Combustion?

• If fossilized organic matter or biomass is heated to certain temperatures in the presence of oxygen it will combust.

• Carbon dioxide and water are released.

• A reaction of a fuel with oxygen, producing energy in the form of heat and/or light.

What is a Limestone?

• Carbon is stored in the form of calcium carbonate.

• Calcium carbonate makes up coral exoskeletons and mollusk shells that is fossilized as limestone.

LOOK AT THE CARBON CYCLE

LOOK AT THE CARBON CYCLE

Carbon Dioxide Fluctuations Within the Year: Fall-Winter

• Less plants so less photosynthesis results in more CO2 in the atmosphere.

Carbon Dioxide Fluctuations Within the Year: Spring-Summer

• More plants so more photosynthesis results in less CO2 in the atmosphere.