Unit 2- Ecology and Ecosystem Dynamics Flashcards
Ecology
The study of the interactions among organisms, and between organisms and their abiotic environment
Population
A group of organisms of the same species that live and interact together
Community
Consists of all the populations of different species that live and interact together
Biotic
Living things
Ecosystem
Biotic communities and their abiotic components that interact in a defined geographic area
Abiotic
Non-living
What are the 4 spheres
- Atmosphere-air and gases
- Lithosphere-rock layer
- Hydrosphere-water
- Biosphere-organisms
The focus in ecology is restricted to?
The superficial layer
Species
Individuals that share common genetic characteristics and are able to breed and produce viable offspring
Landscapes
Connections linking several ecosystems in a particular region
What are feedback loops?
The output of the system feeds back into the system as an input and leads to changes in that system
Negative feedback loops
Input and output cancel each other out, stabilizing the system
ex. internal temp, predator and prey (population)
Positive feedback loops
The output feeds back into the system and drives it further in one direction towards an extreme. A big increase or decrease
ex. Overpopulation, soil erosion, deforestation, climate change with CO2 emissions
What would happen if there was only positive feedback?
The ecosystem would be thrown off balance
Energy flows in ____ direction?
One
Energy
The capacity/ability to do work
What are the forms of energy to consider?
Potential (stored)
Kinetic (motion, work, heat, light)
First law of thermodynamics
Energy cannot be created nor destroyed but can be transformed
ex. solar energy transformed into thermal energy, solar energy into sugar (photosynthesis)
Three categories of organisms based on how they obtain nourishment
- Producers (plants)
Trap solar energy and turn it into sugars (photosynthesis)
-Energy is trapped in the bonds between C, H, and O - Consumers/Heterotrophs
Feed on others to obtain potential energy
-Herbivores
-Carnivores
-Omnivores - Decomposers
Break down remains and waste products as a part of the cycling of materials
-Fungi
-Bacteria
Second law of thermodynamics
Energy transformations are inefficient (loss of energy)
As energy is transformed from one form to another, there is loss that cannot be used for useful work
With each transformation there is energy loss
What is necessary for photosynthesis?
Carbon dioxide + water + solar energy = glucose/sugar + oxygen
Stored potential energy trapped in the chemical bonds in the sugar is converted to _____ by all living organisms?
Kinetic energy
Kinetic energy includes
Work
Heat
Light
Respiration includes
Glucose/sugar + oxygen = Carbon dioxide + water + kinetic energy
Flow of Energy
Food chains and Food webs
Each level is a trophic level
1st trophic level: Producers
2nd trophic level: Primary consumers
3rd trophic level: Secondary consumers
4th trophic level: Tertiary consumers
5th trophic level: Decomposers
Biological production
A method to quantify the energy trapped by plants
P = Biomass 2 - Biomass 1
Used to asses changes over time, between locations etc.
Materials move from one place (source) to another (sink) by way of a _____ called _______.
Pathway
Reservoirs
What are macronutrients? (sponch)
Required in large amounts as cell “building blocks”
Sulfur, phosphorus, oxygen, nitrogen, carbon, hydrogen
Micronutrients
Elements required in small amounts or moderate amounts by only some forms of life (vitamins, coenzymes)
The availability of these chemicals (macro and micro nutrients) influences?
What species will be present in the environment and how many individuals can be supported in that environment
Carbon exists in which two forms?
- Inorganic
-Carbonic acid/bicarbonates/carbonates that move through the environment without biotic influence - Organic
-Glucose, cellular material that is related to biotic processes
What are the two types of carbon cycles?
- Geological
-Physical and chemical process
-no life involved
ex. Erosion
- Biological
-Involved in our food web
ex. Photosynthesis
The carbon cycle steps
- Release of CO2 into the Atmosphere by volcanism
- CO2 combines with rain to form carbonic acid
- Carbonic acid reacts with rocks
- Carbon is carried by rivers
- Carbon is used to form animal shells
- When animals die, their shells form limestone
- Subduction of carbonate rocks
Photosynthesis moves _____ from the _____ to the _______.
Respiration, decomposition, and combustion moves ______ from the _______ to the _______.
Carbon dioxide, atmosphere, biosphere
Carbon dioxide, biosphere, atmosphere
The carbon cycle reactions occur _____ of biota
Independently
Photosynthesis, respiration, decoposition, and combustion contribute to the movement of _____ between the ______ and ______ and vice versa.
Sedimentation of dead organisms contributes to the formation of _________ within the ______.
Carbon, atmosphere, biosphere
Fossil fuels (coal, natural gas, oil), lithosphere
Human influences on the carbon cycle
- Extraction/combustion of fossil fuels (which disrupts the cycle)
- Landscape alterations (deforestation/climate change)
-fossil fuel combustion adds carbon to the atmosphere
-deforestation reduces the movement of carbon from the atmosphere to the biosphere
Increase fires from climate change moves carbon to the atmosphere
The atmosphere is ____% nitrogen gas
78%
Is N2 available to most organisms?
No
What transforms nitrogen from one form to another to be available for organisms?
Bacteria
What are the 4 forms of nitrogen?
- Nitrogen gas in the atmosphere
- Ammonia
- Nitrate
- Organic forms (proteins, DNA, RNA, etc.)
Step 1(nitrogen cycle)
Nitrogen fixation
Taking N2 gas from the atmosphere and turning it into ammonia
Which bacteria is found in nodules found in the roots of legumes?
Rhizobium
Which bacteria is found in water?
Cyanobacteria
How are humans no longer reliant on bacterial reactions to create fertilizers?
The Haber Process reaction
-annual N2 fixation rates double
-can lead to water contamination
Step 2 (nitrogen cycle)
Nitrification
-ammonia converted to nitrate through nitrifying bacteria
Step 3 (nitrogen cycle)
Denitrification
-nitrate converted back to nitrogen gas through denitrifying bacteria
Step 4 (nitrogen cycle)
Ammonia and nitrate uptake
-Organisms (plants/bacteria) take up ammonia to create amino acids and proteins
Step 5 (nitrogen cycle)
Ammonification
-N-wastes generated, decaying organisms
-Proteins, wastes are transformed back into ammonia through ammonifying bacteria
Is there any phosphorus in the atmosphere?
No
Phosphorus exists in the form of P combined with ____ and other molecules
Oxygen (orthophosphate)
What are the reservoirs of the phosphorus cycle?
Rock (lithosphere), soils, plants and animals, sediments of lakes and oceans, polluted water
Phosphorus cycle
P liberated from rock through the slow process of weathering and erosion
Phosphorus is essential in
Building DNA, energy, and healthy bones
