Productivity + Measuring Productivity Flashcards
Ecosystem
A community and its physical environment treated together as a functional system
Abiotic components
- Non-living components of ecosystems
- Solar energy provides practically all the energy for ecosystems.
- Inorganic substances (ex. water, minerals) tend to cycle through ecosystems.
- Organic compounds, such as proteins, carbohydrates, lipids, and other complex molecules, form a link between biotic and abiotic components of the system
Made by living organisms
organic substances
Not made by living organisms
Inorganic substances
Biotic compontnets
- Living components of ecosystems
- Can be classified according to their mode of energy acquisition
Autotrophs
An organisms that can capture the energy in light or chemicals and use it to produce carbohydrates from simple molecules such as carbon dioxide
Heterotrophs
An organisms that cannot make its own food and instead relies on consuming other organisms; all animals, fungi and protozoans are heterotrophic, as well as most bacteria
The first stage of how things
are produced
Primary productivity
Photosynthesis
Process of using light energy to synthesise glucose from carbon dioxide and water (plants and algae)
Chemosynthesis
The production of organic compounds by bacteria or other living organisms using the energy derived from reactions with inorganic chemicals (chemosynthetic organisms)
A fundamental life process to create ATP (energy) for metabolic processes in the all living organisms
Cellular Respiration
Aerobic respiration requires…
oxygen and glucose (organic chemical) which comes from the products of photosynthesis
Source of chemical energy for life
Photosynthesis
Where does photosynthesis occur in plants and algae?
In the Chlorophyll
90% of living organisms in aquatic environments live here…
Photic zone
Biomass
Living mass of an organism
Photic zone
Place with a lot of light/access with to light
Biomass is created by…
the synthesis of organic chemicals
Most important producers in marine ecosystem:
- Phytoplankton
- Seagrass
- Kelp
Factors that Affect Photosynthesis
- Available nutrients for photosynthetic organisms
- Amount of available light (light intensity)
- Temperature
- Concentration of carbon dioxide
How does temperature affect photosynthesis?
When the water is too hot or too cold it can affect
how much carbon dioxide is dissolved. No CO2
No photosynthesis.
Light energy in the photic zone…
increases the water temperature
Increasing the temperature will increase…
kinetic particle movement and reduce the density of water (as the move apart)
Photic surface water is…
less dense and warmer
Aphotic means…
No light
Aphotic deep water is…
more dense and closer
Deep water has…
more nutrients
More nutrients means…
more productivity (photosynthesis) that can happen where light can still penetrate, but nutrients are more abundant
Chemoautotrohs
Bacteria that oxidize reduced inorganic substances (typically sulfur and ammonia compounds) and produce complex organic compounds.
The species that exist near hydrothermal vents
Extremophiles
Example of mutualistic relationship within Chemosyntheic bacteria
Giant tube worms and mussels that have the bacterial living in their gills
First Law of Thermodynamics
Energy can be converted from one form to another, but cannot be created or destroyed
Second Law of Thermodynamics
Transformations of energy always result in some loss or dissipation of energy
or
In energy exchanges in a closed system, the potential energy of the final state will be less than that of the initial state
or
Entropy tends to increase (entropy = amount of unavailable energy in a system)
The amount of new biomass made by the producers
Primary Productivity
Gross Primary Production
The amount of light or chemical energy fixed by producers in a given length of time in a given area
Net Primary Production
The amount of energy that is left over after respiration to be made into new plant biomass
The rate at which they store energy is called…
Net production
The rate of production of new biomass by consumers, using the energy gained by eating producers
Secondary Production
Formula for Net production
Net production = gross production – respiratory loses
Trophic structure of an ecosystem is…
The pattern of energy flow among different organisms
Energy Losses Through Trophic Levels
-Limits to 4/5 organisms
• Insufficient energy is available to support a large enough breeding population at trophic levels higher than these
-Total mass of organisms in a particular place (biomass) is less at higher trophic levels
-Total amount of energy stored is less at each level as one moves op a food chain
-Only 5-20% (avg. 10%) of energy in one trophic level is passed to the next.
What is the amount of energy available measured in
Kilojoules per square metre per year (kJ/m2/year)
Energy efficiency formula
(energy AFTER transfer) / (energy BEFORE transfer)×100
How much enerygy is passed to the next trophic level?
10%
What is P=C−R−F−U?
P is the energy available to pass to the next trophic level C is the energy consumed (eaten) R is the energy used in respiration F is the energy lost in faeces U is the energy lost in urine
An organisms that maintains its body temperature by exchanging heat with its surroundings (cold blooded)
Ectothermic
An organisms that maintains its body temperature by generating heat in metabolic processes (warm blooded)
Endothermic
The more efficient energy transfer is…
the more trophic levels can be supported in a food chain
A diagram that shows the number of organisms in each trophic level of a food chain
Pyramids of Numbers
A diagram that shows the biomass present in each trophic level of a food chain
Pyramid of Biomass
Biomass is a measure of…
Dry mass - water must be removed from the sample to accurately measure the mass of living tissue
To measure dry mass the organisms must be…
killed - therefore estimates are made of the population and multiplied by the typical dry mass of the species
A diagram that shows the amount of energy in each trophic level of a food chain
Pyramid of Energy
