Ecology Lesson 4 Flashcards
(60 cards)
Ecosystem function
Species interactions. Energy and nutrient flows. It is how an ecosystem ‘works’. Humans are altering ecosystem function. It’s responsible for the ability of the earth to support life. Can be viewed as how energy passes through and the cycling of nutrients.
Components of an ecosystem
Embedded within the physical environment (climate, geology, oceanography, etc.). Living and non-living components:
* Living organisms
* Dead organisms
* Physical environment
Layers of ecosystem
Primary produces are autotrophs (first layer that turns light into energy). Then primary consumers eat them, and secondary consumer eats primary. Then detritus is dead organisms, and decomposers break down dead materials to cycle back.
What are heterotrophs in the cycle
Primary and secondary consumers. Decomposers.
This is to ensure the ecosystems are sustainable we must what?
Turn dead organisms into nutrients.
Living components
Group of organisms that process energy and nutrients in similar ways (aka feed the same way).
How are the components connected?
Organisms to organisms (energy flow) and Organisms to the physical environment (nutrients flow)
What is the ecosystem function characterized by?
the connections between components and the flow of energy and nutrients.
The ecosystem energetics
Ecosystems (and life) are powered by the sun (the energy that it releases. Radiant energy to photosynthesis to chemical energy.
What do primary producers do?
Capture radiant energy (photosynthesis) and store chemical energy (molecular bonds in organic compounds like carbs, sugars, ATP, and it’s stored in the organism as chemical energy). It takes the light and turns it into their physical structure.
What do ecosystems transfer?
Transfer chemical energy through consumption (transfer to consumers) and death (transfer to detritus).
Detritus
A pool of energy. The producers and consumers die and their body on ground becomes detritus.
What do ecosystems lose?
Ecosystems lose heat energy through respiration. Each level does respiration.
What must the ecosystem have?
Continuous energy in from the sun.
Decomposers
Bacteria that eat detritus. They help the flow of energy. Invertebrates, fungi, bacteria. Obtain chemical energy and nutrients from detritus (dead
organisms) then recycle it to keep the flow going.
Return some nutrients to physical environment.
One way energy flow in ecosystems?
enters as radiant energy, stored and transferred as chemical energy, leaves as heat energy.
How much energy is lost during each tropic level?
10% of the energy is lost. This can be because the consumer doesn’t eat the whole thing.
How can we compare ecosystem energy flows?
Amount of energy reaching ecosystem
Efficiency of energy capture
Transfer rates
Rates of energy loss
Circular flow of nutrients?
Nutrients mostly retained. Cycle between organisms and physical environment. The nutrients in the environment goes back into the primary producers.
Carbon cycle
Plants get CO 2 from atmosphere and convert to organic carbon (Org C). Org C transferred among components. CO 2 returned to atmosphere through respiration, then back into the plants.
How can we compare ecosystem nutrient cycles?
Nutrient stores in physical environment.
Efficiency of nutrient uptake (some organisms evolved to flourish in low nutrient environments).
Transfer rates (how fast are the nutrients moving around).
Retention of nutrients in the environment.
Ecosystem Health
An ecosystem processes and transfers energy and
nutrients
* Fueled by energy from outside the ecosystem.
* Cycle and recycle nutrients from and to the
physical environment.
An ecosystem might be ‘unhealthy’ if it is less
able to what?
Obtain or transfer energy (ie. not enough producers)
Cycle or retain nutrients (not enough species)
Rate of primary production
Rate that primary producer biomass is built. How effective is sunlight being turned into primary produce of biomass. Energy capture and nutrient
uptake. Death rates. Plant respiration (heat loss). Use satellites to measure how much chlorophyll is in the plant (the productivity of the plant).
