What is an ecosystem and what are its components?
-Ecosystem: particular location on Earth distinguished by its particular mix of interacting biotic and abiotic components
-Biotic: trees, plants, birds, mammals, insects, fungi, bacgeria
--Distinct, represent biodiversity of ecosystem
-Abiotic: sunlight,
How would you know when you left one ecosystem and entered another?
-Boundaries vary greatly, can depend on what component of ecosystem you are looking at
-Many boundaries can be defined by biotic and abiotic components: help trace cycling of energy and matter
-Well defined: cave, aquatic
-Subjective/difficult to define:
How are ecosystem boundaries imposed by humans sometimes different from natural boundaries?
-National park boundaries don't necessarily mark end of one ecosystem, beginning of another-->organisms, matter, and energy go in and out of boundaries
Why is photosynthesis an important process?
-Most energy comes from sun (solar energy is a form of kinetic energy), so photosynthesis is an important process that producers/autotrophs use to convert solar energy into usable energy
-solar energy+CO2+water-->C6H12O6 (glucose)
-Glucose is usable by ma
What determines the productivity of an ecosystem?
-Gross primary productivity: total amt of solar energy that producers in an ecosystem capture via photosynthesis over a given amt of time (must determine rate of photosynthesis and respiration); total amt of energy captured by producers
-Net primary produ
How efficiently is energy transferred between trophic levels in an ecosystem?
--Ecological efficiency: proportion of consumed energy that can be passed from one trophic level to another
--avg abt 10% across all ecosystems (of total biomass, only 10% can be converted into energy @ the next higher trophic level
What are the dominant elements that make up living organisms?
-Carbon
-Hydrogen
-Nitrogen
-Oxygen
-Phosphorus
What role does water play in nutrient cycling?
-Evaporation-->condensation-->precipitation-->taken up by plants, runoff, goes into groundwater
-Carries nutrients throughout all parts of Earth
What are the main similarities and differences among the carbon, nitrogen, and phosphorus cycles?
...
Why is Hubbard Brook valuable as a study area? What does it teach us?
-Hubbard Brook is an ideal watershed situation: no deep percolation of water, all precip leaves watershed by evapotranspiration or runoff
-Helps us understand effects of clear-cutting and subsequent suppression of plant regrowth
-Learned that forests, gra
What is the difference between resistance and resilience in an ecosystem?
-Resistance: measure of how much a disturbance can affect the flows of energy and matter (high resistance: no effect on overall flow of energy and matter
-Resilience: rate at which an ecosystem returns to its original state after a disturbance (high resil
What is the intermediate disturbance hypothesis?
-ecosystems experiencing intermediate levels of disturbance are more diverse than those w/ high or low disturbance levels
What factors go into calculating the instrumental value of an ecosystem?
-something that has worth as an instrument or a tool that can be used to accomplish a goal
-how much economic benefit a species bestows
-i.e. lumber or pharmaceutical drugs
What are the five categories of ecosystem services?
-Provisions: goods that humans can use directly (i.e. lumber, crops, medicinal plants)
-Regulating services: regulate environmental conditions (i.e. ecosystems remove CO2 from atmosphere, gives us more time w/ climate change)
-Support systems: natural hel
How do the instrumental and intrinsic values of ecosystems differ?
-Instrumental value: quantitative value that can be assigned to a natural product
-Intrinsic value: cannot be quantified, value independent of any benefit it may provide to humans
NPP of ecosystems
25-50% of GPP, or as little as .25% of solar energy striking planet
-1% sun's energy captured by a producer (indv GPP), 60% used to fuel producer's respiration, remaining energy (indv NPP) is 40% used to support growth and reproduction
-Helps us observe c
Eutrophication
algae covers surface, plants underneath can't photosynthesize-->die, no enough oxygen for other organisms-->DEAD ZONES (loss of biodiversity)