Ecosystem Ecology Flashcards
What is needed to maintain complex biological life?
constant input of energy
Nutrients can partially
be recycled indefinetly
What is sustainable harvesting?
over time, tree population reaches a stable age (or stage) distribution after which population growth either stabilizes, declines, or increases
How much of the world’s energy does the US use?
19%
When building, what is most energy used for?
space heating/cooling and water heating
What is an ecosystem?
biological community plus abiotic factors
What is the main focus of ecosystem ecology?
the study of energy flow and mineral cycling
What is autotroph?
captures energy and carbon from inorganic sources
What is photosynthesis?
captures energy from light to build carbon compounds
What is chemosynthesis?
uses energy from inorganic sources to build carbon compounds
What are primary producers examples
photosynthetic plants and algae
What is respiration?
releases energy from chemicals for use in sustaining life
What type of organism captures energy from inorganic sources?
autotrophs
What happens to solar energy if refelcted?
lost
What happens to solar energy is absorbed and released as heat?
lost
What happens to solar energy for gross primary production (GPP)?
absorbed and potentially used to sustain life
What happens to solar energy for autotrophic respiration (Ra)?
lost
What is Net primary productivity (NPP) available for?
growth
What is Odum’s Sankey Diagrams?
arrows show direction and magnitude of flows and cycles in ecosystem
What is the first law of thermodynamics?
in a closed system, energy cannot be created or destroyed, it can only change form
What is the second law of thermodynamics?
due to losses of energy as heat during reactions, closed systems increase in disorder (entropy) over time
What is needed to sustain order (complexity)?
external energy
What do the laws of thermodynamics demonstrate?
that life on Earth is only sustainable due to the energy input of the sun
Where does all energy and carbon originate?
in the primary producer
What do energy relationships determine?
how much land area is needed for such things as heating energy, food, and waste handling capacity of ecosystems
What is ecological footprint?
the area of land needed to sustainable support food and fiber, timber and paper, livestock, etc
What is the ecological footprint calculated to be?
1.5x area of earth
What is the carbon cycle?
movement of carbon among ecosystem compartments (living and nonliving entities)
What is primary productivity often measured in?
biomass
What does below ground NPP contribute to?
long term carbon storage (source or sink) in soils
What type of reaction is Photosynthesis (GPP)?
endergonic (endothermic)
What are endergonic reactions used for in photosynthesis?
to capture energy and build carbohydrates from inorganic carbon
What type of reaction is respiration (R)?
exergonic (exothermic) reactions used
What are exergonic reactions used for?
to release energy from organic compounds such as carbohydrates
In stable situations what does GPP equal?
R
In stable situations, what does NPP equal?
zero
Ordinarily, what does GPP equal?
> R
Ordinarily, what does NPP equal?
positive