chapter 42: ecosystems and energy Flashcards
what is an ecosystem?
consists of all the organisms living in a community, as well as the abiotic factors with which they interact
what are some examples of abiotic factors that affect ecosystem?
1) nutrients
2) temperature
3) salinity
d) weather
e) climate
f) precipitation
g) terrain
h) rocks
i) pH
j) sunlight
what two main processes do all ecosystems have?
energy flow and chemical cycling
what happens to the energy in an ecosystem?
no matter what ecosystem we look at, there is energy flow. the energy is transferred from organism to organism through consumption. ultimately, a large portion of the energy is given off as heat, which relates to the second law of thermodynamics
where does the energy for an ecosystem come from?
the sun
can a cycle go on without a continuous input of energy?
no
what happens to chemicals/ elements/ nutrients in an ecosystem?
they are constantly being cycled around. they get transferred and transformed.
what is the first law of thermodynamics?
energy cannot be created or destroyed, only transferred or transformed
what is the second law of thermodynamics?
every exchange of energy increases the entropy of the universe
what is the law of conservation of mass?
matter cannot be created or destroyed.
what are sinks?
places where nutrients and/or energy can be stored for a long time
what are autotrophs?
autotrophs build molecules themselves using photosynthesis or chemosynthesis as an energy source. they are always the base of the pyramid
what are heterotrophs?
they depend on the biosynthetic output of other living organisms.
what is biosynthetic output?
stuff made by living organisms
what is the order energy flows from in a food pyramid?
from autotrophs / primary producers -> primary consumers/ herbivores -> secondary consumers / carnivores -> tertiary consumers / carnivores -> quaternary consumers
why are the terms herbivores and carnivores not used as much?
because they can be omnivore instead of just herbivore or carnivore
can organisms be part of two trophic levels?
yes
what is the level that links all organisms together?
detritivores / decomposers
what are detritivores?
they are consumers that derive their energy from detritus, non-living organic matter (used to be alive and then died)
what are some important detritivores?
prokaryotes and fungi
who feeds on detritrivores?
every one
what do detritivores do to energy?
pass on energy to other microorganisms and release some of it as heat
what is primary production?
the amount of light converted to chemical energy by autotrophs during a given period of time
what is primary production measured in?
g/ m^2
how do they measured primary production?
take the dry mass of all the plants.
why is the dry mass of plants taken?
because some plants hold more water than others
does every ecosystem have the same amount of primary production?
no
what can vary the level of primary production?
1) levels of plants ( a lot of plant life is limited by amount of water)
2) slopes
3) terrains
4) sunlight exposure
5) angle of sunlight (steeper = less sunlight absorbed; perpendicular = more sunlight absorbed)