lecture 20 - ecosystem energy flow Flashcards
energy ______ through ecosystem while chemicals ______
flow; cycle
can energy be lost
yes as heat
sun is what type of energy and heat lost to environment is what type of energy
sun = high energy
heat lost to environment = low-form energy
photoautotrophs convert
CO2 into organic moleqs
how do heterotrophs return CO2 to environment
by performing cellular respiration
what does photosynthtesis by plants remove
substantial amounts of atmospheric CO2 each year is about equal to CO2 added to atmosphere through celluluar respiration by producers and consumers
carbon can be sequestered in forms that are not readily…
bioavailable
burning of fossil fuels and wood is…
non biotic way in which CO2 is contributed to atmospher; volcanos contribute too
is nitrogen biologically available
no, but N2 is abundant
what forms of nitrogen are biologically useful as nutrients for microbes and plants
ammonium, nitrate, and nitrite
waht forms of N can animals take up
organic forms (ie amino acids)
nitrogen conversions are mediated by what
microbe metabolism
available ______ is often a limiting resource
nitrogen
what has increased total nitrogen
industrial production of N fertilzers
what are the main limiting micornutrients
-nitrogen (nitrite, nitrate, amminium)
-phosphate
-iron
-calcium
-potassium
in terrestt5rial habitats, what is the limiting nutrient usually
available nitrogen
what is an daptation legumes have regarding nitrogen
legumes have symbiont nitrogen fixing bacteria in root nodules
-convert atmospheric nitorgen gas into NH3
what is typically limiting in freshwater ecosustems
phosphate
eutrophication
process by which a body of water becomes enriched in dissolved nutrinets (such as phosphate) that stimulate the growth of aquatic plant life
what was banned in all detergents in US in in 1993
phosphate
how does energy enter ecosystem
net prunart production (new plant biomass)
how does energy flow though ecosystem
trophic interactions (consumption of other organisms)
heterotrophs =
quaternary, tertiary, secondary, prumary consymers
what do detrivores eat
-quaternary, tertiary, secondary, primary consumers and primary consumers
what moves up trophic levels as heterotrophs consume other orgnaisms
matter and energy move
food chains
show how food energy is transferred from trophic level to trophic level, beginning with producers
decomposers =
detritivores
decomposers eat
deritus
deritus
decaying materal, waste products and dead organisms
food webs
show more complex interactions among orgnisms than food chain
can a species play more than one role at more than one trophic level
yes
how can food webs be simplified
by grouping species with similar trophic relationships into broad functional groups
