The flux of energy and matter through ecosystems Flashcards
Primary Production
process by which solar energy is converted to plant biomass
what is primary production usually measured in?
dry biomass or carbon per unit of ground area
Gross Flux
total amount of CO2 fixed by plants
Net Flux
all material left behind after plants have respired
Net Primary Production depends on…
temperature, moisture, solar radiation and nutrients
Net Primary Productivity over succession
Increases rapidly at first than levels off as climax community is approached
Why does net primary production change the way it does over succession?
taller plants block out light to others
space becomes limiting
Leaf Area Index (definition)
total one-sided area of leaves per unit of ground area
What can leaf area index be used to predict?
the gross primary productivity
Leaf Area Index (formula)
LAI = leaf area (m2)/ ground area (m2)
Destructive harvesting
e.g.) grasslands, shrublands and croplands
rate of change = plant production
Allometric equations
e.g.) trees
mathematical relationship defined by some measure of size between an easy-to-measure parameter and component of NPP -> e.g.) stem diameter, foliage
Allometric requires a…
large data set
Allometric equations are…
very approximate
Allometric equations ignore…
seasonal changes
