Terrestrial
Production
ProcessesPrepared by: Nikki Rose D. Dapanas
BS Environmental Science III
Prof. Magdalyna Dulay
Course Outline:Chapter 1:Terrestrial
Production Processes
Overview
Gross Primary Production (GPP)
Plant Respiration
Course Outline:
Chapter 1:Terrestrial
Production Processes
Net Primary Production (NPP)
Net Ecosystem Production
Net Ecosystem Exchange
Overview…The balance between gross
primary production and
ecosystem respiration
determines the net carbon
accumulation by the biosphere.
Overview…This chapter describes
the factors that regulate
the carbon balance of
terrestrial vegetation and
ecosystems.
Gross Primary Production
(GPP)… total influx of
carbon into an
ecosystem
through the
photosynthetic
fixation of CO2
Net Primary Production
(NPP)…
gross carbon influx
discounted for plant
respiratory costs of
growth and
maintenance.
NPP= GPP-
Respiration(Plant)
major carbon
fluxes of an
ecosystem.
Carbon as
GPP, through
photosynthesis
by plants. Roots
and aboveground
portions of
plants return
about half of this
carbon to the
atmosphere as
plant respiration
(Rplant).
Net Ecosystem Production
(NEP)…
correlates more
strongly w/time
since disturbance
than w/
environment
Net Ecosystem Exchange
(NEE)…provides a direct
measure of the
net CO2
exchange
between
ecosystems and
the atmosphere.
Measuring GPP and
NPP
Meteorological
towers
Satellites
Other remote
sensing devices
Figure 2: Meteorological towers like
this one located in a temperate forest
are distributed across ecosystems in
all continents except
Antarctica, providing assessments of
carbon uptake by
forest, grassland, desert, and crop
ecosystems.
Terrestrial Primary Production
and Global Change
climate change is
affecting the
primary production
of terrestrial
ecosystems &
conversely
Terrestrial Primary Production
and Global Change
ecosystems may
moderate changes in
global climate by
absorbing
anthropogenic CO2
emissions.
Terrestrial Primary Production
and Global Change
important ecosystem
service
locking up carbon in
biomass that might
exist in the
atmosphere as CO2
Terrestrial Primary Production
and Global Change
terrestrial NPP may
be declining in
response to global
warming and
accompanying
drought
Terrestrial Primary Production
and Global Change
reduce carbon
sequestration
by terrestrial
ecosystems
Terrestrial Primary Production
and Global Change
compromise food
security
disrupt the
foundation of food
webs.