Lesson 32 Mineral Cycling - Alaska Geobotany Center

Carbon and nitrogen cycling in terrestrial ecosystems are
tightly linked: Terrestrial Ecosystem Model
From McGuire, Melilllo, and Joyce 1995
Carbon
• C enters the vegetation pool (C v ). as
gross primary production (GPP).
• Transfers either to the atmosphere as
autotrophic plant respiration (R A )orto
the soil pool ( C S ) as litter (L C ).
• Leaves the soil pool as soil
heterotrophic respiration (R H ).
Nitrogen
• N enters the vegetation pool (N V )from
the inorganic N pool of the soil (N AV )as
NUPTAKE.
• Transfers from the vegetation to the
organic soil pool (N S ) in litter production
as the flux (L N ).
• Net nitrogen mineralization (NETNMIN)
accounts for nitrogen exchanged
between the organic and inorganic
nitrogen pool of the soil through
decomposition.
• NINPUT and NLOST are the inputs
and outputs of N to and from the
system.
Other nutrients are linked to this cycle as
they become needed for
photosynthesis, metabolism, or
structural plant tissues.