Soil C:N

[wwieder]

Preliminary results suggest total C:N doesn't show enough spatial / latitudinal variability in MIMICS-CN.

@melanniehartman and Emily Kyker-Snowman suggested just increasing FI(struc) from 0.1 to 0.3 to evaluate the model sensitivity to this parameter change.

• As expected, this increased soil C:N by increasing C stocks the SOMc pool (and decreasing LITs).
  • Mean C:N = 13 [range 6-31] when FI=0.3 vs.
  • Mean CN = 11 [range 6-18] when FI = 0.1
• Results in boreal forests look promising, but changes in the tropics are not as convincing.
• Moreover, increases in tropical SOC stocks are w/in reality, but maybe shouldn't keep increasing?
• I'm assuming that increases in total C:N are driven by increases in SOMc, but most of the tropical SOM in in the SOMp pools, resulting in modest changes in tropical total C:N.

• The other interesting bit, is that by decreasing LITs, we're also driving a shift in microbial community composition, with a higher relative fraction of MICr in the new simulations

  NOTE the new simulation (FI = 0.3, blue lines) are not yet spun up completely and results are subject to change.

Here's the breakdown of individual pools sizes by latitude for each simulation

[wwieder]

Differences in the two simulations are pretty subtle, when looking at a map... Obs from GSDE on the left, and two MIMICS runs in center and right.