22 Dec 2006.
Summary of discussions that took place during the visit of Christine
Klass and Sévrine Sailley,
November 27-30 2006
The visit had three purpuses. First to discuss the progress and plans of Sevrine's thesis,
second to set the basis of a zooplankton comparison (possibly also bacteria),
third to propose some model simulations that can help understand the role of loss processes.
Summary of discussions regarding Sevrine's project:
- Sevrine has a database on ciliates, and will make a similar database on dinoflagellates.
- Christine will look at CGE at optimum growth conditions (from the synthesis of lab data).
- Sevrine will work on grazing as a function of different food.
- Sevrine will compare rates from lab experiments with rates from Rivkin's database.
- Christine will apply for Euroceans funding to make a database on rates and biomass of
nano-zooplankton (for Hiwi student)
- Sevrine will come to BAS for ~1 year in Sept 2007 and work closely with Roisin.
Basic information that we would like to compare for zooplankton (possibly also bacteria)
Life time, biomass, and grazing rates are approximate. We need solid information for
those. The Q10 and GGE are values used in the PlankTOM model (from published paper or Erik's database
analysis).
| ............. | Life time | Biomass (PgC) | grazing (PgC/y) | Q10 of mortality | Q10 of grazing | Q10 of respiration | GGE | GGE from James' analysis |
| bacteria | 1 day | ? | 10 | ? | -- | 3-4 | 0.374-0.0104T | g<r |
| nano | ? | ? | ? | ? | ? | ? | ? | ? |
| micro | 1 week | 1.0 | 29 | ? | 2.20 | 2.20 | 0.3 (Straile) | 0.0727+0.0104T (g>r) |
| meso | <1 year | 0.2 | 6 | 1.99 | 1.77 | 3.16 | 0.26 (Straile) | 0.32+0.00337T (g>r, but not significant) |
| macro | 1-7 years | ? | ? | 2.06 | 1.50-1.18 | 1.96 | ? | 0.0342+0.0107T (g>r) |
(In)consistencies across data:
- The T-dependence of grazing appears to decrease with size
- if g>r, then Q10 grazing should be larger than Q10 respiration, thus the dataset is inconsistent for
both micro, meso, and macro zooplankton.
- T-dependence of mortality should be T-dependence of the grazing by the predator (for the largest zooplankton in the model).
Proposed model simulations:
This needs much more thinking.
- all zoo with the same T-dependence
- all zoo with Q10 respiration > Q10 grazing
- test for low GGE of ciliates
- remove the mortality of all zooplankton except the largest
- include a threshold concentration of feeding and remove the protection against extinction