Using my own VWC data for an hourly run of the micro model

[Brandon Van Huizen]

Hi Mike,

I am working on modelling the temperature for my nests. Right now, I have the model predict what the VWC would be at each node, however, I do have observed VWC data, and was wondering if I could use that instead? Or does it require me to have VWC observations across all 10 soil nodes (I only have observations for 5 and 10 cm). 

I was also wondering which variables directly impact the evaporation calculations? I have LAI and PCTWet, but the LAI has a bigger impact on the model outputs. I wasn't really clear from the vignette  what evaporation approach was being used, it looked like a Dalton method?

Cheers,

Brandon

[Brandon Van Huizen]

As a followup to this, when running the DEB model and Ectotherm model, if I am running it for 1 year, and it outputs that the Birthday is 0, does that mean the model is predicting that none of the eggs will hatch?

I am using a microclimate model at an hourly timestep, driven by my own site specific data. But the yearout table shows the following
DEVTIME BIRTHDAY BIRTHMASS MONMATURE MONREPRO LENREPRO FECUNDITY CLUTCHES ANNUALACT MINRESERVE LASTFOOD 1 365 0 0 0 0 0 0 0 0 16204.89 0 TOTFOOD MINTB MAXTB Pct_Des LifeSpan GenTime R0 rmax Length 1 0 -24.46649 23.74627 0 0 0 0 0 61.81012

[NicheMapR]

Hi Brandon,

You can find details about the soil moisture calculations here and in this paper. Evaporation from the soil profile is influenced by the plant parameters (transpiration component) and the soil hydraulic properties that determine surface wetness (surface evaporation part). The whole model is essentially taken out of Campbell's Soil Physics with Basic book. Soil water potential and humidity drive egg water loss. You can give the model prescribed soil moisture but you would have to make assumptions for all depths, as you suggested. Instead, you could use your data to see how well the model is performing.

Re the DEB model calculations - I'd be checking the plots of the DEB state variables and see what's happening and see if it is consistent with what the YEAROUT table is saying - it does suggest development was failing. Do you have DEB parameters for your species?

All the best,
Mike

[Brandon Van Huizen]

Okay sounds good, I think I got the model to generally agree with moisture and temperature data. 

Re the DEB, yes, my species is a Blaning's Turtle (Emydoidea blandingii) which is in the database. Is there a way to specify when the eggs are first lain? I think part of the issue might be that it is starting the incubation process on January 1st, and so maybe it is too cold (Location is central Ontario, Canada). But I couldn't find a parameter that let me specify when the eggs were lain. Or do I have to truncate the time series and start the model at that date (when eggs are lain)?

[NicheMapR]

Hi Brandon,

Truncating the time series is the way to go, but let the microclimate model stabilise for a while (say 6 months) or "warm start" it with known soil moisture and temperature. It's worth trying some simulations for constant environments first to see that it's all making sense.

All the best,

Mike

[Brandon Van Huizen]

Okay sounds good. Just so I'm clear, to truncate it, do I shorten the input meteorlogical data and all of the daily values to start on the day the eggs were laid? Then run the model? Or do I run the micro climate model for the full year, and then truncate the output from the microclimate model?