Maximum number of years range seems to be 235 ?

[Klemet]

Working with PnET-Succession, I made a spinup climate file (monthly format) that went from 1700-1950 (250 years).

I got a strange bug that happened at this line in a PnET library, because the climate library returned a list of years that only had 235 index (even thought there was 250 years in the file). This created an "out of bound" error.

Switching to a climate file that went from 1800-1950 solved the issue. I have no idea why it only registers 235 years and doesn't go beyond it 🤔.

[mslucash]

If you'd like me to look at this error, I'd need the full error message to try to track down the problem.

[mslucash]

Id also need your scenario file, climate txt file and two csv files to really diagnose the issue.

[Klemet]

Thank you Melissa ! Yeah, I should have given some files.

In this folder, you will find :

• The test files that are creating the issue (TestScenarioPnET.zip)
• The docker image used to run the simulation (Clean_Docker_LANDIS-II_8_AllExtensions_PnETCalibration.zip). I've added some lines at the end of the dockerfile that can be uncommented to re-build the PnET-Cohort library to add a couple of debug messages in the functions of the PnET-Cohort library that seems to be causing the issue (EcoregionData.GetClimateRegionData()).

Here is the original error message (without debug messages, which can be found in this log : LANDIS-log_WithoutDebug.txt) :

2026-02-09 08:06:04,213 - Running Output-PnET ...
2026-02-09 08:06:04,353 - Current time: 10
2026-02-09 08:06:04,353 - Running PnET-Succession ...
2026-02-09 08:06:05,072 - Running Output-PnET ...
2026-02-09 08:06:05,166 - Current time: 20
2026-02-09 08:06:05,166 - Running PnET-Succession ...
2026-02-09 08:06:05,790 - Running Output-PnET ...
2026-02-09 08:06:05,864 - Current time: 30
2026-02-09 08:06:05,864 - Running PnET-Succession ...
2026-02-09 08:06:05,865 - Internal error occurred within the program:
2026-02-09 08:06:05,865 -   Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
2026-02-09 08:06:05,865 - 
2026-02-09 08:06:05,865 - Stack trace:
2026-02-09 08:06:05,874 -    at System.Collections.Generic.List`1.get_Item(Int32 index)
   at Landis.Library.PnETCohorts.EcoregionData.GetClimateRegionData(IEcoregionPnET ecoregion, DateTime start, DateTime end)
   at Landis.Extension.Succession.BiomassPnET.PlugIn.AgeCohorts(ActiveSite site, UInt16 years, Nullable`1 successionTimestep) in /usr/bin/LANDIS_Linux/Core-Model-v8-LINUX/Extension-PnET-Succession/src/PlugIn.cs:line 679
   at Landis.Library.Succession.ExtensionBase.AgeCohorts(IEnumerable`1 sites, Boolean isSuccessionTimestep)
   at Landis.Library.Succession.ExtensionBase.Run()
   at Landis.Extension.Succession.BiomassPnET.PlugIn.Run() in /usr/bin/LANDIS_Linux/Core-Model-v8-LINUX/Extension-PnET-Succession/src/PlugIn.cs:line 697
   at Landis.Model.Run(ExtensionMain extension)
   at Landis.Model.Run(String scenarioPath, IUserInterface ui)
   at Landis.App.Main(String[] args) in /usr/bin/LANDIS_Linux/Core-Model-v8-LINUX/Tool-Console/src/App.cs:line 98

The problem goes away if we reduce the number of years in the spinup file (in the test files I sent, using the file dataFrameClimate_SpinupMonthly_Ouranos_1800.csv for the spinup in ClimateConfigSimpleSims.txt instead of dataFrameClimate_SpinupMonthly_Ouranos.csv removes the error).

To see the issue with the number "235", I'm inserted a couple of debug messages in the code to show the state of the variables (especially those in EcoregionData.GetClimateRegionData() of PnET-Cohort, which is where we can see the problem happening). The debug is a raise a of new exception in EcoregionData.GetClimateRegionData() to show which is the variable causing the index error. Here, we can see that it's once the simulation has reached 235 years after the earliest year in the spinup file (1700), it reaches a year index that is above the maximum count of yearly values returned by the Climate library with Climate.Climate.FutureEcoregionYearClimate[ecoregion.Index] (here in the code). So the problem doesn't seem to come from the PnET-Cohort code, as the check is correct; what's not normal is that the climate library seems to return a list of years that only goes up to 235 years, even though there should be more.

Here is the error with the new exception for the debug (in this other log : LANDIS-log_WithDebug.txt) :

2026-02-09 07:58:37,547 - Internal error occurred within the program:
2026-02-09 07:58:37,547 -   Year index 236 (year 1935) out of range for ecoregion 1. Max: 235
2026-02-09 07:58:37,547 - 
2026-02-09 07:58:37,547 - Stack trace:
2026-02-09 07:58:37,556 -    at Landis.Library.PnETCohorts.EcoregionData.GetClimateRegionData(IEcoregionPnET ecoregion, DateTime start, DateTime end)
   at Landis.Extension.Succession.BiomassPnET.PlugIn.AgeCohorts(ActiveSite site, UInt16 years, Nullable`1 successionTimestep) in /usr/bin/LANDIS_Linux/Core-Model-v8-LINUX/Extension-PnET-Succession/src/PlugIn.cs:line 679
   at Landis.Library.Succession.ExtensionBase.AgeCohorts(IEnumerable`1 sites, Boolean isSuccessionTimestep)
   at Landis.Library.Succession.ExtensionBase.Run()
   at Landis.Extension.Succession.BiomassPnET.PlugIn.Run() in /usr/bin/LANDIS_Linux/Core-Model-v8-LINUX/Extension-PnET-Succession/src/PlugIn.cs:line 697
   at Landis.Model.Run(ExtensionMain extension)
   at Landis.Model.Run(String scenarioPath, IUserInterface ui)
   at Landis.App.Main(String[] args) in /usr/bin/LANDIS_Linux/Core-Model-v8-LINUX/Tool-Console/src/App.cs:line 98

My guess is that the number 235 might be a currently hard-coded limitation in the climate library. Maybe a int limit or something like this ? Not sure !