3. How to prepare your own data to be used for GRASSMIND?

In the following section, the file formats of relevant input files for GRASSMIND as well as the format of (required and possible additional) observation data from your grassland site are described.

3.1 Basic information

Basic information on your site and the respective plot(s) should be provided in a TXT‐file (tab-separated) with the following format and specifications:

File Format: TXT

File name: DEIMS.iD_PlotInfo.txt,

                        e.g. 102ae489‐04e3‐481d‐97df‐45905837dc1a_PlotInfo.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: PlotID latitude longitude mowing fertilization grazing irrigation

Lines: each row below the header represents the basic information of each plot included for your specific site

Columns: the following columns should include plot‐specific information on

• PlotID = a unique identifier to differentiate the plots included for your site
  
• latitude = geographical latitude of the plot (decimal unit)
  
• longitude = geographical longitude of the plot (decimal unit)
  
• mowing = value of either 0 (no mowing) or 1 (mowing) as management action
  
• fertilization = value of either 0 (no fertilization) or 1 (fertilization) as management action
  
• grazing = value of either 0 (no grazing) or 1 (grazing) as management action
  
• irrigation = value of either 0 (no irrigation) or 1 (irrigation) as management action

Please use the DEIMS.iD of your site (cf. https://deims.org/) in the filename (cf. example above).

3.2 Weather data

Weather data are required as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_Weather.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: Date Precipitation[mmd-1] Temperature[degC] PPFD[mmolm-2s-1] PET[mmd-1]

Lines: each row below the header represents the weather data of 1 day of model simulation

• first line below the header = 1st day of the envisaged simulation period
  
• last line in the file = last day of the envisaged simulation period
  
• leap years are included
  

Columns: weather variables include the following columns

• Date = date of observed weather variables (format: yyyy‐mm‐dd)
  
• Precipitation = daily sum of rainfall (unit: mm per day)
  
• Temperature = daily mean air temperature (unit: C°), e.g. measured at about 1 m height
  
• PPFD = daily mean photosynthetic photon flux density (unit: μmolphoton per m² per s)
  
• PET = potential evapotranspiration (unit: mm per day)
  

Calculations of the daily mean or sum of weather variables consider the full day of 24 hours.

You can contact us for support on PET calculation from other weather variables or for unit conversion to PPFD.

3.3 Soil data

Soil data are required as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_Soil.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: 1^st line: Silt Clay Sand

                  4^th line: Layer FC[V%] PWP[V%] POR[V%] KS[mm/d]

Lines: each row provides static soil properties in total (2^nd line) or for each soil layer (5^th – 24^th lines)

• 2^nd line: fractions of silt, clay and sand (should sum to 1)
  
• 5^th – 24^th line: properties for the respective soil layers of 10 cm depth, starting from the top (0‐10 cm, 5^th line) to the bottom soil layer (190 – 200 cm, 24^th line)
  

Columns: soil variables include the following columns

• Layer = soil layer number (numbered from top to bottom), in total 20 layers each 10 cm deep (all following variables given for each layer)
  
• FC = field capacity (unit: V% of the soil volume)
  
• PWP = permanent wilting point (unit: V% of the soil volume)
  
• POR = soil porosity, i.e. pore volume (unit: V% of the soil volume)
  
• KS = saturated hydraulic conductivity (unit: mm per day) 

Note that soil texture refers to the entire soil volume of 2 m depth and fractions of sand, silt and clay should sum up to one. All   other properties are required for each soil layer. If this information is not available per soil layer but for the total soil volume, the same values can be entered for each soil layer.

You can contact us for support on estimations of soil properties based on soil texture for specific soil layers.

3.4 Management data

Management information is required as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_Management.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: Date MowHeight[m] Fertilizer[gm-2] Irrigation[mm]

Lines: each row below the header represents one day‐specific event of a respective management action (in temporal order of occurrence within the simulation period)

Columns: management variables include the following columns

Date = date of the respective management action (format: yyyy‐mm‐dd)

MowHeight = height to which the grassland is cut down (unit: m) (> 0 if mowing is done, = 0 for no mowing on this day)

Fertilizer = added amount of nitrogen to the topsoil layer (unit: g/m²) (> 0 if fertilization is done, = 0 for no fertilization on this day)

Irrigation = added water to the topsoil layer (unit: mm) (> 0 if irrigation is done, = 0 for no irrigation on this day)

You may either use separate lines if more than one management action on the same day are planned (e.g. on 2015‐06‐22 in the screenshot above) or also combine several management actions on the same day in one line.

3.5 Grassland observation data

In the following subsections, different characteristics of grasslands are described that may have been measured. For your site, please go to the respective subsection for instructions on how to prepare the data files for comparison with model simulation results:

• Plant species composition (*required): subsection 3.5.1
  
• Vegetation cover: subsection 3.5.2
  
• Aboveground biomass: subsection 3.5.3
  
• Yield: subsection 3.5.4
  
• Leaf area index: subsection 3.5.5
  
• Any other measure: subsection 3.5.6
  

3.5.1 Plant species composition

Plant species composition should be provided as relative abundances of each PFT for at minimum one date (ideally, several dates). The data file should be provided as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_RelativeAbundance.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: 1^st line: Type of observation:

                  2^nd line: Date Grass SmallHerb TallHerb Legumes

Lines: each row below the header represents one day‐specific event of a measurements in the field referring to the observations (in a temporal order of its occurrence within the simulation period).

Columns:

• Date = date of the respective measurement (format: yyyy‐mm‐dd)
  
• Grass = relative abundance of all plant species assigned to PFT Grasses (unit: ‐)
  
• SmallHerb = relative abundance of all plant species assigned to PFT SmallHerbs (unit: ‐)
  
• TallHerb = relative abundance of all plant species assigned to PFT TallHerbs (unit: ‐)
  
• Legume = relative abundance of all plant species assigned to PFT Legumes (unit: ‐)
  

If relative abundances are recorded for each plant species, we can support you in grouping them into plant functional types (PFTs) based on their scientific Latin names. Relative abundance can be calculated based on different measurements (e.g. number of plants, biomass, cover, or other), so please also provide this information to us in order to do a correct comparison with the model simulations (type after colon in first header line Type of observation).

In the example above, we used the vegetation cover as observation type for the calculation of relative abundance of each PFT as follows:

Note that relative abundances of the four PFTs per observation date should sum up to 1. Missing values should be set to NaN.

3.5.2 Vegetation cover

Information can be provided as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_Cover.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: Date Total Grass SmallHerb TallHerb Legume Dead _Tree_Shrub __NotFound

Lines: each row below the header represents one day of the respective observation (in temporal order of occurrence within the simulation period)

Columns: observation variables include the following columns

• Date = date of the respective observation (format: yyyy‐mm‐dd)
  
• Total = cover of vegetation (unit: ‐)
  
• Grass = cover of vegetation assigned to PFT Grasses only (unit: ‐)
  
• SmallHerb = cover of vegetation assigned to PFT SmallHerbs only (unit: ‐)
  
• TallHerb = cover of vegetation assigned to PFT TallHerbs only (unit: ‐)
  
• Legume = cover of vegetation assigned to PFT Legumes only (unit: ‐)
  
• Dead = cover of dead vegetation (irrespective of PFTs) (unit: ‐)
  
• _Tree_Shrub = cover of any woody vegetation (e.g. trees or shrubs) (unit: ‐)
  
• __NotFound = cover of any non‐woody vegetation that could not be assigned to the respective four PFTs (e.g. mosses) (unit: ‐)
  

Note that the Total cover need not equal the sum of cover of the four PFTs per observation date as they may have been measured independently. All values for cover should relate to the ground area considered. If you have measured only parts of the variables, please add NaN for those not measured. Missing values should also be set to NaN.

The measurements of Grass, SmallHerb, TallHerb and Legume can be used for deriving the relative abundances of PFTs (see subsection 3.5.1 on plant species composition; Type of observation: Cover).

3.5.3 Aboveground biomass

Information can be provided as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_Biomass.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: 1^st line: Clipping height [cm]

              2^nd line: Date Total Grass SmallHerb TallHerb Legume Dead _Tree_Shrub __NotFound

Lines: each row below the header represents one day of the respective observation (in temporal order of occurrence within the simulation period)

Columns: observation variables include the following columns

• Date = date of the respective observation (format: yyyy‐mm‐dd)
  
• Total = total aboveground biomass of vegetation (unit: g_ODM per m²)
  
• Grass = aboveground biomass of vegetation assigned to PFT Grasses only (unit: g_ODM per m²)
  
• SmallHerb = aboveground biomass of vegetation assigned to PFT SmallHerbs only (unit: g_ODM per m²)
  
• TallHerb = aboveground biomass of vegetation assigned to PFT TallHerbs only (unit: g_ODM per m²)
  
• Legume = aboveground biomass of vegetation assigned to PFT Legumes only (unit: g_ODM per m²)
  
• Dead = aboveground biomass of dead vegetation (irrespective of PFTs) (unit: g_ODM per m²)
  
• _Tree_Shrub = aboveground biomass of any woody vegetation (e.g. trees or shrubs) (unit: g_ODM per m²)
  
• __NotFound = aboveground biomass of any non‐woody vegetation that could not be assigned to the respective four PFTs (e.g. mosses) (unit: g_ODM per m²)
  

Note that the sum of aboveground biomass of the four PFTs and the Dead biomass per observation date should equal the Total aboveground biomass. If present, additional biomass from species assigned to _Tree_Shrub or __NotFound should NOT be included in the Total aboveground biomass. Please also add the information at which height biomass was clipped for measurements (add after colon in first header line Clipping height). If you have measured only parts of the variables, please add NaN for those not measured. Missing values should also be set to NaN.

The measurements of Grass, SmallHerb, TallHerb and Legume can be used for deriving the relative abundances of PFTs (see subsection 3.5.1 on plant species composition; Type of observation: Biomass).

3.5.4 Yield

Information can be provided as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_Yield.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: Date Total

Lines: each row below the header represents one day of the respective observation (in temporal order of occurrence within the simulation period)

Columns: observation variables include the following columns

• Date = date of the respective observation (format: yyyy‐mm‐dd)
  
• Total = total yield (or mown aboveground biomass) of vegetation (unit: g_ODM per m²)

Note that yield (or mown aboveground biomass) refers to the cutting height defined in the management file (section 3.4). Missing values should be set to NaN.

3.5.5 Leaf area index

Information can be provided as a TXT‐file (tab‐separated) with the following format and specifications:

File format: TXT

File name: DEIMS.iD_PlotID_LAI.txt

Separator: \t (tab)

Decimal representation: . (dot)

Header: Date Total

Lines: each row below the header represents one day of the respective observation (in temporal order of occurrence within the simulation period)

Columns: observation variables include the following columns

• Date = date of the respective observation (format: yyyy‐mm‐dd)
  
• Total = leaf area index of vegetation (unit: m² per m²)
  

Missing values should be set to NaN.

3.5.6 Any other observations of grassland vegetation

Additional measurements might encompass the number of plants (individuals), vegetation height or any other observation not listed above. If you would like to add such information for the comparison of model simulations with your data, please contact us. You may also prepare already own TXT‐files (tab‐separated) with a file structure comparable to the files described above (with one TXT‐file for each additional type of observation).

3.5.7 Additional plot or site information

Please add any additional information on specific characteristics, treatments or history of your site or plots into a plain TXT‐file. This could be, for example, details on whether the plot has been sown at a specific date, weeded, or fertilized with CO2, or any site‐specific characteristics that might influence plant growth (located on a slope, located nearby agricultural fields sprayed with pesticides, …).

3.6 Examples and templates