spwb {medfate}R Documentation

Soil-plant water balance

Description

Function spwb() is a water balance model that determines changes in soil moisture, soil water potentials, plant transpiration and drought stress at daily steps for a given forest stand during a period specified in the input climatic data. Function pwb() performs plant water balance only (i.e. soil moisture dynamics is an input) at daily steps for a given forest stand during a period specified in the input climatic data. On both simulation functions plant transpiration and photosynthesis processes are conducted with different level of detail depending on the transpiration mode.

Usage

spwb(
  x,
  meteo,
  latitude,
  elevation,
  slope = NA_real_,
  aspect = NA_real_,
  CO2ByYear = numeric(0),
  waterTableDepth = NA_real_
)

pwb(
  x,
  meteo,
  W,
  latitude,
  elevation,
  slope = NA_real_,
  aspect = NA_real_,
  canopyEvaporation = numeric(0),
  snowMelt = numeric(0),
  soilEvaporation = numeric(0),
  herbTranspiration = numeric(0),
  CO2ByYear = numeric(0)
)

Arguments

x

An object of class spwbInput.

meteo

A data frame with daily meteorological data series. Row names of the data frame should correspond to date strings with format "yyyy-mm-dd" (see Date). Alternatively, a column called "dates" or "Dates" can contain Date or POSIXct classes. The following columns are required and cannot have missing values:

  • MinTemperature: Minimum temperature (in degrees Celsius).

  • MaxTemperature: Maximum temperature (in degrees Celsius).

  • Precipitation: Precipitation (in mm).

The following columns are required but can contain missing values (NOTE: missing values will raise warnings):

  • MinRelativeHumidity: Minimum relative humidity (in percent).

  • MaxRelativeHumidity: Maximum relative humidity (in percent).

  • Radiation: Solar radiation (in MJ/m2/day).

The following columns are optional:

  • WindSpeed: Above-canopy wind speed (in m/s). This column may not exist, or can be left with NA values. In both cases simulations will assume a constant value specified in defaultControl.

  • CO2: Atmospheric (above-canopy) CO2 concentration (in ppm). This column may not exist, or can be left with NA values. In both cases simulations will assume a constant value specified in defaultControl.

  • Patm: Atmospheric pressure (in kPa). This column may not exist, or can be left with NA values. In both cases, a value is estimated from elevation.

latitude

Latitude (in degrees).

elevation, slope, aspect

Elevation above sea level (in m), slope (in degrees) and aspect (in degrees from North).

CO2ByYear

A named numeric vector with years as names and atmospheric CO2 concentration (in ppm) as values. Used to specify annual changes in CO2 concentration along the simulation (as an alternative to specifying daily values in meteo).

waterTableDepth

Water table depth (in mm). When not missing, capillarity rise will be allowed if lower than total soil depth.

W

A matrix with the same number of rows as meteo and as many columns as soil layers, containing the soil moisture of each layer as proportion of field capacity.

canopyEvaporation

A vector of daily canopy evaporation (from interception) values (mm). The length should match the number of rows in meteo.

snowMelt

A vector of daily snow melt values (mm). The length should match the number of rows in meteo.

soilEvaporation

A vector of daily bare soil evaporation values (mm). The length should match the number of rows in meteo.

herbTranspiration

A vector of daily herbaceous transpiration values (mm). The length should match the number of rows in meteo.

Details

The simulation functions allow using three different sub-models of transpiration and photosynthesis:

Simulations using the 'Sperry' or 'Sureau' transpiration mode are computationally much more expensive than 'Granier'.

Value

Function spwb returns a list of class 'spwb' whereas function pwb returns a list of class 'pwb'. There are many elements in common in these lists, so they are listed here together:

When transpirationMode = "Granier", element "Plants" is a list with the following subelements:

If transpirationMode="Sperry" or transpirationMode="Sureau", element "Plants" is a list with the following subelements:

Author(s)

References

De Cáceres M, Martínez-Vilalta J, Coll L, Llorens P, Casals P, Poyatos R, Pausas JG, Brotons L. (2015) Coupling a water balance model with forest inventory data to predict drought stress: the role of forest structural changes vs. climate changes. Agricultural and Forest Meteorology 213: 77-90 (doi:10.1016/j.agrformet.2015.06.012).

De Cáceres M, Mencuccini M, Martin-StPaul N, Limousin JM, Coll L, Poyatos R, Cabon A, Granda V, Forner A, Valladares F, Martínez-Vilalta J (2021) Unravelling the effect of species mixing on water use and drought stress in holm oak forests: a modelling approach. Agricultural and Forest Meteorology 296 (doi:10.1016/j.agrformet.2020.108233).

Granier A, Bréda N, Biron P, Villette S (1999) A lumped water balance model to evaluate duration and intensity of drought constraints in forest stands. Ecol Modell 116:269–283. https://doi.org/10.1016/S0304-3800(98)00205-1.

Ruffault J, Pimont F, Cochard H, Dupuy JL, Martin-StPaul N (2022) SurEau-Ecos v2.0: a trait-based plant hydraulics model for simulations of plant water status and drought-induced mortality at the ecosystem level. Geoscientific Model Development 15, 5593-5626 (doi:10.5194/gmd-15-5593-2022).

Sperry, J. S., M. D. Venturas, W. R. L. Anderegg, M. Mencuccini, D. S. Mackay, Y. Wang, and D. M. Love. 2017. Predicting stomatal responses to the environment from the optimization of photosynthetic gain and hydraulic cost. Plant Cell and Environment 40, 816-830 (doi: 10.1111/pce.12852).

See Also

spwbInput, spwb_day, plot.spwb, extract, summary.spwb, forest, aspwb

Examples


#Load example daily meteorological data
data(examplemeteo)

#Load example plot plant data
data(exampleforest)

#Default species parameterization
data(SpParamsMED)

#Define soil with default soil params (4 layers)
examplesoil <- defaultSoilParams(4)

#Initialize control parameters
control <- defaultControl("Granier")

#Initialize input
x1 <- spwbInput(exampleforest,examplesoil, SpParamsMED, control)

#Call simulation function
S1 <- spwb(x1, examplemeteo, latitude = 41.82592, elevation = 100)

#Switch to 'Sperry' transpiration mode
control <- defaultControl("Sperry")

#Initialize input
x2 <- spwbInput(exampleforest,examplesoil, SpParamsMED, control)

#Call simulation function
S2 <- spwb(x2, examplemeteo, latitude = 41.82592, elevation = 100)

#Switch to 'Sureau' transpiration mode
control <- defaultControl("Sureau")

#Initialize input
x3 <- spwbInput(exampleforest,examplesoil, SpParamsMED, control)

#Call simulation function
S3 <- spwb(x3, examplemeteo, latitude = 41.82592, elevation = 100)
[Package medfate version 4.4.0 Index]