medfate (version 1.1.0)

growth: Forest growth

Description

Function growth is a forest growth model that calculates changes in leaf area, sapwood area and structural variables for all plant cohorts in a given forest stand during a period specified in the input climatic data.

Usage

growth(x, soil, meteo,  latitude, elevation = NA, slope = NA, aspect = NA)

Arguments

x

An object of class growthInput.

soil

A list containing the description of the soil (see soil).

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). When x$TranspirationMode = "Granier" the following columns are required:

• MeanTemperature: Mean temperature (in degrees Celsius).

• Precipitation: Precipitation (in mm).

• Radiation: Solar radiation (in MJ/m2/day), required only if snowpack = TRUE.

• PET: Potential evapotranspiration (in mm).

• WindSpeed: Wind speed (in m/s). If not available, this column can be left with NA values.

When x$TranspirationMode = "Sperry" the following columns are required:

• MeanTemperature: Mean temperature(in degrees Celsius).

• MinTemperature: Minimum temperature (in degrees Celsius).

• MaxTemperature: Maximum temperature (in degrees Celsius).

• MinRelativeHumidity: Minimum relative humidity (in percent).

• MaxRelativeHumidity: Maximum relative humidity (in percent).

• Precipitation: Precipitation (in mm).

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

• WindSpeed: Wind speed (in m/s). If not available, this column can be left with NA values.

latitude

Latitude (in degrees). Required when x$TranspirationMode = "Sperry".

elevation, slope, aspect

Elevation above sea level (in m), slope (in degrees) and aspect (in degrees from North). Required when x$TranspirationMode = "Sperry". Elevation is also required for 'Granier' if snowpack dynamics are simulated.

Value

A list of class 'growth' with the following elements:

• "latitude": Latitude (in degrees) given as input.

• "topography": Vector with elevation, slope and aspect given as input.

• "growthInput": A copy of the object x of class growthInput given as input.

• "soilInput": A copy of the object soil of class soil given as input.

• "WaterBalance": A data frame where different water balance variables (see spwb).

• "EnergyBalance": A data frame with the daily values of energy balance components for the soil and the canopy (only for transpirationMode = "Sperry"; see spwb).

• "Temperature": A data frame with the daily values of minimum/mean/maximum temperatures for the atmosphere (input), canopy and soil (only for transpirationMode = "Sperry"; see spwb).

• "Soil": A data frame where different soil variables (see spwb).

• "Stand": A data frame where different stand-level variables (see spwb).

• "Plants": A list of daily results for plant cohorts (see spwb).

• "SunlitLeaves" and "ShadeLeaves": A list with daily results for sunlit and shade leaves (only for transpirationMode = "Sperry"; see spwb).

• "PlantCarbonBalance": A list of daily carbon balance results for plant cohorts, with elements:

  • "GrossPhotosynthesis": Gross photosynthesis rate per dry weight of living biomass (g gluc <U+00B7> g dry-1).

  • "MaintentanceRespiration": Maintenance respiration rate per dry weight of living biomass (g gluc <U+00B7> g dry-1).

  • "GrowthRespiration": Growth respiration rate per dry weight of living biomass (g gluc <U+00B7> g dry-1).

  • "CarbonBalance": Carbon balance (photosynthesis - respiration) per dry weight of living biomass (g gluc <U+00B7> g dry-1).

  • "SugarLeaf": Sugar concentration (mol<U+00B7>l-1) in leaves.

  • "StarchLeaf": Starch concentration (mol<U+00B7>l-1) in leaves.

  • "SugarSapwood": Sugar concentration (mol<U+00B7>l-1) in sapwood.

  • "StarchSapwood": Starch concentration (mol<U+00B7>l-1) in sapwood.

• "PlantGrowth": A list of daily growth results for plant cohorts, with elements:

  • "SapwoodArea": Daily amount of sapwood area (in cm2) for an average individual of each plant cohort.

  • "LeafArea": Daily amount of leaf area (in m2) for an average individual of each plant cohort.

  • "FineRootArea": Daily amount of fine root area (in m2) for an average individual of each plant cohort (only for transpirationMode = "Sperry").

  • "SAgrowth": Sapwood area relative growth rate (in cm2<U+00B7>cm-2<U+00B7>day-1) for an average individual of each plant cohort.

  • "LAgrowth": Leaf area growth relative to sapwood area (in m2<U+00B7>cm-2<U+00B7>day-1) for an average individual of each plant cohort.

  • "FRAgrowth": Fine root area growth relative to sapwood area (in m2<U+00B7>cm-2<U+00B7>day-1) for an average individual of each plant cohort (only for transpirationMode = "Sperry").

• "StandStructures": A list with the aboveground structure of the stand at the beginning of the simulation and after each simulated year.

• "StandSummary": A data frame with stand-level summaries (leaf area index, tree basal area, tree density, shrub cover, etc.) at the beginning of the simulation and after each simulated year.

• "subdaily": A list of objects of class growth_day, one per day simulated (only if required in control parameters, see defaultControl).

Details

Detailed model description is available in the vignettes section. Simulations using the 'Sperry' transpiration mode are computationally much more expensive than those using the simple transpiration mode.

See Also

growthInput, growth_day, plot.growth

Examples

# NOT RUN {
#Load example daily meteorological data
data(examplemeteo)

#Load example plot plant data
data(exampleforestMED)

#Default species parameterization
data(SpParamsMED)

#Initialize control parameters
control = defaultControl()

#Initialize soil with default soil params (4 layers)
examplesoil1 = soil(defaultSoilParams(4))

#Initialize vegetation input
x1 = forest2growthInput(exampleforestMED, examplesoil1, SpParamsMED, control)

#Call simulation function
G1<-growth(x1, examplesoil1, examplemeteo, latitude = 41.82592, elevation = 100)

# }
# NOT RUN {
#Switch to 'Sperry' transpiration mode
control$transpirationMode="Sperry"

#Initialize soil with default soil params (4 layers)
examplesoil2 = soil(defaultSoilParams(4))

#Initialize vegetation input
x2 = forest2growthInput(exampleforestMED,examplesoil2, SpParamsMED, control)

#Call simulation function (11 days)
d = 100:110
G2<-growth(x2, examplesoil2, examplemeteo[d,], latitude = 41.82592, elevation = 100)
# }