Fitting pressurevolume curves
fit_PV_curve(
data,
varnames = list(psi = "psi", mass = "mass", leaf_mass = "leaf_mass", bag_mass =
"bag_mass", leaf_area = "leaf_area"),
title = NULL
)
Dataframe
Variable names. varnames = list(psi = "psi", mass = "mass", leaf_mass = "leaf_mass", bag_mass = "bag_mass", leaf_area = "leaf_area") where psi is leaf water potential in MPa, mass is the weighed mass of the bag and leaf in g, leaf_mass is the mass of the leaf in g, bag_mass is the mass of the bag in g, and leaf_area is the area of the leaf in cm2.
Graph title
fit_PV_curve fits pressurevolume curve data to determine: SWC: saturated water content per leaf mass (g H2O g leaf dry mass ^ 1), PI_o: osmotic potential at full turgor (MPa), psi_TLP: leaf water potential at turgor loss point (TLP) (MPa), RWC_TLP: relative water content at TLP (%), eps: modulus of elasticity at full turgor (MPa), C_FT: relative capacitance at full turgor (MPa ^ 1), C_TLP: relative capacitance at TLP (MPa ^ 1), and C_FTStar: absolute capacitance per leaf area (g m ^ 2 MPa ^ 1). Element 1 of the output list contains the fitted parameters, element 2 contains the waterpsi graph, and element 3 contains the 1/psi100RWC graph.
Koide RT, Robichaux RH, Morse SR, Smith CM. 2000. Plant water status, hydraulic resistance and capacitance. In: Plant Physiological Ecology: Field Methods and Instrumentation (eds RW Pearcy, JR Ehleringer, HA Mooney, PW Rundel), pp. 161183. Kluwer, Dordrecht, the Netherlands
Sack L, Cowan PD, Jaikumar N, Holbrook NM. 2003. The 'hydrology' of leaves: coordination of structure and function in temperate woody species. Plant, Cell and Environment, 26, 13431356
Tyree MT, Hammel HT. 1972. Measurement of turgor pressure and water relations of plants by pressure bomb technique. Journal of Experimental Botany, 23, 267
# \donttest{
# Read in data
data < read.csv(system.file("extdata", "PV_curve.csv",
package = "photosynthesis"
))
# Fit one PV curve
fit < fit_PV_curve(data[data$ID == "L2", ],
varnames = list(
psi = "psi",
mass = "mass",
leaf_mass = "leaf_mass",
bag_mass = "bag_mass",
leaf_area = "leaf_area"
)
)
# See fitted parameters
fit[[1]]
#> SWC PI_o psi_TLP RWC_TLP eps C_FT C_TLP C_FTStar
#> 1 2.438935 1.399302 1.75 88.67684 12.20175 0.06456207 0.09923338 0.5161476
# Plot water mass graph
fit[[2]]
# Plot PV Curve
fit[[3]]
# Fit all PV curves in a file
fits < fit_many(data,
group = "ID",
funct = fit_PV_curve,
varnames = list(
psi = "psi",
mass = "mass",
leaf_mass = "leaf_mass",
bag_mass = "bag_mass",
leaf_area = "leaf_area"
)
)
#>

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# See parameters
fits[[1]][[1]]
#> SWC PI_o psi_TLP RWC_TLP eps C_FT C_TLP C_FTStar
#> 1 2.438935 1.399302 1.75 88.67684 12.20175 0.06456207 0.09923338 0.5161476
# See water mass  water potential graph
fits[[1]][[2]]
# See PV curve
fits[[1]][[3]]
# Compile parameter outputs
pars < compile_data(
data = fits,
output_type = "dataframe",
list_element = 1
)
# Compile the water mass  water potential graphs
graphs1 < compile_data(
data = fits,
output_type = "list",
list_element = 2
)
# Compile the PV graphs
graphs2 < compile_data(
data = fits,
output_type = "list",
list_element = 3
)
# }