reco: Model R_eco from CO2 exchange closed chamber data.

In flux: Flux Rate Calculation from Dynamic Closed Chamber Measurements

Model R_eco from CO2 exchange closed chamber data.

Description

Model R_eco from CO2 exchange closed chamber data.

Usage

reco(R, Temp, Tref = 10, T0 = -46.02, method = "all", min.dp = 6)

Arguments

R	Numeric vector with ecosystem respiration (R_eco) flux rates.
Temp	Numeric vector with corresponding temperature values.
Tref	Numeric value giving the reference temperature used in the Arrhenius type model. Defaults to 10 (°C).
T0	Numeric value giving the activation temperature used in the Arrhenius type model. Defaults to -46.02 (°C).
method	Specifies the model to be used. Partial match is possible. One can either check all included models ("all"), select the best performing model (according to AIC; "best"), or do all models that do not fail in fitting ("not.failed") or specify one particular model: "linear", "arrhenius", "Q10", "lt" (Lloyd & Taylor), "ltr" (Lloyd & Taylor restricted), "logistic". See details.
min.dp	Integer. Minimum number of data points accepted. If number is below function execution is stopped and a warning is issued.

Details

Respiration is controlled by both biological and physical factors. Work by Arrhenius and van’t Hoff in the late-19th century on the temperature dependence of chemical reactions lead to the insight that there is a certain relationship between temperature and respiration (see review by Lloyd and Taylor, 1994). The most prominent models that have been used extenively in the literature can be fitted with this function. For an in-depth review, even more models and references see Richardson et al. 2006.

Models (T = Temperature):

linear	R = t1 + t2*T
arrhenius	R = t1 * exp(E0 * (1/(Tref-T0) - 1/(T-T0)))
Q10	R = t1 * t2^((Temp-Tref)/10)
lt	R = t1 * exp(-t2 / (T+273.15-t3))
ltr	R = t1 * exp(-308.56 / (T + 46.02))
logistic	R = t1 / (1+exp(t2-t3*T))

Value

Either returns a list of R_eco models or the specified model structure. The wanted or resultant model can be fed into gpp or used on its own to predict Reco values.

Note

In its current implementation the lt and logistic models are easily over parameterized and therefore find singular gradients and provide no fit.

Author(s)

Gerald Jurasinski, [e-mail]

References

Lloyd J, Taylor JA, 1994. On the temperature dependence of soil respiration. Functional Ecology 8:315–323.

Richardson et al. 2006. Comparing simple respiration models for eddy flux and dynamic chamber data. Agricultural and Forest Meteorology 141:219–234.

See Also

gpp

Examples

## see examples at gpp

flux documentation built on June 26, 2022, 9:05 a.m.