lemna is a software package for the language R. It implements model equations and default parameters to simulate the toxicokinetic-toxicodynamic (TKTD) model of the Lemna aquatic plant. Lemna is a standard test macrophyte used in ecotox effect studies. The model was described and published by the SETAC Europe Interest Group Effect Modeling (Klein et al. 2022). It is a refined description of the Lemna TKTD model published by Schmitt et al. (2013). This package contains the model’s reference implementation which is provided by the SETAC interest group.


## install directly from CRAN

## install latest development version from GitHub
remotes::install_github("nkehrein/lemna", dependencies=TRUE)


The lemna package provides model equations and some useful helpers to simulate the growth of Lemna (duckweed) aquatic plant populations. A simulation is run by using the lemna() function. The required scenario data are either supplied individually on function call or are passed as a pre-defined scenario object, such as the focusd1 sample scenario:


# simulate sample scenario
result <- lemna(focusd1)
#>   time       BM     M_int        C_int  FrondNo
#> 1    0 80.00000 0.0000000 0.0000000000 200000.0
#> 2    1 79.48177 0.6614503 0.0004983256 198704.4
#> 3    2 79.00414 2.2061048 0.0016720907 197510.3
#> 4    3 78.57538 4.1750616 0.0031817050 196438.5
#> 5    4 78.23362 6.2899397 0.0048143381 195584.0
#> 6    5 78.01035 8.3810150 0.0064332127 195025.9


Learning lemna

The package contains two vignettes that may help you getting started:


The package and its source code is free and open-source software available under the MIT license.


If you find any issues or bugs within the package, please create a new issue on GitHub.