hpmdpredict hpmdpredict provides model HPM-leaching from (Teickner, Pebesma, and Knorr 2024) and functions to make predictions with this model. HPM-leaching models the fraction of initial mass remaining in Sphagnum litterbag experiments in dependency of species, degree of saturation, and distance below the water table, and it also models the magnitude of initial leaching losses. Installation You can install the development version of hpmdpredict in R by downloading the tar.gz file in this repository and executing: install.packages("hpmdpredict_0.0.0.9000.tar.gz", type = "source") Example To make predictions, one first has to define some variables like the incubation duration. Here, we predict remaining masses and initial leaching losses for S. fuscum incubated at a degree of saturation of 0.6 L L−1 pores during the first five years. library(hpmdpredict) d ggplot(aes(ydist = mass_relative_mass * 100, x = incubation_duration)) + stat_lineribbon() + scale_fill_brewer() + labs( y = "Fraction of initial mass (%)", x = "Incubation duration (yr)" ) Model parameters Model parameters that can be modified when making predictions are shown in the following table. Column “HPM parameter name” contains the names of the parameters in the Holocene Peatland Model (HPM) (Frolking et al. 2010) for the parameters from the decomposition module of the HPM. Parameter Description HPM parameter name phi_2 Precision parameter for the beta distribution modeling remaining fractions of inital masses predicted by HPM-leaching. Larger values imply smaller errors in remaining masses (-). alpha_2 Parameter that controls how fast decomposition rates decrease as mass is lost during the decomposition (-). m69_p1 Peat degree of saturation where aerobic decomposition rates are maximal (Lwater Lpores-1). Wopt m69_p2 Curvature of the relation of aerobic decomposition rates to the degree of saturation (larger values imply a more peaked relation) (-). c1 m68_p1 Minimum anaerobic decomposition rate (yr-1). fmin m68_p2 Anoxia scale length. Represents limitation of anaerobic decomposition rates with increasing distance below the annual water table depth (m). c2 m68_p3_2 Maximum possible decomposition rate for the Sphagnum species (yr-1). k0,i hpm_k_2_p1 Shape parameter for the gamma distribution modeling decomposition rates predicted by the HPM (-). hpm_l_2_p1 Intercept for average Sphagnum initial leaching losses at a degree of saturation of 0 Lwater Lpores-1 (logit scale). hpm_l_2_p3 Slope for the relation between Sphagnum initial leaching losses and the degree of saturation (logit scale) (Lpores Lwater-1). hpm_l_2_p4 Precision parameter for the beta distribution modeling initial leaching losses predicted by HPM-leaching. Larger values imply smaller errors in leaching losses (-). Licenses Text and figures : CC BY 4.0 Code : See the DESCRIPTION file Acknowledgements Development of this software was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) grant no. KN 929/23-1 to Klaus-Holger Knorr and grant no. PE 1632/18-1 to Edzer Pebesma. References Frolking, S., N. T. Roulet, E. Tuittila, J. L. Bubier, A. Quillet, J. Talbot, and P. J. H. Richard. 2010. “A New Model of Holocene Peatland Net Primary Production, Decomposition, Water Balance, and Peat Accumulation.” Earth System Dynamics 1 (1): 1–21. https://doi.org/10.5194/esd-1-1-2010. Teickner, Henning, Edzer Pebesma, and Klaus-Holger Knorr. 2024. “Underestimation of Anaerobic Decomposition Rates in Sphagnum Litterbag Experiments by the Holocene Peatland Model Depends on Initial Leaching Losses.” Unpublished preprint.