Description of Yasso

Yasso20 is the latest version of the model. Yasso15, Yasso07 and Yasso are the earlier versions.

Model versions

Yasso20
Yasso15
Yasso07
Yasso

Yasso20

The latest version of the model
Better temperature input representation and calibration approach compared to the earlier versions
Based on about 18 000 litter decomposition and soil organic carbon measurements worldwide (Fig. 1)

Viskari, T., Pusa, J., Fer, I., Repo, A., Vira, J., and Liski, J. 2022 Calibrating the soil organic carbon model Yasso20 with multiple datasets, Geosci. Model Dev., 15, 1735–1752. https://doi.org/10.5194/gmd-15-1735-2022

Yasso15

Soil-carbon-fraction-specific climate impacts on decomposition
Based on about 18 000 litter decomposition and soil organic carbon measurements worldwide (Fig. 1)

Viskari, T., Laine, M., Kulmala, L., Mäkelä, J., Fer, I., and Liski, J. 2020. Improving Yasso15 soil carbon model estimates with ensemble adjustment Kalman filter state data assimilation, Geosci. Model Dev., 13, 5959–5971. https://doi.org/10.5194/gmd-13-5959-2020

Fig. 1. Sites of Yasso15 database.

Yasso07

The first model version based on a Bayesian calibration approach (Fig. 2)
Based on a global database containing 10 000 measurements of litter decomposition and soil organic carbon

Tuomi, M., Rasinmäki, J., Repo, A., Vanhala, P. & Liski. J. 2011. Soil carbon model Yasso07 graphical user interface. Environmental Modeling and Software 26 (11): 1358-1362. doi:10.1016/j.envsoft.2011.05.009

Tuomi, M., Laiho, R., Repo, A., & Liski. J. 2011. Wood decomposition model for boreal forests. Ecological Modelling 222 (3): 709-718. doi:10.1016/j.ecolmodel.2010.10.025

Tuomi, M., Thum, T., Järvinen, H., Fronzek, S., Berg, B., Harmon, M., Trofymow, J.A., Sevanto, S. & Liski, J. 2009. Leaf litter decomposition - Estimates of global variability based on Yasso07 model. Ecological Modelling 220 (23):3362-3371. doi:10.1016/j.ecolmodel.2009.05.016

Tuomi, M., Vanhala, P., Karhu, K., Fritze, H. & Liski, J. 2008. Heterotrophic soil respiration - comparison of different models describing its temperature dependence. Ecological Modelling 211(1-2): 182-190. doi:10.1016/j.ecolmodel.2007.09.003

Fig. 2. Yasso07 flowchart. The boxes represent soil carbon fractions and the arrows carbon fluxes; only fluxes significantly larger than zero shown.

Yasso

First version of the model

Liski, J., Palosuo, T., Peltoniemi, M. & Sievänen, R., 2005. Carbon and decomposition model Yasso for forest soils. Ecological Modelling 189(1-2): 168-182. doi:10.1016/j.ecolmodel.2005.03.005

Liski, J., Nissinen, A., Erhard, M. & Taskinen, O. 2003. Climatic effects on litter decomposition from arctic tundra to tropical rainforest. Global Change Biology 9(4): 575-584. doi:10.1046/j.1365-2486.2003.00605.x