Description of Yasso

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

Model versions


  • Latest version of the model
  • Based on a global database containing 18 500 measurements of litter decomposition and soil organic carbon (Fig. 1)

Järvenpää, M., Repo, A., Akujärvi, A., Kaasalainen, M. & Liski, J. Soil carbon model Yasso15 - Bayesian calibration using worldwide litter decomposition and carbon stock data. Manuscript in preparation (PDF 4 MB)

Repo, A., Järvenpää, M., Kollin, J., Rasinmäki, J. & Liski, J. 2016. Yasso15 graphical user-interface manual  (PDF 1 MB)

Yasso database map

Fig. 1. Sites of Yasso15 database.


  • First version of the model using advanced mathematical modelling (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

Yasso07 flowchart

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


  • 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