Mondrian is a computer model of wetland community and ecosystem ecology (Currie et al. 2014, Ecological Modelling 282: 69-82). Its main strength is that it spans four levels of organization in a unified, integrated fashion: (1) individual plants and their physiology; (2) population-level processes including fecundity and mortality; (3) community-level processes including competition among native plant and invasive plant species; (4) ecosystem processes including complete carbon and nitrogen cycles that are driven by plant growth, competition, and litter decomposition, while also responding to those processes. It has been used for a variety of purposes, each time expanding the model to include more processes and more complex integration across ecological levels of organization. It was expanded to include light competition and the effects of varying water levels and hydroperiod and used to study the integrated effects of water level and nutrient inflows on the joint outcomes of wetland C budgets and the success or failure of plant invasions (Martina et al. 2016, Ecosphere 7(9): e01459). It has been used to better understand the ecology of clonal wetland plants and plant competition more broadly (Elgersma et al. 2015, Goldberg et al. in press). Basic research with this model has been funded by NASA, including a new grant to link Mondrian to LHM, a large watershed hydrogeochemical model developed at MSU, and to apply the linked models to simulate alternative future scenarios of socioeconomic development, land use, and climate change.
Mondrian was also expanded to simulate the effects of wetland management and restoration practices to fight invasive plants in coastal wetlands (Elgersma et al. 2017). This applied research has been funded by the EPA Great Lakes Restoration Initiative and by the Michigan Department of Natural Resources, Michigan Invasive Species Grants Program.
Bill Currie is currently working on the code for a significantly updated and improved version of Mondrian, in collaboration with Jason Martina (Texas A&M), Kenneth Elgersma (University of Northern Iowa), and Deborah Goldberg (Ecology and Evolutionary Biology, University of Michigan). The new version will allow branching of clonal wetland plants, while continuing to allow parent plants to provide C and N subsidies to daughter plants through their rhizomes. This will provide increased realism in the way the different plant species compete spatially for nutrients and light. Over the next couple years we will also be adding phosphorous cycling to Mondrian, allowing us to explore differences between, and interactions among, N and P limitation and its effects on wetland plant communities.
To date, Mondrian has been applied only in Great Lakes coastal wetlands. However, the model processes are general enough that it could be used to study wetlands in other regions. Hundreds of parameters representing plant traits or environmental drivers could be changed by the user by making simple changes in input files. Many of the plant parameters are species-specific. For example, traits like maximum relative growth rate, foliar tissue C:N ratio, and dozens of others can be given different values for each species. Part of the reason for this design was to enable different research groups to explore a wide range of research questions in different wetland systems. We are also working on a detailed User Guide that describes model processes, as well as how to install and use the model. If you are interested inusing Mondrian in your research, contact Bill Currie.