Model enables precise simulation of forest landscapes
Digital twin depicts the forest in 100 years
Charred tree trunks and blackened soil are typical of the desolation that a forest fire leaves behind. Inevitably, the question arises whether it will be possible to restore a green natural landscape. According to Rupert Seidl, Professor of Ecosystem Dynamics and Forest Management, this is possible, but the “how” decides how much the new forest will benefit the climate, nature and people.
“Today’s forest ecosystems are not particularly well adapted to future climate conditions,” says Rupert Seidl. “Over the next decades they will presumably come under increasing pressure from water shortage and insect pests, and may even die off. This is why it makes sense to use measures such as the reforestation of disturbed areas to strategically select tree species and take future developments into consideration.”
But how to anticipate which species of tree could contribute to a climate-resilient forest landscape in twenty, thirty or forty years? Experiment-based studies can often provide only limited answers, as they spotlight just a narrow segment of the decades or centuries it takes for forest ecosystems to develop. This type of analysis is also insufficient to gauge the long-term effects of a large-scale bark beetle infestation. But this is what’s needed to lay the groundwork for the forests of tomorrow, today.
Creating a tree portfolio with a digital twin
Researchers are therefore using landscape simulation models, that is, software that creates a digital image of reality and can represent complex ecological interactions. The team around Rupert Seidl and Werner Rammer has developed such a simulation model: iLand can create a digital twin of varying forest landscapes and calculate their long-term development under different climate scenarios, for example under constant climatic conditions, a climate warming of 1°C, or of 4.8°C.
Other models work in a similar way to that of the TUM research team, but they consider individual tree stands covering just a few hectares. “With iLand, we can simulate the dynamic interaction between individual trees, or that between trees and, say, bark beetles, over decades to centuries – and this over large areas of up to 100,000 hectares, meaning that we can study entire national parks,” says Werner Rammer. “This is currently not possible with other models.”
This means that iLand has a wide range of possible applications, as the high resolution of the model allows it to simulate forest management measures in great detail. For example, it can calculate how deforestation or the planting of specific tree species affects the rest of the forest or which tree species portfolio absorbs the most CO2 and builds up biomass quickly for raw material use. Extreme events such as forest fires, storms or droughts can also be simulated.
Open to further development
Seidl, Rammer and the team have been working on iLand and its ongoing development for twelve years. It has now been used as a model in more than 50 studies by various research institutions. “We can simulate 150 tree species in our digital forest and we’ve expanded the model, so that it can be used on three continents,” says Werner Rammer. “Those who wish to work with it can develop the program and adapt it to their needs. This is intended to enable as many researchers as possible to use iLand for their own work.”
Rammer, W., Thom, D., et al.: The individual-based forest landscape and disturbance model iLand: Overview, progress, and outlook, Ecological Modelling (2024). DOI: doi.org/10.1016/j.ecolmodel.2024.110785
Thom, D., Rammer, W., et al.: Parameters of 150 temperate and boreal tree species and provenances for an individual-based forest landscape and disturbance model, Data in Brief (2024). DOI: doi.org/10.1016/j.dib.2024.110662
- iLand is free to use: https://iland-model.org/
- The development of iLand was funded by a Consolidator Grant from the European Research Council (ERC).
- The Chair for ecosystem dynamics and forest management in mountain landscapes belongs to the TUM School of Life Sciences.
Contacts to this article:
Prof. Dr. Rupert Seidl
Technical University of Munich
Chair for ecosystem dynamics and forest management in mountain landcapes
Tel: +49 8161-71 4691
rupert.seidl@tum.de
Dr. Werner Rammer
Technische Universität München
Chair for ecosystem dynamics and forest management in mountain landcapes
Tel: +49 8161-71 4685
werner.rammer@tum.de
