Simulation of high-latitude vegetation

LAVESI is an individual-based, spatially explicit model developed to simulate the complete life cycle of larch species — from seeds to mature trees. The model was originally designed to enhance our understanding of past and future treeline dynamics under changing climates, with a particular focus on open larch forest ecosystems in Arctic environments underlain by permafrost.

Today, LAVESI has been extended to simulate all key boreal tree species within the Taiga–Tundra Ecotone (TTE) — the northern boundary of the boreal forest — including both Arctic treeline regions and elevational treelines in northern mountain systems. The model incorporates key ecological processes such as growth, seed production and dispersal, establishment, and mortality, each represented through submodules parameterized using field data and literature-derived evidence.

Simulations run in yearly time steps and are driven by monthly temperature and precipitation data, allowing both reconstructions of past conditions and projections of future scenarios.

LAVESI is written in C++ using standard template libraries, with parallelization enabling high computational efficiency. Its modular design allows straightforward adaptation and further development. Recent enhancements include the integration of additional tree taxa, extending the model’s applicability to larger spatial domains and more southern boreal forests. Moreover, the implementation of full genetic inheritance among individual trees enables a novel and more realistic representation of seed and pollen dispersal, validated against genetic data. This advancement provides new opportunities to disentangle the historical and future dynamics of the TTE in North America and Siberia.