The role of large mammalian herbivores for regeneration and diversity over time in boreal forest landscapes

Boreal forests make up around 30 percent of the world’s forest area and include both pristine and managed forests. In Sweden, these forests provide important ecosystem services, including timber production, carbon storage, recreation, biodiversity, and are fundamental for reindeer husbandry.

At the same time, they are shaped by a complex disturbance regime that varies across space and time, where wildfires and commercial forestry play a central role.

Large herbivores such as moose and other ungulates are another important part of this system. These animals are an important component of biodiversity in northern Swedish forests, while also depending on and influencing ecosystems both above and below ground. Through selective browsing, trampling, and nutrient inputs via dung and urine, large herbivores can directly affect vegetation biomass and height development, as well as soil processes, and indirectly shape plant and lichen community composition. 

Lichens are the main food source for reindeer in winter and are thus crucial for reindeer husbandry, but their abundance has declined significantly in Sweden’s northern forests due to modern forestry. 

Despite the importance of both disturbance history and large herbivores in shaping boreal forest ecosystems, few studies have explicitly examined their interactions.

This project investigates how the abundance and diversity of plant and lichen communities are impacted by forest age and disturbance history (fire vs clear-cutting), and how these factors interact with habitat use by large herbivores in the northern boreal forests of Sweden. The project also examines how the presence of large herbivores affects soil fungi, such as mycorrhizal fungi, and how these communities interact with trees and other vegetation.

The project utilises a unique study system comprising established experimental plots in northern Sweden, representing different stages of recovery following disturbance: 1–109 years after clear-cutting and 4–375 years after forest fire.

Research team

PhD student: Hjalmar Stake

Main supervisor: Maja Sundqvist

Assistant supervisors: 

Robert Spitzer

Michael Gundale

Project period: May 2025 – May 2029

This project is part of WIFORCE – the Wallenberg Initiative in Forest Research, funded by the Knut and Alice Wallenberg Foundation.