At the Estonian University of Life Sciences (EULS), researchers have been monitoring tree plantations established on former agricultural land for nearly 20 years. Their latest study, recently published in New Forests (Tullus et al., 2025), explores an important question for Europe’s green transition:
Do plantations of fast-growing tree species such as silver birch (Betula pendula) and hybrid aspen (Populus tremula × P. tremuloides) support biodiversity in the same way?
Both species are widely planted across Northern and Eastern Europe for their fast growth, high biomass yield, and carbon sequestration potential. Yet, their impact on biodiversity can differ significantly depending on species, management, and environmental conditions.
In this long-term study, the EULS team compared 20 sample plots of birch and hybrid aspen stands. They examined tree structure, light conditions, litter, soil characteristics, and the diversity of vascular plants, bryophytes, lichens, and soil fungi.
Their findings reveal that:
- Hybrid aspen stands hosted a higher number of ground bryophytes and epiphytic lichens, and soils contained more ectomycorrhizal and saprotrophic fungi.
- Silver birch stands, on the other hand, had a denser canopy and more leaf litter, supporting richer communities of epiphytic bryophytes.
- The number of vascular plant species and forest-characteristic species was similar in both stands.
Overall, after two decades, both tree species have created habitats that foster a variety of plant and fungal communities — though not in identical ways. The researchers conclude that combining different species in afforestation efforts could help sustain a broader range of biodiversity on former farmland.
This research contributes to one of the ECOLOOP’s Use Cases, which studies the potential wood production and ecological impacts of deciduous tree species on different soil types, providing valuable insights into sustainable land use and biodiversity enhancement.