New research reveals that protected old-growth forests in Sweden host far richer deadwood habitats and greater cryptogam biodiversity than managed production forests.
The study compared 35 forest sites across Sweden—including 24 spruce-dominated production forests and 11 protected nature reserves—to assess differences in deadwood quantity, quality, and associated cryptogam communities (bryophytes, lichens and wood-decay fungi).
Key findings include:
Nature reserves contain nearly ten times more deadwood than production forests.
Deadwood quality, measured in terms of diameter diversity and decay stages, was significantly higher in reserves, providing vital habitats for forest organisms.
Indicator and red-listed cryptogam species were almost exclusively found in protected old-growth forests, underscoring the conservation importance of these habitats.
Although managed forests with retention practices showed some deadwood presence, they did not support the same range of sensitive species as reserves.
The results highlight that protected old-growth forests remain irreplaceable for maintaining high levels of deadwood diversity and associated biodiversity. Increasing deadwood volume and structural complexity in production forests could help support biodiversity, but such measures are unlikely to fully substitute for the ecological functions of long-standing natural forests.
This research advances understanding of how forest management influences key ecosystem components and species conservation, offering insights for future strategies that balance production goals with biodiversity objectives.
