Even forests in Sweden that were clear-cut more than 65–85 years ago still harbor significantly lower biodiversity than nature reserves, according to recent research. Although some recovery occurs with age, production forests remain less suitable as habitats for species that depend on dead wood and structurally diverse forests.
Sweden's forestry landscape has been dominated by clearcutting—especially since the 1950s. Production forests managed in this way tend to have uniform structures, fewer large trees and lower amounts of dead wood compared with untouched or protected forests. These characteristics make them less hospitable for many saproxylic (dead-wood dependent) species, including red-listed beetles and other conservation-sensitive organisms.
In a recent study led by researchers at Linköping University, the diversity and composition of wood-living beetle communities were compared between production forests of different ages and nearby nature reserves. Results show that production forests—even those 65–85 years after harvest—remain far poorer in species richness and in the presence of key indicator and red-listed species than protected natural forests.
One of the main drivers of this difference is the amount of dead wood, which is generally much lower in production forests. In nature reserves, dead wood levels were found to be about 5–10 times higher than in production forests of similar age, providing essential habitat for a wide range of organisms.
While Swedish forestry policy underwent reforms in 1993 to strengthen nature conservation, the study suggests that the current legal framework and management practices still do not produce the structural features needed to support many saproxylic species even decades after harvest.
The findings highlight the long legacy of intensive forestry on biodiversity and underscore the value of old, structurally complex forests—especially protected areas—for maintaining species that depend on diverse forest habitats.
