The researchers studied how the age of Norway spruce forests affects the amount and characteristics of fine roots in southeast Norway. They looked at trees and understory plants in stands of different ages (10, 30, 60, and 120 years old) and found that fine root biomass and morphology changed with stand age. The 30-year-old stand had the highest biomass, while the 10-year-old stand had the lowest. Most fine roots were found in the upper soil layers. The number of root tips increased with depth, and branching frequency decreased. Fine root biomass was higher in spring compared to fall. Overall, the finest roots were most affected by stand age, showing that fine root growth is strongly influenced by how old the forest is.