9802 Jädraås: Nutrient Optimization Fertilization (IH2)

Summary

Nitrogen fertilization generally increases tree productivity in boreal forests. In mature forests, however, the growth response typically lasts less than 10 years after fertilization. We hypothesized that long-term annual fertilization in young forests could permanently shift ecosystem functioning, maintaining increased productivity through improved nitrogen cycling even after fertilization ceases. To test this hypothesis, we used a long-term fertilization experiment in a Scots pine (Pinus sylvestris) forest in Jädraås, Sweden. Annual fertilization combined with irrigation was applied for 15 years from 1974 to 1990. We assessed foliar nutrient concentrations, tree growth, and soil nutrient stocks, with final tree measurements conducted in 2024.

Gödsling IH2 Jädraås; Ivantjärns heden