The dynamics of biomass production in relation to foliar and root traits in a grey alder (Alnus incana (L.) Moench) plantation on abandoned agricultural land

Summary The dynamics of the above-ground biomass production of a grey alder plantation on abandoned farmland was investigated during 11 years after establishment. In the 12-year-old stand, the total biomass of the above-ground part of the stand was 68.8 t dry matter (DM) ha 1 and the current annual production (CAP ) was 14.0 t DM ha 1 year 1 . The predicted mean annual increment (MAI) reached is maximum at the age of 16 years, which indicates bulk maturity (the stand age when CAI = MAI) and appropriate rotation time for obtaining maximum biomass production. In the case of short-rotation forestry, initial stand density should not be higher than 6500 – 6000 trees per hectare. Below-ground biomass accounted for 18 and 16 per cent of total stand biomass at a stand age of 5 and 10 years, respectively. The biomass of the nodules was estimated at 155 ± 63 kg DM ha 1 and the biomass of the fi ne roots was estimated at 870 ± 130 kg DM ha 1 in the 10-year-old grey alder stand. Of the fi ne roots, 80 per cent and almost all nodules were located in the upper 0 – 20 cm soil layer in both the 5-year-old and the 10-year-old stand. The value of leaf area index increased with stand age, ranging between 1.38 and 5.43 m 2 m 2 during the development of the stand. Specifi c leaf area varied in different years from 11.1 to 13.5 m 2 kg 1 .