Fine root biomass, productivity and turnover in two contrasting aspects in natural Chir Pine (Pinus roxburghii Sarg.) forests of Central Himalaya

Fine roots (≥1 mm) production in Chir Pine (Pinus roxburghii Sarg.) forests was estimated across three different seasons for one year at four sites located between 1600–1850 meters elevation on two contrasting aspects. At each site three different slope positions (ridge slope, mid hill slope and hill base) were selected for the study. The tree density across the study sites ranged between 390 to 1910 tree/ha–1. The fine root biomass and productivity was estimated upto 40 cm soil depth. The total fine root biomass ranged between 3.34 and 3.72 t ha–1 across southern aspect while it ranged between 2.70 and 2.94 t ha–1 across northern aspect. Across the studied forest the NPP ranged between 1.02 and 2.2 t ha–1yr–1 and total turnover ranged between 0.52 and 0.96 yr–1.The fine root biomass declined as the soil depth increased and varied significantly (P < 0.001) across the soil depths and seasons. The fine root net primary production was positively correlated (P < 0.001) with soil organic carbon (t ha–1) and showed an inverse relationship with soil moisture percent and soil bulk density (g/cc).