The dynamics of fine root length, biomass, and nitrogen content in two northern hardwood ecosystems

Abstract

The dynamics of fine (−1•year⁻¹, respectively, at the southern and northern sites. Corresponding biomass mortality (i.e., turnover) values were 6700 and 4800 kg•ha⁻¹•year⁻¹, and total nitrogen returns to the soil from fine root mortality were 72 kg•ha⁻¹•year⁻¹ at the southern site and 54 kg•ha⁻¹•year⁻¹ at the northern site. Fine roots dominated total biomass and N litter inputs to the soil in both ecosystems, accounting for over 55% of total biomass and nearly 50% of total N returns. In both ecosystems, roots <0.5 mm comprised the bulk of fine root biomass and N pools, and the contribution of these roots to northern hardwood ecosystem carbon and nitrogen budgets may have been underestimated in the past.