Figure 1: Contrasting increment versus biomass relationships for Pinus sylvestris (lower lines) and Populus species (upper lines). Rate of net biomass increment from yield table (open symbols) and modeled ((11), solid line). Gross production (net increment + mortality) from yield table (closed squares) and modeled ((12), dotted line). The higher and lower of Pinus compared to Populus ((1)–(3), Table 2) lead to the contrasting relationships for the two species.