therefore have no effect on options that
maintain carbon stocks at a constant level, such
as maintaining forest without alteration (assumed
to be in equilibrium) or that have many
short oscillations over the time horizon, such as
pulpwood plantations. Discount rates greater
than zero reduce the attractiveness of options
that accumulate carbon slowly over the period,
such as accumulation as fossil fuel substitution
from charcoal plantations, or to a lesser extent,
in wood product pools in sawlog plantations.
Charcoal plantations can displace so much
fossil carbon over the course of the 96 year time
horizon for these plantations that their average
stocks approach that of maintaining the forest,
but only if the discount rate is zero. At a 5%
discount rate the average carbon stock for
charcoal plantations falls to almost half this
value, while the benefit of forest maintenance
remains unchanged.