We studied three approaches to carbon management: (1) the
potential gains in CO2 mitigation from altering forest management,
(2) the potential role of carbon credits in contributing to economic return
from forest land with various carbon credit assumptions, and (3) the potential
for the land base of the Upper Peninsula of Michigan to be used in greenhouse
gas mitigation. (1) Regarding forest
management, using the current USDOE 1605(b) guidelines, alteration of management
practices in a northern hardwoods stand offered limited but measurable
improvements to carbon storage (a gain of
<0.5 Mt CO2 ha-1 y-1 over a
reference case). More promising was
changing from pulp wood harvest to bioenergy harvest,
resulting in a gain of >2 Mt CO2 ha-1 y-1
compared with the reference case. (2) Using various assumptions about carbon
credits in a red pine model system, we found that carbon credits offered an additional
revenue source that would sometimes allow the decision to plant abandoned
fields to be financially viable where it would not be viable with only revenue
from timber management. Furthermore,
carbon credits shift the optimal financial harvest date to a longer rotation
than would be chosen without carbon credits.
This allows reforestation to also qualify for carbon credits because a
substantial change in management occurs, and these older stands sequester more
carbon. The first two findings [(1) and
(2)] are very specific case studies and may not be broadly applicable. (3) Finally, we are evaluating land suitable
for carbon management projects such as afforestation
and inventory-related considerations for providing bioenergy
feedstocks in this region. Our results to date highlight the promise of bioenergy in this region as a source of sustainable energy
and greenhouse gas mitigation. Some
potential also exists for the use of afforestation
and altered silvicultural practices as CO2
mitigation tools.