Carbon storage and sequestration in red pine and mixed hardwood stands established in Michigan old fields

We examined a northern Michigan landscape in which red pine (Pinus resinosa) stands had been established in an old-field successional landscape of regenerating mixed northern hardwood species. This 60+ yr controlled experiment allowed for the direct comparison of species effects on ecosystem properties. Following 60+ yr of stand development, we found higher total ecosystem C storage in mixed hardwood than adjacent red pine plots (255 ±14 vs. 201 ± 10 Mg C/ha), both of which were greater than the pasture site (107 ± 6 Mg C/ha)..  The live root C average was higher for hardwood than red pine (44 ± 3 and 18 ± 1 Mg C/ha), while red pine stands had more C stored in the forest floor (7.6 ± 0.4 and 3.0 ± 0.3 Mg C/ha).  There was no difference in soil C to 1 m depth despite higher above and belowground C inputs, leaf area index and light interception rates for the hardwood stands. The differences for on-site C storage contrasted off-site C sequestration (solid wood products, land-fills, bio-energy), for which equal quantities of C were exported. Taken together these results indicate a high capacity for management of species composition to increase C storage on low quality sites in the upper mid-west, and that afforestation can result in significant C sequestration compared to adjacent pastures. Finally, the fate of post-harvest off-site C can exert a larger influence on C sequestration rates than management of species composition for increased on-site C storage.