Background/Question/Methods
In a new era of carbon (C) markets, harvested ecosystems will be valued for C sequestration in addition to product yields. While ecologists work to resolve the mechanisms that will affect C storage of managed ecosystems in the future, policy makers aim to define C values of various land management practices. Recently established incentives for bioenergy encourage new land management that has not yet been thoroughly evaluated by the scientific community. Specifically, the effect on ecosystem C budgets of managing biomass for fuel feedstocks needs to be evaluated.

Results/Conclusions Comparisons of C dynamics in harvested ecosystems that include temperate timberlands and croplands revealed general differences in C sequestration among ecosystem types. The annual C sequestration rate of perennial grass crops is greater than that of other harvested ecosystems, but the efficiency of C assimilation is dependent on management choices in all cases. The timing of harvest significantly affects the stability of C storage in most ecosystems. The relative potential for C sequestration in harvested ecosystems is directly relevant to new policies governing greenhouse gas reduction and biomass for bioenergy.