The extent to which forest carbon sequestration can help mitigate climate change will be determined in large part by future land use. Here we quantify the impacts of five divergent future land-use scenarios on aboveground forest carbon stocks and fluxes throughout New England. These scenarios, four co-designed with stakeholders from throughout the region and the fifth a continuation of recent trends in land use, were simulated by coupling a land-cover change model with a mechanistic forest growth model to produce estimates of aboveground carbon over 50 years. We tracked the fate of forest carbon removed through harvesting and development using a standard carbon accounting methodology, modified to fit our modeling framework. Of the simulated changes in land use, changes in harvesting had the most profound and immediate impacts on carbon stocks and fluxes. In one land-use scenario that included a rapid expansion of harvesting for biomass energy, New England’s forests stopped serving as a net carbon sink and became a net carbon source by 2060. In an alternative scenario, relatively small reductions in harvest intensities (i.e., ~10% less biomass removed), coupled with an increased percent of wood going into longer-term storage, led to substantial reductions in net carbon emissions (909 MMtCO₂eq) as compared to a continuation of recent trends in land use. However, these projected gains in carbon storage and reduction in emissions from less intense harvesting regimes can only be realized if they are paired with a reduction in the consumption of the timber products, and their replacements, that otherwise would result in additional emissions from leakage and substitution.

森林碳汇在多大程度上有助于缓解气候变化将在很大程度上取决于未来的土地利用。在这里，我们量化了五种不同的未来土地利用情景对整个新英格兰地上森林碳储量和通量的影响。通过将土地覆盖变化模型与机械森林生长模型相结合来模拟这些情景，其中四个情景是与来自整个地区的利益相关者共同设计的，第五个情景是土地利用近期趋势的延续，以估算 50 年的地上碳. 我们使用标准的碳核算方法跟踪了通过采伐和开发去除的森林碳的命运，并进行了修改以适合我们的建模框架。在模拟的土地利用变化中，收获的变化对碳储量和通量产生了最深远和直接的影响。在一个包括生物质能源收获迅速扩大的土地利用情景中，到 2060 年，新英格兰的森林不再充当净碳汇并成为净碳源。在另一种情景中，收获强度的减少相对较小（即，去除的生物量减少约 10%），再加上进入长期储存的木材百分比增加，导致净碳排放量大幅减少（909 MMtCO₂ eq) 与近期土地利用趋势的延续相比。然而，只有在减少木材产品及其替代品的消耗量的情况下，才能实现这些预计的碳储存收益和较低强度采伐制度排放量的减少，否则会导致泄漏和排放的额外排放。代换。