CANCELLED - Scenarios of future land use change and forest carbon in Massachusetts

Background/Question/Methods

Massachusetts’ forests continue to accrue biomass in the wake of widespread agricultural land abandonment dating to the late nineteenth century. The future contribution of these forests to the Eastern U.S. carbon sink will be constrained by chronic but unknown rates of urban and suburban development. We simulated future scenarios of landscape change and the influence of forest loss on above ground forest carbon stocks in Massachusetts over the next 50 years. We used LANDIS-II, a forest landscape simulation model, coupled to PnET-II, a generalized ecosystem process model, to integrate forest succession, carbon dynamics, and natural and anthropogenic disturbance. We parameterized the spatial pattern of urban and suburban development using CART models that estimated the relationship between recent development (1985 to 1999) and several biophysical, infrastructure, and census variables. Then, using 30 year mean climatic data, we simulated changes in forest carbon under four plausible future scenarios: “no development”, “business as usual” (≈7000 ha dev. yr ^-1), “increased conservation” (≈3500 ha dev. yr ^-1), and “accelerated development” (≈10500 ha dev. yr ^-1).

Results/Conclusions

The CART models identified road density, proximity to the city of Boston, and conservation status as the best spatial predictors of urban and suburban development.   Our preliminary simulations suggested that, compared to the “no development” scenario: “business as usual” reduced carbon stores by 13%; “increased conservation” reduced carbon stores by 7%; and “accelerated development” reduced carbon stores by 20%. We conclude that the rate of forest conversion will be a major determent of the size of the Eastern U.S. carbon sink. Further, conservation policies can help maintain the region’s capacity for carbon sequestration.