Forest harvesting and land-use conversion over two decades in Massachusetts

Forest harvesting is an important, ongoing disturbance that affects the composition, structure, and ecological function of the majority of the world's forests. However, few studies have examined the interaction between land-use conversion and harvesting. We utilize a unique, spatially explicit database of all cutting events (n > 13,000) and land-cover conversions for Massachusetts over the past 20 years to characterize the interactions between land-use conversion and harvesting, and their relationship to physical, social, and economic factors. We examined three key variables: the proportion of forest harvested within an ecoregion (%), the mean harvest intensity (m3 ha−1), and the mean harvest event area (ha). The mean harvest intensity (43 m3 ha−1), mean harvest area (15 ha), and average species composition of harvests were remarkably constant over time. However, the proportion of forest harvested varied widely across the state, ranging from 0.01 to 1.48% annually. Harvesting activity ceases near the far outer suburbs of major metropolitan areas, as well as along the coast. There is a strong negative correlation (r = −0.89) between the proportion of forest lost to land-use conversion and the proportion of forest harvested. CART analysis shows that road density is the most important overall predictor of probability of forest harvest, with median house price also an important predictor. Harvest intensity, in contrast, appears related to ownership type, with state-owned lands having more intensive harvests (53 m3 ha−1). Our results suggest that current forest management regimes are determined largely by the economic influence of nearby urban centers.