Modeling ecological restoration effects on yellow pine forests following southern pine beetle infestations in the southern Appalachian Mountains

Restoring yellow pine (Pinus subgenus Diploxylon) forests affected by a century or more of fire exclusion, frequent windstorms, periodic insect and disease infestations, and other forest environmental threats is a major and urgent challenge. In addition, restoration management represents a long-term investment because its effects are difficult to measure at the time of implementation. Ecological modeling provides a promising opportunity for evaluating various restoration strategies. We used LANDIS, a spatially explicit landscape simulation model, to explore the long-term ecological effects of forest restoration strategies for pine forests damaged by southern pine beetle (SPB, Dendroctonus frontalis Zimmermann) in the southern Appalachian Mountains, USA. We simulated forest succession over a 200-year period under several combined scenarios of various restoration practices in the Grandfather Ranger District of the Pisgah National Forest of North Carolina. Existing forest stand conditions and land types were used as the starting point for landscape simulations. Site specific Forest Management Plans based on Forest Service Practices were then used to determine the desired future forest conditions and specific restoration goals. Our results indicate that a combination of fire and SPB infestations creates sustainable yellow pine forests, and the regimes of multiple interacting disturbances have important implications for succession in yellow pine forests. Our results suggest that Table Mountain pine (Pinus pungens Lamb.) could be a species of particular interest for restoration efforts on low- to mid-elevation ridges and southeast-west facing open slopes in the southern Appalachians. Finally, our model projections imply that reintroducing fire would help maintain open pine stands in this region.