Forest structure and biomass in post‐agricultural forests: Lessons learned with new spatial tools

Abstract

AbstractQuestions: With calls for afforestation to sequester carbon due to climate change, agricultural land will be converted to forests in the near future. Little is known about how the ecosystem services of reforested landscapes with an agricultural land‐use history will differ from reference forests. Our objectives were to (i) test the hypothesis that forests with a history of agricultural land use can provide the same carbon storage and biomass ecosystem services as adjacent reference forests, given some recovery time; (ii) explore whether there is a lag in the recovery of forest community composition due to prior agricultural land use; and (iii) demonstrate how remote‐sensing methods can improve our understanding of land‐use legacies at large spatial scales.Location: Finger Lakes National Forest, NY, USA.Methods: Using historic air photos, landscape‐scale lidar, and field surveys, we compared differences in biomass storage, forest structure, and vegetation communities between reference forests and post‐agricultural forests at different stages of regeneration in the Finger Lakes National Forest, New York, USA. We also used lidar to create a spatial model of biomass across the landscape to analyze the spatial distribution of biomass across our study area.Results: We found biomass and forest structure in post‐agricultural forests generally recovered to levels typical of reference forests within 50 years of abandonment. Conversely, we found the composition of woody and herbaceous communities still varied between reference and post‐agricultural forests after 50 years of abandonment.Conclusions: Collectively our results indicate afforestation efforts can be effective for carbon sequestration at early stages of forest succession. Our spatial model of biomass indicated that biomass levels can be low in forests with extensive edge. Further research is needed to understand how contemporary landscape structure interacts with legacy effects of agriculture to affect biomass and other ecosystem services.