Patterns and controls on island-wide aboveground biomass accumulation in second-growth forests of Puerto Rico

Background

Secondary or second-growth forests after land abandonment are a valuable contribution to global carbon sinks. Approximately 70% of the world’s tropical forests are secondary growth, so understanding the carbon sequestration rates on a large scale is important. Sequestration rates are controlled by both abiotic and biotic factors in each region.

Goals and Methods

The authors aim to understand the patterns and controls of aboveground biomass accumulation (and therefore carbon sequestration) in the secondary tropical forests of Puerto Rico. Using lidar remote sensing, they quantify biomass, determine biomass accumulation rates, and determine the main abiotic controls of biomass accumulation.

Conclusions and Takeaways

Lidar data is valuable to providing fine-scale information over large landscapes in a reasonable amount of time. There are complex spatial patterns of aboveground biomass in secondary forests. Overall, forest age strongly predicts quantities of aboveground biomass accumulation, though it is difficult to determine exact forest age. There is rapid accumulation within the first 2-3 decades of recovery. Overall, biomass increases with precipitation, topographic wetness, and slope. It is also significantly impacted by substrate conditions. Airborne lidar data is important for quantifying biomass variability in large, complex tropical landscapes.