Framework species approach proves robust in restoring forest on fire prone invasive grass: A case study from Panama

Grasses and fire pose a major challenge for forest restoration. Here we evaluate a case study of reforestation in an area invaded by the tall invasive grass Saccharum spontaneum in the Panama Canal Watershed. The project objectives were to (1) replace Saccharum with a forest, (2) restore a stratified mixed species forest and (3) sequester carbon. We aimed to compare the practice of forest restoration with a treatment grounded in theory. Therefore, the first species selection method followed business-as-usual: contractors planted any combination of 130 prescribed species. The second method followed the framework species approach, a mixture of 22 species was planted to ensure early shade, create a stratified forest over time, attract seed dispersers, and for their potential to fix N₂. Both treatments showed successful restoration trajectories 8.5 years after planting, they did not differ in structural characteristics (stem density, basal area, aboveground biomass, height, and amount of Saccharum). However, based on the species present, the framework approach shows more potential to become a stratified forest. As the framework approach also withstood fires much better than the business-as-usual approach, we conclude that it improves restoration success in this human-dominated landscape.