Ash recycling — A method to improve forest production or to restore acidified surface waters?

• This cost-benefit study compares strategies for ash recycling in Southern Sweden.
• Evaluates net value of ash recycling on both forest growth and on acidification.
• Share of acidified forest treated with ash depends on its effect on acidification.
• Ash is likely to do more good by fertilizing forested organic soils.

This cost–benefit analysis compared different strategies for ash recycling in southern Swedish forests, with a special emphasis on the potential to use ash recycling as a measure to ameliorate acidification of soils and surface waters caused by acid deposition. Benefit transfer was used to estimate use values for sport fishing and non-use values in terms of existence values. The results show that the optimal share of acidified forest land that should be treated with ash depends on how optimistic one is about the effect of using ash to restore lakes and streams from acidification. More optimistic assumptions imply that the ash to larger extent should be used to ameliorate acidification. Using the most realistic assumption, given the experiences of forest liming, shows that acidified forest land should not be treated with ash with the aim of restoring lakes and streams from acidification. From a socioeconomic point of view, ash simply does more good as fertilizer on forested organic soils.