Swift recovery of Sphagnum carpet and carbon sequestration after shallow Sphagnum biomass harvesting

Abstract

White horticultural peat is a microbiologically active growing medium which binds significant quantities of nutrients and water due to its favourable cation exchange capacity and porosity. Unfortunately, horticultural peat is only very slowly renewable, and good quality horticultural peat is not common even in peatland-rich countries. Therefore, good-quality and simultaneously renewable alternative growing media are needed. A new growing medium based on Sphagnum moss biomass is introduced in this study. According to our results, harvesting of Sphagnum biomass to a depth of no more than 30 cm will have a relatively short-term effect on Sphagnum carpet coverage and carbon sequestration, allowing a harvesting cycle of ~30 years to be achieved. Therefore, the average harvesting depth will be 30 cm. Only half of the mire surface on each harvesting area will be utilised, the other half being kept intact for transportation routes. This will also secure a reserve of Sphagnum mosses for reseeding and recovery. The end product - Sphagnum biomass based growing medium - will be truly renewable, and environmental effects will be negligible compared with conventional extraction of white horticultural peat. Therefore, Sphagnum biomass harvesting is more comparable with sustainable forestry management than with the production of white peat, which causes drastic and long-term alterations of the mire ecosystem.

Keywords

• carbon sequestration
• renewable growing medium
• Sphagnum biomass harvesting