Sphagnum mosses, the impact of disturbances and anthropogenic management actions on their ecological role in CO2 fluxes generated in peatland ecosystems

• Published in: Global change biology Vol. 30; no. 1; pp. e16972 - n/a
• Main Authors: Pacheco‐Cancino, Patricio A., Carrillo‐López, Rubén F., Sepulveda‐Jauregui, Armando, Somos‐Valenzuela, Marcelo A.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01-01-2024
• Subjects: anthropogenic disturbances; Anthropogenic factors; Aquatic plants; Carbon dioxide; Carbon dioxide emissions; Carbon dioxide flux; Carbon sequestration; Causeway; climate change; CO2 emissions; Disturbances; Ditches; Donor materials; drainage; Ecosystem disturbance; Ecosystems; Emissions; Emissions control; Human influences; Land management; Land use; Land use management; Mosses; paludiculture; Peat; Peatlands; Photosynthesis; Primary production; Recolonization; Reintroduction; Respiration; Restoration; Sphagnum; Vegetation
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.16972

Mosses of the genus Sphagnum are the dominant vegetation in most pristine peatlands in temperate and high‐latitude regions. They play a crucial role in carbon sequestration, being responsible for ca. 50% of carbon accumulation through their active participation in peat formation. They have a significant influence on the dynamics of CO2 emissions due to an efficient maximum potential photosynthetic rate, lower respiration rates, and the production of a recalcitrant litter whose decomposition is gradual. However, various anthropogenic disturbances and land use management actions that favor its reestablishment have the potential to modify the dynamics of these CO2 emissions. Therefore, the objective of this review is to discuss the role of Sphagnum in CO2 emissions generated in peatland ecosystems, and to understand the impacts of anthropogenic practices favorable and detrimental to Sphagnum on these emissions. Based on our review, increased Sphagnum cover reduces CO2 emissions and fosters C sequestration, but drainage transforms peatlands dominated by Sphagnum into a persistent source of CO2 due to lower gross primary productivity of the moss and increased respiration rates. Sites with moss removal used as donor material for peatland restoration emit twice as much CO2 as adjacent undisturbed natural sites, and those with commercial Sphagnum extraction generate almost neutral CO2 emissions, yet both can recover their sink status in the short term. The reintroduction of fragments and natural recolonization of Sphagnum in transitional peatlands, can reduce emissions, recover, or increase the CO2 sink function in the short and medium term. Furthermore, Sphagnum paludiculture is seen as a sustainable alternative for the use of transitional peatlands, allowing moss production strips to become CO2 sink, however, it is necessary to quantify the emissions of all the components of the field of production (ditches, causeway), and the biomass harvested from the moss to establish a final closing balance of C.
Greater Sphagnum cover consolidates carbon storage in peatland ecosystems through the production of recalcitrant litter that decomposes slowly, promoting peat accumulation. Anthropic disturbances exerted on Sphagnum mosses generate CO2 emissions into the atmosphere to different degrees, however drainage is the most harmful. In turn, management actions that promote the reestablishment of moss in degraded peatlands restore the status of CO2 sink in these ecosystems.