Global change alters peatland carbon cycling through plant biomass allocation

• Published in: Plant and soil Vol. 455; no. 1-2; pp. 53 - 64
• Main Authors: Tian, Jing, Branfireun, Brian A., Lindo, Zoë
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-10-2020; Springer; Springer Nature B.V
• Subjects: Biomass; Biomedical and Life Sciences; Carbon; Carbon cycle; Carbon dioxide; Carbon sinks; Climate effects; Climatic conditions; Dissolved organic carbon; Ecology; Ecosystems; Environmental stress; Factorial experiments; Fens; Growing season; Hydrology; Life Sciences; Microorganisms; Peat; Peat-bogs; Peatlands; Plant biomass; Plant Physiology; Plant production; Plant Sciences; Pore water; Regular Article; Soil Science & Conservation; Canada; Warming; Climate change; Sedge-dominated peatland; Carbon cycling; Ecosystem respiration; Elevated carbon dioxide; Global change; Plant biomass; Net ecosystem exchange
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-020-04664-4

Aims
Global change is shown to significantly affect the C storage function of peatlands; however, a majority of previous research is focused on a single environmental stressor such as the increased temperature. As a result, little is known about the interactive effect of multiple environmental stressors on peatland C storage, especially in sedge-dominated fen peatlands.
Methods
We performed a full factorial experiment of increased temperature and elevated atmospheric CO
2
concentration on minerotrophic, sedge-dominated fen monoliths to experimentally examine the individual and interactive effects of simulated future climate conditions on peatland plant biomass, CO
2
exchange, and pore water dissolved organic carbon (DOC) over one full growing season.
Results
Our study demonstrates that warming and elevated atmospheric CO
2
significantly increased aboveground and belowground biomass, respectively, as well as the gross ecosystem production (GEP), while the DOC concentrations and respired CO
2
from peatland soils only increased under warming
Conclusions
Our results suggest that global change will increase both plant production and microbial decomposition, but with altered plant biomass allocation between aboveground and belowground. Our study provides experimental evidence for shifts in ecosystem-level carbon dynamics under global change for a sedge-dominated peatland, and suggests that while carbon stores may weaken, the carbon sink will be maintained in these types of northern peatlands if hydrological conditions are largely maintained.