Patterns of Total Ecosystem Carbon Storage with Changes in Soil Temperature in Boreal Black Spruce Forests

• Published in: Ecosystems (New York) Vol. 12; no. 2; pp. 322 - 335
• Main Authors: Kane, E. S, Vogel, J. G
• Format: Journal Article
• Language: English
• Published: New York New York : Springer-Verlag 01-02-2009; Springer Science+Business Media; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Boreal forests; Carbon sequestration; Climate change; Ecology; Ecosystems; Environmental Management; Forest ecosystems; Forest soils; Forestry; Fundamental and applied biological sciences. Psychology; General aspects; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Geoecology/Natural Processes; Hydrology/Water Resources; Life Sciences; Mineral soils; Organic soils; Permafrost; Picea mariana; Plant Sciences; Soil ecology; Soil temperature; Soil water; Synecology; Temperature; Temperature gradients; Wildfires; Zoology; USA, Alaska; carbon storage; biomass; productivity; permafrost; organic soil; fire; decomposition; black spruce; climate change; Productivity; Boreal forest; Black Forest; Organic soil; Decomposition; Permafrost; Biomass; Carbon; Dynamical climatology; Climate change; Storage; Ecosystem; Fires; Gymnospermae; Coniferales; Spermatophyta; Picea mariana; Soil temperature
• ISSN: 1432-9840; 1435-0629
• DOI: 10.1007/s10021-008-9225-1

To understand how carbon (C) pools in boreal ecosystems may change with warming, we measured above- and belowground C pools and C increment along a soil temperature gradient across 16 mature upland black spruce (Picea mariana Mill. [B·S.P]) forests in interior Alaska. Total spruce C stocks (stand and root C) increased from 1.3 to 8.5 kg C m⁻² with increasing soil summed degree-days (SDD > 0°C at 10 cm) across sites, whereas soil C stocks decreased from 11.9 to 6.3 kg C m⁻² with increasing SDD. Spruce C and organic soil C, which combined represent maximum C accrual since the last fire, increased with soil heat sums until 600 SDD, and then plateaued with increasing SDD across sites (R ² = 0.61, P = 0.002; second-order polynomial regression). The sum of soil and total spruce C (total ecosystem C, TEC) reached its maximum in the middle-range of soil temperatures measured (approximately 600 SDD), and was lower in the coolest (139 SDD) and the warmest (914 SDD) forests. The opposing trends between above- and belowground pools resulted in C shifting from the soil to spruce biomass with warmer soil temperatures. A shift in C distribution from below- to aboveground pools, as temperature increases, has implications for the vulnerability of C lost in boreal forest wildfires. The strongly negative relationship between surface mineral soil C stocks and increasing temperatures warrants further research into the potential loss of deep mineral soil C stocks with continued warming, especially in forests presently underlain with permafrost.