Structure and Function of Peatland‐Forest Ecotones in Southeastern Alaska

• DOI: 10.2136/sssaj2003.1572
• Publication Date: 2010-07-27T20:56:45Z
• Authors: Anthony S. Hartshorn; Randal J. Southard; Caroline S. Bledsoe
• Keywords: Ecotone; Histosol

High‐latitude warming could cause northern peatlands to become C sources. Where border boreal forests, strong differences in ecosystem balances reflect drainage differences. Because local conditions be influenced by alterations temperature and precipitation regimes, peatland‐forest ecotones represent useful locations for monitoring potential impacts of global warming. We characterized the soils, hydrology, forest structure along transects bracketing a ecotone southeastern Alaska. expected find soil properties processes at edge that were intermediate between those from peatland forest. Instead, we found above‐ belowground features did not coincide. Conifers grew on mineral but also Cryofibrists Cryohemists, soils with high organic (SOC) contents 100 cm (57 kg m −2 ) are significantly greater than SOC adjacent forested, non‐Histosol pedons. Soil respiration rates (SRR) edges (0.08 g CO 2 –C h −1 ), contrast, threefold lower differ rates. Respiration strongly water table height. Peatland tables both shallower tables. Our conceptual model suggests if additional expansion warmer summers enhance these stimulate SRR forest‐like levels, 23 ultimately mineralized extensive boundaries. Afforestation margins under this scenario transient positive feedback rising atmospheric levels.