| Abstract: | Boreal forests and wetlands are thought to be significant carbon sinks, and they could become net C sources as the Earth warms. Most of the C of boreal forest ecosystems is stored in the moss layer and in the soil. The objective of this study was to estimate soil C stocks (including moss layers) and rates of accumulation and loss for a 733 km2 area of the BOReal Ecosystem-Atmosphere Study site in northern Manitoba, using data from smaller-scale intensive field studies. A simple process-based model developed from measurements of soil C inventories and radiocarbon was used to relate soil C storage and dynamics to soil drainage and forest stand age. Soil C stocks covary with soil drainage class, with the largest C stocks occurring in poorly drained sites. Estimated rates of soil C accumulation or loss are sensitive to the estimated decomposition constants for the large pool of deep soil C, and improved understanding of deep soil C decomposition is needed. While the upper moss layers regrow and accumulate C after fires, the deep C dynamics vary across the landscape, from a small net sink to a significant source. Estimated net soil C accumulation, averaged for the entire 733 km2 area, was 20 g C m-2 yr-1 (28 g C m-2 yr-1 accumulation in surface mosses offset by 8 g C m-2 yr-1 lost from deep C pools) in a year with no fire. Most of the C accumulated in poorly and very poorly drained soils (peatlands and wetlands). Burning of the moss layer in only 1% of uplands would offset the C stored in the remaining 99% of the area. Significant interannual variability in C storage is expected because of the irregular occurrence of fire in space and time. The effects of climate change and management on fire frequency and on decomposition of immense deep soil C stocks are key to understanding future C budgets in boreal forests. |
| Genre: | Article |
| ProdID: | 70020301 |
| Citation Author: | Rapalee, G.; Trumbore, S. E.; Davidson, E. A.; Harden, J. W.; Veldhuis, H. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 701 |
| Citation Issue: | 4 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Global Biogeochemical Cycles |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 15 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Soil carbon stocks and their rates of accumulation and loss in a boreal forest landscape; 1998; Article; Journal; Global Biogeochemical Cycles; Rapalee, G.; Trumbore, S. E.; Davidson, E. A.; Harden, J. W.; Veldhuis, H. |
| Citation Start Page: | 687 |
| Citation Volume: | 12 |
| Citation Year: | 1998 |
| Type: | citation/reference |
| Text: | Soil carbon stocks and their rates of accumulation and loss in a boreal forest landscape; 1998; Article; Journal; Global Biogeochemical Cycles; Rapalee, G.; Trumbore, S. E.; Davidson, E. A.; Harden, J. W.; Veldhuis, H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1998 00:00 -0600 |
| Publisher: | |
