Title: Long and short term carbon (C) accumulation rates in forests and peatlands along a climatic gradient in northwestern Canada
Citation: Bhatti, J., Errington, R., & Tarnoca, C. (2012). Long and short term carbon (C) accumulation rates in forests and peatlands along a climatic gradient in northwestern Canada. NWT Discovery Portal. https://nwtdiscoveryportal.enr.gov.nt.ca/geoportal/catalog/search/resource/details.page?uuid=%7B258FA6E4-FA51-4F76-B25A-B47D9223BEA5%7D
Study Site: Mackenzie Valley Region, Northwest Territories
Purpose: In the Mackenzie Valley Region, there is a north-south climatic gradient that is evident in the vegetation zonation and permafrost regimes. The Mackenzie Valley also lies within a region that has been warming over the last 30 years, encompasses large areas of permafrost-affected peat soils, and is predicted to be strongly impacted by future climate warming. By examining rates of C accumulaton in sites along the Valley, we hope to elucidate climatic controls on soil C accumulation rates over both the long- and short-term. In particular, by examining cores from peat plateaux, collapse scars, and adjacent upland forests, we hope to examine the role of permafrost in soil C sequestration. Long-term accumulation rates will provide information on soil C accumulation as the peatland systems developed in the varying climatic conditions of the Holocene. For a more detailed look at responses of extant ecosystem types to recorded climatic history and landscape disturbances, short-term accumulation will be examined. It is important to study these northern forest and peatland systems because of their pivotal role in the global C cycle. It is with an eye to understanding the C source - sink dynamics of these northern systems, and their responses to changing climate conditions, that this study was intiated.
Abstract: Cores for examining long-term rates of C accumulation will be collected using a motorized CRREL Auger for permafrost-affected sites. In the collapse scars, hand coring with a Macaulay sampler will be the method of choice. In peat sites, cores will be taken to the base of the peat deposit while upland cores will be taken as deep as possible. Cores will be sampled for macrofossil and physiochemical analyses will be collected every 5 cm for the top 50 cm of the core, and at 10 cm intervals for the remaining core depth. Ten radiocarbon samples will be collected throughout each peat core and known plant matter will be selected to form sub-samples which will be sent for AMS 14C dating. Fewer dates will be required for upland soil cores. Physiochemical analyses will include: bulk density, loss on ignition, and C content. Duplicate cores for short-term C accumulation will be collected to a depth of 1 m (or base of the active layer) from peat plateau and collapse scar regions, using 10 cm diameter PVC pipes. Cores will be cut in the laboratory into contiguous 3 cm slices which will then be cut in half, sending one half slice for 210Pb dating while retaining one half slice for macrofossil and physiochemical analyses. As with long cores, physiochemical analyses will include: bulk density, loss on ignition, C and N content.
Supplemental Information Summary:
Research:
Further Info:
Status: Complete
Keywords:
soil carbon,
peat properties,
nitrogen,
climate change,
Geographical coordinates: North: 68.3133, South: 68.3111 East: -133.3832 West: -133.3834
Bounding Temporal Extent: Start Date: , End
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