UVicSpace

A 100-year retrospective and current carbon budget analysis for the Sooke Lake Watershed: Investigating the watershed-scale carbon implications of disturbance in the Capital Regional District’s water supply lands

Show simple item record

dc.contributor.author Smiley, Byron
dc.date.accessioned 2015-05-01T22:10:18Z
dc.date.available 2015-05-01T22:10:18Z
dc.date.copyright 2015 en_US
dc.date.issued 2015-05-01
dc.identifier.uri http://hdl.handle.net/1828/6117
dc.description.abstract Northern forest ecosystems play an important role in global carbon (C) cycling and are considered to be a net C sink for atmospheric C (IPCC, 2007; Pan, et al., 2011). Reservoir creation is a common cause of deforestation and when coupled with persistent harvest activity that occurs in forest ecosystems, these disturbance events can significantly affect the C budget of a watershed. To understand the effects of these factors on carbon cycling at a landscape level, an examination of forest harvest and reservoir creation was carried out in the watershed of the Sooke Lake Reservoir, the primary water supply for the Greater Victoria area in British Columbia. Covering the period between 1910 and 2012, a detailed disturbance and forest cover dataset was generated for the Sooke Lake Watershed (SLW) and used as input into a spatially-explicit version of the Carbon Budget Model of the Canadian Forest Sector 3 (CBM-CFS3). The model was modified to include export of C out of the forest system in the form of dissolved organic C (DOC) into streams. The fraction of decaying C exported through this mechanism was tuned in the model using DOC measurements from three catchments within the SLW. Site-specific growth and yield curves were also generated for watershed forest stand types, in part, by using LiDAR-derived site indices. C transfers associated with disturbances were adjusted to reflect the disturbance types that occurred during the 100-year study period. Due to the removal of C resulting from wildfire, logging and residue burning, as well as deforestation disturbances, total ecosystem C stocks dropped from 700 metric tonnes of C per hectare (tC ha-1) in 1910 to their current (2012) level of ~550 tC ha-1 across the SLW. Assuming no change in management priorities and negligible effects of climate change, total ecosystem C stocks will not recover to 1910 levels until 2075. The cumulative effect of reservoir creation and expansion on the C budget resulted in 14 tC ha-1 less being sequestered (111,217 tC total) across the watershed by 2012. In contrast, sustained yield forestry within the Capital Regional District’s tenure accounts for a 93 tC ha-1 decrease by 2012, representing an impact six times greater than deforestation associated with reservoir creation. The proportionally greater impact of forestry activity is partly due to current C accounting rules (Intergovernmental Panel on Climate Change) that treats C removed from the forest in the form of Harvested Wood Products as C immediately released to the atmosphere as carbon dioxide. Cumulative DOC export to the Sooke Lake reservoir was ~30,660 tC by 2012, representing a substantial pathway for C leaving the forest ecosystem. However, more research is required to understand what fraction of terrestrially-derived DOC is sequestered long term in lake sediment. The results of this study will assist forest manager decision making on the appropriate management response to future forest disturbance patterns that could result from climate change and to improve climate change mitigation efforts. en_US
dc.language English eng
dc.language.iso en en_US
dc.rights Available to the World Wide Web en_US
dc.subject Carbon budgets en_US
dc.subject Deforestation en_US
dc.subject Disturbance history en_US
dc.subject Forest cover change en_US
dc.subject CBM-CFS3 en_US
dc.subject LiDAR en_US
dc.title A 100-year retrospective and current carbon budget analysis for the Sooke Lake Watershed: Investigating the watershed-scale carbon implications of disturbance in the Capital Regional District’s water supply lands en_US
dc.title.alternative One hundred-year retrospective and current carbon budget analysis for the Sooke Lake Watershed en_US
dc.type Thesis en_US
dc.contributor.supervisor Trofymow, J. A.
dc.contributor.supervisor Niemann, K. O.
dc.degree.department Department of Geography en_US
dc.degree.level Master of Science M.Sc. en_US
dc.description.scholarlevel Graduate en_US
dc.description.proquestcode 0478 en_US
dc.description.proquestcode 0425 en_US
dc.description.proquestcode 0368 en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search UVicSpace


Browse

My Account

Statistics

Help