Understanding historic fire regimes to develop benchmarks for emulating historic natural disturbance processes in the interest of conserving biodiversity has been actively pursued for approximately 30 years. Mixed-severity fire regimes are increasingly becoming a recognized component of historic fire regimes. Mixed-severity fire regimes are inherently difficult to classify and characterize given the complexity of the process and the multiple scales at which this complexity is expressed. I utilized a systematic study design to gather fire scar and stand dynamic information in order to describe and classify the historic fire regime. I established the presence of mixed disturbance regime dominated by a mixed-severity fire regime. The historic fire regime was mixed-severity over time dominated by individual high severity fire events occurring at a frequency of 60-130 years with some areas that experienced lower severity fire events occurring at a frequency of 20 - 40 years. Twenty-one per cent of the current landscape was dominated by high-severity fire, 42% by mixed-severity and 37% had an unknown fire history. I developed a fire regime classification scheme that provides a useful tool for considering fire severity in mixed-severity system with forest species that generate strong establishment cohorts. I was able to combine time-since-fire methods with a systematic study design and this combination provided an excellent tool to explore mixed-severity fire characteristics in a complicated mixed-disturbance forest. I found limited relationships between topographic controls and fire severity. I found a number of significant relationships that fit the broadly held perceptions of how fire severity would affect species relative densities and stand structure attributes. The existing stand origin map and the Vegetation Resource Inventory stand age were largely accurate for high-severity 20th century fires but had decreasing accuracy in older forests and for mixed and unknown fire severity. The accuracy of the Vegetation Resource Inventory leading species accuracy was quantified at only 60%. My results have implications for fire and forest management in south-eastern British Columbia and in other forest systems that had historic mixed-severity fire regimes with tree species that have strong establishment cohorts. / Graduate / 0478 / 0329 / rick.kubian@pc.gc.ca
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/4944 |
| Date | 24 September 2013 |
| Creators | Kubian, Richard |
| Contributors | Higgs, Eric |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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