Stratigraphic Relationships of Meter-Thick Cycles (Parasequences) to Third Order Cycles"within the Cambrian Pika, Arctomys and Waterfowl Formations of the Southern Canadian Rocky Mountains: A Case Study"

In this paper we present evidence for a large-scale (synoptic-scale) meteorological mechanism controlling the fire frequency in the southern Canadian Rocky Mountains. This large-scale control may explain the similarity in average fire frequencies and timing of change in average fire frequencies for the southern Canadian Rocky Mountains. Over the last 86 years the size distribution of fires (annual area burned) in the southern Canadian Rockies was distinctly bimodal, with a separation between small- and large-fire years at approximately 10–25 ha annual area burned. During the last 35 years, large-fire years had significantly lower fuel moisture conditions and many mid-tropospheric surface-blocking events (high-pressure upper level ridges) during July and August (the period of greatest fire activity). Small-fire years in this period exhibited significantly higher fuel moisture conditions and fewer persistent mid-tropospheric surface-blocking events during July and August. Mid-tropospheric surface-blocking events during large-fire years were teleconnected (spatially and temporally correlated in 50 kPa heights) to upper level troughs in the North Pacific and eastern North America. This relationship takes the form of the positive mode of the Pacific North America pattern.

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Canadian Rocky Mountains

Geographical Journal ◽

10.2307/1775674 ◽

1903 ◽

Vol 21 (6) ◽

pp. 685

Author(s):

J. Norman Collie

Keyword(s):

Rocky Mountains ◽

Canadian Rocky Mountains

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Spatial and temporal variations of fire regimes in the Canadian Rocky Mountains and Foothills of southern Alberta

International Journal of Wildland Fire ◽

10.1071/wf15120 ◽

2016 ◽

Vol 25 (11) ◽

pp. 1117 ◽

Cited By ~ 18

Author(s):

Marie-Pierre Rogeau ◽

Mike D. Flannigan ◽

Brad C. Hawkes ◽

Marc-André Parisien ◽

Rick Arthur

Keyword(s):

Rocky Mountains ◽

Fire History ◽

Fire Severity ◽

Ecological Integrity ◽

Fire Regimes ◽

Temporal Variations ◽

Fire Season ◽

Canadian Rocky Mountains ◽

Southern Alberta ◽

Fire Exclusion

Like many fire-adapted ecosystems, decades of fire exclusion policy in the Rocky Mountains and Foothills natural regions of southern Alberta, Canada are raising concern over the loss of ecological integrity. Departure from historical conditions is evaluated using median fire return intervals (MdFRI) based on fire history data from the Subalpine (SUB), Montane (MT) and Upper Foothills (UF) natural subregions. Fire severity, seasonality and cause are also documented. Pre-1948 MdFRI ranged between 65 and 85 years in SUB, between 26 and 35 years in MT and was 39 years in UF. The fire exclusion era resulted in a critical departure of 197–223% in MT (MdFRI = 84–104 years). The departure in UF was 170% (MdFRI = 104 years), while regions of continuous fuels in SUB were departed by 129% (MdFRI = 149 years). The most rugged region of SUB is within its historical range of variation with a departure of 42% (MdFRI = 121 years). More mixed-severity burning took place in MT and UF. SUB and MT are in a lightning shadow pointing to a predominance of anthropogenic burning. A summer fire season prevails in SUB, but occurs from spring to fall elsewhere. These findings will assist in developing fire and forest management policies and adaptive strategies in the future.

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