scholarly journals Fire Exclusion Destroys Habitats for At-Risk Species in a British Columbia Protected Area

Fire ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 48
Author(s):  
Kira M. Hoffman ◽  
Sara B. Wickham ◽  
William S. McInnes ◽  
Brian M. Starzomski
Keyword(s):  
British Columbia ◽  
Fire History ◽  
Prescribed Burning ◽  
Douglas Fir ◽  
Conifer Encroachment ◽  
Oak Trees ◽  
Composition And Structure ◽  
Fire Exclusion ◽  
History Of

Fire exclusion and suppression has altered the composition and structure of Garry oak and associated ecosystems in British Columbia. The absence of frequent low severity ground fires has been one of the main contributors to dense patches of non-native grasses, shrubs, and encroaching Douglas-fir trees in historical Garry oak dominated meadows. This case study uses remote sensing and dendrochronology to reconstruct the stand dynamics and long-term fire history of a Garry oak meadow situated within Helliwell Provincial Park located on Hornby Island, British Columbia. The Garry oak habitat in Helliwell Park has decreased by 50% since 1950 due to conifer encroachment. Lower densities and mortalities of Garry oak trees were associated with the presence of overstory Douglas-fir trees. To slow conifer encroachment into the remaining Garry oak meadows, we recommend that mechanical thinning of Douglas-fir be followed by a prescribed burning program. Reintroducing fire to Garry oak ecosystems can restore and maintain populations of plants, mammals, and insects that rely on these fire resilient habitats.

scholarly journals Adjacency to a harvest trail increases drought resistance of interior Douglas-fir (Pseudotsuga menziesii var. glauca) in partially harvested stands in central British Columbia

2018 ◽  
Vol 48 (7) ◽  
pp. 809-820 ◽  
Author(s):  
Neil P. Thompson ◽  
Kathy J. Lewis ◽  
Lisa M. Poirier
Keyword(s):  
British Columbia ◽  
Drought Tolerance ◽  
Pseudotsuga Menziesii ◽  
Growth Rates ◽  
Habitat Management ◽  
Odocoileus Hemionus ◽  
Douglas Fir ◽  
Ring Analysis ◽  
The Relationship

Drought tolerance of trees may be affected by competition, but most studies quantifying the relationship do not consider the effect of stem clustering. Trees are often clustered in interior Douglas-fir (Pseudotsuga menziesii var. glauca (Mayr) Franco) forests near the grassland interface in central British Columbia due to past harvesting practices or habitat management for mule deer (Odocoileus hemionus hemionus (Rafinesque, 1817)). Climate change projections indicate continued increases in temperature, an outcome that would stress trees growing in dry environments. Trees placed in different states of competition by mechanical harvesting in the 1970s were sampled to provide a 40-year comparison of three levels of competition during 1–2 year droughts. Tree-ring analysis was used to assess the reduction in growth during drought years and resumption of growth in subsequent years. A clear separation of growth rates was evident between open-growing trees, trees on the edge of harvesting trails, and trees within the unharvested interior. Edge trees had intermediate growth rates but no differences were found in the long-term climate–growth relationship compared with open-growing trees. Both Edge and Open classes showed less relative growth reduction during droughts than Interior trees growing between harvest trails. Precipitation throughfall rates and competition for resources are likely driving short-term drought tolerance in combination with other factors.

Settlement and Sea-Levels on the Central Coast of British Columbia: Evidence from Shell Midden Cores

2000 ◽  
Vol 65 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Aubrey Cannon
Keyword(s):  
British Columbia ◽  
High Tide ◽  
Cost Effective ◽  
Shell Midden ◽  
Central Coast ◽  
Sea Levels ◽  
History Of ◽  
Cost Effective Alternative ◽  
Strong Linear Relationship

AbstractCoring of shell-midden sites provides a regional chronology of site settlement in the Namu vicinity on the central coast of British Columbia. Coring proved an accurate and cost-effective alternative to traditional test-excavation, and its application in only two short field seasons doubled the number of sites tested in this region. The dating of basal cultural deposits from the cores shows initial occupation of sites ranging from 10,000 to 800 B.P. These dates exhibit a strong linear relationship with the current elevation of deposits above average high tide, suggesting that the settlement history of known shell-midden sites in this region is strongly linked to gradual long-term decline in relative sea levels.

scholarly journals A Disrupted Historical Fire Regime in Central British Columbia

2021 ◽  
Vol 9 ◽  
Author(s):  
Wesley Brookes ◽  
Lori D. Daniels ◽  
Kelsey Copes-Gerbitz ◽  
Jennifer N. Baron ◽  
Allan L. Carroll
Keyword(s):  
British Columbia ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Spatial Scales ◽  
Fire Frequency ◽  
Dry Forest ◽  
Moderate Severity ◽  
High Severity ◽  
Wide Range ◽  
Fire Exclusion

In the 2017 and 2018, 2.55 million hectares burned across British Columbia, Canada, including unanticipated large and high-severity fires in many dry forests. To transform forest and fire management to achieve resilience to future megafires requires improved understanding historical fire frequency, severity, and spatial patterns. Our dendroecological reconstructions of 35 plots in a 161-hectare study area in a dry Douglas-fir forest revealed historical fires that burned at a wide range of frequencies and severities at both the plot- and study-area scales. The 23 fires between 1619 and 1943 burned at intervals of 10–30 years, primarily at low- to moderate-severity that scarred trees but generated few cohorts. In contrast, current fire-free intervals of 70–180 years exceed historical maximum intervals. Of the six widespread fires from 1790 to 1905, the 1863 fire affected 86% of plots and was moderate in severity with patches of higher severity that generated cohorts at fine scales only. These results indicate the severity of fires varied at fine spatial scales, and offer little support for the common assertion that periodic, high-severity, stand-initiating events were a component of the mixed-severity fire regime in these forest types. Many studies consider fires in the late 1800s relatively severe because they generated new cohorts of trees, and thus, emphasize the importance of high-severity fires in a mixed-severity fire regime. In our study area, the most widespread and severe fire was not a stand-initiating fire. Rather, the post-1863 cohorts persisted due disruption of the fire regime in the twentieth century when land-use shifted from Indigenous fire stewardship and early European settler fires to fire exclusion and suppression. In absence of low- to moderate-severity fires, contemporary forests are dense with closed canopies that are vulnerable to high-severity fire. Future management should reduce forest densities and to restore stand- and landscape-level heterogeneity and increase forest resilience. The timing and size of repeat treatments such as thinning of subcanopy trees and prescribed burning, including Indigenous fire stewardship, can be guided by our refined understanding of the mixed-severity fire regime that was historically dominated by low- to moderate-severity fires in this dry forest ecosystem.

Fires in temperate peatlands (southern Quebec): past and recent trends

2007 ◽  
Vol 85 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Claude Lavoie ◽  
Stéphanie Pellerin
Keyword(s):  
Fire History ◽  
Fire Regime ◽  
Fire Frequency ◽  
Time Interval ◽  
Temperate Region ◽  
Forest Expansion ◽  
Short Period ◽  
History Of ◽  
Recent Trends

In this study, we reconstructed the long-term fire history of a set of ombrotrophic peatlands (bogs) located in a temperate region of southern Quebec (Bas-Saint-Laurent). Past and recent fire-free intervals (time interval between two consecutive fires) were compared using macrofossil analyses. During most of the Holocene epoch, fires were relatively rare events in bogs of the Bas-Saint-Laurent region. The fire-free intervals were approximately ten times longer (all sites considered) before the beginning of agricultural activities in the region (1800 AD) than after. This strongly suggests an anthropogenic influence on the fire regime prevailing in the bogs over the last 200 years. However, the shortening of the fire-free intervals was mainly the result of the ignition of one or two fires in almost every site during a relatively short period (200 years), rather than a higher fire frequency in each of the bogs. In some cases, fires had an influence on the vegetation structure of bogs, but it is more likely that a combination of several disturbances (fire, drainage, and drier than average summers) favoured the establishment of dense stands of pine and spruce, a forest expansion phenomenon that is now widespread in temperate bogs.

Effects of Forest Fires on Archaeological Resources at Grand Canyon National Park

1987 ◽  
Vol 7 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Anne Trinkle Jones ◽  
Robert C. Euler
Keyword(s):  
Forest Fires ◽  
Fire History ◽  
Prescribed Burning ◽  
Grand Canyon ◽  
Cultural Resources ◽  
Experimental Conditions ◽  
The North ◽  
Before And After ◽  
History Of ◽  
Fire Area

For a number of years archaeologists have discussed the effects of forest fires on archaeological resources. Studies under experimental conditions and of sites after they were burned form the bulk of this effort but, for the most part, they have not been published. This article examines the fire history of the North Rim of the Grand Canyon and the effects of the Dutton Point wildfire on prehistoric architecture and artifacts—particularly ceramics. Armed with those data, a modest experiment useful in any proposed prescribed fire area containing cultural resources, was designed. This involved “before and after” studies of a ruin that was to be subjected to prescribed burning and included buried temperature controls and the varying effects upon the resource. Finally, a hypothesis regarding the effect of wildfires on archaeological sites is presented.

scholarly journals Paleoecological Investigation of Vegetation, Climate and Fire History in, and Adjacent to, Kootenay National Park, Southeastern British Columbia, Canada

2022 ◽  
Vol 9 ◽  
Author(s):  
Thomas J. Rodengen ◽  
Marlow G. Pellatt ◽  
Karen E. Kohfeld
Keyword(s):  
British Columbia ◽  
National Park ◽  
Fire History ◽  
Accumulation Rate ◽  
Fire Frequency ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Carbon Accumulation ◽  
Early Holocene ◽  
In Fire

Paleoecological investigation of two montane lakes in the Kootenay region of southeast British Columbia, Canada, reveal changes in vegetation in response to climate and fire throughout the Holocene. Pollen, charcoal, and lake sediment carbon accumulation rate analyses show seven distinct zones at Marion Lake, presently in the subalpine Engelmann Spruce-Subalpine Fir (ESSF) biogeoclimatic (BEC) zone of Kootenay Valley, British Columbia. Comparison of these records to nearby Dog Lake of Kootenay National Park of Canada in the Montane Spruce (MS) BEC zone of Kootenay Valley, British Columbia reveals unique responses of ecosystems in topographically complex regions. The two most dramatic shifts in vegetation at Marion Lake occur firstly in the early Holocene/late Pleistocene in ML Zone 3 (11,010–10,180 cal. yr. B.P.) possibly reflecting Younger Dryas Chronozone cooling followed by early Holocene xerothermic warming noted by the increased presence of the dry adapted conifer, Douglas-fir (Pseudotsuga menziesii) and increasing fire frequency. The second most prominent change occurred at the transition from ML Zone 5 through 6a (∼2,500 cal. yr. B.P.). This zone transitions from a warmer to a cooler/wetter climate as indicated by the increase in western hemlock (Tsuga heterophylla) and subsequent drop in fire frequency. The overall cooling trend and reduction in fire frequency appears to have occurred ∼700 years later than at Dog Lake (∼43 km to the south and 80 m lower in elevation), resulting in a closed montane spruce forest, whereas Marion Lake developed into a subalpine ecosystem. The temporal and ecological differences between the two study sites likely reflects the particular climate threshold needed to move these ecosystems from developed forests to subalpine conditions, as well as local site climate and fire conditions. These paleoecological records indicate future warming may result in the MS transitioning into an Interior Douglas Fir (IDF) dominated landscape, while the ESSF may become more forested, similar to the modern MS, or develop into a grassland-like landscape dependent on fire frequency. These results indicate that climate and disturbance over a regional area can dictate very different localized vegetative states. Local management implications of these dynamic landscapes will need to understand how ecosystems respond to climate and disturbance at the local or ecosystem/habitat scale.

Reconstruction of the long-term fire history of an old-growth deciduous forest in Southern Québec, Canada, from charred wood in mineral soils

2005 ◽  
Vol 64 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Brigitte Talon ◽  
Serge Payette ◽  
Louise Filion ◽  
Ann Delwaide
Keyword(s):  
Forest Fires ◽  
Sugar Maple ◽  
Fire History ◽  
Deciduous Forest ◽  
Old Growth ◽  
History Of ◽  
Mineral Soils ◽  
Tree Uprooting ◽  
Conifer Trees

AbstractCharcoal particles are widespread in terrestrial and lake environments of the northern temperate and boreal biomes where they are used to reconstruct past fire events and regimes. In this study, we used botanically identified and radiocarbon-dated charcoal macrofossils in mineral soils as a paleoecological tool to reconstruct past fire activity at the stand scale. Charcoal macrofossils buried in podzolic soils by tree uprooting were analyzed to reconstruct the long-term fire history of an old-growth deciduous forest in southern Québec. Charcoal fragments were sampled from the uppermost mineral soil horizons and identified based on anatomical characters. Spruce (Picea spp.) fragments dominated the charcoal assemblage, along with relatively abundant wood fragments of sugar maple (Acer saccharum) and birch (Betula spp.), and rare fragments of pine (Pinus cf. strobus) and white cedar (Thuja canadensis). AMS radiocarbon dates from 16 charcoal fragments indicated that forest fires were widespread during the early Holocene, whereas no fires were recorded from the mid-Holocene to present. The paucity of charcoal data during this period, however, does not preclude that a fire event of lower severity may have occurred. At least eight forest fires occurred at the study site between 10,400 and 6300 cal yr B.P., with a dominance of burned conifer trees between 10,400 and 9000 cal yr B.P. and burned conifer and deciduous trees between 9000 and 6300 cal yr B.P. Based on the charcoal record, the climate at the study site was relatively dry during the early Holocene, and more humid from 6300 cal yr B.P. to present. However, it is also possible that the predominance of conifer trees in the charcoal record between 10,400 and 6300 cal yr B.P. created propitious conditions for fire spreading. The charcoal record supports inferences based on pollen influx data (Labelle, C., Richard, P.J.H. 1981. Végétation tardiglaciaire et postglaciaire au sud-est du Parc des Laurentides, Québec. Géographie Physique et Quaternaire 35, 345-359) of the early arrival of spruce and sugar maple in the study area shortly after deglaciation. We conclude that macroscopic charcoal analysis of mineral soils subjected to disturbance by tree uprooting may be a useful paleoecological tool to reconstruct long-term forest fire history at the stand scale.

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