Abstract We developed a fire history for Voyageurs National Park (VNP), MN, USA based on 129 fire... more Abstract We developed a fire history for Voyageurs National Park (VNP), MN, USA based on 129 fire-scarred cross sections collected at 39 disjunct locations to develop a baseline understanding of the history of fire in the region. We dated 443 scars representing 126 unique fire years with the earliest fire recorded in 1665 and the most recent in 1972. The Weibull Median Fire Interval from individual fire intervals at the 39 sites is about 18 years and two years for the study area as a whole. Site-scale fire intervals were relatively short, with about 75% of the intervals between fires less than 30 years and more than half of the intervals shorter than 20 years. Approximately 61% of the 126 unique fire years were recorded at only 1 site and about 20% of fires were recorded at 2 or more sites. The median interval between fires that were synchronous at 3 or more sites is 7 years, with the earliest synchronous fire occurring in 1718 and the last in 1936. Fires occurring at more than three sites coincided with summers that are significantly drier than average during the fire year. In VNP, several lines of evidence are suggestive of the potential role of people in augmenting the fire regime above that which would have occurred due to lightning alone. The patterns of fire activity in VNP highlight the same issues that have been noted elsewhere, namely that fires have been prominent in the past in shaping the character of Upper Great Lakes forests and that fire activity has been much reduced since the 20th century. The reduction of fire activity observed after the early 20th century could be as much related to the reduction of human ignition and the removal of people from the landscape as it is to active suppression. This research suggests that the appropriate use of planned fire should be employed as an important management tool, likely through the intentional ignition of fires rather than a reliance on lightning starts alone. This research represents another step in better understanding the processes that have shaped the landscape of Voyageurs National Park, while continuing a dialogue around the future of an ecologically, economically, and culturally significant subset of the Border Lakes landscape.
We reconstructed fire occurrence near a fur-trade era canoe travel corridor (used ca. 1780-1802) ... more We reconstructed fire occurrence near a fur-trade era canoe travel corridor (used ca. 1780-1802) in the Quetico-Superior region west of Lake Superior to explore the possibility of human influence on pre-fire suppression rates of fire occurrence. Our research objectives were to (1) examine the spatial and temporal patterns of fire in the study area, (2) test fires' strength of association with regional drought, and (3) assess whether reconstructed fire frequencies could be explained by observed rates of lightning fire ignition over the modern period of record. We developed a 420-year fire history for the eastern portion of Lac La Croix in the Boundary Waters Canoe Area Wilderness (BWCAW). Seventy-one fire-scarred samples were collected from remnant Pinus resinosa Ait. (red pine) stumps and logs from thirteen distinct island and three mainland forest stands. Collectively these samples contained records of 255 individual fire scars representing 79 fire events from 1636 to 1933 (study area mean fire intervals [MFI] 3.8 yr). Reconstructed fires were spatially and temporally asynchronous and not strongly associated with regional drought (P > 0.05). When compared to the conservative, tree-ring reconstructed estimate of historical fire occurrence and modern lightning-caused fires (1929-2012), a noticeable change in the distribution and frequency of fires within the study area was evident with only two lightning-ignited island fires since 1934 in the study area. Our results suggest a high likelihood that indigenous land use contributed to surface fire ignitions within our study area and highlights the importance of examining the potential effects of past indigenous land use when determining modern approaches to fire and wilderness management in fire-adapted ecosystems.
Craters of the Moon (COM) National Monument is a basaltic volcanic complex on the eastern Snake R... more Craters of the Moon (COM) National Monument is a basaltic volcanic complex on the eastern Snake River Plain that has formed over eight eruptive periods during the Holocene. Since the last eruption, limber pine (Pinus flexilis) and Douglas-fir (Pseudotsuga menziesii Mirb Franco.) have established on lava flows and ancient weathered cinder cones. These rare long-lived trees have survived for 400 - 1000 years on well-drained porous rock, inviting the possibility that tree-ring widths will show elevated moisture sensitivity. Four tree-ring records have been constructed from living trees and remnant wood that include limber pine total ring-width (937-2009 AD), Douglas-fir total ring-width, and partial earlywood and latewood widths (1468-2009 AD). During 1550-2009 AD, the covariance between records is moderately significant (0.31-0.34, p<0.01) for standard chronologies, but residual chronologies show little association (0.05-0.08). Monte-Carlo correlations between tree-ring widths and ...
Trends toward an earlier spring season onset in the western United States have been increasingly ... more Trends toward an earlier spring season onset in the western United States have been increasingly documented and are of interest to many different users of climate information throughout the region. Studies, however, have not adequately quantified the variability of spring season temperatures on multidecadal time scales. This study examines the spatio-temporal variability of spring season minimum temperatures in the western
Abstract Fire history was determined ,for part of the ,Routt-Medicine Bow National Forest in sout... more Abstract Fire history was determined ,for part of the ,Routt-Medicine Bow National Forest in south-eastern Wyoming ,using fire-scar and age-class analysis. A composite ,chronology of fire events was used to determine mean fire intervals (MFI) for pre-EuroAmericansettle- ment, EuroAmerican settlement (before 1868 ad ), EuroAmerican settlement and modern
Abstract We developed a fire history for Voyageurs National Park (VNP), MN, USA based on 129 fire... more Abstract We developed a fire history for Voyageurs National Park (VNP), MN, USA based on 129 fire-scarred cross sections collected at 39 disjunct locations to develop a baseline understanding of the history of fire in the region. We dated 443 scars representing 126 unique fire years with the earliest fire recorded in 1665 and the most recent in 1972. The Weibull Median Fire Interval from individual fire intervals at the 39 sites is about 18 years and two years for the study area as a whole. Site-scale fire intervals were relatively short, with about 75% of the intervals between fires less than 30 years and more than half of the intervals shorter than 20 years. Approximately 61% of the 126 unique fire years were recorded at only 1 site and about 20% of fires were recorded at 2 or more sites. The median interval between fires that were synchronous at 3 or more sites is 7 years, with the earliest synchronous fire occurring in 1718 and the last in 1936. Fires occurring at more than three sites coincided with summers that are significantly drier than average during the fire year. In VNP, several lines of evidence are suggestive of the potential role of people in augmenting the fire regime above that which would have occurred due to lightning alone. The patterns of fire activity in VNP highlight the same issues that have been noted elsewhere, namely that fires have been prominent in the past in shaping the character of Upper Great Lakes forests and that fire activity has been much reduced since the 20th century. The reduction of fire activity observed after the early 20th century could be as much related to the reduction of human ignition and the removal of people from the landscape as it is to active suppression. This research suggests that the appropriate use of planned fire should be employed as an important management tool, likely through the intentional ignition of fires rather than a reliance on lightning starts alone. This research represents another step in better understanding the processes that have shaped the landscape of Voyageurs National Park, while continuing a dialogue around the future of an ecologically, economically, and culturally significant subset of the Border Lakes landscape.
We reconstructed fire occurrence near a fur-trade era canoe travel corridor (used ca. 1780-1802) ... more We reconstructed fire occurrence near a fur-trade era canoe travel corridor (used ca. 1780-1802) in the Quetico-Superior region west of Lake Superior to explore the possibility of human influence on pre-fire suppression rates of fire occurrence. Our research objectives were to (1) examine the spatial and temporal patterns of fire in the study area, (2) test fires&#39; strength of association with regional drought, and (3) assess whether reconstructed fire frequencies could be explained by observed rates of lightning fire ignition over the modern period of record. We developed a 420-year fire history for the eastern portion of Lac La Croix in the Boundary Waters Canoe Area Wilderness (BWCAW). Seventy-one fire-scarred samples were collected from remnant Pinus resinosa Ait. (red pine) stumps and logs from thirteen distinct island and three mainland forest stands. Collectively these samples contained records of 255 individual fire scars representing 79 fire events from 1636 to 1933 (study area mean fire intervals [MFI] 3.8 yr). Reconstructed fires were spatially and temporally asynchronous and not strongly associated with regional drought (P &gt; 0.05). When compared to the conservative, tree-ring reconstructed estimate of historical fire occurrence and modern lightning-caused fires (1929-2012), a noticeable change in the distribution and frequency of fires within the study area was evident with only two lightning-ignited island fires since 1934 in the study area. Our results suggest a high likelihood that indigenous land use contributed to surface fire ignitions within our study area and highlights the importance of examining the potential effects of past indigenous land use when determining modern approaches to fire and wilderness management in fire-adapted ecosystems.
Craters of the Moon (COM) National Monument is a basaltic volcanic complex on the eastern Snake R... more Craters of the Moon (COM) National Monument is a basaltic volcanic complex on the eastern Snake River Plain that has formed over eight eruptive periods during the Holocene. Since the last eruption, limber pine (Pinus flexilis) and Douglas-fir (Pseudotsuga menziesii Mirb Franco.) have established on lava flows and ancient weathered cinder cones. These rare long-lived trees have survived for 400 - 1000 years on well-drained porous rock, inviting the possibility that tree-ring widths will show elevated moisture sensitivity. Four tree-ring records have been constructed from living trees and remnant wood that include limber pine total ring-width (937-2009 AD), Douglas-fir total ring-width, and partial earlywood and latewood widths (1468-2009 AD). During 1550-2009 AD, the covariance between records is moderately significant (0.31-0.34, p<0.01) for standard chronologies, but residual chronologies show little association (0.05-0.08). Monte-Carlo correlations between tree-ring widths and ...
Trends toward an earlier spring season onset in the western United States have been increasingly ... more Trends toward an earlier spring season onset in the western United States have been increasingly documented and are of interest to many different users of climate information throughout the region. Studies, however, have not adequately quantified the variability of spring season temperatures on multidecadal time scales. This study examines the spatio-temporal variability of spring season minimum temperatures in the western
Abstract Fire history was determined ,for part of the ,Routt-Medicine Bow National Forest in sout... more Abstract Fire history was determined ,for part of the ,Routt-Medicine Bow National Forest in south-eastern Wyoming ,using fire-scar and age-class analysis. A composite ,chronology of fire events was used to determine mean fire intervals (MFI) for pre-EuroAmericansettle- ment, EuroAmerican settlement (before 1868 ad ), EuroAmerican settlement and modern
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