I. Aguilera-Betti, C. Lucas, M. E. Ferrero, A. Muñoz
ABSTRACT Tree-ring research (TRR) in South America (SA) continues to make important contributions in multiple sub-disciplines, including dendrochemistry and dendrohydrology. This report describes some of the advances in TRR in SA presented in a two-day International Meeting Research entitled “An International Network to Promote Advances in Dendrochronology in South America”, organized by the Laboratory of Dendrochronology and Environmental Studies of the Pontifical Catholic University of Valparaíso in Valparaíso, Chile, on January 21–22, 2019. The objective of the meeting was to communicate recent advances in TRR within a network of laboratories in Argentina, Brazil, Chile, Peru, and Uruguay. Novel methodologies and results in dendrochemistry and wood anatomy were also presented by collaborating researchers from German institutions. This report describes some of the research within the subdisciplines of tree-ring science, including dendrochemistry, anatomy and dendrohydrology, and their application to understanding spatio-temporal variability in heavy metal contamination, climate, hydrology, fire regimes and other critical components of South American forest and woodland ecosystems. The meeting demonstrated expansion and diversification of inquiry and applications of TRR in SA, whereby collaboration across research centers has been critical for the advances made in broad-scale comparative studies as well as multi-proxy approaches and the study of global and hemisphere-scale climate phenomena.
{"title":"A Network for Advancing Dendrochronology, Dendrochemistry and Dendrohydrology in South America","authors":"I. Aguilera-Betti, C. Lucas, M. E. Ferrero, A. Muñoz","doi":"10.3959/TRR2019-12","DOIUrl":"https://doi.org/10.3959/TRR2019-12","url":null,"abstract":"ABSTRACT Tree-ring research (TRR) in South America (SA) continues to make important contributions in multiple sub-disciplines, including dendrochemistry and dendrohydrology. This report describes some of the advances in TRR in SA presented in a two-day International Meeting Research entitled “An International Network to Promote Advances in Dendrochronology in South America”, organized by the Laboratory of Dendrochronology and Environmental Studies of the Pontifical Catholic University of Valparaíso in Valparaíso, Chile, on January 21–22, 2019. The objective of the meeting was to communicate recent advances in TRR within a network of laboratories in Argentina, Brazil, Chile, Peru, and Uruguay. Novel methodologies and results in dendrochemistry and wood anatomy were also presented by collaborating researchers from German institutions. This report describes some of the research within the subdisciplines of tree-ring science, including dendrochemistry, anatomy and dendrohydrology, and their application to understanding spatio-temporal variability in heavy metal contamination, climate, hydrology, fire regimes and other critical components of South American forest and woodland ecosystems. The meeting demonstrated expansion and diversification of inquiry and applications of TRR in SA, whereby collaboration across research centers has been critical for the advances made in broad-scale comparative studies as well as multi-proxy approaches and the study of global and hemisphere-scale climate phenomena.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"101 - 94"},"PeriodicalIF":1.6,"publicationDate":"2020-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44659660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evan Montpellier, P. Knapp, P. T. Soulé, Justin T. Maxwell
ABSTRACT Latewood ring widths of longleaf pine (Pinus palustris Mill.) growing on Carolina bay sand rims on the coastal plains of North Carolina are effective recorders of tropical cycone precipitation (TCP). Longleaf pine are hypothesized to be effective recorders of TCP because of their extensive lateral root structure that is exposed to enhanced soil moisture when TCP events raise the water table to root level, but this hypothesis has not been empirically tested. In this study, we used a combination of North Carolina Phase 1 LiDAR and high-precision georeferenced data to investigate the relationship between radial tree growth, TCP, and microelevation. Our findings suggest that the strength of correlations between latewood ring widths and TCP are positively correlated (p < 0.05) with tree elevation on Carolina bay sand rims, resulting in greater sensistivity of trees at higher elevations. These findings suggest that in some environments, microelevational differences (<1 m) may significantly affect climate/radial growth relationships and the use of high-resolution LiDAR technology may be an effective tool for better understanding the role of microtopography on radial growth patterns.
{"title":"Microelevational Differences Affect Longleaf Pine (Pinus palustris Mill.) Sensitivity to Tropical Cyclone Precipitation: A Case Study Using Lidar","authors":"Evan Montpellier, P. Knapp, P. T. Soulé, Justin T. Maxwell","doi":"10.3959/TRR2019-9","DOIUrl":"https://doi.org/10.3959/TRR2019-9","url":null,"abstract":"ABSTRACT Latewood ring widths of longleaf pine (Pinus palustris Mill.) growing on Carolina bay sand rims on the coastal plains of North Carolina are effective recorders of tropical cycone precipitation (TCP). Longleaf pine are hypothesized to be effective recorders of TCP because of their extensive lateral root structure that is exposed to enhanced soil moisture when TCP events raise the water table to root level, but this hypothesis has not been empirically tested. In this study, we used a combination of North Carolina Phase 1 LiDAR and high-precision georeferenced data to investigate the relationship between radial tree growth, TCP, and microelevation. Our findings suggest that the strength of correlations between latewood ring widths and TCP are positively correlated (p < 0.05) with tree elevation on Carolina bay sand rims, resulting in greater sensistivity of trees at higher elevations. These findings suggest that in some environments, microelevational differences (<1 m) may significantly affect climate/radial growth relationships and the use of high-resolution LiDAR technology may be an effective tool for better understanding the role of microtopography on radial growth patterns.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"89 - 93"},"PeriodicalIF":1.6,"publicationDate":"2020-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48643114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Klutsch, Chen X. Kee, E. P. Cappa, B. Ratcliffe, B. Thomas, N. Erbilgin
ABSTRACT Injury from sampling increment cores may induce defense responses in trees, which may vary between species and reflect differing defense allocation strategies against attack by insects and pathogens. We recorded presence of systemic induction of traumatic resin ducts from early-season increment coring in mature white spruce (Picea glauca) and lodgepole pine (Pinus contorta var. latifolia) trees. In the year of coring, traumatic resin ducts formed three months later, 20 cm below the initial coring site in the xylem of white spruce and showed little variation in response among the spruce families. In contrast, lodgepole pine did not form traumatic resin ducts in trees cored earlier in the growing season. Although traumatic resin ducts are induced by biotic and abiotic disturbances, we found a species-specific defense response to increment coring in two common boreal forest tree species.
{"title":"INCREMENT CORING INDUCED TRAUMATIC RESIN DUCTS IN WHITE SPRUCE BUT NOT IN LODGEPOLE PINE","authors":"J. Klutsch, Chen X. Kee, E. P. Cappa, B. Ratcliffe, B. Thomas, N. Erbilgin","doi":"10.3959/TRR2019-5","DOIUrl":"https://doi.org/10.3959/TRR2019-5","url":null,"abstract":"ABSTRACT Injury from sampling increment cores may induce defense responses in trees, which may vary between species and reflect differing defense allocation strategies against attack by insects and pathogens. We recorded presence of systemic induction of traumatic resin ducts from early-season increment coring in mature white spruce (Picea glauca) and lodgepole pine (Pinus contorta var. latifolia) trees. In the year of coring, traumatic resin ducts formed three months later, 20 cm below the initial coring site in the xylem of white spruce and showed little variation in response among the spruce families. In contrast, lodgepole pine did not form traumatic resin ducts in trees cored earlier in the growing season. Although traumatic resin ducts are induced by biotic and abiotic disturbances, we found a species-specific defense response to increment coring in two common boreal forest tree species.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"54 - 58"},"PeriodicalIF":1.6,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49470958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alci Albiero-Júnior, A. Venegas‐González, M. Rodriguez‐Caton, J. M. Oliveira, T. Longhi-Santos, F. Galvão, L. G. Temponi, P. Botosso
ABSTRACT Edge effects are a major cause of natural dynamics of fragmented forests; however, studies that evaluate edge effects during the lifetime of trees are relatively rare. Through a long-term perspective of tree growth, dendroecology can contribute to a better understanding of the influence of edge effects. In order to frame our interpretation, we raised the following hypotheses: (1) trees located close to a forest edge have lower growth rates compared to trees growing far from edges, and (2) climate sensitivity of trees naturally growing on the forest edge is different from the trees in the interior. This study was conducted in Southern Brazil, where 21 Araucaria angustifolia located 50 m from the edge and 19 individuals located 4000 m from the forest edge were sampled. Dendrochronological study followed the usual procedures and growth patterns were evaluated using basal area increment, specific threshold value of fast and slow growth, and principal components analysis. During the 54 years analyzed, results indicated that the edge effect reduced growth by 30% in diameter increment and wood production of A. angustifolia trees. Regarding the influence of climatic variability on tree growth, we observed that edge effects may exert strong pressure on growth responses to climate in A. angustifolia located on forest edges, making individuals in those environments potentially more sensitive to variations in temperature and rainfall, mainly at warmer times of year. We therefore emphasize the importance of considering edge trees as potential bioindicators of historical environmental changes and forest fragmentation. Future studies should be carried out in other forest types and with different tree species (e.g. pioneer vs. shade-tolerant, trees vs. shrubs) to test the reliability of our results and provide more robust conclusions about this phenomenon.
{"title":"EDGE EFFECTS MODIFY THE GROWTH DYNAMICS AND CLIMATE SENSITIVITY OF ARAUCARIA ANGUSTIFOLIA TREES","authors":"Alci Albiero-Júnior, A. Venegas‐González, M. Rodriguez‐Caton, J. M. Oliveira, T. Longhi-Santos, F. Galvão, L. G. Temponi, P. Botosso","doi":"10.3959/TRR2018-9","DOIUrl":"https://doi.org/10.3959/TRR2018-9","url":null,"abstract":"ABSTRACT Edge effects are a major cause of natural dynamics of fragmented forests; however, studies that evaluate edge effects during the lifetime of trees are relatively rare. Through a long-term perspective of tree growth, dendroecology can contribute to a better understanding of the influence of edge effects. In order to frame our interpretation, we raised the following hypotheses: (1) trees located close to a forest edge have lower growth rates compared to trees growing far from edges, and (2) climate sensitivity of trees naturally growing on the forest edge is different from the trees in the interior. This study was conducted in Southern Brazil, where 21 Araucaria angustifolia located 50 m from the edge and 19 individuals located 4000 m from the forest edge were sampled. Dendrochronological study followed the usual procedures and growth patterns were evaluated using basal area increment, specific threshold value of fast and slow growth, and principal components analysis. During the 54 years analyzed, results indicated that the edge effect reduced growth by 30% in diameter increment and wood production of A. angustifolia trees. Regarding the influence of climatic variability on tree growth, we observed that edge effects may exert strong pressure on growth responses to climate in A. angustifolia located on forest edges, making individuals in those environments potentially more sensitive to variations in temperature and rainfall, mainly at warmer times of year. We therefore emphasize the importance of considering edge trees as potential bioindicators of historical environmental changes and forest fragmentation. Future studies should be carried out in other forest types and with different tree species (e.g. pioneer vs. shade-tolerant, trees vs. shrubs) to test the reliability of our results and provide more robust conclusions about this phenomenon.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"11 - 26"},"PeriodicalIF":1.6,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47602395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
World-renowned geochemist Wallace “Wally” Broecker, 87, died on February 18, 2019. Wally was born November 29, 1931, in Chicago, Illinois, and later attendedWheaton College and then Columbia University for his graduate work and Ph.D. He was Newberry Professor in the Department of Earth and Environmental Sciences at Columbia University, a scientist at Columbia’s Lamont-Doherty Earth Observatory (LDEO), and a sustainability fellow at Arizona State University (linked to his previous service as chief scientific advisor for Biosphere 2). Over his career, Wally’s work variously focused on topics related to geochronology, chemical oceanography, the carbon cycle, and climate change. Besides hundreds of publications and numerous awards (including the National Medal of Science in 1996), Wally has been credited with popularizing the term “global warming” (and was known to remark “The climate system is an angry beast, and we are poking it with sticks”), with identifying a world-wide ocean circulation current dubbed the “great ocean conveyor belt” (Thermohaline Circulation, THC), and with developing the hypothesis of how the slowdown of the THC might have contributed to the Younger Dryas cold event 12,000 years ago. He also published more than a dozen books, including How to Build a Habitable Planet in 1984 and Fixing Climate in 2008. Many more details of Broecker’s extraordinary life and achievement are described in the tribute penned by LDEO (https://www.ldeo.columbia.edu/news-events/walla ce-broecker-early-prophet-climate-change). Given the scope of Wally’s interests in paleoclimate, it should not be surprising to find he made tangible contributions to tree-rings studies. He accomplished this via work with his students, who were soon-to-be colleagues and remarkable scientists in their own right. An early paper in this regard was published in 1963 in the Geological Society of America Bulletin concerning radiocarbon dating of wood from the Two Creeks site in Wisconsin, notable as representing the final advance of the continental ice sheet into the United States. Tree-ring stable-carbon isotope records were being examined in the 1970s and 1980s as a proxies for changes in δ13C of atmospheric CO2 going back hundreds of years (direct atmospheric measurements only go back to the late 1950s). In a 1983 paper in the Journal of Geophysical Research, Wally, Tsung-Hung Peng, and Sue Trumbore modeled the magnitude of fossil-fuel versus land-use change inputs of CO2 to the atmosphere present in a composite tree-ring δ13C record. Finally, Wally participated in mechanistic exploration of hydrogen isotopes in tree rings with Jim White, first in a 1985 paper from Jim’s dissertation research examining H-isotope composition of water in sap as source water for isotopic composition of tree rings and later in a 1994 paper
{"title":"Wallace (“Wally”) S. Broecker 1931–2019","authors":"S. Leavitt","doi":"10.3959/trr2019-11","DOIUrl":"https://doi.org/10.3959/trr2019-11","url":null,"abstract":"World-renowned geochemist Wallace “Wally” Broecker, 87, died on February 18, 2019. Wally was born November 29, 1931, in Chicago, Illinois, and later attendedWheaton College and then Columbia University for his graduate work and Ph.D. He was Newberry Professor in the Department of Earth and Environmental Sciences at Columbia University, a scientist at Columbia’s Lamont-Doherty Earth Observatory (LDEO), and a sustainability fellow at Arizona State University (linked to his previous service as chief scientific advisor for Biosphere 2). Over his career, Wally’s work variously focused on topics related to geochronology, chemical oceanography, the carbon cycle, and climate change. Besides hundreds of publications and numerous awards (including the National Medal of Science in 1996), Wally has been credited with popularizing the term “global warming” (and was known to remark “The climate system is an angry beast, and we are poking it with sticks”), with identifying a world-wide ocean circulation current dubbed the “great ocean conveyor belt” (Thermohaline Circulation, THC), and with developing the hypothesis of how the slowdown of the THC might have contributed to the Younger Dryas cold event 12,000 years ago. He also published more than a dozen books, including How to Build a Habitable Planet in 1984 and Fixing Climate in 2008. Many more details of Broecker’s extraordinary life and achievement are described in the tribute penned by LDEO (https://www.ldeo.columbia.edu/news-events/walla ce-broecker-early-prophet-climate-change). Given the scope of Wally’s interests in paleoclimate, it should not be surprising to find he made tangible contributions to tree-rings studies. He accomplished this via work with his students, who were soon-to-be colleagues and remarkable scientists in their own right. An early paper in this regard was published in 1963 in the Geological Society of America Bulletin concerning radiocarbon dating of wood from the Two Creeks site in Wisconsin, notable as representing the final advance of the continental ice sheet into the United States. Tree-ring stable-carbon isotope records were being examined in the 1970s and 1980s as a proxies for changes in δ13C of atmospheric CO2 going back hundreds of years (direct atmospheric measurements only go back to the late 1950s). In a 1983 paper in the Journal of Geophysical Research, Wally, Tsung-Hung Peng, and Sue Trumbore modeled the magnitude of fossil-fuel versus land-use change inputs of CO2 to the atmosphere present in a composite tree-ring δ13C record. Finally, Wally participated in mechanistic exploration of hydrogen isotopes in tree rings with Jim White, first in a 1985 paper from Jim’s dissertation research examining H-isotope composition of water in sap as source water for isotopic composition of tree rings and later in a 1994 paper","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"59 - 60"},"PeriodicalIF":1.6,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47792532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT An emerging trend in tree-ring research is use of multiple species for reconstructing paleoclimates, but the possible simultaneous use of boreal-cordilleran species is untested. In this study, ring-width chronologies of sympatric Pinus contorta (lodgepole pine, n = 116 series) and Picea albertiana (western white spruce, n = 348 series) were constructed to assess their temporal (dis)similarities and correlative relationships with meteorological variables. Chronology construction was based on multiple Regional Curve Standardization. Most (97.5%) Pinus chronology values occurred within ±1 SD of their Picea counterparts, but Picea values tended to be slightly less (sign-test, p < 0.001, n = 201). Pinus ring widths were more frequently (16 versus 9) and more strongly correlated (U-test, p < 0.009) with 1942–2013 meteorological variables than Picea. Both species were correlated with moisture variables, but Picea was not correlated with those of temperature. Pinus and Picea ring-width variation was best explained by summer (r = –0.434) and annual (r = –0.426) heat-moisture index values (p < 0.001, n = 72) among tested variables, respectively. Although seldom used, P. contorta appears as suitable as conventionally-used P. albertiana based on chronology similarity, but a greater diversity of significant correlation outcomes suggest Pinus is potentially more useful for boreal-cordilleran paleoclimate reconstruction.
{"title":"A DIRECT COMPARISON OF SYMPATRIC HIGH-LATITUDE PINUS CONTORTA AND PICEA ALBERTIANA RING-WIDTH CHRONOLOGIES","authors":"W. Strong","doi":"10.3959/TRR2018-18","DOIUrl":"https://doi.org/10.3959/TRR2018-18","url":null,"abstract":"ABSTRACT An emerging trend in tree-ring research is use of multiple species for reconstructing paleoclimates, but the possible simultaneous use of boreal-cordilleran species is untested. In this study, ring-width chronologies of sympatric Pinus contorta (lodgepole pine, n = 116 series) and Picea albertiana (western white spruce, n = 348 series) were constructed to assess their temporal (dis)similarities and correlative relationships with meteorological variables. Chronology construction was based on multiple Regional Curve Standardization. Most (97.5%) Pinus chronology values occurred within ±1 SD of their Picea counterparts, but Picea values tended to be slightly less (sign-test, p < 0.001, n = 201). Pinus ring widths were more frequently (16 versus 9) and more strongly correlated (U-test, p < 0.009) with 1942–2013 meteorological variables than Picea. Both species were correlated with moisture variables, but Picea was not correlated with those of temperature. Pinus and Picea ring-width variation was best explained by summer (r = –0.434) and annual (r = –0.426) heat-moisture index values (p < 0.001, n = 72) among tested variables, respectively. Although seldom used, P. contorta appears as suitable as conventionally-used P. albertiana based on chronology similarity, but a greater diversity of significant correlation outcomes suggest Pinus is potentially more useful for boreal-cordilleran paleoclimate reconstruction.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"1 - 10"},"PeriodicalIF":1.6,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43956749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Szymczak, A. Bräuning, M. Häusser, E. Garel, F. Huneau, S. Santoni
ABSTRACT Forest fires are an important factor shaping Mediterranean ecosystems and determine the distribution of different species. Information about past forest fires can be obtained with pyrodendroecology. Here, we present a fire history for three sites in the mountain forest belt on the island of Corsica in the Mediterranean Basin. The dating of scars from cores, stem discs, and wedges from 101 pine trees (Pinus nigra and Pinus pinaster) allowed the reconstruction of six definite fire events between 1800 and 2017. Additionally, we reconstructed the spatial extent of a large fire event at AD 2000 with remote sensing data. The study sites are affected by different types of fires. The even-aged forest structure at two sites is clear evidence of past lethal fires, whereas the old-growth Pinus nigra forest at the third site represents the final stage of succession under current climate conditions. The current distribution of both pine species can at least partly be regarded as a result of varying fire frequency at different sites. Although Pinus pinaster stands dominate in areas with frequent fires and can even replace Pinus nigra in cases of high fire frequency, Pinus nigra dominates in areas with low fire frequencies.
{"title":"A DENDROECOLOGICAL FIRE HISTORY FOR CENTRAL CORSICA/FRANCE","authors":"S. Szymczak, A. Bräuning, M. Häusser, E. Garel, F. Huneau, S. Santoni","doi":"10.3959/TRR2019-2","DOIUrl":"https://doi.org/10.3959/TRR2019-2","url":null,"abstract":"ABSTRACT Forest fires are an important factor shaping Mediterranean ecosystems and determine the distribution of different species. Information about past forest fires can be obtained with pyrodendroecology. Here, we present a fire history for three sites in the mountain forest belt on the island of Corsica in the Mediterranean Basin. The dating of scars from cores, stem discs, and wedges from 101 pine trees (Pinus nigra and Pinus pinaster) allowed the reconstruction of six definite fire events between 1800 and 2017. Additionally, we reconstructed the spatial extent of a large fire event at AD 2000 with remote sensing data. The study sites are affected by different types of fires. The even-aged forest structure at two sites is clear evidence of past lethal fires, whereas the old-growth Pinus nigra forest at the third site represents the final stage of succession under current climate conditions. The current distribution of both pine species can at least partly be regarded as a result of varying fire frequency at different sites. Although Pinus pinaster stands dominate in areas with frequent fires and can even replace Pinus nigra in cases of high fire frequency, Pinus nigra dominates in areas with low fire frequencies.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"40 - 53"},"PeriodicalIF":1.6,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42407822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sabrina R. Brown, Ashley Baysinger, P. Brown, Justin L. Cheek, J. Diez, Christopher M. Gentry, T. A. Grant, Jeannine-Marie Jacques, D. Jordan, M. L. Leef, M. K. Rourke, J. Speer, Carrie E. Spradlin, J. T. Stevens, J. Stone, Brian Van Winkle, Nickolas E. Zeibig-Kichas
ABSTRACT Fire is a critical ecosystem process that has played a key role in shaping forests throughout the Beartooth Mountains in northwestern Wyoming. The highly variable topography of the area provides ideal conditions to compare fire regimes across contiguous forest types, yet pyro-dendrochronological research in this area is limited. We reconstructed fire frequency, tree age structure, and post-fire tree growth response in the Clarks Fork Ranger District of the Shoshone National Forest to infer variations in historical fire behavior and stand effects. We collected fire-scarred trees and plot-based tree ages on plots ranging 0.5-5 km2 in size across two forest types separated by 2 km: a lower-elevation forest of mixed Douglas-fir and lodgepole pine and a higher elevation treeline forest dominated by whitebark pine. Fires occurred in the lower-elevation forest in 1664, 1706, 1785, 1804, 1846, and 1900 with a mean fire return interval of 47 years. The fires in 1804 and 1900 were also recorded in the higher elevation forest, with significant tree mortality at high elevation in the 1900 fire. Both forests were multi-aged with little evidence of tree cohorts in response to severe, stand-replacing events. On average, tree growth increased after fires, with mean ring widths after fire 39% wider in Douglas-fir and 40% wider in lodgepole pine than pre-fire averages, suggesting that some tree mortality likely occurred in association with lower-elevation forest fires. Burns were more frequent in the lower-elevation forest and were occasionally able to spread into the upper-elevation whitebark stand. Although we suspect the transition of fires from low-to high-elevation occurred during drier years, we did not find any relationship between fire years and available climatic reconstructions via superposed epoch analysis. Regeneration during the 20th Century in the whitebark forest documents recovery of this forest after the 1900 moderate-severity fire event. Finally, especially in the lower-elevation Douglas-fir forest, the period since the last recorded fire (1900) appears to be longer than any fire-free period in the historical record, suggesting that fire exclusion may be creating changes in landscape and patch-scale stand structures, which will likely impact future fire behavior, especially the extent of crown-replacing fire, in these forests.
{"title":"FIRE HISTORY ACROSS FOREST TYPES IN THE SOUTHERN BEARTOOTH MOUNTAINS, WYOMING","authors":"Sabrina R. Brown, Ashley Baysinger, P. Brown, Justin L. Cheek, J. Diez, Christopher M. Gentry, T. A. Grant, Jeannine-Marie Jacques, D. Jordan, M. L. Leef, M. K. Rourke, J. Speer, Carrie E. Spradlin, J. T. Stevens, J. Stone, Brian Van Winkle, Nickolas E. Zeibig-Kichas","doi":"10.3959/TRR2018-11","DOIUrl":"https://doi.org/10.3959/TRR2018-11","url":null,"abstract":"ABSTRACT Fire is a critical ecosystem process that has played a key role in shaping forests throughout the Beartooth Mountains in northwestern Wyoming. The highly variable topography of the area provides ideal conditions to compare fire regimes across contiguous forest types, yet pyro-dendrochronological research in this area is limited. We reconstructed fire frequency, tree age structure, and post-fire tree growth response in the Clarks Fork Ranger District of the Shoshone National Forest to infer variations in historical fire behavior and stand effects. We collected fire-scarred trees and plot-based tree ages on plots ranging 0.5-5 km2 in size across two forest types separated by 2 km: a lower-elevation forest of mixed Douglas-fir and lodgepole pine and a higher elevation treeline forest dominated by whitebark pine. Fires occurred in the lower-elevation forest in 1664, 1706, 1785, 1804, 1846, and 1900 with a mean fire return interval of 47 years. The fires in 1804 and 1900 were also recorded in the higher elevation forest, with significant tree mortality at high elevation in the 1900 fire. Both forests were multi-aged with little evidence of tree cohorts in response to severe, stand-replacing events. On average, tree growth increased after fires, with mean ring widths after fire 39% wider in Douglas-fir and 40% wider in lodgepole pine than pre-fire averages, suggesting that some tree mortality likely occurred in association with lower-elevation forest fires. Burns were more frequent in the lower-elevation forest and were occasionally able to spread into the upper-elevation whitebark stand. Although we suspect the transition of fires from low-to high-elevation occurred during drier years, we did not find any relationship between fire years and available climatic reconstructions via superposed epoch analysis. Regeneration during the 20th Century in the whitebark forest documents recovery of this forest after the 1900 moderate-severity fire event. Finally, especially in the lower-elevation Douglas-fir forest, the period since the last recorded fire (1900) appears to be longer than any fire-free period in the historical record, suggesting that fire exclusion may be creating changes in landscape and patch-scale stand structures, which will likely impact future fire behavior, especially the extent of crown-replacing fire, in these forests.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"76 1","pages":"27 - 39"},"PeriodicalIF":1.6,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44254376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-08DOI: 10.3959/1536-1098-75.2.86
A. Nautiyal, G. S. Rawat, K. Ramesh, R. Kannan, S. L. Stephenson
ABSTRACT The growth response of earlywood and latewood to precipitation in chir pine (Pinus roxburghii) was studied by examining a series of core samples from the Garhwal Himalaya, India. Earlywood and latewood were observed to contribute about equal proportions towards the total ring width. Comparison of tree-ring data with the CRU TS3.22 (land) precipitation dataset indicates that earlywood is positively correlated with spring and early summer precipitation, whereas latewood is negatively correlated with pre-monsoon and early monsoon precipitation. This seasonally-reversed climate signal is confirmed when regional weather station precipitation data were used. A similar seasonally reversed climate response was found in earlywood and latewood of two datasets obtained from core samples from two other sites located in Nepal and Bhutan. Because chir pine is a light-demanding species, light limitation during the monsoon season could be an important factor behind the negative correlation between latewood and precipitation. NOAA NCEP-NCAR low cloud data were used to test this hypothesis, and the preliminary results support the hypothesis; however, further analysis will be needed to fully validate this hypothesis.
{"title":"SEASONAL PRECIPITATION SIGNAL IN EARLYWOOD AND LATEWOOD RING WIDTH CHRONOLOGIES OF PINUS ROXBURGHII","authors":"A. Nautiyal, G. S. Rawat, K. Ramesh, R. Kannan, S. L. Stephenson","doi":"10.3959/1536-1098-75.2.86","DOIUrl":"https://doi.org/10.3959/1536-1098-75.2.86","url":null,"abstract":"ABSTRACT The growth response of earlywood and latewood to precipitation in chir pine (Pinus roxburghii) was studied by examining a series of core samples from the Garhwal Himalaya, India. Earlywood and latewood were observed to contribute about equal proportions towards the total ring width. Comparison of tree-ring data with the CRU TS3.22 (land) precipitation dataset indicates that earlywood is positively correlated with spring and early summer precipitation, whereas latewood is negatively correlated with pre-monsoon and early monsoon precipitation. This seasonally-reversed climate signal is confirmed when regional weather station precipitation data were used. A similar seasonally reversed climate response was found in earlywood and latewood of two datasets obtained from core samples from two other sites located in Nepal and Bhutan. Because chir pine is a light-demanding species, light limitation during the monsoon season could be an important factor behind the negative correlation between latewood and precipitation. NOAA NCEP-NCAR low cloud data were used to test this hypothesis, and the preliminary results support the hypothesis; however, further analysis will be needed to fully validate this hypothesis.","PeriodicalId":54416,"journal":{"name":"Tree-Ring Research","volume":"75 1","pages":"100 - 86"},"PeriodicalIF":1.6,"publicationDate":"2019-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44495786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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