4 research outputs found
Variation in climate-growth relationships for Douglas-fir growth across spatial and temporal scales on southern Vancouver Island, British Columbia
Continental-Scale Tree-Ring-based Projection of Douglas-Fir Growth: Testing the Limits of Space-for-time Substitution
A central challenge in global change research is the projection of the future behavior of a system based upon past observations. Tree-ring data have been used increasingly over the last decade to project tree growth and forest ecosystem vulnerability under future climate conditions. But how can the response of tree growth to past climate variation predict the future, when the future does not look like the past? Space-for-time substitution (SFTS) is one way to overcome the problem of extrapolation: the response at a given location in a warmer future is assumed to follow the response at a warmer location today. Here we evaluated an SFTS approach to projecting future growth of Douglas-fir (Pseudotsuga menziesii), a species that occupies an exceptionally large environmental space in North America. We fit a hierarchical mixed-effects model to capture ring-width variability in response to spatial and temporal variation in climate. We found opposing gradients for productivity and climate sensitivity with highest growth rates and weakest response to interannual climate variation in the mesic coastal part of Douglas-fir\u27s range; narrower rings and stronger climate sensitivity occurred across the semi-arid interior. Ring-width response to spatial versus temporal temperature variation was opposite in sign, suggesting that spatial variation in productivity, caused by local adaptation and other slow processes, cannot be used to anticipate changes in productivity caused by rapid climate change. We thus substituted only climate sensitivities when projecting future tree growth. Growth declines were projected across much of Douglas-fir\u27s distribution, with largest relative decreases in the semiarid U.S. Interior West and smallest in the mesic Pacific Northwest. We further highlight the strengths of mixed-effects modeling for reviving a conceptual cornerstone of dendroecology, Cook\u27s 1987 aggregate growth model, and the great potential to use tree-ring networks and results as a calibration target for next-generation vegetation models
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Continentalâscale treeâringâbased projection of Douglasâfir growth: Testing the limits of spaceâforâtime substitution
A central challenge in global change research is the projection of the future behavior of a system based upon past observations. Treeâring data have been used increasingly over the last decade to project tree growth and forest ecosystem vulnerability under future climate conditions. But how can the response of tree growth to past climate variation predict the future, when the future does not look like the past? Spaceâforâtime substitution (SFTS) is one way to overcome the problem of extrapolation: the response at a given location in a warmer future is assumed to follow the response at a warmer location today. Here we evaluated an SFTS approach to projecting future growth of Douglasâfir (Pseudotsuga menziesii), a species that occupies an exceptionally large environmental space in North America. We fit a hierarchical mixedâeffects model to capture ringâwidth variability in response to spatial and temporal variation in climate. We found opposing gradients for productivity and climate sensitivity with highest growth rates and weakest response to interannual climate variation in the mesic coastal part of Douglasâfir's range; narrower rings and stronger climate sensitivity occurred across the semiâarid interior. Ringâwidth response to spatial versus temporal temperature variation was opposite in sign, suggesting that spatial variation in productivity, caused by local adaptation and other slow processes, cannot be used to anticipate changes in productivity caused by rapid climate change. We thus substituted only climate sensitivities when projecting future tree growth. Growth declines were projected across much of Douglasâfir's distribution, with largest relative decreases in the semiarid U.S. Interior West and smallest in the mesic Pacific Northwest. We further highlight the strengths of mixedâeffects modeling for reviving a conceptual cornerstone of dendroecology, Cook's 1987 aggregate growth model, and the great potential to use treeâring networks and results as a calibration target for nextâgeneration vegetation models.SK acknowledges the support of the
USDA-AFRI grant 2016-67003-24944; MEKE was supported by the National Science Foundation
under award DBI-1802893. FB acknowledges statutory funds from the W. Szafer Institute of Botany
PAS, as well as support from the project âInside outâ (#POIR.04.04.00-00-5F85/18-00) funded by the
HOMING programme of the Foundation for Polish Science, co-financed by the European Union
under the European Regional Development Fund.12 month embargo; first published: 20 May 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Continentalâscale treeâringâbased projection of Douglasâfir growth: Testing the limits of spaceâforâtime substitution
A central challenge in global change research is the projection of the future behavior of a system based upon past observations. Treeâring data have been used increasingly over the last decade to project tree growth and forest ecosystem vulnerability under future climate conditions. But how can the response of tree growth to past climate variation predict the future, when the future does not look like the past? Spaceâforâtime substitution (SFTS) is one way to overcome the problem of extrapolation: the response at a given location in a warmer future is assumed to follow the response at a warmer location today. Here we evaluated an SFTS approach to projecting future growth of Douglasâfir (Pseudotsuga menziesii), a species that occupies an exceptionally large environmental space in North America. We fit a hierarchical mixedâeffects model to capture ringâwidth variability in response to spatial and temporal variation in climate. We found opposing gradients for productivity and climate sensitivity with highest growth rates and weakest response to interannual climate variation in the mesic coastal part of Douglasâfir's range; narrower rings and stronger climate sensitivity occurred across the semiâarid interior. Ringâwidth response to spatial versus temporal temperature variation was opposite in sign, suggesting that spatial variation in productivity, caused by local adaptation and other slow processes, cannot be used to anticipate changes in productivity caused by rapid climate change. We thus substituted only climate sensitivities when projecting future tree growth. Growth declines were projected across much of Douglasâfir's distribution, with largest relative decreases in the semiarid U.S. Interior West and smallest in the mesic Pacific Northwest. We further highlight the strengths of mixedâeffects modeling for reviving a conceptual cornerstone of dendroecology, Cook's 1987 aggregate growth model, and the great potential to use treeâring networks and results as a calibration target for nextâgeneration vegetation models.SK acknowledges the support of the
USDA-AFRI grant 2016-67003-24944; MEKE was supported by the National Science Foundation
under award DBI-1802893. FB acknowledges statutory funds from the W. Szafer Institute of Botany
PAS, as well as support from the project âInside outâ (#POIR.04.04.00-00-5F85/18-00) funded by the
HOMING programme of the Foundation for Polish Science, co-financed by the European Union
under the European Regional Development Fund.12 month embargo; first published: 20 May 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]