Nonlinear Growth and Physiological Responses of White Spruce at North American Arctic Treeline ...
Much is still unknown about the growth and physiological responses of trees to global change at the northern treeline. We combined tree-ring width data with century-long stable carbon and oxygen isotope records to investigate growth and physiological responses of white spruce at two treeline sites i...
| Main Authors: | , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
ETH Zurich
2023
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.3929/ethz-b-000610778 http://hdl.handle.net/20.500.11850/610778 |
| Summary: | Much is still unknown about the growth and physiological responses of trees to global change at the northern treeline. We combined tree-ring width data with century-long stable carbon and oxygen isotope records to investigate growth and physiological responses of white spruce at two treeline sites in the Canadian Arctic to concurrent increases in temperature, atmospheric CO2 concentration (ca), and decline in sea ice extent over the past century. The tree-ring records were assessed during three periods with contrasting climatic conditions: (a) the early 20th century warming, (b) the 1940–1970 cooling period, and (c) the anthropogenic late 20th century warming period. We found opposing growth trends between the two sites, but similar carbon isotope discrimination (Δ13C) and intrinsic water-use efficiency (iWUE) trajectories. While tree growth (defined as basal area increment) increased at the site nearer to the Arctic Ocean during the 20th century following the rise in temperature and sea ice loss, growth ... : Journal of Geophysical Research: Biogeosciences, 128 (4) ... |
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