Tree-Rings Reveal Accelerated Yellow-Cedar Decline with Changes to Winter Climate after 1980 ...

• Published in: ARCTIC
• Main Authors: Comeau, Vanessa M., Daniels, Lori D., Knochenmus, Garrett, Chavardès, Raphaël D., Zeglen, Stefan
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2020
• Subjects: Archipelago; Alaska
• Online Access: https://dx.doi.org/10.14288/1.0388192; https://doi.library.ubc.ca/10.14288/1.0388192

Research Highlights: Yellow-cedar decline on the island archipelago of Haida Gwaii is driven by warm winter temperatures and low winter precipitation, which is caused by anthropogenic climate change and exacerbated by the positive phase of the Pacific Decadal Oscillation (PDO). Background and Objectives: Declining yellow-cedars are limited by physiological drought during the growing season, caused by freezing damage to fine roots through a complex pathway identified by research in Alaska. Given this, we hypothesized: (1) yellow-cedars on Haida Gwaii were limited by the winter climate. (2) Trees of different health classes were responding differently to climatic variation. (3) Changing climate-growth relations would vary among phases of the PDO. Materials and Methods: We sampled 15 stands exhibiting crown symptoms and developed three regional chronologies from trees that were healthy, had crown or tree-ring symptoms of decline, and trees that had died. We tested for growth responses to inter-annual and ...