Skip to Main Content
Contrasting drivers and trends of coniferous and deciduous tree growth in interior AlaskaAuthor(s): Sean M. P. Cahoon; Patrick F. Sullivan; Annalis H. Brownlee; Robert R. Pattison; Hans-Erik Andersen; Kate Legner; Teresa N. Hollingsworth
Source: Ecology. 99(6): 1284-1295.
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
Download Publication (3.0 MB)
DescriptionThe boreal biome represents approximately one third of the world’s forested area and plays an important role in global biogeochemical and energy cycles. Numerous studies in boreal Alaska have concluded that growth of black and white spruce is declining as a result of temperature-induced drought stress. The combined evidence of declining spruce growth and changes in the fire regime that favor establishment of deciduous tree species has led some investigators to suggest the region may be transitioning from dominance by spruce to dominance by deciduous forests and/or grasslands. Although spruce growth trends have been extensively investigated, few studies have evaluated long-term radial growth trends of the dominant deciduous species (Alaska paper birch and trembling aspen) and their sensitivity to moisture availability. We used a large and spatially extensive sample of tree cores from interior Alaska to compare long-term growth trends among contrasting tree species (white and black spruce vs. birch and aspen). All species showed a growth peak in the mid-1940s, although growth following the peak varied strongly across species. Following an initial decline from the peak, growth of white spruce showed little evidence of a trend, while black spruce and birch growth showed slight growth declines from ~1970 to present. Aspen growth was much more variable than the other species and showed a steep decline from ~1970 to present. Growth of birch, black and white spruce was sensitive to moisture availability throughout most of the tree-ring chronologies, as evidenced by negative correlations with air temperature and positive correlations with precipitation. However, a positive correlation between previous July precipitation and aspen growth disappeared in recent decades, corresponding with a rise in the population of the aspen leaf miner (Phyllocnistis populiella), an herbivorous moth, which may have driven growth to a level not seen since the early 20th century. Our results provide important historical context for recent growth and raise questions regarding competitive interactions among the dominant tree species and exchanges of carbon and energy in the warming climate of interior Alaska.
- Visit PNW's Publication Request Page to request a hard copy of this publication.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationCahoon, Sean M. P.; Sullivan, Patrick F.; Brownlee, Annalis H.; Pattison, Robert R.; Andersen, Hans-Erik; Legner, Kate; Hollingsworth, Teresa N. 2018. Contrasting drivers and trends of coniferous and deciduous tree growth in interior Alaska. Ecology. 99(6): 1284-1295. https://doi.org/10.1002/ecy.2223.
KeywordsBetula neoalaskana, boreal forest, climate change, dendrochronology, Phyllocnistis populiella, Picea glauca, Picea mariana, Populus tremuloides, SPEI.
- Site-index comparisons for tree species in northern Minnesota.
- Biological growth functions describe published site index curves for Lake States timber species.
- Proceedings of the ninth Lake States Forest Tree Improvement Conference, August 22-23, 1969.
XML: View XML