Sticky Situation: Recent Sugar Maple ring-width declines and possible climatic drivers

Keywords: Sugar maple (Acer saccharum), dendrochronology, productivity, climate
Session Type: Virtual Paper Abstract
Day: Monday
Session Start / End Time: 2/28/2022 05:20 PM (Eastern Time (US & Canada)) - 2/28/2022 06:40 PM (Eastern Time (US & Canada))
Room: Virtual 6

Abstract

Recent narrowing of sugar maple (Acer saccharum) annual growth rings in central portions of
the species’ range has been attributed to several possible causes, including acid deposition, pests and climate. Climate change is of particular concern because temperature, precipitation and drought patterns have changed across the entirety of sugar maple’s range. However, the role of climate change in sugar maple decline remains unclear. Our objectives were to test for trends in ring-width productivity to assess the responsiveness of sugar maple trees to regional environmental stressors, and to test relationships between annual ring-widths and climatic characteristics (temperature, precipitation and drought) to determine whether these may be driving ring-width declines. Analysis was based on ring-width measurements from 335 sugar maple trees from three adjacent ecoregions. Analysis was segmented by ecoregion to enable comparison between these biogeoclimatically distinct areas. Ring-width data and climate data had a common period of 1912-2011, which included a period of climatic warming and wetting. Ring-width productivity declined recently in the Algonquin Highlands (-46 mm2/year, 1993-
2011) and Adirondack Mountains (-33 mm2/year, 1991-2011), but not in the Frontenac Arch (located between the two). Ring-widths had a significant response to some monthly climatic variables (coefficients ±0.3), and responses were stronger in some decades (coefficients ±0.6) but did not show ecoregional patterns of responsiveness over time, despite climatic change. No clear climatic driver of sugar maple decline emerged, but ecoregional differences in decline trends may hint at important decline drivers.