Authors: Jen N Baron*, University of British Columbia, Lori D Daniels, University of British Columbia, Fred J Longstaffe, University of Western Ontario
Topics: Biogeography, Environmental Science, Land Use
Keywords: Dendrochronology, white pine, climate change, oak savanna, conservation
Session Type: Virtual Paper
Presentation File: No File Uploaded
Anthropogenic climate change poses a significant threat to the composition, structure, and function of protected areas. The Pinery Provincial Park, Ontario, Canada contains some of the most rare, biodiverse, and threatened oak savanna and coastal dune ecosystems in North America; however, it is not well understood how climate change impacts tree growth in this protected area. We quantified the impacts of climate change on Pinus strobus (Eastern white pine) growth at the Pinery from 1950–2017 using annual ring-width index (RWI), stable carbon isotope composition of cellulose (carbon), and intrinsic water use efficiency (iWUE). Breakpoint and climate-growth analyses detected significant changes in the growth (RWI, carbon), and iWUE chronologies in the early 1990s and early 2000s associated with shifts in winter and late-spring precipitation, temperature, and standardized precipitation evapotranspiration index (SPEI). Specifically, decreased growth and increased iWUE in the 1990s is associated with dry and warm conditions, while increased growth and constant iWUE through the 2000s is associated with wet and warm conditions. Additional breakpoints in the carbon isotope record distinguish growth phases in the 1950s, 1960s, and 1970–1990s coinciding with management decisions related to infrastructure, pine plantations, and prescribed burns. Based on these results, we suggest that climate change and anthropogenic management have driven growth of P. strobus at the Pinery since 1950, with the impact of climate change becoming increasingly important since 1990. We discuss the implications of these findings in the context of future climate change and oak savanna conservation.