title: Drought causes reduced growth of trembling aspen in western Canada.
abstract: Adequate and advance knowledge of the response of forest ecosystems to temperature-induced drought is critical for a comprehensive understanding of the impacts of global climate change on forest ecosystem structure and function. Recent massive decline in aspen-dominated forests and an increased aspen mortality in boreal forests have been associated with global warming, but it is still uncertain whether the decline and mortality are driven by drought. We used a series of ring-width chronologies from 40 trembling aspen (Populus tremuloides Michx.) sites along a latitudinal gradient (from 52° to 58°N) in western Canada, in an attempt to clarify the impacts of drought on aspen growth by using Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Results indicated that prolonged and large-scale droughts had a strong negative impact on trembling aspen growth. Furthermore, the spatiotemporal variability of drought indices is useful for explaining the spatial heterogeneity in the radial growth of trembling aspen. Due to ongoing global warming and rising temperatures, it is likely that severer droughts with a higher frequency will occur in western Canada. As trembling aspen is sensitive to drought, we suggest that drought indices could be applied to monitor the potential effects of increased drought stress on aspen trees growth, achieve classification of eco-regions and develop effective mitigation strategies to maintain western Canadian boreal forests.
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.|Graduate School of Environmental Science, Hokkaido University, N19W8, Sapporo, 060-0819, Japan.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.|Institut de Recherche Sur Les Forêts, Université du Québec en Abitibi-Témiscamingue, 445, boulevard de l'Université, Rouyn-Noranda, QC, J9X 5E4, Canada.
authors.forename: Jian-Guo
authors.identifier: 0000-0003-3830-0415
authors.initials: JG
authors.lastname: Huang
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.|Department of Physics, University of Helsinki, P.O. Box 48, FI-00014, Helsinki, Finland.
authors.forename: Syed Ashraful
authors.initials: SA
authors.lastname: Alam
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Zhai
authors.affiliation: Department of Geosciences, University of Arizona, Tucson, AZ, 85721, USA.
authors.forename: Andria
authors.initials: A
authors.lastname: Dawson
authors.affiliation: Forest Management Branch, Sustainable Resource Development, 9820, 106 Street, Edmonton, AB, T5K 2J6, Canada.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Stadt
authors.affiliation: Department of Renewable Resources, University of Alberta, 116 Street and 85 Avenue, Edmonton, AB, T6G 2R3, Canada.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Comeau
mesh_terms: D002170:Canada; D057231:Climate Change; D055864:Droughts; D065928:Forests; D032107:Populus / Q000254:growth & development*; D014197:Trees
keywords: boreal forest; drought; radial growth; spatial variation; trembling aspen