Inter-annual and decadal changes in teleconnections drive continental-scale synchronization of tree reproduction

• Published in: Nature Communications
• Main Authors: Ascoli, Davide, Vacchiano, Giorgio, Turco, Marco, Conedera, Marco, Drobyshev, Igor, Maringer, Janet, Motta, Renzo, Hacket-Pain, Andrew
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: annual variation; atmospheric circulation; climate variation; coniferous tree; database; decadal variation; masting; North Atlantic Oscillation; reproduction; teleconnection; Fagus sylvatica; Picea abies; Norway; North Atlantic; North Atlantic oscillation
• Online Access: https://depositum.uqat.ca/id/eprint/1064/; https://depositum.uqat.ca/id/eprint/1064/1/ascolietal_nc_2017.pdf; https://doi.org/10.1038/s41467-017-02348-9

Climate teleconnections drive highly variable and synchronous seed production (masting) over large scales. Disentangling the effect of high-frequency (inter-annual variation) from low-frequency (decadal trends) components of climate oscillations will improve our understanding of masting as an ecosystem process. Using century-long observations on masting (the MASTREE database) and data on the Northern Atlantic Oscillation (NAO), we show that in the last 60 years both high-frequency summer and spring NAO, and low-frequency winter NAO components are highly correlated to continent-wide masting in European beech and Norway spruce. Relationships are weaker (non-stationary) in the early twentieth century. This finding improves our understanding on how climate variation affects large-scale synchronization of tree masting. Moreover, it supports the connection between proximate and ultimate causes of masting: indeed, large-scale features of atmospheric circulation coherently drive cues and resources for masting, as well as its evolutionary drivers, such as pollination efficiency, abundance of seed dispersers, and natural disturbance regimes.