A relationship between galactic cosmic radiation and tree rings
Article first published online: 14 SEP 2009
© The Authors (2009). Journal compilation © New Phytologist (2009)
Volume 184, Issue 3, pages 545–551, November 2009
How to Cite
Dengel, S., Aeby, D. and Grace, J. (2009), A relationship between galactic cosmic radiation and tree rings. New Phytologist, 184: 545–551. doi: 10.1111/j.1469-8137.2009.03026.x
- Issue published online: 16 OCT 2009
- Article first published online: 14 SEP 2009
- Received: 10 July 2009 Accepted: 14 August 2009
- diffuse radiation;
- galactic cosmic rays;
- Sitka spruce (Picea sitchensis);
- tree rings;
- volcanic eruptions
- •Here, we investigated the interannual variation in the growth rings formed by Sitka spruce (Picea sitchensis) trees in northern Britain (55°N, 3°W) over the period 1961–2005 in an attempt to disentangle the influence of atmospheric variables acting at different times of year.
- •Annual growth rings, measured along the north radius of freshly cut (frozen) tree discs and climatological data recorded at an adjacent site were used in the study. Correlations were based on Pearson product–moment correlation coefficients between the annual growth anomaly and these climatic and atmospheric factors.
- •Rather weak correlations between these variables and growth were found. However, there was a consistent and statistically significant relationship between growth of the trees and the flux density of galactic cosmic radiation. Moreover, there was an underlying periodicity in growth, with four minima since 1961, resembling the period cycle of galactic cosmic radiation.
- •We discuss the hypotheses that might explain this correlation: the tendency of galactic cosmic radiation to produce cloud condensation nuclei, which in turn increases the diffuse component of solar radiation, and thus increases the photosynthesis of the forest canopy.