scholarly journals Stable carbon and oxygen isotopes in tree rings show physiological responses of Pericopsis elata to precipitation in the Congo Basin

2016 ◽  
Vol 32 (3) ◽  
pp. 213-225 ◽  
Author(s):  
Daniele Colombaroli ◽  
Paolo Cherubini ◽  
Maaike De Ridder ◽  
Matthias Saurer ◽  
Benjamin Toirambe ◽  
...  

Abstract:In equatorial regions, where tree rings are less distinct or even absent, the response of forests to high-frequency climate variability is poorly understood. We measured stable carbon and oxygen isotopes in anatomically distinct, annual growth rings of four Pericopsis elata trees from a plantation in the Congo Basin, to assess their sensitivity to recorded changes in precipitation over the last 50 y. Our results suggest that oxygen isotopes have high common signal strength (EPS = 0.74), and respond to multi-annual precipitation variability at the regional scale, with low δ18O values (28–29‰) during wetter conditions (1960–1970). Conversely, δ13C are mostly related to growth variation, which in a light-demanding species are driven by competition for light. Differences in δ13C values between fast- and slow-growing trees (c. 2‰), result in low common signal strength (EPS = 0.37) and are driven by micro-site conditions rather than by climate. This study highlights the potential for understanding the causes of growth variation in P. elata as well as past hydroclimatic changes, in a climatically complex region characterized by a bimodal distribution in precipitation.

2008 ◽  
Vol 32 (-1) ◽  
pp. 37-46 ◽  
Author(s):  
Steffen Holzkämper ◽  
Peter Kuhry ◽  
Seija Kultti ◽  
Björn Gunnarson ◽  
Eloni Sonninen

Stable Isotopes in Tree Rings as Proxies for Winter Precipitation Changes in the Russian Arctic over the Past 150 Years We present results from an analysis of tree ring width and stable carbon and oxygen isotopes in tree ring cellulose of Siberian Spruce collected from remote forest islands in the northwestern Russian tundra. Ring width is often considered a proxy for summer temperatures. The aim of this pilot study was to test whether stable isotopes can provide additional information about climate during the growth of trees in this extreme environment. Comparison of δ13C and δ18O with observed meteorological data shows that there is a link between stable isotopes and winter precipitation. This may be explained by the strong influence that snow exerts on the isotopic composition of soil moisture during spring and early summer, when the new cellulose is formed. Our results show that winter precipitation in the study area was increasing from 1865-1900, and thereafter decreasing until ~ 1930. The 1960-1980 period was again rather humid, followed by a drying trend until 1990. The study highlights the potential of stable carbon and oxygen isotopes in tree rings as proxies for winter precipitation.


2010 ◽  
Vol 270 (1-4) ◽  
pp. 216-226 ◽  
Author(s):  
Päivi Kaislahti Tillman ◽  
Steffen Holzkämper ◽  
Peter Kuhry ◽  
A. Britta K. Sannel ◽  
Neil J. Loader ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document