| Title | Relevance of using whole-ring stable isotopes of black spruce trees in the perspective of climate reconstruction |
| |
| Author | Alvarez, C; Bégin, C; Savard, M M ; Dinis, L; Marion, J; Smirnoff, A; Bégin,
Y |
| Source | Dendrochronologia vol. 50, 2018 p. 64-69, https://doi.org/10.1016/j.dendro.2018.05.004 |
| Image |  |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20170328 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Newfoundland and Labrador |
| NTS | 13B; 13C; 13F; 13G; 13J; 13K |
| Area | Labrador; Churchill River; Lake Melville; Happy Valley-Goose Bay |
| Lat/Long WENS | -62.0000 -58.0000 55.0000 52.0000 |
| Subjects | environmental geology; mathematical and computational geology; geochronology; Nature and Environment; dendrochronology; climatology; stable isotope studies; carbon isotopes; oxygen isotopes; statistical
analyses; temperature; hydrologic properties; surface waters; rivers; discharge rates; Churchill River Basin; Methodology; Trees |
| Illustrations | location maps; bar graphs; tables; time series; scatter diagrams |
| Program | Climate Change Geoscience Essential Climate Variable Monitoring |
| Released | 2018 05 19 |
| Abstract | Studies in dendroisotope chemistry suggested that latewood cellulose contains better climatic records than whole-ring cellulose. However, this approach has never been tested on northeastern Canadian
spruce trees. This study compares dendroisotopic series of cellulose from late and whole ring, and analyses their statistical relationships with hydro-climatic variables with the aim of selecting the best suited protocol for future hydro-climatic
reconstruction in the downstream sector of Churchill River basin of Labrador, Canada. To this end, delta-13C and delta-18O series from latewood (LW) and whole ring (WR) alpha-cellulose of black spruce trees (Picea mariana [Mill.] B.S.P.) were
produced for the 1940-2010 period. The results show strong correlations between LW and WR isotopic series suggesting that there are no important variation in the isotopic ratios during the growing year and that black spruce trees use photosynthates
of the current growing season to form their earlywood. Moreover, LW and WR delta-13C and delta-18O show similar relationships with both maximum temperature (Tmax) and Churchill River discharge. Correlations are higher when combining delta-13C and
delta-18O for LW and WR. Overall, those correlations support the indirect relationship between tree-ring isotopic series and river discharge, as they are integrators of several climatic variables and derived parameters (Tmax, relative humidity,
evapotranspiration, etc.). The LW and WR isotopic series give similar statistical relationships with hydro-climatic variables, and the WR treatment is faster (separation easier compared to LW). Thus, for black spruce the use of combined isotopic
series in WR can be favored over LW for hydro-climatic reconstruction in the study region. |
| Summary | (Plain Language Summary, not published)
In order to produce the best climatic reconstructions from carbon and oxygen isotopic values of tree-rings, we tested whether it was better to analyze
only the final part of the ring (latewood) rather than the entire ring (total ring). Indeed, some studies have shown that it is better to use only the latewood in paleoclimatic studies since the initial part of the ring (earlywood) would be
constituted from the reserves produced at the end of the previous year, which induces a bias in the climatic signal of the current tree ring. Our results showed that there are no significant variations in isotope ratios during the growing season and
that the two studied parts of the ring have the same climate signals. In the case of black spruce in northeastern Canada, it does not appear necessary to specifically use the latewood part of tree-rings in dendroisotopic studies devoted to climate
reconstructions. |
| GEOSCAN ID | 306438 |
|
|