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The science of tropical dendrochronology is now emerging in regions where tree-ring dating had previously not been considered possible. Here, we combine wood anatomical microsectioning techniques and radiocarbon analysis to produce the first tree-ring chronology with verified annual periodicity for a new dendrochronological species, Neltuma alba (commonly known as “algarrobo blanco”) in the tropical Andes of Bolivia. First, we generated a preliminary chronology composed of six trees using traditional dendrochronological methods (i.e., cross-dating). We then measured the 14 C content on nine selected tree rings from two samples and compared them with the Southern Hemisphere (SH) atmospheric 14 C curves, covering the period of the bomb 14 C peak. We find consistent offsets of 5 and 12 years, respectively, in the calendar dates initially assigned, indicating that several tree rings were missing in the sequence. In order to identify the tree-ring boundaries of the unidentified rings we investigated further by analyzing stem wood microsections to examine anatomical characteristics. These anatomical microsections revealed the presence of very narrow terminal parenchyma defining several tree-ring boundaries within the sapwood, which was not visible in sanded samples under a stereomicroscope. Such newly identified tree rings were consistent with the offsets shown by the radiocarbon analysis and allowed us to correct the calendar dates of the initial chronology. Additional radiocarbon measurements over a new batch of rings of the corrected dated samples resulted in a perfect match between the dendrochronological calendar years and the 14 C dating, which is based on good agreement between the tree-ring 14 C content and the SH 14 C curves. Correlations with prior season precipitation and temperature reveal a strong legacy effect of climate conditions prior to the current Neltuma alba growing season. Overall, our study highlights much potential to complement traditional dendrochronology in tree species with challenging tree-ring boundaries with wood anatomical methods and 14 C analyses. Taken together, these approaches confirm that Neltuma alba can be accurately dated and thereby used in climatic and ecological studies in tropical and subtropical South America.
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Divergent water use efficiency trends among eastern North American temperate tree species
The datasets included were used to analyze data for the manuscript titled "Divergent water use efficiency trends among eastern North American temperate tree species" and contain two files: (1) d13_temp_elev.csv contains tree ring stable carbon isotope ratio values for 12 tree species, the mean elevation of the watershed in which samples were collected, and the mean growing season temperature in the watershed where samples were collected; and (2) iwue_longterm_predictors.csv contains climate and atmospheric deposition data from the sites where tree core samples were collected. Climate variables represent growing season months (JJA) while atmospheric pollution variables represent annual totals. Metadata includes units, location codes, and species codes.
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- Award ID(s):
- 2224545
- PAR ID:
- 10660190
- Publisher / Repository:
- University of Virginia Dataverse
- Date Published:
- Edition / Version:
- 1.0
- Subject(s) / Keyword(s):
- Earth and Environmental Sciences
- Format(s):
- Medium: X Size: 65401; 96898 Other: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet; application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
- Size(s):
- 65401 96898
- Sponsoring Org:
- National Science Foundation
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