Growth Assessment of Native Tree Species from the Southwestern Brazilian Amazonia by Post-AD 1950 14C Analysis: Implications for Tropical Dendroclimatology Studies and Atmospheric 14C Reconstructions

Abstract

Tree-ring width chronologies of cedro (Cedrela fissilis Vell.) (1875 to 2018), jatobá (Hymenaea courbaril L.) (1840 to 2018) and roxinho Peltogyne paniculata Benth.) (1910 to 2018) were developed by dendrochronological techniques in the southern Amazon Basin. Acceptable statistics for the tree-ring chronologies were obtained, and annual calendar dates were assigned. Due to the lack of long-term chronologies for use in paleoclimate reconstructions in degraded forest areas, dendrochronological dating was validated by 14C analysis. Tree-rings selected for analysis corresponded to 1957, 1958, 1962, 1963, 1965, 1971, and 1972. Those are critical calendar years in which atmospheric 14C changes were the highest, and therefore their tree-ring cellulose extracts 14C signatures when in alignment with existing post-AD 1950 atmospheric 14C atmospheric curves would indicate annual periodicity. Throughout our correlated calendar years and post-AD 1950 14C signatures, we indicate that H. courbaril shows an erratic sequence of wood ages. The other two tree species, C. fissilis and P. paniculata, are annual in nature and can be used successfully as paleoclimate proxies. Moreover, due to the sampling site’s strategic location in relation to the Tropical Low-Pressure Belt over South America, these trees can be used to enhance the limited amount of observational data in Southern Hemisphere atmospheric 14C calibration curves.

Longevity Estimates of Canary Palms and Dragon Trees via Radiocarbon Dating: Initial Results

“…While Canary palms and dragon trees have not been the target of radiocarbon dating until now, at least two other palm species have been investigated using radiocarbon methods [ 62 , 63 ]. In those studies, emphasis was placed on 14 C concentrations related to the “bomb spike” of the early 1960s, which is a useful marker often employed even for verifying uncertain tree-ring dating [ 64 ]. Furthermore, tissue samples were pre-treated with acid–base–acid washes only, and, while chemical methods based on extracting holocellulose from wood are sufficient to remove most if not all non-structural compounds [ 27 ], acid–base–acid processing normally fails to remove contaminants with aromatic rings [ 65 ].…”

Insights into Growth, Ring Formation and Maximum Ages of Brazil Nut Trees (Bertholletia excelsa) Using 14C Dating and Tree-Ring Analysis

“…All samples were subjected to the same lab protocols, including the reference materials. We included the post-AD 1950 14 C barley mash (FIRI-J) and blank (HTC) standards in every batch for quality control and background correction (Boaretto et al 2002;Santos et al 2020Santos et al , 2021. As the samples were previously glued to a wooden support with adhesive in aqueous dispersion based on vinyl polyacetate (PVAC), we measured the effect of the glue with the standards (FIRI-J and HTC), as well as the pure glue without any chemical treatment.…”

Soil fertility and drought interact to determine large variations in wood production for a hyperdominant Amazonian tree species

“…Average tree growth was estimated over different time intervals by using radiocarbon measurements to determine the calendar year of wood growth at several points in radial sections for each tree. Radiocarbon measurements were used to determine whether growth rings were recognizable in the wood (Andreu-Hayles et al, 2015;Schöngart et al, 2017); however, when ring counts were compared with radiocarbon, many missing rings were found in most trees (Ohashi et al, 2016;Herrera-Ramirez et al, 2017;Santos et al, 2021). As we could not rely on ring-counting for some species, instead we used the difference in the 14 Cdetermined calendar year to estimate the time interval during which a specific radial growth increment took place, especially in species without annual rings.…”