Exploring the 14C Bomb Peak with Tree Rings of Tropical Species from the Amazon Forest

Radiocarbon ◽  
2017 ◽  
Vol 59 (2) ◽  
pp. 303-313 ◽  
Author(s):  
R Linares ◽  
H C Santos ◽  
A F N Brandes ◽  
C F Barros ◽  
C S Lisi ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Tree Rings ◽  
Wood Anatomy ◽  
Growth Ring ◽  
Ring Formation ◽  
Tropical Species ◽  
Amazon Forest ◽  
Good Match ◽  
Individual Tree ◽  
Northern Brazil

AbstractIn this work we explore the radiocarbon (14C) signal as an independent tool to assess the year of formation of individual tree rings of tropical species in northern Brazil. Three different species were analyzed in this work: Dipteryx magnifica, Enterolobium maximum, and Hymenolobium petraeum. The studied samples are from the stem of only one individual of each species, all cut down in 2008 in Porto Trombetas, Pará, Brazil. Individual tree rings were identified based on wood anatomy and they were counted from bark to pith. Several rings were selected for 14C analysis in order to cover the overall shape of the 14C atmospheric bomb peak (after 1955). The 14C content was measured at Laboratory of Radiocarbon, Universidade Federal Fluminense (LAC-UFF). Results are compared with the Southern Hemisphere 14C atmospheric calibration curves. For E. maximum and H. petraeum the 14C signal exhibits an overall good match with the SH zone 3 and suggests annual seasonality in the growth-ring formation. These species offer suitable characteristics for dendrochronology. The D. magnifica shows mismatches in the 14C measurements that are likely a result of difficulties in identifying ring boundaries with certainty. Additional techniques may be helpful to disentangle the origin of this discrepancy.

Drought signals inferred from ring-width and stable carbon isotope chronologies from Thuja occidentalis trees growing at their northwestern distribution limit, central Canada

2012 ◽  
Vol 42 (3) ◽  
pp. 517-531 ◽  
Author(s):  
Robert Au ◽  
Jacques C. Tardif
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Stable Carbon Isotopes ◽  
Stable Carbon Isotope ◽  
Ring Width ◽  
Ring Formation ◽  
Moisture Regime ◽  
Stable Carbon ◽  
Thuja Occidentalis ◽  
Central Canada

Stable carbon isotopes (δ13C) fixed in tree rings are dependent upon environmental conditions. Old northern white-cedar ( Thuja occidentalis L.) trees were sampled at their northwestern limit of distribution in central Canada. The objectives of the study were (i) to investigate the association between tree-ring δ13C values and radial growth in addition to the response of these variables to climate, (ii) to assess site differences between two sites varying in moisture regime, and (iii) to compare tree-ring δ13C of T. occidentalis with that of other boreal tree species growing at the northern limit of their distribution in central Canada. Over 2500 tree rings comprised of 15 T. occidentalis trees were analyzed for δ13C. Annually resolved δ13C (1650–2006) and ring-width (1542–2006) chronologies were developed. During the year of ring formation, ring width was associated with spring and early-summer conditions, whereas δ13C was more indicative of overall summer conditions. However, compared with δ13C values, ring width was more often associated with climate conditions in the year prior to ring formation. Conditions conducive to moisture stress were important for both parameters. Although ring width and δ13C corresponded to the drought intervals of the 1790s, 1840s, 1890s, 1930s, and 1960–1970, ring width may be more responsive to prolonged drought than δ13C. Tree-ring δ13C could, however, provide important information regarding physiological adaptations to drought.

Tree-Ring Formation, Radial Increment Periodicity, and Phenology of Tree Species from a Seasonal Semi-Deciduous Forest in Southeast Brazil

IAWA Journal ◽  
2008 ◽  
Vol 29 (2) ◽  
pp. 189-207 ◽  
Author(s):  
Claudio S. Lisi ◽  
Mário Tomazello Fo ◽  
Paulo C. Botosso ◽  
Fidel A. Roig ◽  
Vivian R.B. Maria ◽  
...  
Keyword(s):  
Tree Rings ◽  
Tree Species ◽  
Deciduous Forest ◽  
Growth Ring ◽  
Climatic Conditions ◽  
Dry Season ◽  
Tree Age ◽  
Radial Increment ◽  
Future Studies ◽  
Southeast Brazil

Many tropical tree species produce growth rings in response to seasonal environmental factors that influence the activity of the vascular cambium. We applied the following methods to analyze the annual nature of treering formation of 24 tree species from a seasonal semi-deciduous forest of southeast Brazil: describing wood anatomy and phenology, counting tree rings after cambium markings, and using permanent dendrometer bands. After 7 years of systematic observations and measurements, we found the following: the trees lost their leaves during the dry season and grew new leaves at the end of the same season; trunk increment dynamics corresponded to seasonal changes in precipitation, with higher increment (active period) during the rainy season (October–April) and lower increment (dormant period) during the dry season (May–September); the number of tree rings formed after injuries to the cambium coincided with the number of years since the extraction of the wood samples. As a result of these observations, it was concluded that most study trees formed one growth ring per year. This suggests that tree species from the seasonal semi-deciduous forests of Brazil have an annual cycle of wood formation. Therefore, these trees have potential for use in future studies of tree age and radial growth rates, as well as to infer ecological and regional climatic conditions. These future studies can provide important information for the management and conservation of these endangered forests.

scholarly journals Reintroduction of the Golden Conure (Guaruba guarouba) in Northern Brazil: Establishing a Population in a Protected Area

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 198
Author(s):  
Marcelo Rodrigues Vilarta ◽  
William Wittkoff ◽  
Crisomar Lobato ◽  
Rubens de Aquino Oliveira ◽  
Nívia Gláucia Pinto Pereira ◽  
...  
Keyword(s):  
Power Lines ◽  
Food Supplementation ◽  
Territorial Disputes ◽  
Amazon Forest ◽  
Nest Boxes ◽  
In Captivity ◽  
Viable Population ◽  
In The Wild ◽  
Northern Brazil ◽  
Native Foods

Brazil has the highest number of parrots in the world and the greatest number of threatened species. The Golden Conure is endemic to the Brazilian Amazon forest and it is currently considered as threatened by extinction, although it is fairly common in captivity. Here we report the first reintroduction of this species. The birds were released in an urban park in Belem, capital of Para State, where the species was extinct more than a century ago. Birds were trained to recognize and consume local food and to avoid predators. After the soft-release, with food supplementation and using nest boxes, we recorded breeding activity in the wild. The main challenges before the release were the territorial disputes within the aviary and the predation by boa snakes. During the post-release monitoring the difficulties were the fast dispersion of some individuals and the dangers posed by anthropic elements such as power lines that caused some fatalities. Released birds were very successful at finding and consuming native foods, evading predators, and one pair reproduced successfully. Monitoring continues and further releases are programmed to establish an ecologically viable population.

Using tree rings to assess the potential of thinning to alleviate drought stress in a dry forest of western Canada

2021 ◽  
Author(s):  
David Montwé ◽  
Audrey Standish ◽  
Miriam Isaac-Renton ◽  
Jodi Axelson
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Basal Area ◽  
Dry Forest ◽  
Tree Level ◽  
Severe Drought ◽  
Western Canada ◽  
Drought Event ◽  
Individual Tree ◽  
Potential Benefits

<p>Increasing frequency of severe drought events under climate change is a major cause for concern for millions of hectares of forested land. One practical solution to improving forest resilience may be thinning. There may be several potential benefits, chief of which is that drought tolerance could be improved in the remaining trees due to lower competition for resources and increased precipitation throughfall. By improving resilience to drought, this may increase productivity of the remaining trees while lowering risks of mortality. Such potential benefits can effectively be quantified with data from statistically-sound, long-term field experiments, and tree rings provide a suitable avenue to compare treatments. We work with an experiment that applied different levels of tree retention to mature interior Douglas fir (<em>Pseudotsuga menziesii</em> var. <em>glauca</em>) in a dry ecosystem of western Canada. The treatments were applied in the winter of 2002/2003, coinciding with the aftermath of a severe natural drought event in 2002. We used tree-rings to quantify the extent to which thinning improves recovery and resilience of treated trees as compared to non-thinned controls. Tree-ring samples as well as height and diameter data were obtained from 83 trees from 8 treatment units of the randomized experimental design. Indicators for resilience to drought were calculated based on basal area increments. Thinning substantially increased basal area increments at the individual tree level, but more importantly, led to significantly higher recovery and resilience relative to the control. The results of this tree-ring analysis suggest that thinning may be a viable silvicultural intervention to counteract effects of severe drought events and to maintain tree cover.</p>

Using growth ring formation to study growth patterns of exploited sea urchin (Loxechinus albus) populations

2018 ◽  
Vol 201 ◽  
pp. 88-97 ◽  
Author(s):  
Cecilia Balboa ◽  
Carlos Molinet ◽  
Nancy Barahona ◽  
Patricio A. Díaz ◽  
Dagoberto Subiabre ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Growth Ring ◽  
Growth Patterns ◽  
Ring Formation ◽  
Loxechinus Albus

Validating putatively cross-dated Callitris tree-ring chronologies using bomb-pulse radiocarbon analysis

2011 ◽  
Vol 59 (1) ◽  
pp. 7 ◽  
Author(s):  
Stuart Pearson ◽  
Quan Hua ◽  
Kathryn Allen ◽  
David M. J. S. Bowman
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Arid Zone ◽  
Isotopic Signature ◽  
Individual Tree ◽  
Seasonally Dry ◽  
Nuclear Weapons Testing ◽  
Independent Verification ◽  
Variable Precipitation ◽  
Cross Dating

Nuclear weapons testing during the 1950s generated an atmospheric pulse of the carbon isotope, 14C. Worldwide, trees growing during that period and in subsequent decades assimilated 14C-enriched CO2, leaving a distinct isotopic signature that can be used to precisely date tree rings. Thirty single-ring samples were extracted for AMS 14C analysis from cores taken from living trees of five different Callitris species [C. endlicheri (Parl.) F.M. Bailey, C. glaucophylla Joy Thomps. & L.A.S. Johnson, C. intratropica Benth., C. preissii Miq., and C. rhomboidea R.Br. ex Rich. & A. Rich] at 13 sites. The ages of individual tree rings were determined by both 14C bomb-pulse dating and cross-dating (based on 20–30 cores from the same site) in order to (1) provide independent verification of tree-ring dates, (2) detect false or missing rings from sites with otherwise good chronologies, and (3) test whether growth rings were annual for cores from sites where cross-dating was not possible. Our approach confirmed dates on chronologies from monsoon tropical sites, provided checked chronologies in subtropical and temperate sites, and improved dating control on arid-zone ring counts. It was found that Callitris are more likely to form regular annual rings when growing in seasonally dry environments than in more arid sites with highly variable precipitation patterns.

scholarly journals Matching Dendrochronological Dates with the Southern Hemisphere 14C Bomb Curve to Confirm Annual Tree Rings in Pseudolmedia rigida from Bolivia

Radiocarbon ◽  
2015 ◽  
Vol 57 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Laia Andreu-Hayles ◽  
Guaciara M Santos ◽  
David A Herrera-Ramírez ◽  
Javier Martin-Fernández ◽  
Daniel Ruiz-Carrascal ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Tree Rings ◽  
Geographic Location ◽  
Data Sets ◽  
Atmospheric Concentration ◽  
Concentration Data ◽  
Data Set ◽  
Dendrochronological Analysis ◽  
Before And After ◽  
Ring Analysis

This study used high-precision radiocarbon bomb-pulse dating of selected wood rings to provide an independent validation of the tree growth periodicity of Pseudolmedia rigida (Klotzsch & H. Karst) Cuatrec. from the Moraceae family, collected in the Madidi National Park in Bolivia. 14C content was measured by accelerator mass spectrometry (AMS) in 10 samples from a single tree covering over 70 yr from 1939 to 2011. These preliminary calendar dates were determined by dendrochronological techniques and were also used to select the samples for 14C AMS. In order to validate these preliminary dates using the established Southern Hemisphere (SH) 14C atmospheric concentration data set, the targeted rings were selected to be formed during periods before and after the 14C bomb spike nuclear tests (i.e. 1950s–1960s). The excellent agreement of the dendrochronological dates and the 14C signatures in tree rings associated with the same dates provided by the bomb-pulse 14C atmospheric values for the SH (SHCal zone 1–2) confirms the annual periodicity of the observed growth layers, and thus the high potential of this species for tree-ring analysis. The lack of discrepancies between both data sets also suggests that there are no significant latitudinal differences between the 14C SHCal zone 1–2 curve and the 14C values obtained from the selected tree rings at this geographic location (14°33′S, 68°49′W) in South America. The annual resolution of P. rigida tree rings opens the possibility of broader applications of dendrochronological analysis for ecological and paleoclimatic studies in the Bolivian tropics, as well as the possibility of using wood samples from some tree species from this region to improve the quality of the bomb-pulse 14C SHCal curve at this latitude.

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