scholarly journals High resolution <sup>14</sup>C bomb-peak dating and climate response analyses of subseasonal stable isotope signals in wood of the African baobab – A case study from Oman

2019 ◽  
Author(s):  
Franziska Slotta ◽  
Lukas Wacker ◽  
Frank Riedel ◽  
Karl-Uwe Heußner ◽  
Kai Hartmann ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Tree Ring ◽  
Monsoon Season ◽  
Precipitation Amount ◽  
Ring Width ◽  
Tree Ring Width ◽  
Adansonia Digitata ◽  
Potential Growth ◽  
Rain Events ◽  
Tree Ring Cellulose

Abstract. The African baobab, Adansonia digitata, has great paleoclimatological potential because of its wide distributional range and millennial lifespan. However, dendroclimatological approaches are hampered by dating uncertainties due to its parenchyma-dominated wood anatomy. Here, securely-dated time series of annual wood increment growth and intra-ring stable isotopes of carbon and oxygen of cellulose for a baobab tree from Oman covering 1941 to 2005 were established. Precise dating with the bomb peak by highly resolved 14C measurements proved the annual character of the baobab's growth rings. But, F14C values of tree-ring cellulose were found up to 8.8 % lower than in the corresponding atmospheric CO2 for the period around the bomb peak. In conjunction with a considerable autocorrelation of the δ13C series this points to the incorporation of previous years' carbon significantly affecting the average age of derived wood. Terminal parenchyma bands, marking the tree-ring boundaries, were found to be significantly younger than their corresponding tree ring indicating that parenchyma tissue is alive for many years undergoing cell division, reorganization and potential growth. No autocorrelation was found in the δ18O series of tree-ring cellulose despite the huge water-storage potential of this stem-succulent tree species. Tree-ring width and stable isotope ratios have revealed significant climate sensitivity. δ18O was found to be a good climate proxy followed by tree-ring width and δ13C. Tree-ring width and intra-ring δ18Omin correlated well with each other and with precipitation amount for the period from pre-monsoon May to the end of the monsoon season in September/October. Intra-annual stable isotope courses were found rather similar for both δ13C and δ18O. Years with particularly low monsoon rain were reflected by increased stable isotope values in the mid-section of intra-annual courses. Distinct patterns with low subseasonal isotope values seem indicative for years with heavy rainfall events from pre-monsoonal cyclones. Rain events from post-monsoonal cyclones may also be recorded, however, only two years of observation prevent from a conclusive evaluation.

scholarly journals High-resolution <sup>14</sup>C bomb peak dating and climate response analyses of subseasonal stable isotope signals in wood of the African baobab – a case study from Oman

2021 ◽  
Vol 18 (12) ◽  
pp. 3539-3564
Author(s):  
Franziska Slotta ◽  
Lukas Wacker ◽  
Frank Riedel ◽  
Karl-Uwe Heußner ◽  
Kai Hartmann ◽  
...  
Keyword(s):  
Time Series ◽  
Stable Isotope ◽  
Tree Ring ◽  
Monsoon Season ◽  
Precipitation Amount ◽  
Secondary Growth ◽  
Ring Width ◽  
Tree Ring Width ◽  
Adansonia Digitata ◽  
Tree Ring Cellulose

Abstract. The African baobab, Adansonia digitata L., has great paleoclimatological potential because of its wide distributional range and millennial length life span. However, dendroclimatological approaches are hampered by dating uncertainties due to its unique, parenchyma-dominated stem anatomy. Here, securely dated time series of annual wood increment growth and intra-ring stable isotopes of carbon and oxygen of cellulose for a baobab tree from Oman covering 1941 to 2005 were established and tested for relationships to hydroclimate variability. Precise dating with the atomic bomb peak (ABP) using highly resolved 14C measurements confirmed the annual character of the baobab's growth rings. F14C values of tree-ring cellulose were found up to 8.8 % lower than in the corresponding atmospheric CO2 for the period around the ABP, which in conjunction with a considerable autocorrelation of the δ13C series points to the incorporation of previous year's carbon contributing to the average age of intra-ring wood samples. F14C of terminal parenchyma bands, marking the tree-ring boundaries, were found to be considerably younger than their corresponding tree ring, indicating that parenchyma tissue is alive for many years, probably undergoing cell division and structural reorganization and contributing to secondary growth. In contrast to the δ13C time series, no significant autocorrelation was found in the δ18O series of tree-ring cellulose despite the enormous water storage potential of this stem-succulent tree species. Year-to-year variability in tree-ring width and stable isotope ratios revealed radial stem growth and the geochemistry of wood cellulose are influenced by fluctuations in the hydroclimate. In particular, δ18O was found to be a good climate proxy, followed by tree-ring width and δ13C. Tree-ring width and intra-ring δ18Omin correlated well with each other and with precipitation amount for the period from pre-monsoon May to the end of the monsoon season in September/October. Intra-annual stable isotope courses were found to be rather similar for both δ13C and δ18O. Years with particularly low monsoon rain were reflected by increased stable isotope values in the mid-section of intra-annual courses. Distinct patterns with low subseasonal isotope values seem indicative for years with heavy rainfall events from pre-monsoonal cyclones. Rain events from post-monsoonal cyclones may also be recorded; however, only 2 years of observation prevented a more conclusive evaluation.

Compression wood has a minor effect on the climate signal in tree-ring stable isotope records of montane Norway spruce

2020 ◽  
Vol 40 (8) ◽  
pp. 1014-1028
Author(s):  
Karolina Janecka ◽  
Ryszard J Kaczka ◽  
Holger Gärtner ◽  
Jill E Harvey ◽  
Kerstin Treydte
Keyword(s):  
Stable Isotope ◽  
Norway Spruce ◽  
Tree Ring ◽  
Compression Wood ◽  
Ring Width ◽  
Minor Effect ◽  
Main Role ◽  
Climate Signal ◽  
Tree Ring Cellulose ◽  
Δ13c And Δ18o

Abstract Compression wood (CW) is a common tissue present in the trunk, branches and roots of mechanically stressed coniferous trees. Its main role is to increase the mechanical strength and regain the vertical orientation of a leaning stem. Compression wood is thought to influence the climate signal in different tree-ring measures. Hence trees containing CW are mostly excluded from tree-ring studies reconstructing past climate variability. There is a large gap of systematic work testing the potential effect of CW on the strength of the climate signal in different tree-ring parameters, especially stable isotope records. Here we test for the first time the effect of CW contained in montane Norway spruce (Picea abies L. Karst) on both δ13C and δ18O tree-ring cellulose records by analyzing compression and opposite wood radii from several disturbed trees together with samples from undisturbed reference trees. We selected four trees tilted by geomorphic processes that were felled by wind and four undisturbed reference trees in the Tatra Mountains, Poland. We qualitatively classified the strength of CW using wood cell anatomical characteristics (tracheid shape, cell wall thickness and presence of intercellular spaces). Then we developed tree-ring width and δ13C and δ18O chronologies from the CW radii, from the opposite radii of the tilted trees and from the reference radii. We tested the effect of CW on tree-ring cellulose δ13C and δ18O variability and on the climate signal strength. We found only minor differences in the means of δ13C and δ18O of compression (δ13C: −22.81‰, δ18O: 28.29‰), opposite (δ13C: −23.02‰; δ18O: 28.05‰) and reference (δ13C: −22.78‰; δ18O: 27.61‰) radii. The statistical relationships between climate variables, δ13C and δ18O, remained consistent among all chronologies. Our findings suggest that moderately tilted trees containing CW can be used to reconstruct past geomorphic activity and for stable isotope-based dendroclimatology.

Compression wood has a minor effect on the climate signal in tree-ring stable isotopes of montane Norway spruce

2020 ◽  
Author(s):  
Karolina Janecka ◽  
Ryszard Kaczka ◽  
Holger Gärtner ◽  
Jill E. Harvey ◽  
Kerstin Treydte
Keyword(s):  
Stable Isotope ◽  
Norway Spruce ◽  
Tree Ring ◽  
Compression Wood ◽  
Ring Width ◽  
Minor Effect ◽  
Main Role ◽  
Vertical Orientation ◽  
Climate Signal ◽  
Tree Ring Cellulose

&lt;p&gt;Compression wood is a common tissue present in the trunk, branches and roots of mechanically stressed coniferous trees. Its main role is to increase the mechanical strength and regain the vertical orientation of a leaning stem. Compression wood is thought to influence the climate signal in different tree-ring measures. Hence trees containing compression wood are mostly excluded from tree-ring studies reconstructing past climate variability. There is a large gap of systematic work testing the potential effect of compression wood on the strength of the climate signal in different tree-ring parameters, and especially stable isotope records.&lt;/p&gt;&lt;p&gt;Here we test for the first time the effect of compression wood contained in montane Norway spruce (Picea abies L. Karst) on both &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O tree-ring cellulose records by analyzing compression and opposite wood radii from several disturbed trees together with samples from undisturbed reference trees. We selected four trees tilted by geomorphic processes that were felled by wind, and four undisturbed reference trees in the Tatra Mountains, Poland. We qualitatively classified the strength of compression wood using wood cell anatomical characteristics (tracheid shape, cell wall thickness and presence of intercellular spaces). Then we developed tree-ring width, &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O chronologies from the compression wood radii and the opposite radii of the tilted trees, and from the radii of the reference trees. We tested the effect of compression wood on tree-ring cellulose &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O variability and on the climate signal strength. Only minor differences were found in the means of &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O compression, opposite and reference radii. The statistical relationships between climate variables, &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O remained consistent among all chronologies. Our findings suggest that moderately tilted trees containing compression wood can be used to both reconstruct past geomorphic activity, and stable-isotope based dendroclimatological research.&lt;/p&gt;

Climate control of cambial dynamics and tree-ring width in two tropical pines in Thailand

2021 ◽  
Vol 303 ◽  
pp. 108394
Author(s):  
Nathsuda Pumijumnong ◽  
Piyarat Songtrirat ◽  
Supaporn Buajan ◽  
Sineenart Preechamart ◽  
Uthai Chareonwong ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Tree Ring Width ◽  
Climate Control

Climatic implications of a 3585-year tree-ring width chronology from the northeastern Qinghai-Tibetan Plateau

2010 ◽  
Vol 29 (17-18) ◽  
pp. 2111-2122 ◽  
Author(s):  
X. Shao ◽  
Y. Xu ◽  
Z.-Y. Yin ◽  
E. Liang ◽  
H. Zhu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Ring Width ◽  
Tree Ring Width

Tree growth across the Nepal Himalaya during the last four centuries

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Environmental Changes ◽  
Ring Width ◽  
High Elevation ◽  
Forest Growth ◽  
Tree Ring Width ◽  
Early 19Th Century ◽  
Tree Ring Data ◽  
Instrumental Records

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.

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