Supplementary material to "Cambial-age related correlations of stable isotopes and tree-ring widths in wood samples of tree-line conifers"

Abstract. Stable isotopes in tree-ring cellulose are important tools for climatic reconstructions even though their interpretation could be challenging due to non-climate signals, primarily those related to tree ageing. Previous studies on the presence of tree-age related trends during juvenile as well as adult growth phases in δD, δ18O and δ13C time series yielded variable results that are not coherent among different plant species. We analysed possible trends in the extracted cellulose of tree-rings of 85 larch trees and 119 cembran pine trees, i.e. in samples of one deciduous and one evergreen conifer species collected at the treeline in the Alps covering nearly the whole Holocene. The age trend analyses of all tree-ring variables were conducted on the basis of mean curves established by averaging the cambial-age aligned tree series. For cambial ages over 100 years, our results prove the absence of any age-related effect in the δD, δ18O and δ13C time series for both the evergreen as well the deciduous conifer species, with the only exception of larch δD. However, for lower cambial ages, we found trends that differ for each isotope and species. I.e., mean δ13C values in larch do not vary with ageing and can be used without detrending, whereas those in cembran pine show a juvenile effect and the data should be detrended. Mean δ18O values present two distinct ageing phases for both species complicating detrending. Similarly, mean δD values in larch change in the first 50 yr whereas cembran pine between 50–100 yr. Values for these two periods of cambial age for δD and δ18O should be used with caution for climatic reconstructions, ideally complemented by additional information regarding mechanisms for these trends.

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Alpine Holocene tree-ring dataset: age-related trends in the stable isotopes of cellulose show species-specific patterns

Biogeosciences ◽

10.5194/bg-17-4871-2020 ◽

2020 ◽

Vol 17 (19) ◽

pp. 4871-4882

Author(s):

Tito Arosio ◽

Malin M. Ziehmer ◽

Kurt Nicolussi ◽

Christian Schlüchter ◽

Markus Leuenberger

Keyword(s):

Time Series ◽

Stable Isotopes ◽

Tree Ring ◽

Tree Age ◽

Conifer Species ◽

Adult Growth ◽

Age Related ◽

Cambial Age ◽

Cembran Pine ◽

Δ18o And Δ13c

Abstract. Stable isotopes in tree-ring cellulose are important tools for climatic reconstructions even though their interpretation could be challenging due to nonclimate signals, primarily those related to tree aging. Previous studies on the presence of tree-age-related trends during juvenile as well as adult growth phases in δD, δ18O, and δ13C time series yielded variable results that are not coherent among different plant species. We analyzed possible trends in the extracted cellulose of tree rings of 85 larch trees and 119 cembran pine trees, i.e., in samples of one deciduous and one evergreen conifer species collected at the tree line in the Alps, covering nearly the whole Holocene. The age trend analyses of all tree-ring variables were conducted on the basis of mean curves established by averaging the cambial-age-aligned tree series. For cambial ages over 100 years, our results prove the absence of any age-related effect in the δD, δ18O, and δ13C time series for both the evergreen and the deciduous conifer species, with the only exception being larch δD. However, for lower cambial ages, we found trends that differ for each isotope and species; i.e., mean δ13C values in larch do not vary with aging and can be used without detrending, whereas those in cembran pine show a juvenile effect, and the data should be detrended. Mean δ18O values present two distinct aging phases for both species, complicating detrending. Similarly, mean δD values in larch change in the first 50 years, whereas cembran pine changes between 50 and 100 years. Values for these two periods of cambial age for δD and δ18O should be used with caution for climatic reconstructions, ideally complemented by additional information regarding mechanisms for these trends.

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Cambial-age related correlations of stable isotopes and tree-ring widths in wood samples of tree-line conifers

10.5194/bg-2020-406 ◽

2020 ◽

Author(s):

Tito Arosio ◽

Malin M. Ziehmer-Wenz ◽

Kurt Nicolussi ◽

Christian Schlüchter ◽

Markus Leuenberger

Keyword(s):

Stable Isotopes ◽

Tree Ring ◽

Ring Width ◽

Recent Analysis ◽

Tree Ring Width ◽

Juvenile Period ◽

Cambial Age ◽

Adult Trees ◽

Cembran Pine ◽

Δd And Δ18o

Abstract. A recent analysis of stable isotopes of the Alpine Holocene Tree-Ring Dataset, consisting of samples from 192 larch and cembran pine trees, revealed that δD and δ18O exhibit no trends in adult trees, but evidence trends in the juvenile period of the first 100 years of cambial age. In this work we applied the Spearman statistical analysis on different cambial age classes to verify if these changes were correlated with tree-ring width values, that are known to show age trends. The results prove a significant correlation between tree-ring-width (TRW) and both hydrogen and oxygen stable isotopes before 100 year of cambial age, but not afterwards, in both larch and cembran pine. A trend in the correlation values was also found between the two water isotopes, while no trend was found in correlations involving δ13C. We hypothesized the δD and δ18O values reflect the higher xylogenesis activity of the juvenile period, that is associated with reduced atom exchanges of photosynthates with xylem water. The result indicates that the climate response of δD and δ18O may differ in the juvenile and mature period of tree life at treeline.

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Tree Vitality and Forest Health: Can Tree-Ring Stable Isotopes Be Used as Indicators?

Current Forestry Reports ◽

10.1007/s40725-021-00137-8 ◽

2021 ◽

Cited By ~ 1

Author(s):

Paolo Cherubini ◽

Giovanna Battipaglia ◽

John L. Innes

Keyword(s):

Air Pollution ◽

Stable Isotopes ◽

Tree Ring ◽

Forest Decline ◽

Forest Health ◽

Stress Factors ◽

Tree Vitality ◽

The Past ◽

Physiological Processes

Abstract Purpose of Review Society is concerned about the long-term condition of the forests. Although a clear definition of forest health is still missing, to evaluate forest health, monitoring efforts in the past 40 years have concentrated on the assessment of tree vitality, trying to estimate tree photosynthesis rates and productivity. Used in monitoring forest decline in Central Europe since the 1980s, crown foliage transparency has been commonly believed to be the best indicator of tree condition in relation to air pollution, although annual variations appear more closely related to water stress. Although crown transparency is not a good indicator of tree photosynthesis rates, defoliation is still one of the most used indicators of tree vitality. Tree rings have been often used as indicators of past productivity. However, long-term tree growth trends are difficult to interpret because of sampling bias, and ring width patterns do not provide any information about tree physiological processes. Recent Findings In the past two decades, tree-ring stable isotopes have been used not only to reconstruct the impact of past climatic events, such as drought, but also in the study of forest decline induced by air pollution episodes, and other natural disturbances and environmental stress, such as pest outbreaks and wildfires. They have proven to be useful tools for understanding physiological processes and tree response to such stress factors. Summary Tree-ring stable isotopes integrate crown transpiration rates and photosynthesis rates and may enhance our understanding of tree vitality. They are promising indicators of tree vitality. We call for the use of tree-ring stable isotopes in future monitoring programmes.

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Summer temperature in northeastern Siberia since 1642 reconstructed from tracheid dimensions and cell numbers of Larix cajanderi

Canadian Journal of Forest Research ◽

10.1139/x03-109 ◽

2003 ◽

Vol 33 (10) ◽

pp. 1905-1914 ◽

Cited By ~ 53

Author(s):

Irina P Panyushkina ◽

Malcolm K Hughes ◽

Eugene A Vaganov ◽

Martin AR Munro

Keyword(s):

Cell Wall ◽

Wall Thickness ◽

Cell Number ◽

Cell Wall Thickness ◽

Cell Dimension ◽

Cell Numbers ◽

Age Related ◽

Cambial Age ◽

Northeastern Siberia ◽

Larix Cajanderi

We reconstructed air temperature for two periods in the growth season from cell dimension and cell number variability in cross-dated tree rings of Larix cajanderi Mayr. from northeastern Siberia. Thirteen tree-ring chronologies based on cell size, cell wall thickness, and cell number were developed for AD 16421993. No clear evidence was found of an age-related trend in cell dimensions in the sampled materials, but cell numbers were correlated with cambial age. The chronologies contain strong temperature signals associated with the timing of xylem growth. We obtained reliable reconstructions of mean June temperature from the total cell number and JulySeptember temperature from the cell wall thickness of latewood. June temperature and JulySeptember temperature covaried for most of the period from AD 1642 to AD 1978. After that time, June temperature became cooler relative to JulySeptember temperature. This difference caused disproportional changes in earlywood tracheids because of the late start of growth and cool conditions in June followed by warming during the rest of the season. The identification of this unusual recent change has shown that intraseasonal resolution may be achieved by cell dimension and cell number chronologies.

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Different climate sensitivity for radial growth, but uniform for tree-ring stable isotopes along an aridity gradient in Polylepis tarapacana, the world’s highest elevation tree-species

Tree Physiology ◽

10.1093/treephys/tpab021 ◽

2021 ◽

Author(s):

Milagros Rodriguez-Caton ◽

Laia Andreu-Hayles ◽

Mariano S Morales ◽

Valérie Daux ◽

Duncan A Christie ◽

...

Keyword(s):

Stable Isotopes ◽

Carbon Source ◽

Tree Ring ◽

Tree Growth ◽

Carbon Sink ◽

Growing Season ◽

Wood Formation ◽

Aridity Gradient ◽

Leaf Level ◽

Δ13c And Δ18o

Abstract Tree growth is generally considered to be temperature-limited at upper elevation treelines. Yet, climate factors controlling tree growth at semiarid treelines are poorly understood. We explored the influence of climate on stem growth and stable isotopes for Polyepis tarapacana, the world’s highest elevation tree-species found only in the South American Altiplano. We developed tree-ring width index (RWI), oxygen (δ18O) and carbon (δ13C) chronologies for the last 60 years at four P. tarapacana stands located above 4,400 meters in elevation, along a 500-km latitude-aridity gradient. Total annual precipitation decreased from 300 to 200 mm from the northern to the southern sites. We used RWI as a proxy of wood formation (carbon sink) and isotopic tree-ring signatures as proxies of leaf-level gas exchange processes (carbon source). We found distinct climatic conditions regulating carbon-sink processes along the gradient. Current-growing season temperature regulated RWI at wetter-northern sites, while prior-growing season precipitation determined RWI at arid-southern sites. This suggests that the relative importance of temperature to precipitation in regulating tree growth is driven by site-water availability. In contrast, warm and dry growing-seasons resulted in enriched tree-ring δ13C and δ18O at all study sites, suggesting that similar climate conditions control carbon-source processes. Site-level δ13C and δ18O chronologies were significantly and positively related at all sites, with the strongest relationships among the southern-drier stands. This indicates an overall regulation of intercellular carbon dioxide via stomatal conductance for the entire P. tarapacana network, with greater stomatal control when aridity increases. The manuscript also highlights a coupling and decoupling of physiological processes at leaf level versus wood formation depending on their respectively uniform and distinct sensitivity to climate. This study contributes to better understand and predict the response of high-elevation Polylepis woodlands to rapid climate changes and projected drying in the Altiplano.

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