Supplementary material to "Alpine Holocene Tree-Ring Dataset: Age-related trends in the stable isotopes of cellulose show species-specific patterns"

Stable isotopes of tree rings are frequently used as proxies in climate change studies. However, species-specific relationships between climate and tree-ring stable isotopes have not yet been studied in riparian forests in the savannas of West Africa. Four cross-dated discs, each of Afzelia africana Sm. (evergreen) and Anogeissus leiocarpus (DC.) Guill. & Perr. (deciduous) in the humid (HSZ) and dry (DSZ) savanna zones of the Volta basin in Ghana were selected from a larger tree-ring dataset to assess the relationships between the tree-ring carbon isotope composition (δ13C values) and climatic parameters. The atmospherically corrected δ13C values of both studied species showed that A. africana was enriched in 13C compared to A. leiocarpus. Strong correlations were found between δ13C values of A. africana and A. leiocarpus with temperature, but weak correlations with precipitation. Spatial correlation analysis revealed significant relationships between δ13C values of both tree species and Sea Surface Temperatures in the Gulf of Guinea in the southern Atlantic Ocean. The results suggest that the carbon isotope composition of riparian trees in the Volta river basin has a potential to reconstruct climate variability and to assess tree ecological responses to climate change.

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Alpine Holocene Tree-Ring Dataset: Age-related trends in the stable isotopes of cellulose show species-specific patterns

10.5194/bg-2020-166 ◽

2020 ◽

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 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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Molecular and phenotypic analysis of rodent models reveals conserved and species-specific modulators of human sarcopenia

Communications Biology ◽

10.1038/s42003-021-01723-z ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Anastasiya Börsch ◽

Daniel J. Ham ◽

Nitish Mittal ◽

Lionel A. Tintignac ◽

Eugenia Migliavacca ◽

...

Keyword(s):

Muscle Mass ◽

Inflammatory Responses ◽

Molecular Data ◽

Model Organisms ◽

Sequencing Data ◽

Phenotypic Analysis ◽

Age Related ◽

Analogous Data ◽

Species Specific ◽

And Function

AbstractSarcopenia, the age-related loss of skeletal muscle mass and function, affects 5–13% of individuals aged over 60 years. While rodents are widely-used model organisms, which aspects of sarcopenia are recapitulated in different animal models is unknown. Here we generated a time series of phenotypic measurements and RNA sequencing data in mouse gastrocnemius muscle and analyzed them alongside analogous data from rats and humans. We found that rodents recapitulate mitochondrial changes observed in human sarcopenia, while inflammatory responses are conserved at pathway but not gene level. Perturbations in the extracellular matrix are shared by rats, while mice recapitulate changes in RNA processing and autophagy. We inferred transcription regulators of early and late transcriptome changes, which could be targeted therapeutically. Our study demonstrates that phenotypic measurements, such as muscle mass, are better indicators of muscle health than chronological age and should be considered when analyzing aging-related molecular data.

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Variability in nitrogen-derived trophic levels of Arctic marine biota

Polar Biology ◽

10.1007/s00300-020-02782-4 ◽

2020 ◽

Author(s):

Renske P. J. Hoondert ◽

Nico W. van den Brink ◽

Martine J. van den Heuvel-Greve ◽

Ad M. J. Ragas ◽

A. Jan Hendriks

Keyword(s):

Stable Isotopes ◽

Enrichment Factors ◽

Trophic Levels ◽

The Arctic ◽

Marine Biota ◽

Arctic Ecosystems ◽

Arctic Species ◽

Single Region ◽

Benthic Food ◽

Species Specific

AbstractStable isotopes are often used to provide an indication of the trophic level (TL) of species. TLs may be derived by using food-web-specific enrichment factors in combination with a representative baseline species. It is challenging to sample stable isotopes for all species, regions and seasons in Arctic ecosystems, e.g. because of practical constraints. Species-specific TLs derived from a single region may be used as a proxy for TLs for the Arctic as a whole. However, its suitability is hampered by incomplete knowledge on the variation in TLs. We quantified variation in TLs of Arctic species by collating data on stable isotopes across the Arctic, including corresponding fractionation factors and baseline species. These were used to generate TL distributions for species in both pelagic and benthic food webs for four Arctic areas, which were then used to determine intra-sample, intra-study, intra-region and inter-region variation in TLs. Considerable variation in TLs of species between areas was observed. This is likely due to differences in parameter choice in estimating TLs (e.g. choice of baseline species) and seasonal, temporal and spatial influences. TLs between regions were higher than the variance observed within regions, studies or samples. This implies that TLs derived within one region may not be suitable as a proxy for the Arctic as a whole. The TL distributions derived in this study may be useful in bioaccumulation and climate change studies, as these provide insight in the variability of trophic levels of Arctic species.

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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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Contrasting tree ring Hg records in two conifer species: Multi-site evidence of species-specific radial translocation effects in Scots pine versus European larch

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.144022 ◽

2021 ◽

Vol 762 ◽

pp. 144022

Author(s):

Tereza Nováková ◽

Tomáš Navrátil ◽

Jason D. Demers ◽

Michal Roll ◽

Jan Rohovec

Keyword(s):

Tree Ring ◽

Scots Pine ◽

European Larch ◽

Conifer Species ◽

Species Specific

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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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