TREE-RING STUDIES IN INDIA PAST APPRAISAL, PRESENT STATUS AND FUTURE PROSPECTS

A large number of tree species, especially of conifers growing in the Himalaya and a few broad-leaved taxa in the peninsular region, have been dendrochronologically analyzed in India. This paper is a review providing information as regards the present status and future prospects of tree-ring research in India. Many trees are recorded to have datable tree rings but only some of them have been used for climate reconstruction and other aspects, e.g., glacial fluctuation or palaeo-seismic dating. In future not only ring width which is widely used so far, but also other tree-ring parameters need to be analyzed for a better understanding of the regional climate and its linkage with other climatic phenomena in a global perspective.

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Advanced X-ray CT scanning can boost tree ring research for earth system sciences

Annals of Botany ◽

10.1093/aob/mcz126 ◽

2019 ◽

Vol 124 (5) ◽

pp. 837-847 ◽

Cited By ~ 6

Author(s):

Jan Van den Bulcke ◽

Marijn A Boone ◽

Jelle Dhaene ◽

Denis Van Loo ◽

Luc Van Hoorebeke ◽

...

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Tree Species ◽

Ring Width ◽

Ct Scanning ◽

Earth System ◽

X Ray ◽

Spatial Coverage ◽

Wood Traits ◽

Ct System

AbstractBackground and AimsTree rings, as archives of the past and biosensors of the present, offer unique opportunities to study influences of the fluctuating environment over decades to centuries. As such, tree-ring-based wood traits are capital input for global vegetation models. To contribute to earth system sciences, however, sufficient spatial coverage is required of detailed individual-based measurements, necessitating large amounts of data. X-ray computed tomography (CT) scanning is one of the few techniques that can deliver such data sets.MethodsIncrement cores of four different temperate tree species were scanned with a state-of-the-art X-ray CT system at resolutions ranging from 60 μm down to 4.5 μm, with an additional scan at a resolution of 0.8 μm of a splinter-sized sample using a second X-ray CT system to highlight the potential of cell-level scanning. Calibration-free densitometry, based on full scanner simulation of a third X-ray CT system, is illustrated on increment cores of a tropical tree species.Key ResultsWe show how multiscale scanning offers unprecedented potential for mapping tree rings and wood traits without sample manipulation and with limited operator intervention. Custom-designed sample holders enable simultaneous scanning of multiple increment cores at resolutions sufficient for tree ring analysis and densitometry as well as single core scanning enabling quantitative wood anatomy, thereby approaching the conventional thin section approach. Standardized X-ray CT volumes are, furthermore, ideal input imagery for automated pipelines with neural-based learning for tree ring detection and measurements of wood traits.ConclusionsAdvanced X-ray CT scanning for high-throughput processing of increment cores is within reach, generating pith-to-bark ring width series, density profiles and wood trait data. This would allow contribution to large-scale monitoring and modelling efforts with sufficient global coverage.

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

Canadian Journal of Forest Research ◽

10.1139/x2012-012 ◽

2012 ◽

Vol 42 (3) ◽

pp. 517-531 ◽

Cited By ~ 5

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.

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Contrasting Signals of the Westerly Index and North Atlantic Oscillation over the Drought Sensitivity of Tree-Ring Chronologies from the Mediterranean Basin

Atmosphere ◽

10.3390/atmos11060644 ◽

2020 ◽

Vol 11 (6) ◽

pp. 644 ◽

Cited By ~ 1

Author(s):

Pablo Casas-Gómez ◽

Raúl Sánchez-Salguero ◽

Pedro Ribera ◽

Juan C. Linares

Keyword(s):

North Atlantic Oscillation ◽

Tree Ring ◽

North Atlantic ◽

Tree Species ◽

Ring Width ◽

Pinus Nigra ◽

Western Mediterranean ◽

Drought Severity ◽

Drought Sensitivity ◽

Westerly Index

Extreme drought events are becoming increasingly frequent and extended, particularly in Mediterranean drought-prone regions. In this sense, atmospheric oscillations patterns, such as those represented by the North Atlantic Oscillation (NAO) index and the Westerly Index (WI) have been widely proven as reliable proxies of drought trends. Here, we used the Standardized Precipitation–Evapotranspiration Index (SPEI), as a reliable indicator of drought, to investigate the drought sensitivity of tree-ring width data (TRW) from several long-lived tree species (Abies borisii-regis, Abies cilicica, Abies pinsapo, Cedrus atlantica, Cedrus libanii, Pinus nigra, Pinus heldreichii). NAO and WI relations with TRW were also investigated in order to identify potential non-stationary responses among those drought proxies. Our temporal and spatial analyses support contrasting Mediterranean dipole patterns regarding the drought sensitivity of tree growth for each tree species. The spatial assessment of NAO and WI relationships regarding SPEI and TRW showed on average stronger correlations westward with non-stationary correlations between annual WI index and TRW in all species. The results indicate that the drought variability and the inferred drought-sensitive trees species (e.g., C. atlantica) are related to the NAO and the WI, showing that TRW is a feasible proxy to long-term reconstructions of Westerly Index (WI) variability in the Western Mediterranean region. Spatial variability of drought severity suggests a complex association between NAO and WI, likely modulated by an east–west Mediterranean climate dipole.

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Dendrochronological analysis and growth patterns of Polylepis reticulata (Rosaceae) in the Ecuadorian Andes

IAWA Journal ◽

10.1163/22941932-40190240 ◽

2019 ◽

Vol 40 (2) ◽

pp. 331-S5 ◽

Cited By ~ 3

Author(s):

C. Alvites ◽

G. Battipaglia ◽

G. Santopuoli ◽

H. Hampel ◽

R.F. Vázquez ◽

...

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Stand Structure ◽

Climatic Factors ◽

Southern Oscillation ◽

Ring Width ◽

Vapour Pressure Deficit ◽

Growth Patterns ◽

Tree Ring Width ◽

Sources Of Information

ABSTRACTRelict tree species in the Andean mountains are important sources of information about climate variability and climate change. This study deals with dendroclimatology and growth patterns in Polylepis reticulata Hieron., growing at high elevation (mean of 4000 m a.s.l.) in three sites of the Ecuadorian Andes. The aims of the research were: (i) characterizing tree-ring boundaries; (ii) describing tree-ring patterns of the study sites; (iii) investigating the relationships between climate and radial tree growth; and (iv) determining the spatial correlation between seasonal climatic factors and tree-ring width of P. reticulata. Tree rings were characterized by semi-ring porosity and slight differences in fibre wall thickness between latewood and subsequent earlywood. In all sampling sites, tree rings in heartwood were more clearly visible than in sapwood. Tree-ring width was more related to temperature than to precipitation, with growth being also affected by site conditions and stand structure, as well as other local factors. No significant relationships were found between tree-ring chronologies of P. reticulata and El Niño-Southern Oscillation (ENSO) and Vapour Pressure Deficit indices. The study highlights that there is not a clear driving climate factor for radial growth of P. reticulata. Additional research is needed to study growth dynamics of this species and the impacts of local environmental variables.

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A 3585-YEAR RING-WIDTH DATING CHRONOLOGY OF QILIAN JUNIPER FROM THE NORTHEASTERN QINGHAI-TIBETAN PLATEAU

IAWA Journal ◽

10.1163/22941932-90000226 ◽

2009 ◽

Vol 30 (4) ◽

pp. 379-394 ◽

Cited By ~ 20

Author(s):

Xuemei Shao ◽

Shuzhi Wang ◽

Haifeng Zhu ◽

Yan Xu ◽

Eryuan Liang ◽

...

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

Tree Species ◽

Qaidam Basin ◽

Ring Width ◽

Northwestern China ◽

Tree Ring Width ◽

Living Tree ◽

Qilian Juniper

This article documents the development of a precisely dated and wellreplicated long regional tree-ring width dating chronology for Qilian juniper (Juniperus przewalskii Kom.) from the northeastern Qinghai- Tibetan Plateau. It involves specimens from 22 archeological sites, 24 living tree sites, and 5 standing snags sites in the eastern and northeastern Qaidam Basin, northwestern China. The specimens were cross-dated successfully among different groups of samples and among different sites. Based on a total of 1438 series from 713 trees, the chronology covers 3585 years and is the longest chronology by far in China. Comparisons with chronologies of the same tree species about 200 km apart suggest that this chronology can serve for dating purposes in a region larger than the study area. This study demonstrates the great potential of Qilian juniper for dendrochronological research.

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Retrospective analysis of growth A contribution to sustainable forest management in the tropics

IAWA Journal ◽

10.1163/22941932-20170173 ◽

2017 ◽

Vol 38 (3) ◽

pp. 297-S21 ◽

Cited By ~ 1

Author(s):

Neda Lotfiomran ◽

Michael Köhl

Keyword(s):

Forest Management ◽

Tropical Forests ◽

Tree Ring ◽

Tree Rings ◽

Tree Species ◽

Sustainable Forest Management ◽

Cedrela Odorata ◽

Tree Ring Analysis ◽

Hymenaea Courbaril ◽

Ring Analysis

Reliable information on tree growth is a prerequisite for sustainable forest management (SFM). However, in tropical forests its implementation is often hampered by insufficient knowledge of the growth dynamics of trees. Although tree ring analysis of tropical trees has a long history, its application for SFM has only recently been considered. In the current study, we illustrate both the potentials and limitations of a retrospective growth assessment by tree ring analysis under the prevailing tropical conditions in a Surinamese rain forest. For this purpose, 38 commercial tree species were screened and grouped into three categories according to the visibility of their tree ring boundaries: (I) tree rings absent or indistinct, (II) distinct but partially vague tree rings which enable approximate age estimation, (III) very distinct tree rings. In 22 out of 38 commercial tree species distinct to very distinct tree ring boundaries could be identified. The anatomy of tree ring boundaries was described following Worbes and Fichtler (2010). Four species with distinct growth rings, Cedrela odorata, Hymenaea courbaril, Pithecellobium corymbosum and Goupia glabra, were studied in greater detail. Time-series analysis was used to characterise their radial growth. From the tree ring width, the annual diameter increment and cumulative diameter growth were calculated to find long-term growth patterns. Pithecellobium corymbosum and partially Hymenaea courbaril followed a typical S-shaped growth curve. By contrast, Goupia glabra and Cedrela odorata did not exhibit an age-related decrease of growth, but showed a constant linear growth over their entire life span. If based on more sample trees, such data can provide target-oriented information for improving SFM in tropical forests.

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Tree-ring reconstruction of June-July mean temperatures in the northern Daxing’an Mountains, China

Geochronometria ◽

10.2478/geochr-2020-0007 ◽

2020 ◽

Vol 47 (1) ◽

pp. 13-22

Author(s):

Yangao Jiang ◽

Yu Wang ◽

Junhui Zhang ◽

Shijie Han ◽

Cassius E.O. Coombs ◽

...

Keyword(s):

Tree Ring ◽

Southern Oscillation ◽

Regional Climate ◽

Ring Width ◽

Temperature Reconstruction ◽

Global Scale ◽

Spatial Correlations ◽

Regional Study ◽

Average Value ◽

Daxing’An Mountains

AbstractIn this study, the mean temperature of June to July was reconstructed for the period of 1880 to 2014 by using the Larix gmelinii tree-ring width data for the Mangui region in the northern Daxing’an Mountains, China. The reconstruction accounts for 43.6% of the variance in the temperature observed from AD 1959–2014. During the last 134 years, there were 17 warm years and 17 cold years, which accounted for 12.7% of the total reconstruction years, respectively. Cold episodes occurred throughout 1887–1898 (average value is 14.2°C), while warm episodes occurred during 1994–2014 (15.9°C). Based on this regional study, the warmer events coincided with dry periods and the colder events were consistent with wet conditions. The spatial correlation analyses between the reconstructed series and gridded temperature data revealed that the regional climatic variations were well captured by this study and the reconstruction represented a regional temperature signal for the northern Daxing’an Mountains. In addition, Multi-taper method spectral analysis revealed the existence of significant periodicities in our reconstruction. Significant spectral peaks were found at 29.7, 10.9, 2.5, and 2.2 years. The significant spatial correlations between our temperature reconstruction and the El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and Solar activity suggested that the temperature in the Daxing’an Mountains area indicated both local-regional climate signals and global-scale climate changes.

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On the ‘Divergence Problem’ in the Alatau Mountains, Central Asia: A Study of the Responses of Schrenk Spruce Tree-Ring Width to Climate under the Recent Warming and Wetting Trend

Atmosphere ◽

10.3390/atmos10080473 ◽

2019 ◽

Vol 10 (8) ◽

pp. 473 ◽

Cited By ~ 3

Author(s):

Zhang ◽

Jiang ◽

Bagila ◽

Ainur ◽

...

Keyword(s):

Central Asia ◽

Tree Ring ◽

Tree Growth ◽

Tree Species ◽

Climatic Factors ◽

Ring Width ◽

Tree Ring Width ◽

Recent Warming ◽

Divergence Problem ◽

The Stability

The divergence problem, which manifests as an unstable response relationship between tree-ring growth and climatic factors under the background of global warming, poses a challenge to both the traditional theory of dendroclimatology and the reliability of climatic reconstructions based on tree-ring data. Although Schrenk spruce, as the dominant tree species in the Tianshan Mountains, is frequently applied in the dendrochronological studies, the understanding of the divergence problem of this tree species is still limited. This study conducted correlation analysis between climatic factors and tree-ring width chronologies from 51 living and healthy specimens of Schrenk spruce at sites of high and low elevation in the Alatau Mountains to determine the stability of the response. The results revealed that the tree-ring width of the spruce specimens was correlated positively with precipitation and correlated negatively with temperature. Although the variations of the two tree-ring chronologies were similar, the radial growth of the spruce at the low elevation was found more sensitive to climatic factors. Furthermore, the sensitivity of tree growth to climate demonstrated an obvious increase after an abrupt change of climate under the background of the recent warming and wetting trend. Increased drought stress, calculated based on climatic data, was regarded as the main reason for this phenomenon. The results supply the gap of the stability of climatic response of tree growth in Central Asia to some extent.

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Dendroclimatology and Dendroecology

Quaternary Research ◽

10.1016/0033-5894(71)90057-3 ◽

1971 ◽

Vol 1 (4) ◽

pp. 419-449 ◽

Cited By ~ 101

Author(s):

Harold C. Fritts

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Climatic Factors ◽

Physiological Activity ◽

Ring Width ◽

Growing Season ◽

Dry Matter Accumulation ◽

New Developments ◽

Cambial Age ◽

Tree Ring Data

Dendrochronology is the science of dating annual growth layers (rings) in woody plants. Two related subdisciplines are dendroclimatology and dendroecology. The former uses the information in dated rings to study problems of present and past climates, while the latter deals with changes in the local environment rather than regional climate.Successful applications of dendroclimatology and dendroecology depend upon careful stratification. Ring-width samples are selected from trees on limiting sites, where widths of growth layers vary greatly from one year to the next (sensitivity) and autocorrelation of the widths is not high. Rings also must be cross-dated and sufficiently replicated to provide precise dating. This selection and dating assures that the climatic information common to all trees, which is analogous to the “signal”, is large and properly placed in time. The random error or nonclimatic variations in growth, among trees, is analogous to “noise” and is reduced when ring-width indices are averaged for many trees.Some basic facts about the growth are presented along with a discussion of important physiological processes operating throughout the roots, stems, and leaves. Certain gradients associated with tree height, cambial age, and physiological activity control the size of the growth layers as they vary throughout the tree. These biological gradients interact with environmental variables and complicate the task of modeling the relationships linking growth with environment.Biological models are described for the relationships between variations in ring widths from conifers on arid sites, and variations in temperature and precpitation. These climatic factors may influence the tree at any time in the year. Conditions preceding the growing season sometimes have a greater influence on ring width than conditions during the growing season, and the relative effects of these factors on growth vary with latitude, altitude, and differences in factors of the site. The effects of some climatic factors on growth are negligible during certain times of the year, but important at other times. Climatic factors are sometimes directly related to growth and at other times are inversely related to growth. Statistical methods are described for ascertaining these differences in the climatic response of trees from different sites.A practical example is given of a tree-ring study and the mechanics are described for stratification and selection of tree-ring materials, for laboratory preparation, for cross-dating, and for computer processing. Several methods for calibration of the ring-width data with climatic variation are described. The most recent is multivariate analysis, which allows simultaneous calibration of a variety of tree-ring data representing different sites with a number of variables of climate.Several examples of applications of tree-ring analysis to problems of environment and climate are described. One is a specification from tree rings of anomalies in atmosphere circulation for a portion of the Northern Hemisphere since 1700 A.D. Another example treats and specifies past conditions in terms of conditional probabilities. Other methods of comparing present climate with past climate are described along with new developments in reconstructing past hydrologic conditions from tree rings.Tree-ring studies will be applied in the future to problems of temperate and mesic environments, and to problems of physiological, genetic, and anatomical variations within and among trees. New developments in the use of X-ray techniques will facilitate the measurement and study of cell size and cell density. Tree rings are an important source of information on productivity and dry-matter accumulation at various sites. Some tree-ring studies will deal with environmental pollution. Statistical developments will improve estimation of certain past anomalies in weather factors and the reconstructtion of atmosphere circulation associated with climate variability and change. Such information should improve chances for measuring and assessing the possibility of inadvertent modification of climate by man.

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Tree ring research in the Himalayas – a key resource for extending environmental records into the pre-instrumental period

10.5194/egusphere-egu21-9237 ◽

2021 ◽

Author(s):

Nazimul Islam ◽

Torsten Vennemann ◽

Stuart N. Lane

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Environmental Changes ◽

Volcanic Eruptions ◽

Tibet Plateau ◽

Lower Latitude ◽

High Latitudes ◽

Climate Conditions ◽

Wide Range ◽

The Himalaya

Original dendrochronological research has developed rapidly over the last few decades to cover a wide range of environmental reconstruction, not only mean climate conditions but also climate extremes (e.g. floods, droughts) and other environmental hazards (e.g. landslides, debris flows, sea-level rise, volcanic eruptions). Similarly, the focus has expanded its geographical coverage from the temperate and high latitudes to lower latitudes (e.g.&#160; the Himalaya, Tibet Plateau). Analysis of the two main dedicated dendrochronology journals (Dendrochronologia (2002-) and Tree Ring Research (2015-)) shows that the focus of the majority of published papers has been temperate and high latitudes and many fewer have considered lower latitudes such as the Himalaya. This may be due to the long-lasting controversy and doubt of the existence of tree-rings in lower latitude trees and the lower scientific acceptance of seasonal tree growth in such regions. However, such regions have some of the most preferred tree species (e.g. Larix griffithii, Abies spectabilis, Betula utilis, Juniperus polycarpos etc) for dendrochronological analysis making them suitable for tree-ring research and for answering questions regarding century-scale and longer environmental changes in regions with a relatively short history of instrumented recording of environmental parameters.Perhaps the most interesting development in tree ring research is the realization that tree cellulose can be used to acquire information not only of climatic significance but also hydrological significance, by using environmental isotopes. To date, despite of being one of the most climate and geopolitically sensitive regions, the Himalaya has got very less or no attention for combined research of isotopes and anatomical analysis of tree rings. Based on its huge significance, it is critical to combine these two methods to allow us to make linkages between historical climate fluctuations and associated hydrological response. In this poster, we present the conception of a project to do this in a large catchment (4264 km2) in the Sikkim Himalaya with the purpose to understand how climate change is simultaneously impacting both water-related risks and water-related resources and crucially how far downstream which is highly significant as millions of people living downstream get freshwater from the seasonal snow and glacier-melt in this part of the Himalayas.

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