Tree ring variability and climate response of Abies spectabilis along an elevation gradient in Mustang, Nepal

In mountainous areas including the Himalayas, tree lines are expected to advance to higher altitudes due to global climate change affecting the distribution and growth of plant species. This study aimed at identifying the tree ring variability of Abies spectabilis (D. Don) and its response to the climate along an elevation gradient in the high Himalayas of central Nepal. Tree core samples were collected from four sites in Mustang district. All sites were located in the same valley and exposed to similar weather conditions. Out of 232 samples collected from the sites, Titi lower (2700 m), Titi upper (2900 m), Pangukhark (3100 m) and Lete upper (3300 m), 44, 40, 39 and 41 series were successfully cross-dated and ring-width chronologies including 168, 79, 138 and 156 years previous to 2012 were developed, respectively. Statistically significant differences in average annual radial growth were noted among the four sites with the highest radial growth observed at mid-elevation sites. Chronological statistics based on residual chronologies for the common period revealed that A. spectabilis at the upper elevation site was more climate sensitive than at the other three sites. At the highest-elevation sites the correlation between pre-monsoon precipitation and tree growth was positive, and for the month of May this was statistically significant (p<0.05). Moreover, spring temperature (March-June) was negatively correlated with precipitation and with tree growth at all sites, and at the upper elevation site (3300 m) the correlation was significant for March, April and May. Banko Janakari, Vol. 24, No. 1 pp. 3-13

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Fire history and climate-growth response of Abies spectabilis : A case from Langtang National Park, Nepal Himalaya

Banko Janakari ◽

10.3126/banko.v29i2.28093 ◽

2019 ◽

Vol 29 (2) ◽

pp. 3-12

Author(s):

S. Basnet ◽

N. P. Gaire ◽

P. K. Chhetri

Keyword(s):

Tree Ring ◽

Radial Growth ◽

National Park ◽

Fire History ◽

Ring Width ◽

Negative Influence ◽

Himalayan Region ◽

Fire Scars ◽

Fire Event ◽

Abies Spectabilis

This study presents the potential of a conifer species (Abies spectabilis D. Don) to reconstruct fire history by using dendro chronological technique along with thedendroclimatic response in Langtang National Park, Central Himalaya of Nepal. For the fire history reconstruction, altogether eight cross-sections samples from fire affected eight trees and another 20 tree-cores from 10 trees with visible fire scars were taken. In the case of dendroclimatic study, 24 healthy cores of A. spectabilis were selected from the 40 cores extracted from 19 trees. The standard dendro chronological methodology was used for sample preparation and analysis. A 199-year long ring-width chronology of A. spectabilis spanning from 1818 to 2016 AD was developed. In spite of visible fire burn in near bark-surface, no potential fire scars are seen in inner parts in the cross-section samples. However, 12 cores showed that three fire burns occurred simultaneously in the forest area in the years 1917−1918, 1969−1970 and 2009−2010, respectively. Tree-ring-based fire event-record is found to be concurrent to the local people's perceptions/experience about the past fire history in the area. Tree growth climate relationship showed sensitive responses to both growing and non-growing season’s temperature and precipitation variability. Summer temperature had positive influence on growth of the species. Precipitation of monsoon and autumn were found to have negative influence on radial growth whereas pre-monsoon precipitation had positive association with tree radial-growth. This preliminary assessment shows that there is a huge potential of tree-ring research for long-term fire history in the region and helps us to better understand the role of fire in the ecology and management in the Himalayan region. The study can also be replicated in other fire-affected areas of the Himalayan region by using fire sensitive species in the sampling.

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Annual growth trends and response to weather of larch trees at Järvselja Training and Experimental Forest Center stands (Estonia)

Forestry Studies / Metsanduslikud Uurimused ◽

10.1515/fsmu-2015-0012 ◽

2015 ◽

Vol 63 (1) ◽

pp. 111-129 ◽

Cited By ~ 1

Author(s):

Maris Hordo ◽

Vivika Kängsepp ◽

Taavi Kannimäe ◽

Priit Kask

Keyword(s):

Tree Ring ◽

Tree Growth ◽

Environmental Changes ◽

Ring Width ◽

Weather Conditions ◽

Radial Increment ◽

Weather Variables ◽

Larch Species ◽

Growth Variation ◽

Annual Resolution

AbstractLarch is widely used in tree-ring studies, while tree-ring width and signature years provide information on environmental changes with annual resolution. The aim of the study was to build tree-ring (TR), early- (EW) and latewood (LW) width chronologies by larch species (Hybrid, European, Russian, Japanese, Kuril), and to study the response of the radial increment of larches to weather at Järvselja forest stands by using correlation, redundancy analysis, and the pointer year method. The increment cores were collected from 233 trees in Järvselja larch stands during autumn 2014. The increment cores were collected from 24 stands and divided into five groups by larch species. High EPS values (≥ 0.887) for the larch species in all groups indicate that a sufficient number of trees was included in the chronologies to be representable. The results show that different species have a similar sensitivity to various weather variables. Among the factors influencing the size of radial growth of larches were the weather conditions prevailing in the autumn of the previous year and the spring of the current year. An overall RDA revealed that 63.9% of tree growth variation in larch species was explained by the considered weather variables (F = 4.925,p< 0.001). The pointer year analysis distinguished between several common extreme pointer years by larch species; it revealed a significant response to the winter temperature and the temperature in spring. However, these weather characteristics are very complex and the causes that can affect tree growth may vary from year to year.

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Influence of climatic conditions and air pollution on radial growth of Scots pine (Pinus sylvestris L.) in Szczecin’s city forests

Forest Research Papers ◽

10.2478/frp-2018-0011 ◽

2018 ◽

Vol 79 (2) ◽

pp. 105-112

Author(s):

Anna Cedro ◽

Bernard Cedro

Keyword(s):

Air Pollution ◽

Pinus Sylvestris ◽

Tree Ring ◽

Scots Pine ◽

Radial Growth ◽

Ring Width ◽

Weather Conditions ◽

Tree Ring Width ◽

Relative Growth ◽

Chemical Factory

Abstract The aim of the present work was to characterize the growth – climate relationship of pines growing in the Szczecin city forests in intensively used recreational areas and to identify the effect of air pollutants emitted by a nearby chemical factory on tree-ring width. Our research area was located in the Głębokie forest complex, which is one of the most frequently visited. The chemical factory Police that produces fertilizers is located at a distance 11 km away from the study plot. The largest emissions of pollutants from the factory in terms of volume occurred in the 1980s and early 1990s. Wood samples were collected from Scots pine (Pinus sylvestris L.) with the Pressler borer from 30 trees and examined using standard dendrochronological methodology. The result was a local chronology of 169 years from 1848–2016. Dendroclimatological analyses indicated that the weather conditions at the turn from winter to spring are the dominant factors influencing radial growth. For example, higher than average temperatures in February, March and April result in a wide tree-ring in the upcoming growth season. Following Nowacki and Abram’s method, we also determined the relative growth change in order to delimit the timeframe when air pollution potentially alters tree-ring width. Due to the lack of data for the period 1848–1945, the increasing and decreasing relative growth could not be linked to specific events. For the period 1944–1972 however, we observed and increase in the tree-ring width, which in this case can be attributed to favorable weather conditions. The final period, 1973–1991, on the other hand showed the strongest decline in annual growth throughout our chronology and this was largely due to the nearby chemical factories, which released huge amounts of pollution into the atmosphere during this period. At present, despite new technologies and a decrease in overall production by the nearby chemical factory, we found a negative trend in ring width dynamics indicating a need for pollutant monitoring and further research.

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A model analysis of climate and CO<sub>2</sub> controls on tree growth in a semi-arid woodland

Biogeosciences Discussions ◽

10.5194/bgd-12-4769-2015 ◽

2015 ◽

Vol 12 (6) ◽

pp. 4769-4800

Author(s):

G. Li ◽

S. P. Harrison ◽

I. C. Prentice

Keyword(s):

Tree Ring ◽

Tree Growth ◽

Radial Growth ◽

Fine Root ◽

Carbon Allocation ◽

Ring Width ◽

Root Mass ◽

Tree Ring Width ◽

Use Efficiency ◽

Semi Arid

Abstract. We used a light-use efficiency model of photosynthesis coupled with a dynamic carbon allocation and tree-growth model to simulate annual growth of the gymnosperm Callitris columellaris in the semi-arid Great Western Woodlands, Western Australia, over the past 100 years. Parameter values were derived from independent observations except for sapwood specific respiration rate, fine-root turnover time, fine-root specific respiration rate and the ratio of fine-root mass to foliage area, which were estimated by Bayesian optimization. The model reproduced the general pattern of interannual variability in radial growth (tree-ring width), including the response to the shift in precipitation regimes that occurred in the 1960s. Simulated and observed responses to climate were consistent. Both showed a significant positive response of tree-ring width to total photosynthetically active radiation received and to the ratio of modeled actual to equilibrium evapotranspiration, and a significant negative response to vapour pressure deficit. However, the simulations showed an enhancement of radial growth in response to increasing atmospheric CO2 concentration (ppm) ([CO2]) during recent decades that is not present in the observations. The discrepancy disappeared when the model was recalibrated on successive 30-year windows. Then the ratio of fine-root mass to foliage area increases by 14% (from 0.127 to 0.144 kg C m-2) as [CO2] increased while the other three estimated parameters remained constant. The absence of a signal of increasing [CO2] has been noted in many tree-ring records, despite the enhancement of photosynthetic rates and water-use efficiency resulting from increasing [CO2]. Our simulations suggest that this behaviour could be explained as a consequence of a shift towards below-ground carbon allocation.

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Tree growth across the Nepal Himalaya during the last four centuries

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133317714247 ◽

2017 ◽

Vol 41 (4) ◽

pp. 478-495 ◽

Cited By ~ 15

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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Responses of radial growth, wood density and fiber traits to planting space in poplar plantations at a lowland site

Journal of Forestry Research ◽

10.1007/s11676-021-01382-0 ◽

2021 ◽

Author(s):

Yanhua Zhang ◽

Shengzuo Fang ◽

Ye Tian ◽

Linlin Wang ◽

Yi Lv

Keyword(s):

Tree Ring ◽

Radial Growth ◽

Pearson Correlation ◽

Wood Fiber ◽

Negative Relationship ◽

Basic Density ◽

Ring Width ◽

Tree Ring Width ◽

Wood Basic Density ◽

Fiber Traits

AbstractPoplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.

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Growth and yield estimation of Chamaecyparis spp. through tree ring analysis

Banko Janakari ◽

10.3126/banko.v22i2.9197 ◽

2013 ◽

Vol 22 (2) ◽

pp. 36-42 ◽

Cited By ~ 1

Author(s):

D. K. Kharal ◽

T. Fujiwara

Keyword(s):

Tree Ring ◽

Radial Growth ◽

Ring Width ◽

Forest Products ◽

Growth And Yield ◽

Tree Age ◽

Biomass Estimation ◽

Tree Ring Analysis ◽

Ring Density ◽

Ring Analysis

Tree ring analysis is one of the most useful methods in volume and biomass estimation especially of the conifer trees. Ring width and ring density are important parameters in dendrochronological research. The present research was carried out with the aim of estimating the radial and volumetric growth of the Japanese Cypress trees (Chamaecyperis obstusa and C. pisifera). Destructive method was used while collecting the wood samples from the selected trees. Ring width and ring density were measured using soft X-ray densitometry method using micro-densitometer. Computer programme, developed by the Forestry and Forest Products Research Institute, Japan was used to analyze the ring with and ring density data. The average ring width of the Chamaecyparis spp. was found to be about 3.4 mm at the age of 30 years. However, two types of growth pattern were observed in the trees. Average radial growth was about 5% every year during the first 20 years of the tree age, whereas, the average radial growth was negative during the age of 20–30 years. Average density of the tree rings were increased by about 11% in each height of the trees starting from the ground. Similarly, the stem density decreased by about 3.4% annually along the radial direction from the pith.DOI: http://dx.doi.org/10.3126/banko.v22i2.9197Banko Janakari: A Journal of Forestry Information for NepalVol. 22, No. 2, 2012 November Page: 36-42 Uploaded date: 12/1/2013

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A 406-year non-growing-season precipitation reconstruction in the southeastern Tibetan Plateau

Climate of the Past ◽

10.5194/cp-17-2381-2021 ◽

2021 ◽

Vol 17 (6) ◽

pp. 2381-2392

Author(s):

Maierdang Keyimu ◽

Zongshan Li ◽

Bojie Fu ◽

Guohua Liu ◽

Fanjiang Zeng ◽

...

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

Tree Growth ◽

Ring Width ◽

Growing Season ◽

Climatic Conditions ◽

Forest Growth ◽

Drought Severity ◽

Precipitation Reconstruction ◽

Southeastern Tibetan Plateau

Abstract. Trees record climatic conditions during their growth, and tree rings serve as proxy to reveal the features of the historical climate of a region. In this study, we collected tree-ring cores of hemlock forest (Tsuga forrestii) from the northwestern Yunnan area of the southeastern Tibetan Plateau (SETP) and created a residual tree-ring width (TRW) chronology. An analysis of the relationship between tree growth and climate revealed that precipitation during the non-growing season (NGS) (from November of the previous year to February of the current year) was the most important constraining factor on the radial tree growth of hemlock forests in this region. In addition, the influence of NGS precipitation on radial tree growth was relatively uniform over time (1956–2005). Accordingly, we reconstructed the NGS precipitation over the period spanning from 1600–2005. The reconstruction accounted for 28.5 % of the actual variance during the common period of 1956–2005. Based on the reconstruction, NGS was extremely dry during the years 1656, 1694, 1703, 1736, 1897, 1907, 1943, 1982 and 1999. In contrast, the NGS was extremely wet during the years 1627, 1638, 1654, 1832, 1834–1835 and 1992. Similar variations of the NGS precipitation reconstruction series and Palmer Drought Severity Index (PDSI) reconstructions of early growing season from surrounding regions indicated the reliability of the present reconstruction. A comparison of the reconstruction with Climate Research Unit (CRU) gridded data revealed that our reconstruction was representative of the NGS precipitation variability of a large region in the SETP. Our study provides the first historical NGS precipitation reconstruction in the SETP which enriches the understanding of the long-term climate variability of this region. The NGS precipitation showed slightly increasing trend during the last decade which might accelerate regional hemlock forest growth.

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Application and evaluation of the dendroclimatic process-based model MAIDEN during the last century in Canada and Europe

Climate of the Past ◽

10.5194/cp-16-1043-2020 ◽

2020 ◽

Vol 16 (3) ◽

pp. 1043-1059

Author(s):

Jeanne Rezsöhazy ◽

Hugues Goosse ◽

Joël Guiot ◽

Fabio Gennaretti ◽

Etienne Boucher ◽

...

Keyword(s):

Tree Ring ◽

Tree Growth ◽

Meteorological Data ◽

Ring Width ◽

Complex Model ◽

Added Value ◽

Model Parameters ◽

Sources Of Information ◽

Calibration And Validation

Abstract. Tree-ring archives are one of the main sources of information to reconstruct climate variations over the last millennium with annual resolution. The links between tree-ring proxies and climate have usually been estimated using statistical approaches, assuming linear and stationary relationships. Both assumptions may be inadequate, but this issue can be overcome by ecophysiological modelling based on mechanistic understanding. In this respect, the model MAIDEN (Modeling and Analysis In DENdroecology) simulating tree-ring growth from daily temperature and precipitation, considering carbon assimilation and allocation in forest stands, may constitute a valuable tool. However, the lack of local meteorological data and the limited characterization of tree species traits can complicate the calibration and validation of such a complex model, which may hamper palaeoclimate applications. The goal of this study is to test the applicability of the MAIDEN model in a palaeoclimate context using as a test case tree-ring observations covering the 20th century from 21 Eastern Canadian taiga sites and 3 European sites. More specifically, we investigate the model sensitivity to parameter calibration and to the quality of climatic inputs, and we evaluate the model performance using a validation procedure. We also examine the added value of using MAIDEN in palaeoclimate applications compared to a simpler tree-growth model, i.e. VS-Lite. A Bayesian calibration of the most sensitive model parameters provides good results at most of the selected sites with high correlations between simulated and observed tree growth. Although MAIDEN is found to be sensitive to the quality of the climatic inputs, simple bias correction and downscaling techniques of these data improve significantly the performance of the model. The split-sample validation of MAIDEN gives encouraging results but requires long tree ring and meteorological series to give robust results. We also highlight a risk of overfitting in the calibration of model parameters that increases with short series. Finally, MAIDEN has shown higher calibration and validation correlations in most cases compared to VS-Lite. Nevertheless, this latter model turns out to be more stable over calibration and validation periods. Our results provide a protocol for the application of MAIDEN to potentially any site with tree-ring width data in the extratropical region.

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Siberian tree-ring and stable isotope proxies as indicators of temperature and moisture changes after major stratospheric volcanic eruptions

Climate of the Past ◽

10.5194/cp-15-685-2019 ◽

2019 ◽

Vol 15 (2) ◽

pp. 685-700 ◽

Cited By ~ 7

Author(s):

Olga V. Churakova (Sidorova) ◽

Marina V. Fonti ◽

Matthias Saurer ◽

Sébastien Guillet ◽

Christophe Corona ◽

...

Keyword(s):

Tree Ring ◽

Global Climate ◽

Sunshine Duration ◽

Ring Width ◽

Volcanic Eruptions ◽

Climate Dynamics ◽

Global Climate Models ◽

Added Value ◽

Latewood Density ◽

The Impact

Abstract. Stratospheric volcanic eruptions have far-reaching impacts on global climate and society. Tree rings can provide valuable climatic information on these impacts across different spatial and temporal scales. To detect temperature and hydroclimatic changes after strong stratospheric Common Era (CE) volcanic eruptions for the last 1500 years (535 CE unknown, 540 CE unknown, 1257 CE Samalas, 1640 CE Parker, 1815 CE Tambora, and 1991 CE Pinatubo), we measured and analyzed tree-ring width (TRW), maximum latewood density (MXD), cell wall thickness (CWT), and δ13C and δ18O in tree-ring cellulose chronologies of climate-sensitive larch trees from three different Siberian regions (northeastern Yakutia – YAK, eastern Taimyr – TAY, and Russian Altai – ALT). All tree-ring proxies proved to encode a significant and specific climatic signal of the growing season. Our findings suggest that TRW, MXD, and CWT show strong negative summer air temperature anomalies in 536, 541–542, and 1258–1259 at all studied regions. Based on δ13C, 536 was extremely humid at YAK, as was 537–538 in TAY. No extreme hydroclimatic anomalies occurred in Siberia after the volcanic eruptions in 1640, 1815, and 1991, except for 1817 at ALT. The signal stored in δ18O indicated significantly lower summer sunshine duration in 542 and 1258–1259 at YAK and 536 at ALT. Our results show that trees growing at YAK and ALT mainly responded the first year after the eruptions, whereas at TAY, the growth response occurred after 2 years. The fact that differences exist in climate responses to volcanic eruptions – both in space and time – underlines the added value of a multiple tree-ring proxy assessment. As such, the various indicators used clearly help to provide a more realistic picture of the impact of volcanic eruption on past climate dynamics, which is fundamental for an improved understanding of climate dynamics, but also for the validation of global climate models.

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