Changes in Sensitivity of Tree-Ring Widths to Climate in a Tropical Moist Forest Tree in Bangladesh

Tree growth in the tropics is strongly influenced by climate. However, reported tree growth responses to climate are largely inconsistent, varying with geographic location, forest type, and tree species. It is thus important to study the growth responses of tropical trees in sites and species that are under-represented so far. Bangladesh, a country influenced by the Asian monsoon climate, is understudied in terms of tree growth response to climate. In the present study, we developed a 121-year-long regional ring-width index chronology of Chukrasia tabularis A. Juss. sampled in two moist forest sites in Bangladesh to investigate tree growth responses to climate in monsoon South Asia. Standard dendrochronological methods were used to produce the ring-width chronologies. The climate sensitivity of C. tabularis was assessed through bootstrap correlation analysis and the stationarity and consistency of climate–growth relationships was evaluated using moving correlation functions and comparing the regression slopes of two sub-periods (1950–1985 and 1986–2015). Tree growth was negatively correlated with the mean, minimum, and maximum temperatures, particularly during the early growing season (March). Likewise, precipitation negatively influenced tree growth in the later growing season (October). Besides, radial growth of Chukrasia sharply ceased in years following strong and moderate El Niño events. In parallel with a significant positive trend in local temperatures, tree growth sensitivity to early growing season (March–April) mean temperatures and July minimum temperatures increased in recent decades. Tree growth sensitivity to October precipitation and April vapor pressure deficit also increased. Overall, climate–growth relationships were stronger during the period 1986–2015 than during 1950–1985. Changes in climate sensitivity might be linked to a warming trend that induced an increase in the dry season length during recent decades. With a further predicted temperature increase at our study sites, our results suggest that radial growth of C. tabularis will further decline in response to climate warming.

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Physiological and Growth Responses to Increasing Drought of an Endangered Tree Species in Southwest China

Forests ◽

10.3390/f10060514 ◽

2019 ◽

Vol 10 (6) ◽

pp. 514 ◽

Cited By ~ 1

Author(s):

Wuji Zheng ◽

Xiaohua Gou ◽

Jiajia Su ◽

Haowen Fan ◽

Ailing Yu ◽

...

Keyword(s):

Tree Growth ◽

Tree Species ◽

Radial Growth ◽

Intercellular Co2 Concentration ◽

Ring Width ◽

Co2 Concentration ◽

Growth Responses ◽

Endangered Tree ◽

Endangered Tree Species ◽

Intrinsic Water Use Efficiency

Research Highlights: We compared annually resolved records of tree-ring width and stable isotope of dead and surviving Fokienia hodginsii (Dunn) Henry et Thomas trees. We provide new insights into the relationships and sensitivity of tree growth to past and current climate, and explored the underlying mechanism of drought-induced mortality in F. hodginsii. Background and Objectives: Drought-induced tree decline and mortality are increasing in many regions around the world. Despite the high number of studies that have explored drought-induced decline, species-specific responses to drought still makes it difficult to apply general responses to specific species. The endangered conifer species, Fokienia hodginsii, has experienced multiple drought-induced mortality events in recent years. Our objective was to investigate the historical and current responses to drought of this species. Materials and Methods: We used annually resolved ring-width and δ13C chronologies to investigate tree growth and stand physiological responses to climate change and elevated CO2 concentration (Ca) in both dead and living trees between 1960 and 2015. Leaf intercellular CO2 concentration (Ci), Ci/Ca and intrinsic water-use efficiency (iWUE) were derived from δ13C. Results: δ13C were positively correlated with mean vapor pressure deficit and PDSI from previous October to current May, while ring widths were more sensitive to climatic conditions from previous June to September. Moreover, the relationships between iWUE, basal area increment (BAI), and Ci/Ca changed over time. From 1960s to early 1980s, BAI and iWUE maintained a constant relationship with increasing atmospheric CO2 concentration. After the mid-1980s, we observed a decrease in tree growth, increase in the frequency of missing rings, and an unprecedented increase in sensitivity of 13C and radial growth to drought, likely related to increasingly dry conditions. Conclusions: We show that the recent increase in water stress is likely the main trigger for the unprecedented decline in radial growth and spike in mortality of F. hodginsii, which may have resulted from diminished carbon fixation and water availability. Given that the drought severity and frequency in the region is expected to increase in the future, our results call for effective mitigation strategies to maintain this endangered tree species.

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Geographical, Climatological, and Biological Characteristics of Tree Radial Growth Response to Autumn Climate Change

Frontiers in Forests and Global Change ◽

10.3389/ffgc.2021.687749 ◽

2021 ◽

Vol 4 ◽

Author(s):

Shunsuke Tei ◽

Ayumi Kotani ◽

Atsuko Sugimoto ◽

Nagai Shin

Keyword(s):

Climate Change ◽

Northern Hemisphere ◽

Tree Growth ◽

Radial Growth ◽

Forest Ecosystems ◽

Ring Width ◽

Biological Characteristics ◽

Growth Responses ◽

Western Asia ◽

Tree Radial Growth

Terrestrial forest ecosystems are crucial to the global carbon cycle and climate system; however, these ecosystems have experienced significant warming rates in recent decades, whose impact remains uncertain. This study investigated radial tree growth using the tree-ring width index (RWI) for forest ecosystems throughout the Northern Hemisphere to determine tree growth responses to autumn climate change, a season which remains considerably understudied compared to spring and summer, using response function and random forest machine learning methods. Results showed that autumn climate conditions significantly impact the RWI throughout the Northern Hemisphere. Spatial variations in the RWI response were influenced by geography (latitude, longitude, and elevation), climatology, and biology (tree genera); however, geographical and/or climatological characteristics explained more of the response compared to biological characteristics. Higher autumn temperatures tended to negatively impact tree radial growth south of 40° N in regions of western Asia, southern Europe, United State of America and Mexico, which was similar to the summer temperature response found in previous studies, which was attributed to temperature-induced water stress.

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Comparison of the Radial Growth Response of Picea crassifolia to Climate Change in Different Regions of the Central and Eastern Qilian Mountains

Forests ◽

10.3390/f12081015 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1015

Author(s):

Xuan Wu ◽

Liang Jiao ◽

Dashi Du ◽

Changliang Qi ◽

Ruhong Xue

Keyword(s):

Climate Change ◽

Tree Growth ◽

Central Region ◽

Radial Growth ◽

Growing Season ◽

Qilian Mountains ◽

Growth Patterns ◽

Total Precipitation ◽

Picea Crassifolia ◽

The Qilian Mountains

It is important to explore the responses of radial tree growth in different regions to understand growth patterns and to enhance forest management and protection with climate change. We constructed tree ring width chronologies of Picea crassifolia from different regions of the Qilian Mountains of northwest China. We used Pearson correlation and moving correlation to analyze the main climate factors limiting radial growth of trees and the temporal stability of the growth–climate relationship, while spatial correlation is the result of further testing the first two terms in space. The conclusions were as follows: (1) Radial growth had different trends, showing an increasing followed by a decreasing trend in the central region, a continuously increasing trend in the eastern region, and a gradually decreasing trend in the isolated mountain. (2) Radial tree growth in the central region and isolated mountains was constrained by drought stress, and tree growth in the central region was significantly negatively correlated with growing season temperature. Isolated mountains showed a significant negative correlation with mean minimum of growing season and a significant positive correlation with total precipitation. (3) Temporal dynamic responses of radial growth in the central region to the temperatures and SPEI (the standardized precipitation evapotranspiration index) in the growing season were unstable, the isolated mountains to total precipitation was unstable, and that to SPEI was stable. The results of this study suggest that scientific management and maintenance plans of the forest ecosystem should be developed according to the response and growth patterns of the Qinghai spruce to climate change in different regions of the Qilian Mountains.

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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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Residual-tree growth responses to partial stand harvest in the black spruce (Picea mariana) boreal forestThis article is one of a selection of papers published in the Special Forum IUFRO 1.05 Uneven-Aged Silvicultural Research Group Conference on Natural Disturbance-Based Silviculture: Managing for Complexity.

Canadian Journal of Forest Research ◽

10.1139/x07-148 ◽

2007 ◽

Vol 37 (9) ◽

pp. 1563-1571 ◽

Cited By ~ 34

Author(s):

H. C. Thorpe ◽

S. C. Thomas ◽

J. P. Caspersen

Keyword(s):

Boreal Forest ◽

Tree Growth ◽

Picea Mariana ◽

Radial Growth ◽

Growth Response ◽

Black Spruce ◽

Tree Age ◽

Growth Responses ◽

Partial Harvest ◽

Partial Harvesting

Variants of partial harvesting are gaining favour as means to balance ecosystem management and timber production objectives on managed boreal forest landscapes. Understanding how residual trees respond to these alternative silvicultural treatments is a critical step towards evaluating their potential from either a conservation or a wood supply perspective. We used dendroecological techniques combined with a chronosequence approach to quantify the temporal radial growth response pattern of residual black spruce ( Picea mariana (Mill.) BSP) trees to partial harvest in northeastern Ontario. At its peak, 8–9 years after harvest, radial growth of residual trees had doubled. The growth pattern was characterized by a 2-year phase of no response, a subsequent period of increase 3–9 years after harvest, and a stage of declining rates 10–12 years after harvest. The magnitude of tree growth response depended strongly on tree age: peak postharvest growth was substantially higher for young trees, while old trees displayed only modest growth increases. Both the large magnitude and the time delay in postharvest growth responses have important implications for the development of more accurate quantitative tools to project future yields and, more generally, for determining whether partial harvesting is a viable management option for the boreal forest.

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The Radial Growth of Picea wilsonii Was More Restricted by Precipitation Due to Climate Warming on Mt. Guandi, China

Forests ◽

10.3390/f12111602 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1602

Author(s):

Xiaoxia Huang ◽

Xiaoneng Sun ◽

Yuan Jiang ◽

Feng Xue ◽

Minghao Cui ◽

...

Keyword(s):

Climate Warming ◽

Tree Growth ◽

Radial Growth ◽

Management Strategies ◽

Ring Width ◽

Elevational Gradient ◽

Summer Drought ◽

Clear Trend ◽

Biological Variables ◽

Picea Wilsonii

Transitional climate zones (TCZ) are characterized by instability due to rapid changes in climate and biological variables, and trees growing there are particularly sensitive to climate change. Therefore, knowledge about the shifted relationships of tree growth in response to climate warming will shape regional forest conservation and management strategies. China has experienced rapid warming in recent decades. However, how tree growth in semihumid to semiarid regions, such as the Guandi Mountains, responds to more sophisticated changes in the hydrothermal combination is not yet clear. In this study, we used tree-ring width data from three sites along an elevational gradient in the Guandi Mountains to present the response of Picea wilsonii Mast. radial growth to increasing temperature and elevational differences in the relationship between tree growth and climate. The results indicated that the Guandi Mountains have experienced rapid warming with a clear trend toward aridity. From 1959 to 1995, the radial growth of P. wilsonii was mainly influenced by temperature, while it was controlled by both temperature and precipitation after rapid warming in 1996. From 1959 to 2017, this species showed a generally consistent growth–climate relationship at different elevations in the Guandi Mountains. However, the radial growth of trees at higher elevations had a higher climatic correlation than at lower elevations, and it was more conditioned by higher summer temperatures and precipitation in December of the previous year. These results suggested that P. wilsonii was more susceptible to drought and high temperatures due to a warming climate and that more attention should be devoted to forest management, especially the adverse consequences of summer drought on P. wilsonii.

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Weekly xylem production in trembling aspen (Populus tremuloides) in response to artificial defoliation

Canadian Journal of Botany ◽

10.1139/b04-032 ◽

2004 ◽

Vol 82 (5) ◽

pp. 590-597 ◽

Cited By ~ 15

Author(s):

Brin Jones ◽

Jacques Tardif ◽

Richard Westwood

Keyword(s):

Populus Tremuloides ◽

Radial Growth ◽

Regression Models ◽

Wood Anatomy ◽

Ring Width ◽

Growing Season ◽

Early Growth ◽

Trembling Aspen ◽

Forest Sites ◽

Significant Difference

The present study investigated the effect of artificial defoliation on weekly radial xylem production in trembling aspen (Populus tremuloides Michx.). It was hypothesized that defoliated trees would show reduced xylem and vessel production and thinner secondary walls in fibres. Two adjacent natural forest sites were selected within Winnipeg, Manitoba. Microcores were extracted weekly from the stems of 30 aspen trees from May to October 2002. Ten aspen trees were defoliated using pole pruners between 22 June and 6 July. Measurements included weekly xylem increment, annual vessel characteristics, and late growing season fibre dimensions. No significant difference in overall ring width was observed; however, trees from both groups showed a significant reduction in ring width in 2002. The ratio of radial growth in 2002 / radial growth in 2001 was significantly less in defoliated trees, suggesting a higher reduction in radial growth due to defoliation. Sigmoidal regression models suggested early growth cessation in defoliated trees. No significant differences in vessel characteristics were observed between groups; however, the diameter and lumen width of fibres was significantly reduced in defoliated trees. It is speculated that a shorter radial growing season may have led to a reduced cell elongation period. An early cessation of the radial growing season associated with a reallocation of carbohydrates to produce a second flush of leaves could explain the reduced size of fibres from defoliated trees.Key words: wood anatomy, diffuse porous, image analysis, radial growth, cell dimension, dendrochronology.

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Climate Warming Alters Age-Dependent Growth Sensitivity to Temperature in Eurasian Alpine Treelines

Forests ◽

10.3390/f9110688 ◽

2018 ◽

Vol 9 (11) ◽

pp. 688 ◽

Cited By ~ 2

Author(s):

Raúl Sanchez-Salguero ◽

J. Camarero ◽

Emilia Gutiérrez ◽

Antonio Gazol ◽

Gabriel Sangüesa-Barreda ◽

...

Keyword(s):

Climate Warming ◽

Tree Growth ◽

Radial Growth ◽

Terrestrial Ecosystems ◽

Tree Age ◽

Growth Responses ◽

Polar Urals ◽

Cold Environments ◽

Age Related ◽

Old Trees

Treeline ecotones are considered early-warning monitors of the effects of climate warming on terrestrial ecosystems, but it is still unclear how tree growth at treeline will track the forecasted temperature rise in these cold environments. Here, we address this issue by analysing and projecting growth responses to climate on two different cold-limited alpine treelines: Pinus uncinata Ram. in the Spanish Pyrenees and Larix sibirica Ledeb. in the Russian Polar Urals. We assess radial-growth changes as a function of tree age and long-term climate variability using dendrochronology and a process-based model of tree growth. Climate‒growth relationships were compared considering young (age < 50 years) and old trees (age > 75 years) separately. Warm summer conditions enhanced radial growth, particularly after the 1980s, in the Polar Urals sites, whereas growth was positively related to warm spring and winter conditions in the Pyrenees sites. These associations were stronger in young than in old trees for both tree species and regions. Forecasted warm conditions are expected to enhance growth rates in both regions, while the growing season is forecasted to lengthen in the Pyrenees treelines, mostly in young trees. The observed age-related responses to temperature also depend on the forecasted warming rates. Although the temperature sensitivity is overall increasing for young trees, those responses seem more divergent, or even reversed, throughout the contrasting emission scenarios. The RCP 8.5 emission scenario corresponding to the most pronounced warming and drier conditions (+4.8 °C) could also amplify drought stress in young trees from the Pyrenees treelines. Our modelling approach provides accessible tools to evaluate functional thresholds for tree growth in treeline ecotones under warmer conditions.

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Drought Treated Seedlings of Quercus petraea (Matt.) Liebl., Q. robur L. and Their Morphological Intermediates Show Differential Radial Growth and Wood Anatomical Traits

Forests ◽

10.3390/f11020250 ◽

2020 ◽

Vol 11 (2) ◽

pp. 250

Author(s):

Kristine Vander Mijnsbrugge ◽

Arion Turcsán ◽

Éva Erdélyi ◽

Hans Beeckman

Keyword(s):

Drought Stress ◽

Radial Growth ◽

Explanatory Power ◽

Ring Width ◽

Growing Season ◽

Quercus Petraea ◽

Ring Closure ◽

Drought Treatment ◽

Growing Seasons ◽

Earlywood Vessels

Background and Objectives: Studying responses in woody plants upon water limitation is gaining importance due to the predicted increase in frequency and intensity of droughts in Europe. We studied the variation in radial growth and in wood anatomical traits caused by water limited growth conditions in offspring from Quercus petraea (Matt.) Liebl., Q. robur L. and their morphological intermediates grown in the same environment. Materials and Methods: Cross sections were prepared from the stems of 210 three-year-old potted seedlings, comprising control plants and seedlings that experienced from late spring until early autumn of the first growing season two sequential periods of water with-holding each followed by plentiful re-watering. Pith radius, ring width of the three growing seasons and latewood vessel diameter in second and third growing season were measured. Presence of intra-annual density fluctuations, dendritic patterns of latewood vessels and the level of ring closure of earlywood vessels were observed. The traits were modelled to examine the explanatory power of the taxon of the mother tree and the drought treatment. Results: Most of the traits displayed significant differences between offspring from Q. petraea and Q. robur and offspring from the morphological intermediates behaved inconsistent among the traits. Most of the traits were significantly affected by the drought stress in the first growing season. Apart from radial growth, also latewood vessel size was reduced in the two growing seasons following the year in which drought was imposed on the seedlings, suggesting an adaptation to improve the tolerance to drought stress. We also found an indication for a compensation growth mechanism, counteracting the lost growing time during the drought stress, as the level of ring closure of the earlywood vessels in the year following the drought treatment was further advanced in the treated seedlings, an effect that disappeared in the subsequent year. Conclusion: Oaks exposed to drought adapt their growth and xylem structure to improve drought resistance. While youth growth of Q. robur is more competition-oriented, with a faster juvenile growth, Q. petraea seems to invest more in a precautious growth, being more prepared for stressful conditions. It is therefore possible that Q. robur seedlings may suffer more from intensified droughts than Q. petraea seedlings.

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Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and Tibetan Plateau

10.5194/bg-2016-559 ◽

2017 ◽

Author(s):

Lixin Lyu ◽

Susanne Suvanto ◽

Pekka Nöjd ◽

Helena M. Henttonen ◽

Harri Mäkinen ◽

...

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

Tree Growth ◽

Latitudinal Gradient ◽

Ring Width ◽

Growing Season ◽

Climate Variables ◽

Climate Data ◽

Altitudinal Gradients ◽

Summer Temperatures

Abstract. Latitudinal and altitudinal gradients can be utilized to forecast the impacts of climate changes on forests. To improve the understanding of forest dynamics on these gradients, we tested two hypotheses: (1) the change in the tree growth-climate relationship is similar along both latitudinal and altitudinal gradients, and (2) the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. We used tree-ring data from a latitudinal gradient in Finland and two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree-rings and investigated the growth-climate relationships of trees by correlating ring-width index chronologies with climate variables calculated with flexible time-windows, using daily-resolution climate data. The high latitude and altitude plots showed higher correlations between the tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed differing patterns for the gradients. The timing of highest correlation with summer temperatures in southern sites was approximately one month ahead of the northern sites in the latitudinal gradient. In one out of the two altitudinal gradients the timing of strongest negative correlation with summer temperatures at low altitude sites was ahead of the treeline sites, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width was found to increase with increasing mean summer temperatures on both types of gradients. Our results showed similarities of tree growth responses to growing season temperature between latitudinal and altitudinal gradients. However, differences in climate-growth relationships were also found between the gradients, due to differences in other factors, such as moisture conditions. Changes in the timing of the most critical climate variables demonstrated the need to use daily resolution climate data in studies on environmental gradients.

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