Ring-width Variations Research Articles

An interpreted language implementation of the Vaganov–Shashkin tree-ring proxy system model

We describe the implementation of the Vaganov–Shashkin tree-ring growth model (VSM) in MATLAB. VSM, originally written in Fortran, mimics subdaily and daily resolution processes of cambial growth as a function of soil moisture, air temperature, and insolation, with environmental forcing modeled as the principle of limiting factors. The re-implementation in a high level interpreted language, while sacrificing speed, provides opportunities to systematically evaluate model parameters, generate large ensembles of simulated tree-ring chronologies, and embed proxy system modeling within data assimilation approaches to climate reconstruction. We provide a versioned code repository and examples of model applications which permit process-level understanding of tree ring width variations in response to environmental variations and boundary conditions.

Axial changes in wood functional traits have limited net effects on stem biomass increment in European beech (Fagus sylvatica)

During the growing season, trees allocate photoassimilates to increase their aboveground woody biomass in the stem (ABIstem). This ‘carbon allocation’ to structural growth is a dynamic process influenced by internal and external (e.g., climatic) drivers. While radial variability in wood formation and its resulting structure have been intensively studied, their variability along tree stems and subsequent impacts on ABIstem remain poorly understood. We collected wood cores from mature trees within a fixed plot in a well-studied temperate Fagus sylvatica L. forest. For a subset of trees, we performed regular interval sampling along the stem to elucidate axial variability in ring width (RW) and wood density (ρ), and the resulting effects on tree- and plot-level ABIstem. Moreover, we measured wood anatomical traits to understand the anatomical basis of ρ and the coupling between changes in RW and ρ during drought. We found no significant axial variability in ρ because an increase in the vessel-to-fiber ratio with smaller RW compensated for vessel tapering towards the apex. By contrast, temporal variability in RW varied significantly along the stem axis, depending on the growing conditions. Drought caused a more severe growth decrease, and wetter summers caused a disproportionate growth increase at the stem base compared with the top. Discarding this axial variability resulted in a significant overestimation of tree-level ABIstem in wetter and cooler summers, but this bias was reduced to ~2% when scaling ABIstem to the plot level. These results suggest that F. sylvatica prioritizes structural carbon sinks close to the canopy when conditions are unfavorable. The different axial variability in RW and ρ thereby indicates some independence of the processes that drive volume growth and wood structure along the stem. This refines our knowledge of carbon allocation dynamics in temperate diffuse-porous species and contributes to reducing uncertainties in determining forest carbon fixation.

A Direct Comparison of Sympatric High-Latitude Pinus contorta and Picea albertiana Ring-Width Chronologies

An emerging trend in tree-ring research is use of multiple species for reconstructing paleoclimates, but the possible simultaneous use of boreal-cordilleran species is untested. In this study, ring-width chronologies of sympatric Pinus contorta (lodgepole pine, n = 116 series) and Picea albertiana (western white spruce, n = 348 series) were constructed to assess their temporal (dis)similarities and correlative relationships with meteorological variables. Chronology construction was based on multiple Regional Curve Standardization. Most (97.5%) Pinus chronology values occurred within ±1 SD of their Picea counterparts, but Picea values tended to be slightly less (sign-test, p < 0.001, n = 201). Pinus ring widths were more frequently (16 versus 9) and more strongly correlated (U-test, p < 0.009) with 1942–2013 meteorological variables than Picea. Both species were correlated with moisture variables, but Picea was not correlated with those of temperature. Pinus and Picea ring-width variation was best explained by summer (r = –0.434) and annual (r = –0.426) heat-moisture index values (p < 0.001, n = 72) among tested variables, respectively. Although seldom used, P. contorta appears as suitable as conventionally-used P. albertiana based on chronology similarity, but a greater diversity of significant correlation outcomes suggest Pinus is potentially more useful for boreal-cordilleran paleoclimate reconstruction.

Multivariate Climate Field Reconstructions Using Tree Rings for the Northeastern United States

AbstractHigh‐resolution paleoclimate records are essential for improving our understanding of internal variability and the detection and attribution of forced climate system responses. The densely populated northeastern United States is at risk from increasing temperatures, severe droughts, and extreme precipitation, but the region has limited annual and seasonal‐resolution paleoclimate records beyond the instrumental record. Chamaecyparis thyoides, L. (B.S.P.), Atlantic white cedar, a wetland conifer found within 200 km of the Atlantic coastline of the United States, is a promising tree‐ring proxy that can fill in these data gaps. Here, we develop and analyze a new network of Atlantic white cedar tree‐ring chronologies across the northeastern United States and demonstrate that site selection is important for regional paleoclimate reconstructions. Ring width variability reflects winter through summer temperatures at inland and hydrologically stable sites in the northernmost section of the species' range. Ombrotrophic sites along the coast record hydrological signals and correlate with growing season precipitation. We demonstrate skillful regional climate field reconstructions for the last several centuries and show the increased skill from incorporating our moisture sensitive sites into broad‐scale products like the North American Drought Atlas. This comprehensive understanding of the species' climate responses leads to a tree‐ring network that provides the long‐term multivariate climate context at multidecadal and centennial time scales for the large‐scale ocean‐atmospheric processes that influence the climate of the region. We use this network to examine the covariance of temperature and drought across the New England area over the past two centuries.

Dendrochronology of a Rare, Long-Lived Mediterranean Shrub

Ceanothus verrucosus (CEVE) is a globally rare, long-lived, chaparral shrub endemic to coastal southern California (CA) and northern Mexico. There is concern for CEVE persistence because of habitat loss, fire, and climate change, yet little is known about basic features of the plant, including whether it contains annual rings, plant age, and climate–growth response. Growth-ring analysis was challenging because of semi-ring-porous structure, false, and missing rings. We successfully crossdated CEVE annual rings, primarily from Cabrillo National Monument, CA, using a nearby Pinus torreyana chronology. The oldest living individual had 116 rings; the oldest inner-ring date was 1873; and most of the plants established between 1894 and 1905, all older than previous estimates. CEVE mortality occurred during a dry period from the late 1940s through the early 1960s. Correlations between age and stem measurements were weak to moderate (r = 0.10 to 0.56) posing challenges for field-based estimates of plant ages, which are important for population modeling. Variability in CEVE ring width had a strong positive correlation with prior cool-season (October–April) precipitation, yet 2- to 7-day warm-season precipitation events were recorded as rare false rings in multiple years, indicating extreme plasticity in cambial phenology and growth response to moisture.

Tree ring dating using oxygen isotopes: a master chronology for central England

ABSTRACTRing‐width dendrochronology, based on matching patterns of ring width variability, works best when trees are growing under significant environmental (climatic) stress. In the UK, and elsewhere in the temperate mid‐latitudes, trees generally experience low stress, so dating is more difficult and often fails. Oxygen isotopes in tree rings passively record changes in the isotopic ratios of summer precipitation, so they carry a strong common signal, which offers potential for cross‐dating. A master chronology covering the period 1200–2000 ce was constructed using the oxygen isotope ratios of the latewood cellulose of oak samples from central England. Two independent chronologies, developed to verify the isotopic signal, were combined (n = 10 trees) and the method was evaluated by dating timbers of known age and historical timbers that could not be dated by ring‐width dendrochronology, from both within and beyond the central England region. The agreement between samples and the master chronology is exceptionally strong, allowing the dating of timbers with far fewer rings than is normally the case for ring‐width dendrochronology. Tree‐ring oxygen isotope values are more suited to correlation analysis than tree‐ring widths, so it is possible to provide t‐values that conform to Student's t‐distribution and can be converted into probabilities of error. A protocol for assigning dates using ‘stable‐isotope dendrochronology’ is proposed, which has the potential to revolutionize the dating of wooden structures and artefacts, allowing the dating of short and invariant ring sequences from young, fast‐grown trees. Such samples are commonplace throughout the historical building and archaeological records and were, until now, considered impossible to date. © 2019 The Authors. Journal of Quaternary Science Published by John Wiley &amp; Sons Ltd

Radial growth-based assessment of sites effects on pedunculate and greyish oak in southern Romania

This study focuses on the climate growth drivers of Quercus robur L. (pedunculate oak) and Q. robur subsp. pedunculiflora K. Koch. (greyish oak), occurring in the biodiversity of three sites in southern Romania. We determined the degree of tolerance of the greyish oak, between the tardive and praecox varieties, to environmental stress, between 1951 and 2016. Total tree ring-width (RW), and earlywood (EW) and latewood (LW) measurements were subject of periodical and monthly climate-growth analysis. Our results revealed a moderate relationship between climate and tree-growth. A significant and positive relationship was observed between RW and previous growing season precipitation. Mean and minimum temperatures affected both positive and negative tree-rings during the growing season. We also observed that winter and spring represent key seasons for differentiating tardive from praecox varieties, affecting the intra-annual variability of ring-width, and EW and LW parameters. The correlation between the tree-ring measurements and daily climate data shows a clear offset of the starting growth between greyish oak varieties. A weak influence of stressors on tree-growth at the sites was observed through pointer year and resilience components analysis.

Soil fertilization transiently increases radial growth in sessile oaks but does not change their resilience to severe soil water deficit

The future climate is projected to become increasingly problematic for European forest ecosystems, likely leading to the decline of many tree species. Forest management must adapt to cope with the negative effects of these changes. Despite the close interactions between nutrients and water in plant physiology, very few studies have investigated the link between soil fertility and tree response to soil water availability and vapour pressure deficit. The objective of this study was to test whether fertilization would modify forest tree resilience to soil water deficit.The potential impact of fertilization on trees during soil water deficit was assessed in a fertilization experiment carried out on sessile oaks. Three fertilization treatments (NCa, NPKCaMg and an unfertilized control) were applied to 40-year-old oaks that were cored almost 40 years later. The responses to drought in the fertilized and control trees were compared by analysing the radial growth chronologies following two complementary approaches. Firstly, the relationships between radial growth and inter-annual climate variations were investigated through dendroclimatic modelling including water deficit indices computed with the daily soil water balance model Biljou©. Secondly, resistance, recovery and resilience to drought-induced crises were evaluated from tree-ring width and compared among treatments. In addition, the carbon isotope composition (δ13C) of the tree rings was measured to evaluate potential differential gas-exchange processes between fertilized and control trees.Fertilization had an immediate, strong positive effect on oak growth which disappeared after nine years. NCa and NPKCaMg fertilizations had similar effects, suggesting that adding P, K and Mg did not increase radial growth. Whatever the treatment, ring width variations appeared to be identically constrained by climate, especially by the summer water deficits of the current and previous years. Tree resistance to soil water deficit was negatively affected by the severity of the drought event but did not significantly differ between control and fertilized trees. Tree resilience was not affected by fertilization and remained stable across crises. The tree-ring δ13C clearly increased during the severe 1976 water deficit but did not vary among treatments. We discuss the possible mechanisms involved in changes in growth and the lack of any significant effect of fertilization on resilience to drought and conclude that, under the relatively dry conditions and moderately poor soil fertility of our study site, fertilization could temporarily stimulate aboveground growth without inducing imbalances that would modify resilience and resistance to severe drought episodes.

A dry season streamflow reconstruction of the critically endangered Formosan landlocked salmon habitat

This study presents a 259-year (1750–2008 CE) reconstruction for October to February (ONDJF) standardized streamflow index of the Chichiawan Stream, the sole habitat of the critically endangered Formosan landlocked salmon (Oncorhynchus formosanus) remaining natural population. The reconstruction was based on the earlywood ring-width variations of Taiwan Douglas-fir (Pseudotsuga wilsoniana), using ensemble empirical mode decomposition for chronology development. Results showed that a higher average ONDJF streamflow in the 1968–2008 period was positively associated with a wider Taiwan Douglas-fir earlywood ring. During that period, the average ONDJF streamflow was related to the Pacific Decadal Oscillation and El Niño-Southern Oscillation development. Spectral analysis indicated that the reconstructed index had significant peaks around 2∼7 years and less significant peaks around 20–35 years. Based on the derived and reconstructed indices, most of the average ONDJF streamflow between 1750 and 2008 was within the normal range. Furthermore, there was no statistical evidence to suggest that the flow regime of the last few decades had changed, which refuted the speculation that the dry season streamflow natural variability in the 1960s and 1970s might have contributed toward the critically endangered status of Formosan landlocked salmon. The results of this study will be useful for developing short- to mid-term strategies to protect the endangered species and manage water resources.

Effect of climate on tree growth in the Pampa biome of Southeastern South America: First tree-ring chronologies from Uruguay

Tree-ring research in the highland tropics and subtropics represents a major frontier for understanding climate-growth relationships. Nonetheless, there are many lowland regions – including the South American Pampa biome – with scarce tree ring data. We present the first two tree-ring chronologies for Scutia buxifolia in subtropical Southeastern South America (SESA), using 54 series from 29 trees in two sites in northern and southern Uruguay. We cross-dated annual rings and compared tree growth from 1950 to 2012 with regional climate variability, including rainfall, temperature and the Palmer Drought Severity Index – PDSI, the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM). Overall, ring width variability was highly responsive to climate signals linked to water availability. For example, tree growth was positively correlated with accumulated rainfall in the summer-fall prior to ring formation for both chronologies. Summer climate conditions were key for tree growth, as shown by a negative effect of hot summer temperatures and a positive correlation with PDSI in late austral summer. The El Niño phase in late spring/early summer favored an increase in rainfall and annual tree growth, while the La Niña phase was associated with less rainfall and reduced tree growth. Extratropical climate factors such as SAM had an equally relevant effect on tree growth, whereby the positive phase of SAM had a negative effect over radial growth. These findings demonstrate the potential for dendroclimatic research and climate reconstruction in a region with scarce tree-ring data. They also improve the understanding of how climate variability may affect woody growth in native forests – an extremely limited ecosystem in the Pampa biome.

Dendrochronological analysis of Sequoia sempervirens in an interior old-growth forest

Dendrochronological studies of large and old Sequoia sempervirens are limited by access and complex crossdating, but core sampling at regular height intervals along the main trunks of five standing trees allowed for reconstruction of growth, height, and age while providing within-tree replication for crossdating. We developed a crossdated ring-width chronology (1453–2015) for redwoods growing in an easternmost old-growth forest in the Napa Range of California, determined aboveground tree attributes, investigated the inter-annual climate-growth relationships since the late 19th century, and documented long-term growth trends. Age, height, f-DBH (functional diameter at breast height), and aboveground biomass of these co-dominant trees ranged from 241 to 783 years, 45.7 to 61.5 m, 117.0 to 226.9 cm, and 9.34 to 33.62 Mg, respectively. Bootstrapped correlation and response function analysis showed radial growth positively related to May through August Palmer Drought Severity Index (PDSI) and negatively related to maximum June temperature (r ≥ │0.47│, P < 0.0001), explaining 33.3% of ring-width variation. Bootstrapped correlations over a moving 40-year window indicated strengthening relationships with PDSI and minimum temperature. The long-term growth trend, reflected by the size-detrended metric of residual wood volume increment (RWVI), varied over time and showed an average one-year decrease of 13.3% for 20th and 21st century droughts. A fire detected in August 1931 corresponded with a one-year decrease in RWVI of 43.1% followed by >100% increase within five years. Growth dynamics for redwoods in this interior forest provide a point of comparison for redwoods previously studied in old-growth forests along the latitudinal gradient, highlighting range-wide trends and site-specific differences in responses to climate and fire.

Tree ring width variations over western Himalaya in India and its linkage with heat and aridity indices

Tree ring chronologies from different sites of western Himalaya have been carried out in relation to rainfall, temperature, palmer drought severity index, and heat and aridity indices of the region. The first principal component which was developed using the multi-sites chronologies of Himalaya has explained 50% common variance is positively correlated with rainfall, aridity and palmer drought severity index and negatively with temperature and heat index during spring season (February–May). The existence of strong correlation indicates that heat and aridity indices over the region might be one of the important climatic parameters which play the significant role in tree growth process. Particularly, heat index’s influence over the region indicated larger impact on annual ring width patterns than temperature.

Variation of Ring Width and Wood Density in Two Unmanaged Stands of the Mediterranean Oak Quercus faginea

Ring width and wood density variation were studied from pith-to-bark and along the stem in two naturally regenerated stands of Quercus faginea Lam. in Portugal. Ring width was significantly different between sites, in both heartwood and sapwood rings, ranging from 1.83 mm to 2.52 mm and from 0.77 mm to 2.11 mm, respectively. Wood density was significantly different between sites only in the heartwood, i.e., 914 kg m−3 and 1037 kg m−3. Site effects were the main source of variation for ring width and wood density within the heartwood as well as for sapwood ring width, while the between-tree effects explained more the density variation within the sapwood. Wood density showed within-tree uniformity that was not affected by site. The stand characteristics such as basal area and tree age may override the environmental growth conditions. There was also a weak correlation between wood density and ring width components therefore suggesting the possibility of forestry management for both fast tree growth and high wood density.

Dendrochronological Reconstruction of Environmental History of Fagus Grandifolia Subsp. Mexicana in Mexico

Growth-ring analysis is a valuable source of information for reconstructing environmental history. In this study, ring-width series of a sample of Fagus grandifolia subsp. mexicana were used to identify the main events that have affected populations of this species. Core samples were extracted in three representative beech forests in Mexico. These are forests where F. grandifolia subsp. mexicana dominates the canopy. A total of 3355 years of growth rings were measured and three ring-width chronologies were generated. Average annual ring widths were similar between the three sites and ranged from 0.98 to 1.08 mm. A pattern of multiple suppressions and releases was observed, mainly associated with local events, but with a slight climatic influence. Correlations between the ring-width index and climate variables were not statistically significant, with the exception of a seasonal January–June precipitation pattern (1982–2001). There has not been a large-scale disturbance of natural or human origin in the beech forests of the state of Hidalgo in the past 150 years, except in El Gosco, where anthropogenic disturbances have increased in the past decade.

Increased spruce tree growth in Central Europe since 1960s

Tree growth response to recent environmental changes is of key interest for forest ecology. This study addressed the following questions with respect to Norway spruce (Picea abies, L. Karst.) in Central Europe: Has tree growth accelerated during the last five decades? What are the main environmental drivers of the observed tree radial stem growth and how much variability can be explained by them? Using a nationwide dendrochronological sampling of Norway spruce in the Czech Republic (1246 trees, 266 plots), novel regional tree-ring width chronologies for 40(±10)- and 60(±10)-year old trees were assembled, averaged across three elevation zones (break points at 500 and 700m). Correspondingly averaged drivers, including temperature, precipitation, nitrogen (N) deposition and ambient CO2 concentration, were used in a general linear model (GLM) to analyze the contribution of these in explaining tree ring width variability for the period from 1961 to 2013. Spruce tree radial stem growth responded strongly to the changing environment in Central Europe during the period, with a mean tree ring width increase of 24 and 32% for the 40- and 60-year old trees, respectively. The indicative General Linear Model analysis identified CO2, precipitation during the vegetation season, spring air temperature (March–May) and N-deposition as the significant covariates of growth, with the latter including interactions with elevation zones. The regression models explained 57% and 55% of the variability in the two tree ring width chronologies, respectively. Growth response to N-deposition showed the highest variability along the elevation gradient with growth stimulation/limitation at sites below/above 700m. A strong sensitivity of stem growth to CO2 was also indicated, suggesting that the effect of rising ambient CO2 concentration (direct or indirect by increased water use efficiency) should be considered in analyses of long-term growth together with climatic factors and N-deposition.

Ecophysiological modeling of photosynthesis and carbon allocation to the tree stem in the boreal forest

Abstract. A better understanding of the coupling between photosynthesis and carbon allocation in the boreal forest, together with its associated environmental factors and mechanistic rules, is crucial to accurately predict boreal forest carbon stocks and fluxes, which are significant components of the global carbon budget. Here, we adapted the MAIDEN ecophysiological forest model to consider important processes for boreal tree species, such as nonlinear acclimation of photosynthesis to temperature changes, canopy development as a function of previous-year climate variables influencing bud formation and the temperature dependence of carbon partition in summer. We tested these modifications in the eastern Canadian taiga using black spruce (Picea mariana (Mill.) B.S.P.) gross primary production and ring width data. MAIDEN explains 90 % of the observed daily gross primary production variability, 73 % of the annual ring width variability and 20–30 % of its high-frequency component (i.e., when decadal trends are removed). The positive effect on stem growth due to climate warming over the last several decades is well captured by the model. In addition, we illustrate how we improve the model with each introduced model adaptation and compare the model results with those of linear response functions. Our results demonstrate that MAIDEN simulates robust relationships with the most important climate variables (those detected by classical response-function analysis) and is a powerful tool for understanding how environmental factors interact with black spruce ecophysiology to influence present-day and future boreal forest carbon fluxes.

Wild Apple Growth and Climate Change in Southeast Kazakhstan

Wild populations of Malus sieversii [Ldb.] M. Roem are valued genetic and watershed resources in Inner Eurasia. These populations are located in a region that has experienced rapid and on-going climatic change over the past several decades. We assess relationships between climate variables and wild apple radial growth with dendroclimatological techniques to understand the potential of a changing climate to influence apple radial growth. Ring-width chronologies spanning 48 to 129 years were developed from 12 plots in the Trans-Ili Alatau and Jungar Alatau ranges of Tian Shan Mountains, southeastern Kazakhstan. Cluster analysis of the plot-level chronologies suggests different temporal patterns of growth variability over the last century in the two mountain ranges studied. Changes in the periodicity of annual ring-width variability occurred ca. 1970 at both mountain ranges, with decadal-scale variability supplanted by quasi-biennial variation. Seascorr correlation analysis of primary and secondary weather variables identified negative growth associations with spring precipitation and positive associations with cooler fall-winter temperatures, but the relative importance of these relationships varied spatially and temporally, with a shift in the relative importance of spring precipitation ca. 1970 at Trans-Ili Alatau. Altered apple tree radial growth patterns correspond to altered climatology in the Lake Balkhash Basin driven by unprecedented intensified Arctic Oscillations after the late 1970s.

Genetic analysis of lodgepole pine (Pinus contorta) solid-wood quality traits

Potential improvement of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) solid-wood properties was examined by estimating age trends of inheritance, age–age genetic correlations, and the efficiency of early selection using 823 increment cores sampled from 207 half-sib families at two independent progeny trials, aged 34–35 years, located in northern Sweden. High-resolution radial variation of annual ring width, wood density, microfibril angle (MFA), and modulus of elasticity (clearwood stiffness; MOES) was measured using SilviScan. The dynamic stiffness (MOEtof) of standing trees was also obtained using Hitman ST300. Heritabilities ranged from 0.10 to 0.64 for growth and earlywood, transition-wood, and latewood proportions, from 0.29 to 0.77 for density traits, and from 0.13 to 0.33 for MFA and stiffness traits. Genetic correlations between early age and the reference age (26 years) suggested that early selection is efficient at age 4 years for MFA and between ages 5 to 8 years for density and MOES. Unfavorable diameter–stiffness genetic correlations and correlated responses indicate that breeding for a 1% increase in diameter would confer 5.5% and 2.3% decreases in lodgepole pine MOES and MOEtof, respectively. Index selection with appropriate economical weights for growth and wood stiffness is highly recommended for selective breeding.

Radial growth-climate relationships of white ash (Fraxinus americanaL. Oleaceae) in the eastern United States

This study characterized associations between climate variables and radial growth of white ash (Fraxinus americana L.) at 12 sites along a longitudinal climate gradient in the eastern USA. Growth responses of this species to climate stresses have not been well documented, and this study sought to improve understanding of how climate change might affect white ash. Total annual ring-width data were obtained for trees at all sites, and data for earlywood and latewood width were obtained at six sites. Pearson's correlation coefficients were computed among radial growth indices and temperature, precipitation, and Palmer drought severity index (PDSI). Total ring width was positively correlated with precipitation and PDSI and negatively correlated with temperature during the months of May to July, when most radial growth occurs. These spatially replicated correlations indicate that white ash growth is most strongly influenced by drought stress in the first half of the growing season. Correlations between climate variables and latewood width were the same as for total ring width; latewood width explained 98% of the variation in total ring width. Earlywood width exhibited less interannual variation than latewood width did and was weakly correlated with climate variables for months before leaf-out was complete but not after. These correlations were consistent with the ecology and carbon allocation patterns of other tree species with ring-porous wood anatomy. The effect of climate change on white ash growth will depend on how changes in the balance between increasing temperature and precipitation alter the frequency and intensity of early growing-season droughts.

Anatomical and FTIR analyses of phloem and xylem of Tetracentron sinense

The fast growth of Tetracentron sinense is a potential valuable timber resource, but whether its anatomy and chemical components are suitable for timber is unknown. We used light microscopy and SEM to examine the anatomical structure and FITR to measure the chemical components of the phloem and xylem of this tree. Radial variations in growth ring width and tracheid dimensions were also evaluated. The sieve tube, phloem parenchyma cell and sclereids clusters were the main cells in phloem, and the tracheid was the fundamental cell in xylem. An unusual tracheid type, fiber-tracheids or vessel-liked elements was visible. Wood rays nonstoried, uniseriate and multiseriate, including heterogeneous II, occasionally I, and usually 3–6 cells wide. The mean growth-ring width was 2.53 ± 0.46 mm, and the percentage of late wood was over 60%. For radial variation, growth-ring width increased at an early growth stage, and reached the largest increment during years 11–15, then decreased. The maximum growth-ring width was 5.313 mm. During late growth (60–85 years), trees also maintained a high radial growth increment. Radial variation in the percentage of late wood was uniform, about 50–70%, throughout the growth years. Growth patterns in the length and width of early and late wood were similar as the trees aged. From the FTIR results, the chemical components differed significantly between xylem and phloem, hemicellulose in particular was higher in the xylem than in the phloem, where it was apparently absent. All of these suggest that the composition of phloem in T. sinense is very similar to that of hardwood, and it has higher growth ratio and uniform wood properties.