Chinese Pine Research Articles

Early Detection of Dendroctonus valens Infestation with Machine Learning Algorithms Based on Hyperspectral Reflectance

The red turpentine beetle (Dendroctonus valens LeConte) has caused severe ecological and economic losses since its invasion into China. It gradually spreads northeast, resulting in many Chinese pine (Pinus tabuliformis Carr.) deaths. Early detection of D. valens infestation (i.e., at the green attack stage) is the basis of control measures to prevent its outbreak and spread. This study examined the changes in spectral reflectance after initial attacking of D. valens. We also explored the possibility of detecting early D. valens infestation based on spectral vegetation indices and machine learning algorithms. The spectral reflectance of infested trees was significantly different from healthy trees (p < 0.05), and there was an obvious decrease in the near-infrared region (760–1386 nm; p < 0.01). Spectral vegetation indices were input into three machine learning classifiers; the classification accuracy was 72.5–80%, while the sensitivity was 65–85%. Several spectral vegetation indices (DID, CUR, TBSI, DDn2, D735, SR1, NSMI, RNIR•CRI550 and RVSI) were sensitive indicators for the early detection of D. valens damage. Our results demonstrate that remote sensing technology could be successfully applied to early detect D. valens infestation and clarify the sensitive spectral regions and vegetation indices, which has important implications for early detection based on unmanned airborne vehicle and satellite data.

Functional Characterization of Allatostatin C (PISCF/AST) and Juvenile Hormone Acid O-Methyltransferase in Dendroctonus armandi

Allatostatin C (PISCF/AST) is a neuropeptide gene that affects juvenile hormone (JH) synthesis in the corpora allata. Juvenile hormone acid O-methyltransferase (JHAMT) is a key gene in the JH biosynthetic pathway. In this study, two genes encoding DaAST and DaJHAMT were cloned. Both DaAST and DaJHAMT were expressed in the larvae, pupae and adults of Chinese white pine beetle (Dendroctonus armandi), and highly expressed in the head and the gut. The expression of the two genes was induced by JH analog (JHA) methoprene and the functions of the two genes were then investigated by RNAi. Considering the role of hormones in metamorphosis, JHA significantly induced DaAST and DaJHAMT in the larval stage. DaAST knockdown in larvae, pupae and adults significantly increased the DaJHAMT mRNA levels. Moreover, knockdown of DaAST instead of DaJHAMT increased pupae mortality and the abnormal rate of emergence morphology and reduced emergence rates. However, knockdown of DaJHAMT instead of DaAST significantly reduced frontalin biosynthesis in adult males. The results showed that DaAST acts as an allatostatin and inhibits JH biosynthesis, and that JHAMT is a key regulatory enzyme for JH synthesis in the D. armandi.

Chinese pine (Pinus tabuliformis Carr.)

Pinus tabuliformis, commonly called Chinese pine, is a drought- and cold-tolerant heliophilous, indigenous conifer species, widespread in China. It has a giant genome comprising 25.4 Gb, with 12 huge chromosomes. The recently released nearly complete genome of P. tabuliformis provides new perspectives on genome expansion and adaptative and reproductive evolution of conifers. With an expansion of the genome, a multitude of long introns were observed in the P. tabuliformis genome. Interestingly, large genes with ultra-long introns tend to be expressed at higher levels, which suggests that intron length may serve as an evolutionary force in gymnosperms, though the underlying molecular mechanism is still unknown.

The influence of microhabitat factors on the regeneration and species composition of understory woody plants in Pinus tabuliformis plantations on the Loess Plateau

Chinese pine (Pinus tabuliformis) is one of the main tree species for water and soil conservation on the Loess Plateau. However, most of these plantations face a series of ecological problems, such as low diversity of understory plants and difficulty in natural regeneration. Our study focused on the microhabitat factors that affected the species composition of understory woody plants and the distribution and growth of regeneration in Chinese pine plantations. Plots of 50 × 50 m were randomly established in three typical mature plantations, and then each plot was divided into 100 5 × 5 m microplots to investigate the characteristics of canopy trees, Chinese pine regeneration, other understory woody plants, the light environment, litter and soil. The involved microhabitat factors jointly explained 37.68% of the variation in the species composition of understory woody plants, among which soil total phosphorus (2.66%) and available potassium (2.19%) were the main factors. In the regeneration layer, Chinese pine regeneration (7,261 stems·ha−1, 124.6 cm), Quercus liaotungensis (3,114 stems·ha−1, 117.0 cm) and Betula platyphylla (953 stems·ha−1, 305.7 cm) were considered the canopy replacement species with the most potential. Additionally, we found that the regeneration density was significantly affected by soil total nitrogen, available potassium and shrub density, while the differences in regeneration height growth mainly resulted from the density of other understory trees and shrubs, soil total phosphorus and diffuse non-interceptance. The density of saplings and juvenile trees of Chinese pine was more affected by microhabitat factors than that of seedlings, but the effect of the microenvironment on the former two was less different, indicating that the sapling stage may be the critical period for successful recruitment of the plantations. Therefore, gap creation or thinning is suggested to promote the growth of saplings and juvenile trees, thus increasing the opportunity for them to enter the canopy. At the stand scale, soil resources and interspecies interactions were the dominant microhabitat factors influencing the regeneration of Chinese pine, which inspired us to deeply explore the vegetation-soil-microbial systems and the relationship between regeneration and their neighbors in the future. Moreover, managers should pay more attention to the survival and growth of saplings and juvenile trees to promote the sustainable development of Chinese pine plantations. We believe that these plantations will be transformed into coniferous and broad-leaved mixed forests with high stability and species diversity (e.g., P. tabuliformis × B. platyphylla or P. tabuliformis × Q. liaotungensis).

A half-millennium perspective on recent drying in the eastern Chinese Loess Plateau

Northern China has experienced dramatic drying since the 1960s CE. However, the scarcity of long-term observations hampers the evaluation of recent drought variations from a long-term perspective. Here, we present a tree-ring-width chronology of Chinese pine (Pinus tabuliformis Carr.) from the eastern edge of the Chinese Loess Plateau (ECLP), which is the longest tree-ring chronology on the ECLP (1535–2018 CE). This chronology was used to reconstruct the average April-June self-calibrated Palmer Drought Severity Index (scPDSI). The reconstruction explains 64.3% of the variations in the observed scPDSI during the calibration period (1954–2000 CE). The driest and wettest years over the full reconstruction were 1759 CE and 1649 CE, respectively. The two most prolonged drought intervals occurred in 1892–1943 CE and 1737–1775 CE, while the two most prolonged pluvial intervals occurred in 1950–1992 CE and 1645–1682 CE. The reconstruction captures the recent drying since the 1960s. However, we found that the recent notable drying is not unprecedented over the last half-millennium, as more dramatic drought fluctuations occurred around the 1650s-1690s. The spatial correlation with sea surface temperature (SST) indicates that the drought variations on the ECLP might be modulated by the North Atlantic SST tripolar pattern. This study provides a reference for long-term drought evaluation, which may have implications for drought prediction and adaptation on the ECLP.

Biophysical regulations of transpiration and water use strategy in a mature Chinese pine (Pinus tabulaeformis) forest in a semiarid urban environment

AbstractUrban trees and forests provide multiple ecosystem services for urban dwellers. However, forest water use for these benefits has become one of the critical concerns in dryland regions where water is limited. Negative forest water use impacts could be reduced by selecting tree species with low rates of transpiration. However, the possible changes of urban tree transpiration and its biophysical controls are still unclear. This study monitored the sap flow of a 58‐year‐old Chinese pine (Pinus tabulaeformis) plantation in a semiarid urban environment of northern China. Soil moisture played an important role in stand transpiration (Ec). Ec had a strong positive relationship with vapour pressure deficit (VPD) and solar radiation (Rs) when soil water was sufficient. In addition, the sensitivity of leaf stomata to VPD was not related to leaf and branch water potential. Under soil water stress, Ec was significantly reduced by 63.1% (p < 0.001) and was weakly related to VPD and Rs. Canopy conductance (gc) was reduced (p < 0.001) by 74.3% due to leaf stomatal closure, and the sensitivity of leaf stomata to VPD was significantly increased (p < 0.05) with increasing leaf and branch water potential. Wind speed had no significant effects on Ec. P. tabulaeformis tended to be isohydric with a relatively constant midday leaf water potential (i.e. −2.46 to −2.92 MPa) and strong stomatal regulation as a function of soil water stress. However, slopes (0.53–0.56) of the linear relationship between m (dgc/dlnVPD) and reference canopy conductance were significantly lower than the widely recognized 0.6 (p < 0.001). Therefore, urban tree transpiration drivers and forest impacts need to be clarified to better understand the proper tradeoff between water consumption and ecological services for urban areas.

Urban–rural gradients in soil nutrients beneath Chinese pine (Pinus tabulaeformis Carr.) are affected by land-use

Urban–rural gradients of soil nutrients may be affected by many factors including land use, vegetation cover, and management. In this study, focusing on one vegetation type (Chinese pine, Pinus tabulaeformis Carr.) to exclude the effects of vegetation cover, we investigated soil nutrients in three land-use types (neighborhoods, parks and roadsides) along urban–rural gradients in Beijing, China, to explore the differences in soil nutrients across land-use types and the changes of soil nutrients along the urban–rural gradient. Soil nutrients (organic carbon, calcium and magnesium) are significantly higher in neighborhoods and parks than in roadsides, while soil nutrients (except for magnesium) showed no significant differences between in neighborhoods and in parks. Interestingly, soil moisture, nitrate-nitrogen, calcium, magnesium, and available phosphorus and potassium all decreased along urban–rural gradients in parks, while only soil available phosphorus did so in neighborhoods and none soil variables studied showed this trend in roadsides. Thus, land use plays an important role in modifying urban–rural gradients of soil nutrients.

Analyzing the Saturation of Growing Stem Volume Based on ZY-3 Stereo and Multispectral Images in Planted Coniferous Forest

Recently, remote sensing (RS) technology are becoming an increasingly important technology in estimating forest growing stem volume (GSV), and the saturation issue of spectral variables from various optical sensors severely hinders the improvement of mapping forest GSV, especially in the planted forest with high GSV. Forest canopy height is widely considered as one of the major factors to increase the saturation levels in mapping GSV. However, it is rather difficult to invert the forest canopy height without precisely external DEM for large regions. In this study, the canopy height model (CHM) was derived from ZY-3 stereo images with subtracting open-sourced external DEM and the response of saturation levels was analyzed by adding forest height in the planted coniferous forest (Larch and Chinese pine). To further describe the relationships between the forest height and saturation levels, five datasets with five estimation models (Linear, MLR, SVR, KNN, and RF) and three methods of variable selection (Stepwise, LASSO, and Pearson) were applied to estimate the forest GSV using corrected CHM and 49 alternative variables extracted from ZY-3 multispectral images. Meanwhile, a spherical model was employed to quantitatively describe the saturation levels of combined variables. The results showed that values of relative root means square error were decreased from 29.3% to 25% for Larch and from 26.5% to 22.2% for Chinese pine after adding the corrected CHM, respectively. Meanwhile, the saturation level of each combined variable set was successfully determined by the spherical model. The results illustrated that the saturation levels of GSV were significantly increased by adding corrected CHM from open-sourced external DEM. Specially, the averaged saturation levels were increased from 220 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /ha to nearly 300 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /ha for Chinese pine and from 150 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /ha to 220 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /ha for Larch, respectively. It is proved that ZY-3 stereo and multispectral images have great potential for accurate estimation of forest GSV by delaying the saturation levels using extracted CHM with open-sourced external DEM.

Involvement of Ptcol5-Ptnf-Y4 in Reproductive Cone Development and Gibberellin Signaling in Chinese Pine

Involvement of Ptcol5-Ptnf-Y4 in Reproductive Cone Development and Gibberellin Signaling in Chinese Pine

Knockdown of Cyp6cr2 and Cyp6de5 Reduces Tolerance to Host Plant Allelochemicals in the Chinese White Pine Beetle Dendroctonus Armandi

Knockdown of Cyp6cr2 and Cyp6de5 Reduces Tolerance to Host Plant Allelochemicals in the Chinese White Pine Beetle Dendroctonus Armandi

The Chinese pine genome and methylome unveil key features of conifer evolution

Conifers dominate the world's forest ecosystems and are the most widely planted tree species. Their giant and complex genomes present great challenges for assembling a complete reference genome for evolutionary and genomic studies. We present a 25.4-Gb chromosome-level assembly of Chinese pine (Pinus tabuliformis) and revealed that its genome size is mostly attributable to huge intergenic regions and long introns with high transposable element (TE) content. Large genes with long introns exhibited higher expressions levels. Despite a lack of recent whole-genome duplication, 91.2% of genes were duplicated through dispersed duplication, and expanded gene families are mainly related to stress responses, which may underpin conifers' adaptation, particularly in cold and/or arid conditions. The reproductive regulation network is distinct compared with angiosperms. Slow removal of TEs with high-level methylation may have contributed to genomic expansion. This study provides insights into conifer evolution and resources for advancing research on conifer adaptation and development.

Phytohormone profiles and related gene expressions after endodormancy release in developing Pinus tabuliformis male strobili

Development after endo-dormancy release ensures perennial plants, such as forest trees, proper response to environmental changes and enhances their adaptability. In northern hemisphere, megasporophore and microsporophore of conifers undergo dormancy to complete their development. Here combined with transcriptome data, we used high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (ESI-HPLC-MS/MS) to quantitatively analyse the various hormones (Abscisic Acid (ABA), 3-Indoleacetic acid (IAA), Gibberellins (GAs), Cytokinin (CTK), Jasmonic acid (JA) and Salicylic acid (SA)) of Chinese pine (Pinus tabuliformis Carr.) male strobili after endo-dormancy release. More specifically, we analysed endogenous hormones and their related-genes and verified the important role of ABA in plants growth and development. We observed rapid decrease in ABA content after dormancy release, resulting in reducing the inhibitory effect on male strobili growth. Similarly, rapid drop in ABA/GA ratio was observed and was associated with the start of male strobili growth and development. Combined with transcriptome data, we found that HAB2-SnRK2.10 played a central role in the ABA pathway in the entire network of hormones regulating male strobili development. Due to external environment warming, the differentially expressed HAB2-SnRK gene led to ABA content rapid decline, thus initiating male strobili growth. We constructed a network of hormone-regulated development to understand the interactions between hormones after male strobili dormancy release of male strobili. This study provided essential foundations for studying megasporophore and microsporophore growth mechanism after endo-dormancy and offered new ideas for flower development in gymnosperms and angiosperms.

Comparison of canopy transpiration between Pinus sylvestris var. mongolica and Pinus tabuliformis plantations in a semiarid sandy region of Northeast China

Mongolian pine (Pinus sylvestris var. mongolica) has been introduced to vast areas of semiarid sandy region of northern China to create plantations, and it plays an important role in improving environmental conditions. These trees often show obvious dieback after age of 35–40 during extreme drought years, while native Chinese pine (Pinus tabuliformis) plantations grow healthily. Water is the most important resource for tree growth and survival in these regions; however, the transpiration dynamics of introduced Mongolian pine, unlike those of native Chinese pine, are still unknown, limiting proper management of plantations. Here, canopy transpiration and canopy conductance of Mongolian pine and Chinese pine plantations that were both 18 years old were quantified using sap flow method, and environmental variables were monitored concurrently. Results showed that canopy transpiration per unit leaf area (EL) averaged 1.1 and 0.7 mm d − 1 for Mongolian pine and Chinese pine, respectively, indicating that in comparison to native pine species, introduced pine species had a higher transpiration rate due to higher canopy conductance. Sensitivity of EL response to meteorological variables decreased with increasing soil moisture stress for both pine species, but the larger decrease for Mongolian pine indicated a higher sensitivity to drought. Additionally, canopy conductance per unit leaf area for Mongolian pine was 70% higher than that for Chinese pine, and reference canopy conductance decreased with increasing soil moisture stress for both pine species, indicating there are soil water limitations on canopy conductance. However, a higher decrease in stomatal sensitivity to vapor pressure deficit with increasing soil moisture stress in Mongolian pine than in Chinese pine indicates a greater decrease in hydraulic conductance. These findings indicated that in comparison to Chinese pine, Mongolian pine consumes more water but is less able to control transpiration under drought conditions, showing vulnerability to dieback in extreme drought years.

Leaf Functional Traits Vary in Urban Environments: Influences of Leaf Age, Land-Use Type, and Urban–Rural Gradient

An increasing number of studies have focused on the response and adaptation of plants to urbanization by comparing differences in leaf functional traits between urban and rural sites. However, considerable uncertainties remain because differences in land-use type have not frequently been taken into account when assessing the effect of urbanization on leaf traits. In this study, we sampled the needles of Chinese pine (Pinus tabuliformis Carr.) in areas with three land-use types (roadsides, parks, and neighborhoods) along an urban–rural gradient in Beijing, China to determine the effect of urbanization on leaf functional traits. There were significant differences in the values of leaf functional traits between the needles of the current and previous year and across land-use types. Pines growing on roadsides had leaves with smaller length, width, and area, as well as lower stomatal density, compared with those growing in parks and neighborhoods. This implies that on roadsides, plant capacity to acquire resources (e.g., light and carbon dioxide) was degraded. Stomatal density, leaf width, and leaf P concentration increased with increasing distance from the city center, while leaf K concentration decreased with increasing distance from the city center. Importantly, there were significant differences in the urban–rural gradient of leaf functional traits between leaves of different ages, and across land-use types. Leaf age was the most important factor influencing leaf nutrient traits, while land-use type was the most important factor influencing leaf morphological traits in urban environments. Thus, considering the effects of the plant characteristic and land-use type on traits is important for assessing the urban–rural gradients of plant functional traits.

Feasibility of a rapid and non-destructive methodology for the study and discrimination of pine nuts using near-infrared hyperspectral analysis and chemometrics

Spanish pine nut is highly appreciated globally for its aroma and taste. Nevertheless, its market is affected by the growing presence of Chinese pine nuts, entailing mislabeling and counterfeits. In this study, near-infrared hyperspectral imaging (940–1625 nm) coupled to chemometrics, was applied, for the first time, to perform a spectral study (identification of chemical distribution and composition) of commercial pine nuts labeled on their package as Spanish and Chinese and to develop a single class-modelling classification model. Sixty-three pine nuts from both marketed origin labels and different qualities were analysed. Principal component analysis (PCA) and multivariate curve resolution (MCR) showed the chemical distribution of the major compounds (bands around 1170–1210 nm and 1485–1550 nm, associated with fats and fatty acids and water and proteins, respectively) of each marketed origin. Soft independent modelling of class analogies (SIMCA) classified the samples according to their labeling of origin, in a pixel-based and nut-based approach, obtaining 89–98% and 84–100% of correct prediction, respectively. This preliminary study demonstrated that the proposed methodology could be used as a fast, comprehensive and innovative quality control tool (for characterisation and classification) for the pine nut industry. • NIR-HSI was for first-time applied for studying and classifying pine nuts. • It allows studying internal pine nut composition and chemical distribution. • Satisfactory classification models were achieved according to two marketed origins. • This approach shows a comprehensive fast and reliable quality control for pine nuts. • NIR-HSI could enhance pine nut traceability and detection of compositional changes.

Growth and response patterns of Picea crassifolia and Pinus tabuliformis to climate factors in the Qilian Mountains, northwest China

Different tree species exhibit different phenological and physiological characteristics, leading to complexity in inter-species comparison of stem radial growth response to climate change. This study explored the climate-growth responses of Qinghai spruce (Picea crassifolia) and Chinese pine (Pinus tabulaeformis) in the Qilian Mountains, Northwest China. Meanwhile, Vaganov-Shashkin model (VS-oscilloscope) was used to simulate the relationships between radial growth rates and phenology. The results showed that 1) in their radial growth patterns, Qinghai spruce showed a significant increasing trend, while Chinese pine showed a decreasing trend, and Qinghai spruce has a longer growing season than Chinese pine. 2) For the radial growth-climate dynamic response, Qinghai spruce was influenced in an unstable manner by the mean temperature in the mid-growing season of the current year and the late growing season of the previous year and by the mean minimum temperature in the mid-growing season of the current year, while Chinese pine was influenced in a stable manner by the mean temperature and mean maximum temperature during the growing season of the current year. 3) The radial growth rates of the two conifer species were limited by temperature at the initiation and cessation of growth and by soil moisture at the peak of growth. But Chinese pine was more severely affected by soil moisture than Qinghai spruce in the middle of growth. Therefore, different management and restoration measures should be taken based on the differences in ecological responses and physical and physiological properties of the two conifer species to climate change in the subalpine forest ecosystems in the semiarid and arid regions of Northwest China.

Origin of Intra-annual Density Fluctuations in a Semi-arid Area of Northwestern China.

Intra-annual density fluctuation (IADF) is a structural modification of the tree ring in response to fluctuations in the weather. The expected changes in monsoon flow would lead to heterogeneous moisture conditions during the growing season and increase the occurrence of IADF in trees of the arid ecosystems of continental Asia. To reveal the timings and physiological mechanisms behind IADF formation, we monitored cambial activity and wood formation in Chinese pine (Pinus tabuliformis) during 2017–2019 at three sites in semi-arid China. We compared the dynamics of xylem formation under a drought event, testing the hypothesis that drought affects the process of cell enlargement and thus induces the production of IADF. Wood microcores collected weekly from April to October were used for anatomical analyses to estimate the timings of cambial activity, and the phases of enlargement, wall thickening, and lignification of the xylem. The first cells started enlargement from late April to early May. The last latewood cells completed differentiation in mid-September. Trees produced IADF in 2018. During that year, a drought in June limited cell production in the cambium, only 36% of the xylem cells being formed in IADF trees, compared to 68% in normal tree rings. IADF cells enlarged under drought in early July and started wall thickening during the rainfall events of late July. The drought restricted cell enlargement and affected wall thickening, resulting in narrow cells with wide walls. Cambium and cell enlargement recovered from the abundant rainfall, producing a new layer with large earlywood tracheids. IADF is a specific adaptation of trees to cope with water deficit events occurring during xylem formation. Our findings confirmed the hypothesis that the June-July drought induces latewood-like IADFs by limiting the process of cell enlargement in the xylem. Our finding suggests a higher occurrence of IADF in trees of arid and semi-arid climates of continental Asia if the changes to monsoon flows result in more frequent drought events during the earlywood formation in June.

Transcriptomic and proteomic analyses of far-red light effects in inducing shoot elongation in the presence or absence of paclobutrazol in Chinese pine

Transcriptomic and proteomic analyses of far-red light effects in inducing shoot elongation in the presence or absence of paclobutrazol in Chinese pine

Radial Growth Response of Picea crassifolia to Climatic Conditions in a Dryland Forest Ecosystem in Northwest China

As an important barrier against desert invasion in Northwest China, Helan Mountains (HL), Luoshan Mountains (LS) and their natural forests have an extremely important ecological status. It is of great significance to study the relationship between forest growth and climate in this region under the background of global change. At present, relevant research mostly focuses on the Chinese pine (Pinus tabulaeformis Carr.), and little is known about how Qinghai spruce (Picea crassifolia Kom.) responds to climate change. To investigate the potential relationships between radial growth of P. crassifolia and climatic conditions in Ningxia, China, we collected tree-ring samples from P. crassifolia growing in the HL and LS and then established the standard tree-ring width chronologies for the two sites. Correlation analysis together with multivariate linear regression and relative contribution analyses were used, and results showed that radial growth in the HL was determined by the precipitation in the previous September, by the standardized evapotranspiration index (SPEI) in the current March and June, and by the maximum air temperature in the current September. The maximum air temperature in the current September contributed the most (0.348) to the radial growth in the HL. In the LS, radial growth was determined by the precipitation in the previous September and in the current March and by the minimum air temperature in the current July. The factor that made the most contribution was the precipitation in the current March (0.489). Our results suggested that in the wetting and warming future, growth of P. crassifolia in the HL will increase while that in the LS needs further investigation. Our results also provide a basis for predicting how P. crassifolia in northwest China will grow under the background of future climate change and provide a reference for formulating relevant management measures to achieve ecological protection and sustainable development policies.

Short-term resin tapping activities had a minor influence on physiological responses recorded in the tree-ring isotopes of Chinese pine (Pinus tabuliformis)

Resin tapping might affect tree-ring growth, but details on the physiological responses of trees to resin tapping are still lacking, particularly for long-term responses. This study aimed to explore the physiological processes underlying resin-tapping of Chinese pine (Pinus tabuliformis) by using tree-ring stable isotopes. We compared tree-ring earlywood and latewood stable carbon (δ13C) and oxygen (δ18O) isotopes in the pre-resin tapping and post-resin tapping period for tapped trees and compared their values between tapped and untapped trees and their responses to climate variables in a forest stand from 1984 to 2017. Furthermore, we used a dual isotope model to distinguish between the effects of the photosynthetic assimilation rate and stomatal conductance. Results indicated that tapped and untapped trees showed similar inter-annual variation for two isotopes, while the absolute values of tapped trees were slightly (P > 0.05) lower than tapped trees in the two years following resin tapping. Climate response analysis indicated that resin tapping had no significant effect on climatic sensitivity for either stable isotope. Earlywood stable isotopes were mainly influenced by temperature, relative humidity, and Palmer Drought Severity Index (PDSI) from May to July, while latewood isotopes were mainly influence by relative humidity form July to August and PDSI from July to September. The conceptual model results indicated that resin tapping lead to a slight, but not significant, decrease in the intrinsic water-use efficiency caused by increased stomatal conductance for the first two to three years following resin tapping. We conclude that tree-ring physiological responses could be less affected by short-term resin tapping activities.