Cork Oak Research Articles

Green synthesis, characterization, and biochemical impacts of new bioactive isoxazoline-sulfonamides as potential insecticidal agents against the Sphodroxia maroccana Ley.

Sphodroxia maroccana Ley is a pest of cork oak crops that damages the roots of seedlings and can severely impair cork oak regeneration. Since the banning of carbosulfan and chlorpyriphos, which were widely used against the larvae of Sphodroxia maroccana because of their harmful impact on the environment, until now there has been no pesticide against these pests. Therefore, it is particularly urgent to develop highly effective insecticidal molecules with novel scaffolds. Isoxazolines are a class of insecticides that act on γ-aminobutyric acid (GABA)-gated chloride channel allosteric modulators. In this work, a green synthesis of novel 3,5-disubstituted isoxazoline-sulfonamide derivatives was achieved in water via ultrasound-assisted four-component reactions, and their insecticidal activities against fourth-instar larvae of S. maroccana were evaluated. Most of the tested compounds showed insecticidal activity compared to fluralaner as positive control and commercially available insecticide. Especially, the isoxazoline-secondary sulfonamides containing halogens (Br and Cl) on the phenyl group attached to the isoxazoline, 6g (LC50 = 0.31 mg/mL), 6j (LC50 = 0.38 mg/mL), 6k (LC50 = 0.18 mg/mL), 6L (LC50 = 0.49 mg/mL), 6m (LC50 = 0.24 mg/mL), 6q (LC50 = 0.46 mg/mL), exhibited much higher larvicidal activity than fluralaner (LC50 = 0.99 mg/mL). Novel isoxazolines containing sulfonamide moieties were designed, synthesized and confirmed by two single-crystal structures of 4e and 6q. Their bioassay results showed significant larvicidal activity with significant morphological changes in vivo. These results will lay the foundation for the further discovery and development of isoxazoline-sulfonamide derivatives as novel crop protection larvicides of cork oak. © 2023 Society of Chemical Industry.

Differences in Root Endophytic Bacterial Communities of Chinese Cork Oak (Quercus variabilis) Seedlings in Different Growth Years

In forests, seedling renewal is influenced by many environmental factors, including climate change, seed size, wildfires, and ecological factors. It is unclear how different growth years of seedlings affect Chinese cork oak (Quercus variabilis) root endophyte communities. In this study, we took a holistic approach, using Illumina sequencing, to study the composition and function of bacterial communities associated with root microorganisms in four Q. variabilis seedlings after 1, 2, and 3 years of growth. The bacterial alpha diversity indexes were highest in the second year and lowest in the third year, and age was the decisive factor for the differences found in the root endophytic bacterial communities. Total phosphorus had the greatest effect on bacterial communities. The abundance of beneficial bacteria Streptomyces (8.69%) and Novosphingobium (4.22%) was highest in the second-year samples, and their abundance decreased by 7.96% and 3.61% in the third year, respectively. Higher levels of plant disease inhibition and metabolism (23.80%) were in the roots of second-year Q. variabilis seedlings. The metabolic abundance of carbohydrate was 3.66% lower in the first year and 3.95% lower in the third year compared to the second year. Our results suggest that the structure and function of bacterial communities changed with increasing growth years.

Embedding plural values in value chains to enhance sustainability in the management of cork oak landscapes

ContextThe management of Portuguese agroforestry landscapes is currently focused on specialised cork and cattle production. Sustainable landscape management is increasingly discussed as an effective option to foster the multifunctionality of these landscapes. Such management requires consideration of multiple values connected to the landscape and to the products stemming from it.ObjectivesThe aim of this study is to (1) assess the importance of specific values related to cork and to the cork production landscapes, (2) analyse how values differ across the value chain actors, and (3) compare the types of values associated to cork and the cork production landscapes.MethodsWe combine value chain analysis with the concept of plural valuation in order to illuminate the values amongst value chain actors. We conducted interviews with 62 actors divided across the value chain using a semi-structured questionnaire.ResultsWe found that a broad range of instrumental, intrinsic and relational values were expressed by our respondents. Our results show an imbalance between the perception of the ecosystem health expressed by actors involved in the industrial transformation of cork compared to those directly involved with the landscape. This imbalance shows the necessity to find a common management ideal for cork production landscapes favouring multifunctionality.ConclusionsOur study shows the relevance of considering plural values when planning and implementing sustainable landscape management. Integrated into a landscape approach, value chain analysis is useful in reaching actors in order to uncover different points of view towards a single landscape. Our study suggests that focusing on the multifunctional nature of the cork production landscapes may be key in ensuring a sustainable future for this social-ecological system.

Temporal Variation in Tower-Based Solar-Induced Chlorophyll Fluorescence and Its Environmental Response in a Chinese Cork Oak Plantation

With the development of spectrum observation technology, solar-induced chlorophyll fluorescence (SIF)—an effective substitute for photosynthesis—has been widely used to monitor crop stress, vegetation phenology and ecosystem productivity. The relationship between fluorescence and photosynthesis is complicated because they are sensitive to environmental changes. Understanding the response of SIF to environmental factors is of great significance for clarifying the variation dynamic and relationship between SIF and photosynthesis under different conditions. In this study, the canopy SIF and the environmental factors of a Quercus variabilis BI. plantation were observed simultaneously, and the response of SIF to environmental factors at a daily scale and at a half-hour scale was analyzed. The results showed that SIF had obvious seasonal and diurnal dynamics and was mainly driven by photosynthetically active radiation (PAR). The influence of PAR, air temperature (Ta), vapor pressure deficit (VPD), soil moisture (SM) and wind speed (Ws) on SIF varied with the lapse of the growing season. After eliminating the covariant effect of PAR on the Ta and VPD during the whole growing season, the relationship between VPD and SIF was found to be negative, and the effect of Ta on SIF disappeared. This study enriched the ground observation dataset and provided support for understanding the variations in the relationship between SIF and photosynthesis under different conditions.

Bioprospection of the bacterial β-myrcene-biotransforming trait in the rhizosphere

The biocatalysis of β-myrcene into value-added compounds, with enhanced organoleptic/therapeutic properties, may be performed by resorting to specialized enzymatic machinery of β-myrcene-biotransforming bacteria. Few β-myrcene-biotransforming bacteria have been studied, limiting the diversity of genetic modules/catabolic pathways available for biotechnological research. In our model Pseudomonas sp. strain M1, the β-myrcene catabolic core-code was identified in a 28-kb genomic island (GI). The lack of close homologs of this β-myrcene-associated genetic code prompted a bioprospection of cork oak and eucalyptus rhizospheres, from 4 geographic locations in Portugal, to evaluate the environmental diversity and dissemination of the β-myrcene-biotransforming genetic trait (Myr+).Soil microbiomes were enriched in β-myrcene-supplemented cultures, from which β-myrcene-biotransforming bacteria were isolated, belonging to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Sphingobacteriia classes. From a panel of representative Myr+ isolates that included 7 bacterial genera, the production of β-myrcene derivatives previously reported in strain M1 was detected in Pseudomonas spp., Cupriavidus sp., Sphingobacterium sp., and Variovorax sp. A comparative genomics analysis against the genome of strain M1 found the M1-GI code in 11 new Pseudomonas genomes. Full nucleotide conservation of the β-myrcene core-code was observed throughout a 76-kb locus in strain M1 and all 11 Pseudomonas spp., resembling the structure of an integrative and conjugative element (ICE), despite being isolated from different niches.Furthermore, the characterization of isolates not harboring the Myr+-related 76-kb locus suggested that they may biotransform β-myrcene via alternative catabolic loci, being thereby a novel source of enzymes and biomolecule catalogue for biotechnological exploitation.Key points• The isolation of 150 Myr+bacteria hints the ubiquity of such trait in the rhizosphere.• The Myr+trait is spread across different bacterial taxonomic classes.• The core-code for the Myr+trait was detected in a novel ICE, only found in Pseudomonas spp.

Highly informative SNP markers for routine individual identification and certification of forest reproductive material in Quercus ilex and Q. suber and their hybrids

Holm oak (Quercus ilex L.) and cork oak (Q. suber L.) are two species of great ecological and socio-economical relevance in the Mediterranean western basin, mainly in the Iberian Peninsula. However, although breeding programs are in progress, basic materials providing qualified and tested Forest Reproductive Materials (FRM) are still lacking. In order to enable an accurate identification at the individual level, allowing the certification of selected material, efficient and affordable molecular markers are required.We report the identification of different sets of 96 and 500 single nucleotide polymorphism markers, selected in order to: I) allow the unambiguous identification at the individual level, both for holm oak and for cork oak and II) provide an accurate estimation of introgression level in hybrid individuals, at a low genotyping cost. These molecular tools fulfill the requirements for FRM certification, as well as for research and breeding purposes.

Effect of Tree Shelters and Regeneration Method on Survival and Growth of Cork Oak Plantations in the Maamora Forest, Morocco

Effect of Tree Shelters and Regeneration Method on Survival and Growth of Cork Oak Plantations in the Maamora Forest, Morocco

Exploring the diversity of Phytophthora spp. and the role of Phytophthora multivora in cork and holm oak coastal forests in Italy

Exploring the diversity of Phytophthora spp. and the role of Phytophthora multivora in cork and holm oak coastal forests in Italy

Screening of Cork Oak for Resistance to Phytophthora cinnamomi and Micropropagation of Tolerant Seedlings

Massive propagation of cork oak (Quercus suber) individuals tolerant to Phytophthora cinnamomi (Pc) is probably the most important challenge for cork production. Screening for resistance to Pc of ca. 200 seedlings obtained from a single cork oak tree that has survived the epidemic was performed by soil infestation. Twenty months after Pc inoculation, 33 seedlings survived from Pc infection and the four most vigorous seedlings were selected. The plants were forced to produce new shoots under controlled climatic conditions, and the new shoots were used to establish the plants in vitro by axillary budding. High axillary shoot proliferation rates were achieved by culturing the new shoots on Lloyd and McCown (WPM) medium, followed by subculturing for 2 weeks on 0.22 µM benzyladenine (BA) and for 2 weeks further on 0.04 µM BA. Addition of 20 µM silver thiosulphate (STS) increased the proliferation rates and improved the appearance and development of shoots. Rooting rates of 80–100% were obtained by culturing the shoots for 24 or 48 h on Gresshoff and Doy medium with ⅓ macronutrients plus 122.5 µM indole-3-butyric acid and subsequent transfer to root expression medium containing 20 µM STS. The results of this study optimize the micropropagation of a relevant and recalcitrant tree species in forestry.

Insights into the Antimicrobial Potential of Acorn Extracts (Quercus ilex and Quercus suber)

Acorns, frequently left uncollected in the fields, have been a part of the traditional medicine of different cultures. Among the different properties associated with them, their antimicrobial potential is of particular importance. However, this characterization has long been superficial and has not ventured into other topics such as biofilm inhibition. Thus, the current work aimed to characterize the antimicrobial and antibiofilm potential of an array of phenolic rich extracts attained from acorns, two different acorn varieties Q. ilex and Q. suber, considering the fruit and shell separately, fresh and after heat-treating the acorns to aid in the shelling process. To accomplish this, the extracts’ capacity to inhibit an array of different microorganisms was evaluated, the minimum bactericidal concentration (MBC) was determined, time-death curves were drawn whenever an MBC was found and the antibiofilm potential of the most effective extracts was drawn. The overall results showed that Gram-positive microorganisms were the most susceptible out of all the microorganisms tested, with the shell extracts being the most effective overall, exhibiting bactericidal effect against S. aureus, B. cereus and L. monocytogenes as well as being capable of inhibiting biofilm formation via the two S. aureus strains. The attained results demonstrated that acorn extracts, particularly shell extracts, pose an interesting antimicrobial activity which could be exploited in an array of food, cosmetic and pharmaceutical applications.

Mineral nutrients improve phosphonate effectiveness against cork oak root disease

Phosphonate fungicides are the most efficient chemicals for the control of oomycete root diseases which are causing significant economic and ecological losses in Mediterranean climate-type forests and natural ecosystems worldwide. However, a more environmental-friendly disease management demanded by society requires the optimization of chemicals application. Thereby, the main goal of this study was to develop a new resistant inducer (RI) formulation based on potassium phosphonate (PP) combined with mineral nutrients efficient against the root rot caused by Phytophthora cinnamomi and Pythium spiculum on cork oak that improve potassium phosphonate effectiveness. The potential phytotoxicity of five RI formulations composed of PP at five concentrations (25, 40, 50, 100 and 200 g/l) and each including 2.15 g/l ZnCl2 (Zn) and 0.25 g/l CaCl2 (Ca), were tested on 1-year old Quercus suber seedlings. Two weeks after treatments, only seedlings treated with the RIs containing the two highest doses of PP (100 and 200 g/l) showed symptoms of toxicity. RI with 40 g/l of H3PO3 (RI40), as well as its compounds individually and in combination two by two (PP (40 g/l), Ca, Zn, PP + Ca, PP + Zn, Ca + Zn), were tested against root disease development induced by P. cinnamomi and Py. spiculum on cork oak seedlings. For both oomycetes, seedlings submitted to every treatment with PP exhibited a significantly lower severity of root symptoms than plants artificially inoculated and treated with water. Furthermore, plants treated with RI40 did not differ to the plants growing in uninfested soil, improving PP alone effect. These results were validated by a field experiment where 60 mature cork oaks in three different defoliation classes (asymptomatic, slight, and moderate defoliation) were trunk injected with RI40 or water (controls). Three years after treatments, root disease development was significantly lower in cork oaks with slight and moderate initial defoliation level and treated with RI40 in comparison with water-treated controls. No effect was detected over both pathogens’ dynamics in soil. Results strongly support that PP effectiveness in controlling Q. suber root disease caused by P. cinnamomi and Py. spiculum is improved by its combination with Zn and Ca, allowing to reduce the PP application rates according to current society demands and the European Plant Health Legislation.

Do Distance-Dependent Competition Indices Contribute to Improve Diameter and Total Height Tree Growth Prediction in Juvenile Cork Oak Plantations?

Competition indices may improve tree growth modelling in high-density stands, found often in new cork oak plantations. Distance-dependent competition indices have hardly been considered for juvenile cork oak plantations since existing models were developed for low-density mature stands. This study aims at inspecting the potential of including distance-dependent competition indices into diameter at breast height (d) and total height (h) growth models for Quercus suber L., comparing several distance-dependent and distance-independent competition indices. Annual d and h growth were modelled with linear and non-linear growth functions, formulated as difference equations. Base models were initially fitted considering parameter estimates depending only on site index (S) and/or stand density (N). They were refitted, testing the significance of adding each competition index to the model parameters. Selected models included the best-performing distance-dependent or -independent competition indices as additional predictors. Best base d and h growth models showed a modelling efficiency (ef) of ef = 0.9833 and ef = 0.9900, respectively. Adding a distance-dependent competition index slightly improved growth models, to an ef = 0.9851 for d and ef = 0.9902 for h. Best distance-dependent competition indices slightly overperformed distance-independent ones in diameter growth models. Neither S nor N were included on best fitted models. If inter-tree competition is present in juvenile undebarked cork oak plantations, it does not yet strongly impact individual tree growth, which may diminish the importance of using, at this stage, more complex spatially explicit competition indices on predicting individual tree growth.

Corticolous lichen communities in Algerian climax forests

AbstractThe great extension of forests in the Djebel El Ghorra massif of El Kala National Park (north‐eastern Algeria) allowed us to recognise three distinct forest formations: cork oak stands (Quercus suber), zeen oak stands (Quercus canariensis) and mixed oak (Quercus suber and Quercus canariensis) forest. Their peculiarities showed ideal ecological characteristics for the colonisation of corticolous lichens the two phorophytes. The three forest formations were sampled between 2017 and 2022. The identification of the taxa is based on stereo‐microscopic examinations and usual chemical tests. Systematic surveys were conductedand allowed us to establish a list of 141 lichen taxa divided into 30 families.

The Components' Roles in Thermal Stability and Flammability of Cork Powder.

In this study, an analysis of the influence of extractives, suberin and lignocellulosic components on the pyrolysis decomposition and fire reaction mechanisms of a cork oak powder from Quercus suber L. is presented. The summative chemical composition of cork powder was determined. Suberin was the main component at 40% of the total weight, followed by 24% of lignin, 19% of polysaccharides and 14% of extractives. The absorbance peaks of cork and its individual components were further analyzed by means of ATR-FTIR spectrometry. Thermogravimetric analysis (TGA) showed that the removal of extractives from cork slightly increased the thermal stability between 200 °C and 300 °C and led to the formation of a more thermally stable residue at the end of the cork decomposition. Moreover, by removing suberin, a shift of the onset decomposition temperature to a lower temperature was noticed, indicating that suberin plays a major role in enhancing the thermal stability of cork. Furthermore, non-polar extractives showed the highest flammability with a peak of heat release rate (pHRR) of 365 W/g analyzed by means of micro-scale combustion calorimetry (MCC). Above 300 °C, the heat release rate (HRR) of suberin was lower than that of polysaccharides or lignin. However, below that temperature it released more flammable gases with a pHRR of 180 W/g, without significant charring ability, contrary to the mentioned components that showed lower HRR due to their prominent condensed mode of action that slowed down the mass and heat transfer processes during the combustion process.

Latitudinal variation in the functional response of Quercus suber seedlings to extreme drought

Many plant species are being threatened by increasingly drought conditions due to current climate change at planetary scale. This global trend is leading to the scientific community to investigate the potential role of local adaptations through intraspecific differences in functional traits that may boost conservation strategies by modulating the plant responses to reduced water availability. We assessed under controlled conditions the effect of four different drought intensities on the survival time and morphological traits of Quercus suber seedlings collected from nine populations covering the complete latitudinal distribution of the species. Functional morphological traits related to biomass allocation and leaf and root display were analyzed. We then related these traits with the survival time after a terminal desiccation, used as a drought-resistance proxy and expressed as survival time without watering. Abundant watering availability allowed seedlings to survive for a longer period compared to drier conditions. Further, all morphological traits differed across watering levels, showing a very plastic response. Acorns from southern latitudes produced very large seedlings compared to those gathered from northern latitudes. However, the larger biomass implied higher evaporative water loss, inducing lower survival of southern populations under extreme drought conditions. We further found a clear trend toward maximizing those traits related with belowground growth (i.e., root surface area, root average diameter and root volume) in southern populations aimed to increase water uptake, overcoming the most limiting factor for plant growth in that area. Our results support that increased root development allow cork oak to maintain its functioning after being subjected to damage caused by reduced water availability, whereas high aerial biomass allocation is a handicap for survival under drought stress conditions. This study identifies drought-resistant populations and morphological traits related to drought resistance, which can be applied to improve restoration actions under a warmer climate.

A Contingent Valuation-Based Method to Valuate Ecosystem Services for a Proactive Planning and Management of Cork Oak Forests in Sardinia (Italy)

The paper develops a model through a contingent valuation approach to support public authorities in the exploration and assessment of ecosystem services (ESs) generated by forest and woodlands (FOWLs). This approach is employed to the cork oak forests of the Sardinia region (Italy) due to their ability in the provision and regulation of cultural and recreational values to society. The paper describes the economic valuation of cultural ESs through the contingent valuation method (CVM) with the purpose to explore residents and tourists’ willingness to pay (WTP) preferences towards conservation, valorisation, and the management of Goceano’s cork oak forests in Sardinia. The approach may help retain suitable support for DMs, planners, technicians, and operators for a better understanding of the ESs’ role in policy decisions, leading FOWLs towards a learning process between the environment, human beings, and landscape to promote and develop a proactive landscape and forest planning and management within the region.

HB26, a member of HD-Zip I subfamily, is involved in the regulation of hydrolysable tannin biosynthesis in the cupules of Quercus variabilis by transactivation of UGT84A13

Tannins are useful for many industrial applications owing to their strong chelating, antibacterial, and antioxidant properties. Hydrolysable tannins (HTs) are suitable for feed additives to replace antibiotics because of their low anti-nutritional effects. However, regulation of HT biosynthesis in plants remains largely unknown. Here, we found that the HTs are predominant phenols in Chinese cork oak (Quercus variabilis) and their contents in cupules were much higher than those in other tissues; simultaneously, the expression of UGT84A13, a key gene for the first step of HT biosynthesis, was also high. RNA-seq analysis revealed 351 candidate genes whose expressions were correlated with UGT84A13 expressions and HT contents. Comprehensive analysis of the HD-Zip family identified subfamily I members—HB20 and HB26—as candidate genes responsible for regulation of UGT84A13 expression and HT biosynthesis. Subcellular localization assays showed that both HD-Zip proteins were localized to the nucleus. Interestingly, HB20 and HB26 had distinct trans-activating domains. Y1H and luciferase assays finally confirmed that HB26, instead of HB20, interacted with UGT84A13 promoter and activated its expression. This study provides valuable data for different tissues of Q. variabilis and new insights into the transcriptional regulation of UGT84A13 and HT biosynthesis, thereby laying the foundation for molecular breeding and enhancement of HT biosynthesis.

A Metabolome Analysis and the Immunity of Phlomis purpurea against Phytophthora cinnamomi.

Phlomis purpurea grows spontaneously in the southern Iberian Peninsula, namely in cork oak (Quercus suber) forests. In a previous transcriptome analysis, we reported on its immunity against Phytophthora cinnamomi. However, little is known about the involvement of secondary metabolites in the P. purpurea defense response. It is known, though, that root exudates are toxic to this pathogen. To understand the involvement of secondary metabolites in the defense of P. purpurea, a metabolome analysis was performed using the leaves and roots of plants challenged with the pathogen for over 72 h. The putatively identified compounds were constitutively produced. Alkaloids, fatty acids, flavonoids, glucosinolates, polyketides, prenol lipids, phenylpropanoids, sterols, and terpenoids were differentially produced in these leaves and roots along the experiment timescale. It must be emphasized that the constitutive production of taurine in leaves and its increase soon after challenging suggests its role in P. purpurea immunity against the stress imposed by the oomycete. The rapid increase in secondary metabolite production by this plant species accounts for a concerted action of multiple compounds and genes on the innate protection of Phlomis purpurea against Phytophthora cinnamomi. The combination of the metabolome with the transcriptome data previously disclosed confirms the mentioned innate immunity of this plant against a devastating pathogen. It suggests its potential as an antagonist in phytopathogens' biological control. Its application in green forestry/agriculture is therefore possible.

Effects of Shrub Encroachment on Carbon Assimilation and Growth of Mediterranean Cork Oak Trees Depend on Shrub Cover Density

Mediterranean ecosystems are threatened by climate change and shrub encroachment. An increase in shrub cover can intensify the competition for water, aggravating the impacts of drought on ecosystem functioning. The effects of shrubs can be positive or negative, depending on the shrub species and density. We used a Mediterranean cork oak (Quercus suber) woodland to investigate the effects of increasing gum rockrose (Cistus ladanifer) cover on leaf carbon assimilation (Amax) and tree growth. The experiment consisted of a gradient of shrub cover, with four treatments: control, LD, MD, and HD, with 0%, 25%, 45%, and maximum shrub cover (>90%), respectively. Increasing shrub cover significantly decreased Amax in trees from HD (−15%) compared to control treatment, with intermediate effects on trees from LD (−5%) and MD (−12%). There was a large variability in tree growth, resulting in no significant effects of shrub cover, despite higher trunk diameter relative increments in LD (+40%), and lower in MD (−17%) and HD (−32%) compared to the control. The results indicate that a dense shrub cover (>90%) affected cork oak carbon assimilation and growth, while a low-to-medium shrub cover (≤45%) only induced mild intermediate effects. This information is important for the effective management of shrub density to improve the health and productivity of cork oak woodlands.

Method for detecting tree ring boundary in conifers and broadleaf trees using Mask R-CNN and linear interpolation

As tree rings can reveal various information regarding climate and environmental factors, increasing research is being conducted on them. Although tree ring analysis software such as Windendro has been applied, research on the development of analysis software using image preprocessing algorithms and deep learning is recently being attempted as computer vision technology. In this study, Mask R-CNN and linear interpolation were applied from images collected using a smartphone (SM-G973, Samsung, Suwon) and a scanner (CanoScan 9000F, Canon, Otaku) to propose an effective method for detecting tree ring boundaries. Pitch pine (Pinus rigida), Korean pine (Pinus koraiensis), white birch (Betula platyphylla), and cork oak (Quercus variabilis) were selected as tree species. Of the 300 images, 240 were classified as training data and 60 as validation data. As a result of learning, smartphones detected 86.0 % (381 ring boundaries) of the rings in pitch pine, 82.1 % (367 ring boundaries) in Korean pine, 84.7 % (309 ring boundaries) in white birch, and 78.7 % (318 ring boundaries) in cork oak. The scanner detected 93.2 % (413 ring boundaries) of the rings in pitch pine, 90.8 % (405 ring boundaries) in Korean pine, 88.2 % (322 ring boundaries) in white birch, and 89.4 % (361 ring boundaries) in cork oak. In particular, the smartphone showed satisfactory results of 84.7 % and 78.7 % for detecting tree ring boundaries of white birch and cork oak, where the boundaries of the rings were unclear. In the annual growth analysis results, both smartphones and scanners were statistically insignificant, and there was no difference compared with those of Windendro. Therefore, Mask R-CNN might be an effective approach for tree ring boundary detection as it showed satisfactory results, even with smartphones. In addition, although there was distortion in cases where images were acquired with a circular lens, there was no statistically significant difference from Windendro results. Thus, Mask R-CNN and linear interpolation can be used for tree ring boundary detection and growth measurement.