Pinus Pinaster Ait Research Articles

Tree-ring isotopic composition reveals intraspecific variation in water use efficiency of Pinus pinaster Ait. provenances grown in common gardens

Key messageThe physiological responses expressed by variation in carbon and oxygen stable isotopes and iWUE in five provenances of maritime pine grown in four common gardens were primarily determined by genotype differences in phenotypic plasticity and secondarily by genotype.Given the impacts of climate change on forest resources and considering the slowness of evolutionary processes in trees, a need arises to understand the interplay between tree species adaptation to climate, genetic variation, and their impact on tree growth and productivity. Broadening knowledge of the capacity of tree populations to respond to climate-related disturbances is a prerequisite for the development of resilience strategies, including assisted migration and climate-smart forestry. This study tests the physiological ability of different maritime pine provenances, comparing Mediterranean (Corsica, Sardinia, and Tuscany) and Atlantic (Portugal) provenances, to adapt to progressively drier conditions that have occurred in the last thirty years. Four provenance trials with randomized blocks of the five maritime pine provenances were used as test sites in Sardinia (Italy). Wood cores were collected from the 40-year-old plants. Cores were split into five-year segments to determine provenance-related variations in carbon and oxygen stable isotopes and provide information on long-term patterns in intrinsic water use efficiency (iWUE). The provenance × site interaction was the most important source of variation, meaning that the genotypes responded differently to the planting sites. Considering the main effects, both genotype and environmental conditions at the planting sites influenced stable isotope composition in tree rings. This suggests that iWUE was determined by phenotypic plasticity that differed among genotypes. In contrast, provenance responses were stable with time, and the provenance × site interaction was stable across time periods. These findings suggest that provenance selection to improve iWUE in maritime pine may need to consider site conditions but point more to soil conditions than to climate. In any case, they limit our ability to recommend maritime pine provenances based on iWUE until the missing site factors can be identified.

Base-age invariant models for predicting individual tree accumulated annual resin yield using two tapping methods in maritime pine (Pinus pinaster Ait.) forests in north-western Spain

In southern Europe, especially in Spain and Portugal, maritime pine resin is one of the main non-timber forest products. After suffering a crisis at the end of the 20th century, it is currently a growing sector. In Spain, depending on the area, the management of pine forests is one of the pillars of the national bioeconomy. In addition to timber production, these forests may be oriented towards resin production only, or resin production as a complementary activity to timber production. In both cases, as in any sector, it is essential to have tools to manage and anticipate production, especially in the new context of the bioeconomy. For this reason, the aim of this study is to develop a dynamic model to estimate the accumulated resin yield during the resin production season. For this study, 180 trees from three plots located in the northwest of the Iberian Peninsula were resin tapped using two extraction methods (non-mechanized and mechanized circular notching) and stimulant pastes. Four base models were used from which eight equations were derived using ADA and GADA techniques. The most efficient equations, both for modelling with the train data and for prediction with the test data, were those derived from the Bertalanffy-Richards model. The RRMSE was 23% for the non-mechanised method and 29% for the mechanised circular method. The results of this study make it possible to add the cumulative annual resin yield of maritime pine to the processes that the Bertalanffy-Richards equation is capable of modelling. Furthermore, the great versatility of these models will be of great use to the forest manager in optimising the annual harvesting season as well as for the scientific community.

Pollen contamination and mating structure in maritime pine (Pinus pinaster Ait.) clonal seed orchards revealed by SNP markers

Pollen contamination and mating structure in maritime pine (Pinus pinaster Ait.) clonal seed orchards revealed by SNP markers

Resin yield response to different tapping methods and stimulant pastes in Pinus pinaster Ait

Selecting the best resin tapping method and stimulant paste in the resin tapping process is crucial. In timber-oriented rainy Atlantic pine forests of north-west Spain, the interest in resin tapping is raising but information on the best tapping methods and pastes is still lacking. In this study, an appropriate experimental design used on five representative plots of Pinus pinaster, allowed us to explore the resin productive differences between two tapping methods (traditional Spanish method and circular groove) and three stimulant treatments (control, Ethephon and ASACIF). The use of a standardized measure of resin yield allowed to adequately compare methods differing in groove length. Results indicated that the standard resin yield was 1.43 times greater with the traditional method than with the circular groove method. The two stimulant pastes drastically increased resin yield (up to sixfold) in all sites and for all tapping methods. The effectiveness of the paste was also influenced by the tapping method, obtaining greater increases in resin yield after the application of stimulant paste in trees with the circular groove method. Resin yield was only slightly related to the dasometric variables and varied among test sites when no pastes were used, but differences among sites disappeared when stimulant pastes were used. Our results contribute to the understanding of the factors involved in resin performance and the technological development of the sector.

Group selection cutting for regenerating Mediterranean Pinus pinaster plantations: Gap effects on seedling survival

Diversification of forests, both in terms of structure and species, has been identified as one of the main strategies for adapting forests to climate change. Among the different options available for managers to promote diversification, regeneration cuttings are a suitable option to meet these objectives in adult stands close to rotation ages. The regeneration of maritime pine (Pinus pinaster Ait.) stands is a major issue throughout its distribution area, with summer survival being the main bottleneck for seedling establishment and development. Group selection cutting system may be the best option to promote uneven-aged and mixed structures in shade intolerant species, such as maritime pine. Gaps generate different regeneration niches for species of contrasting shade tolerance while creating uneven-aged stands, which are potentially more resilient to the impacts of climate change.In our experiment, gaps of two different sizes (1.5 and 2.5 times the dominant height of the stand, both sizes being smaller than those proposed in literature) were opened up to test the effects on natural regeneration success in a planted 53-year-old maritime pine stand in Central Spain. There were nine gaps of each size, along with nine control plots, containing 1-m radius subplots distributed within them to record natural regeneration of maritime pine and other species, in addition to several ecological factors and seedling characteristics. A survival model was fitted to highlight the main factors driving seedling survival. Gaps were found to have a significant positive effect on seedling survival, as well as mid-shade positions within the gaps and the age of the seedlings. Summer was found to have a negative effect on seedling survival. No effect of inter-species competition (scrub or herbs), litter coverage or geomorphological characteristics (slope, aspect or altitude) was found. Our results indicate, therefore, that group selection system cuttings, even with small gap sizes (1.5 and 2.5 times the dominant height), would provide a suitable method for the regeneration of Mediterranean maritime pine plantations.

The footprint of large wildfires on the multifunctionality of fire-prone pine ecosystems is driven by the interaction of fire regime attributes

BackgroundMediterranean ecosystems dominated by Pinus pinaster Ait. (maritime pine) are subject to a shift from fuel-limited to drought-driven fire regimes, characterized by an increasing wildfire extent, recurrence, and severity. Previous studies have not addressed the interacting effects of fire recurrence and severity on the ecosystem multifunctionality (EMF) of maritime pine forests, although complex relationships between such fire regime attributes are expected. Here, we evaluated the medium-term effects of fire recurrence and severity on the EMF response of unmanaged, native pine ecosystems dominated by Pinus pinaster in the western Mediterranean Basin. We considered four key ecosystem functions computed from functional indicators (carbon regulation, decomposition, soil fertility, and plant production), which were pooled into an EMF construct. The fire regime effects on the trade-offs and synergies between the considered ecosystem functions were also analyzed.ResultsMultiple ecosystem functions responded differentially to fire recurrence and severity. Fire recurrence had a strong effect on soil fertility, decomposition, and plant production functions. No significant effects of fire severity on any of the individual functions were detected. However, both fire regime attributes interacted to determine soil fertility and decomposition functions, suggesting that their performance is only impaired by fire severity when fire recurrence is low. The differing responses to the fire regime attributes among ecosystem functions fostered a significant EMF response to fire severity and its interaction with fire recurrence, indicating that the effect of fire severity on EMF was stronger under low fire recurrence scenarios, even when relationships between individual functions and fire severity were weak. Fire recurrence caused significant trade-offs between functions to emerge. However, these trade-offs were not strong enough to differ significantly from the intrinsic trade-offs (i.e., regardless of the fire regime) of maritime pine ecosystems.ConclusionsOur results indicated the need to use an integrative approach to assess the response of ecosystem functioning to the fire regime in maritime pine ecosystems. Adaptive management responses are necessary towards the minimization of repeated burnings and the reduction of the fuel load in unmanaged maritime pine stands of the western Mediterranean Basin with similar characteristics to those analyzed in this study.

Linking the effects of nursery light and fertilization and post-transplant first summer irrigation on the field survival and growth of Pinus pinaster seedlings

Seedling size-related functional attributes of Mediterranean forest species are critical traits to be considered in nursery practices aimed at improving the survival and performance of seedlings exposed to summer drought in dryland reforestation projects. We looked at how nursery light regimes and nitrogen fertilization affected the survival and performance of Pinus pinaster Ait. under contrasting post-planting watering regimes. Seedlings grown in the nursery for 13 months were given low or high nitrogen doses and exposed to three light regimes (full sun, medium light and low light). After outplanting, half of the seedlings were watered fortnightly during the hottest months of the first summer and the other half were left unwatered. Seedling size-related variables (shoot height, basal diameter, stem volume and sturdiness quotient) were measured at the beginning and at the end of the study, and summer drought survival was checked three times. Our results showed that fertilization and the nursery light regime influenced initial seedling quality and transplant stress. Post-planting first summer watering also increased seedling survival probability. The medium-light and especially the full-sunlight regimes in the nursery decreased the probability of seedling mortality after outplanting. However, a low-light regime in the nursery negatively affected plant traits and increased the probability of post-planting seedling mortality. In comparison with low-N seedlings, high-N fertilization increased post-planting stress (evaluated in the change of sturdiness quotient after one field growth season), but did not affect survival.

Evaluating the Combined Use of the NDVI and High-Density Lidar Data to Assess the Natural Regeneration of P. pinaster after a High-Severity Fire in NW Spain

Pinus pinaster Ait. is an important timber species in NW Spain and is affected by forest fires every year. The persistence of this species after fire mainly depends on natural regeneration, which is very variable. In this study, we evaluated the combined use of the NDVI and LiDAR data for assessing P. pinaster regeneration success after fire in terms of density, cover and height. For this purpose, we selected a P. pinaster stand affected by a high-severity wildfire in October 2017. Field surveys and remotely piloted aircraft flights (with a high-density LiDAR sensor and multispectral camera) were conducted four years after the fire (October 2021). The study area is characterized as being particularly complex terrain, with a combination of pine trees and a high density of scrub and low vegetation. Field measurements were made in 16 study plots distributed over the burned area. Two different types of software and data processing methods were used to calculate the LiDAR-derived metrics. For pine variables, the LiDAR-based estimates of structural characteristics calculated with both data processing methods proved inadequate and were very poorly correlated with the field-measured data, while for shrubland the estimates proved to be more comparable to the field measurements. The inability of the laser pulses to reach the ground due to the complexity of the area/vegetation could lead to loss of information, calling into question the accuracy of LiDAR data in this type of scenario. LiDAR technology continues to expand in different areas and applications, and in forestry, future studies should focus on application in more complex terrain.

A Blind-Identification Test on Criconema annuliferum (de Man, 1921) Micoletzky, 1925 Species Complex Corroborate the Hyper-Cryptic Species Diversity Using Integrative Taxonomy.

Ring nematodes are obligate ectoparasites on crops and natural herbaceous and woody plants, and some species are of economic importance and cause damage to roots of several crops. Recent integrative taxonomical analyses recognized the existence of two cryptic species within the Criconema annuliferum morphotype in Spain. In this study, we corroborated that morphometric, morphological and a multi-locus analysis (including the ribosomal markers D2-D3 expansion segments of 28S rRNA, ITS rRNA, 18S RNA, and the mitochondrial DNA cytochrome oxidase I gene) identified a new lineage clearly separated from C. annuliferum, C. paraannuliferum and C. plesioannuliferum. The new lineage was described herein as Criconema pseudoannuliferum sp. nov., confirming that C. annuliferum species complex species complex comprises a hyper-cryptic species complex. This research analysed soil samples from the rhizosphere of maritime pine (Pinus pinaster Ait.) forests in Bermeja-Crestellina Mountain, located at the western part of Málaga province, southern Spain. The integrative taxonomical analyses revealed the occurrence of a new cryptic species identified using females, males and juveniles with detailed morphology, morphometry and molecular markers, described herein as Criconema pseudoannuliferum sp. nov. All molecular markers (D2-D3, ITS, 18S and COI) were obtained from the same individual that was also used for morphological and morphometric analyses. This research demonstrated the hidden diversity within the C. annuliferum species complex species complex can reach to four lineages under ribosomal and mitochondrial gene markers for one morphospecies group, which includes four species, viz. C. annuliferum, C. paraannuliferum, C. plesioannuliferum, and C. pseudoannuliferum sp. nov. Criconema pseudoannuliferum sp. nov. was detected in moderate soil density in two maritime pine forests (5 and 25 nematodes/500 cm3 of soil) suggesting that does not cause damage to maritime pine.

Assessing the Efficacy of Phenological Spectral Differences to Detect Invasive Alien Acacia dealbata Using Sentinel-2 Data in Southern Europe

Invasive alien plants are transforming the landscapes, threatening the most vulnerable elements of local biodiversity across the globe. The monitoring of invasive species is paramount for minimizing the impact on biodiversity. In this study, we aim to discriminate and identify the spatial extent of Acacia dealbata Link from other species using RGB-NIR Sentinel-2 data based on phenological spectral peak differences. Time series were processed using the Earth Engine platform and random forest importance was used to select the most suitable Sentinel-2 derived metrics. Thereafter, a random forest machine learning algorithm was trained to discriminate between A. dealbata and native species. A flowering period was detected in March and metrics based on the spectral difference between blooming and the pre flowering (January) or post flowering (May) months were highly suitable for A. dealbata discrimination. The best-fitted classification model shows an overall accuracy of 94%, including six Sentinel-2 derived metrics. We find that 55% of A. dealbata presences were widely widespread in patches replacing Pinus pinaster Ait. stands. This invasive alien species also creates continuous monospecific stands representing 33% of the presences. This approach demonstrates its value for detecting and mapping A. dealbata based on RGB-NIR bands and phenological peak differences between blooming and pre or post flowering months providing suitable information for an early detection of invasive species to improve sustainable forest management.

Resin-Tapping Production in Pinus pinaster Ait. Stands in Galicia (NW Spain): Effects of Location, Number of Faces, Wound Width and Production Year

Resin or gum is secreted by conifers, mainly members of the genus Pinus, in response to physical and/or chemical stimulation, which can be induced by tapping live trees, i.e., by making repeated wounds in the trees. Resin production could potentially complement timber production (the main economic activity) in pine stands in Galicia (NW Spain). In addition, the particular characteristics of Galician woodlands (smallholdings, sloping land, presence of shrubs, high density of trees) imply different yields and costs than in pine stands dedicated to resin production in other parts of Spain. Therefore, a specific regional management model that is different from the traditional model established for other resin producing areas in the Iberian Peninsula is required. In this study, resin tapping was applied in each of the three years before the trees were felled, in two different locations, with one or two faces tapped and wounds of two different widths (12 and 16 cm) made across the face(s). Tapping two faces yielded more resin than tapping a single face, thus confirming the study hypothesis. When only one face was tapped, the plot location acquired greater importance, with production being higher in the location characterised by a higher mean annual temperature. Increasing the width of the wound did not always increase the amount of resin obtained per tree, which depended on the number of faces open: when two faces were tapped, increasing the width of the wound increased resin production in both locations in each of the three years of the trial. The weather conditions in each year masked the effect of the tapping season, and production did not follow any particular trend over time. The importance of the local weather conditions in the study areas and the environmental conditions in each year are discussed. The study findings are important for decision-making regarding the treatment and selection of areas for resin extraction.

Diversity and enrichment of breeding material for resilience in European forests

Delivering material selected for breeding purposes into the wild in the context of sustainable forest management might reduce the levels of genetic diversity of future forests in comparison to that of natural populations. Another consequence might be a reduction of their resilience under uncertain future climatic and socio-economic conditions if these new populations lack adaptability. Despite the long tradition of breeding activities in Europe, there is still a need to assess the impact of genetically enriched material on forests’ resilience. In this study, we address (1) the genetic diversity of selected material compared to its wild ancestors, and (2) how to enrich breeding material to support forests’ resilience under changing socio-environmental conditions. We analysed 16 study cases of selected material delivered from breeding activities in four European forest tree species (Pinus halepensis Mill., Pinus nigra J.F. Arnold, Pinus pinaster Ait. and Populus nigra L.) with different levels of breeding. To answer these two questions, we first assessed and compared the genetic diversity of selected material versus natural populations using both putatively neutral and adaptive (based on diverging selection) Single Nucleotide Polymorphisms (SNPs). We then suggest how to enrich these populations for resilience under future climatic conditions by defining a core collection for each species including material from populations that will likely disappear under future conditions. Thanks to the large SNP datasets available for our focal species, we were able to detect some trends in our data. Expected and observed heterozygosity values for selected populations were almost always identical. The selected material showed small but significant genetic differentiation from their original population and their inbreeding coefficient was generally lower. However, the level of genetic improvement (i.e. low vs high) was not correlated with the observed genetic differences between selected material and natural populations.The genetic characterization of natural populations distributed across the species range, and the future projection of their range stability, made it possible to identify core-collections that would significantly enrich breeding populations under uncertain future environmental conditions.

Soil biogeochemistry and microbial community dynamics in Pinus pinaster Ait. forests subjected to increased fire frequency

Fire frequency might increase in many fire-dominated ecosystems of the world due to the combined effects of global warming, land-use change and increased human pressures. Understanding how changes in fire frequency can affect the main soil biogeochemical dynamics, as well as the microbial community, in the long term is utmost important. Here we determined the effect of changes in fire frequency and other fire history characteristics on soil C and N dynamics and the main microbial groups (using soil fatty acid profiles), in Pinus pinaster forests from central Spain. Stands were chosen to differ in the number of fires (1 to 3) occurred between 1976 and 2018, in the time elapsed since the last fire and the interval undergone between the last two consecutive fires. We found that, in general, most of the studied biogeochemical and microbial variables showed clear differences between unburned and burned stands. The time elapsed since the last fire was the most important fire history covariable and governed the main soil nutrient dynamics and microbial groups. Recovery to pre-fire values took 30–40 years. Increased wildfire frequency only modified total C and nitrification rate, but results were not consistent between stands burned twice and thrice. The time interval (years) between the last two fires was not a significant covariable. The fact that some stands burnt up to thrice in a period of 43 years supports the strong capacity of this ecosystem to recover, even under an increased fire frequency.

On the inverse identification of wood elastic properties using a DIC-based FEMU approach

PurposeThis work aims to identify the linear elastic orthotropic material paramters of Pinus pinaster Ait. wood, using full-field measurements and an inverse identification strategy based on the finite element (FE) method updating technique.Design/methodology/approachCompression tests are carried out under uniaxial and quasi-static loading conditions on wood specimens oriented on the radial-tangential (RT) plane, with different grain orientations. Full-field displacements and strains are measured using digital image correlation (DIC), which are then used as a reference in the identification procedure. A FE model is implemented assuming plane stress conditions, where wood is modelled as an orthotropic homogeneous material. Based on the numerical results, a synthetic image reconstruction scheme is implemented to synthetically deform the reference experimental image, which is then processed by DIC and further compared to the experimental results.FindingsThe results for both approaches were similar when both specimen configurations were used in a single run. However, when using the DIC-based FEMU approach with the on-axis configuration, the identified modulus of elasticity in the tangential direction and shear modulus are closer to the reference values.Originality/valueThis approach ensures a fair comparison between both sets of data since the full-field strain maps are obtained through the same filter and therefore have the same strain formulation, spatial resolution and data filtering. Firstly, the identification is performed using a single configuration, either the on-axis or the off-axis specimen. Secondly, the identification is carried out by merging data from both on-axis and off-axis configurations.

Local environment prevails over population variations in growth-climate relationships of Pinus pinaster provenances

In view of the projected decrease in precipitation and increase in temperature, a better understanding on growth-climate responses in different populations of tree species is needed to improve and enhance the conservation and management strategies for major forest tree species. In this study, we assessed differences in growth traits (i.e., stem diameter, tree height, and stem radial growth) and analysed climate-growth relationships in five provenances of maritime pine (Pinus pinaster Ait.) grown in four replicated common gardens in Sardinia (Italy). Stem radial growth increased under a positive water balance in late winter and early spring. Conversely, high temperature and low precipitation in summer had a negative impact on stem radial growth. At age 40, none of the considered provenances (Portugal, Corsica, Tuscany, Sardinia-Telti, Sardinia-Limbara) showed a substantial advantage in more than one common garden site for tree height and stem diameter. Nevertheless, differences were found among common garden sites in terms of dendrometric parameters, stem radial growth, and growth-climate responses (including sensitivity to summer drought), suggesting a greater site dependent over tree growth. Although in juvenile stages the Portuguese provenance (in particular) showed greater growth than the Sardinian ones, this study showed that, with tree age, the differences among the five provenances tends to narrow. Therefore, irrespective of the seed source, tree growth patterns and growth-climate responses were similar at age 40. This result can be important for implementing forest management strategies to balance adaptation and mitigation potential of maritime pine plantations in harsh environmental conditions.

Chemical composition and industrial applications of Maritime pine (Pinus pinaster Ait.) bark and other non-wood parts

Maritime pine (Pinus pinaster Ait.) is native to the western Mediterranean basin and has an economic importance in southwestern Europe. This importance is based on the use of its wood in the construction, furniture, and paper industries. Bark and other parts of the plant, such as resin, needles, and cones, are by-products with potential industrial application. These parts of the tree stand out because of the presence of secondary metabolites, the main ones being phenolic compounds and terpenes. Bark contains both, while other parts of the plant are mainly composed of terpenes. All these compounds have biological potential, mainly antioxidant and antimicrobial properties. The bark has the widest range of industrial applications, and it can be used to obtain dietary supplements and functional foods, adsorbents, and bio-based resins and foams. Resin has a prominent industrial role too, especially in chemical industry. In this manuscript, an overview of these applications is described, opening an innovation opportunity for enterprises to use the by-products and residue of maritime pine. Still, albeit the described application, maritime pine has further applications that are right now being studied under the premises of circular economy.

Identification of Orthotropic Elastic Properties of Wood by a Synthetic Image Approach Based on Digital Image Correlation.

This work aims to determine the orthotropic linear elastic constitutive parameters of Pinus pinaster Ait. wood from a single uniaxial compressive experimental test, under quasi-static loading conditions, based on two different specimen configurations: (a) on-axis rectangular specimens oriented on the radial-tangential plane, (b) off-axis specimens with a grain angle of about 60° (radial-tangential plane). Using digital image correlation (DIC), full-field displacement and strain maps are obtained and used to identify the four orthotropic elastic parameters using the finite element model updating (FEMU) technique. Based on the FE data, a synthetic image reconstruction approach is proposed by coupling the inverse identification method with synthetically deformed images, which are then processed by DIC and compared with the experimental results. The proposed methodology is first validated by employing a DIC-levelled FEA reference in the identification procedure. The impact of the DIC setting parameters on the identification results is systematically investigated. This influence appears to be stronger when the parameter is less sensitive to the experimental setup used. When using on-axis specimen configuration, three orthotropic parameters of Pinus pinaster (, and ) are correctly identified, while the shear modulus () is robustly identified when using off-axis specimen configuration.

Chemical Characterisation, Antioxidant and Antibacterial Activities of Pinus pinaster Ait. and Pinus pinea L. Bark Polar Extracts: Prospecting Forestry By-Products as Renewable Sources of Bioactive Compounds

Agroforestry by-products have gained rising attention in recent years as they represent inexpensive and abundant raw materials that are a source of added-value chemicals, e.g., for food and pharmaceutical applications, as well as for bioenergy generation. Pinus pinaster Ait. bark extracts are consumed worldwide for their cardiovascular benefits, whilst the health potential of Pinus pinea L. bark has not yet been deeply exploited. Therefore, this study highlights the chemical characterisation of Portuguese P. pinaster Ait. and P. pinea L. bark polar extracts, via ultra-high performance liquid chromatography-diode array detection-tandem mass spectrometry (UHPLC-DAD-MSn) analysis, and their antioxidant and antibacterial activities. Quinic acid, an A-type procyanidin dimer isomer, protocatechuic acid, and quercetin were identified for the first time as P. pinea L. bark components. Moreover, this bark demonstrated a higher total content of identified polar compounds than P. pinaster Ait. bark, with quinic acid being the most abundant compound identified. Regarding antioxidant activity, the pine bark polar extracts exhibited strong reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) radical scavenging effects compared to natural antioxidants. Moreover, the bactericidal actions of pine bark extracts were shown against Staphylococcus aureus and Escherichia coli at a 3.13–25 mg mL−1 range. Globally, these promising insights can boost the sustainable exploitation of P. pinea L. bark, as already occurs with P. pinaster Ait. bark, for the food and biomedical fields.

Effects of site preparation and postplanting cultural treatments on the establishment and early growth of maritime pine (Pinus pinaster Ait.)

Maritime pine (Pinus pinaster Ait.) is a fast-growing pine species of the western Mediterranean Basin with important ecological (e.g., site restoration), economic (e.g., wood production), and social (e.g., recreation) values. Due to global climate change, the growing incidence of drought and wildfires challenges the distribution and growth of maritime pine. Mechanical site preparation (SP) either alone or integrated with chemical weed control can enhance site conditions for conifer seedlings, specifically by improving the physical and chemical condition of the soil and eliminating weeds. The study was established in the eastern Marmara Region of Turkey and included various SP techniques and cultural treatments (CT) of differing intensity applied in a factorial design before the plantation of one-year-old maritime pine seedlings. The SP treatments included raking by a bulldozer (SPB), raking by a bulldozer and then spraying with 1%-(v:v) glyphosate (SPH), and raking by a bulldozer followed by the broadcasting of the subsoil via bulldozer (SPS), the latter being the standard and the most intensive forest management SP treatment. The CT included various combinations of hoeing and foliar applications of glyphosate after planting. The SPH treatment was the overall best SP treatment in terms of seedling performance and physical and chemical soil properties at one and two YAT. The most intensive treatment (SPS) resulted in significantly reduced seedling growth, survival, and deterioration of physical and chemical soil properties, especially soil organic matter and nutrients. Hoeing in a 1-m radius around seedlings one year after planting (i.e. once during the experiment) (H1) significantly improved seedling survival and vigor compared to the control (H0). No additional gain in seedling survival or growth occurred with more intensive CT combinations. In summary, hoeing at the end of the first summer (H1) following the SPH is recommended for enhanced early seedling performance and soil productivity.

Genetic variation in height, diameter and second flushing in four-year old maritime pine progeny tests in Türkiye

Abstract A maritime pine (Pinus pinaster Ait.) breeding program was initiated in Türkiye by selecting plus trees from plantations across the country. Quantifying genetic variation in growth traits is essential for this program. Four-year old trees from 140 open-pollinated maritime pine families were assessed for height (HT), root collar diameter (D) and number of shoots in the fourth growing season (S) in three progeny test plantations (Kefken, Gebze and Çatalca) in northwest Türkiye. Growth was greater in Kefken, followed by Gebze and Çatalca. Both individual tree (h i 2) and family mean (h f 2) heritability estimates were greatest for HT (h i 2=0.22 and h f 2 =0.77) followed by D (0.16 and 0.59) and S (0.08 and 0.45). While genetic correlation between HT and D was strong (r A =0.72), S was correlated moderately with HT (0.56) and weakly with D (0.11). Genotype × environment interaction was significant only for D. While modest genetic gains (up to 15.20 % over the average of family means) from selections at age four seem possible for growth, changes in patterns of genetic variation and interrelationships among the traits as the trees age remains to be explored in the future.