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Common mistletoe is increasingly mentioned as contributing not only to the decline of deciduous trees at roadside and in city parks, but to conifers in stands. The presence of Viscum in fir stands has been known for many years, but since 2015 has also been the cause of damage to pine. In 2019, mistletoe was observed on 77.5 thousand hectares of Scots pine stands in southern and central Poland. Drought resulting from global climate change is implicated as an important factor conducive to weakening trees and making them more susceptible to the spread of mistletoe and other pests. This paper presents an overview of the latest information on the development of this semi-parasitic plant in Poland, its impact on tree breeding traits and raw material losses, as well as current options for its prevention and eradication.

Purpose Today, the decrease in water resources in the worldwide has become an undeniable reality. In addition to climate change, wild agricultural irrigation also increases the rapid consumption of this vital source. The main purpose of this study is to evaluate the effectiveness of olive tree-OTB and pine tree biochar-PTB used for enhancing the water retention capacity of hydrogel against water scarcity stress on the arugula plant. Method The PVA/SA were used for hydrogel synthesis and 0.1%, 0.25%, 0.5%, and 1% OTB and PTB were used as additives in hydrogel. Characterization of hydrogels were carried out with SEM and FTIR analyzes. The swelling properties of hydrogels were determined gravimetrically. A 1% and 1.5% hydrogel/turf ratio was added to the pots to determine the effectiveness of hydrogels on growth parameters of arugula under the water scarcity. Results and Conclusion The results showed that biochar-doped hydrogels had higher swelling capacity than pure hydrogels. When the hydrogels achieved the equilibrium swelling capacity, the best efficiency was obtained from 1% PTB-doped hydrogel as 141.05% and 0.1% OTB-doped hydrogel as 103.60%. However, OTB-doped hydrogels faster swelled than PTB-doped hydrogels. The effects of hydrogels on growth parameters of arugula under different water scarcity were also determined. The results showed that 0.25% OTB- and 1% PTB-doped hydrogels had positive effects on plant under water scarcity. Besides that, the 1% hydrogel/turf ratio was enough for PTB-doped hydrogels for healthy plant. In summary, it was determined that it was appropriate to use pine tree biochar by doping in the hydrogels that will be applied in the fight against drought.

The pine-tree lappet moth, D. pini, is a harmful defoliator of pine forests in Europe and Asia and a potentially invasive species in North America. The lures for trapping D. pini males based on two known components of its sex pheromone appeared weakly attractive to male moths. Identification of all components of the sex pheromone might allow for the development of more effective lures. The pheromone was sampled from virgin females using SPME and analyzed using gas chromatography coupled with mass spectrometry. Four new likely components ((Z5)-dodecenal, (Z5)-dodecen-1-ol, (Z5)-decen-1-yl acetate, (Z5)-tetradecen-1-yl acetate) and two known components ((Z5,E7)-dodecadienal, (Z5,E7)-dodecadien-1-ol) were identified based on comparison against authentic standards, Kováts indices and spectra libraries. The samples also contained several sesquiterpenes. Wind tunnel and field experiments showed that some blends of synthetic pheromone components alone or enriched with Scots pine essential oil (SPEO) were attractive to D. pini males. One component—(Z5)-decen-1-yl acetate—had a repelling effect. The presented knowledge of D. pini sex pheromone provides a basis for developing optimal lures for monitoring or controlling insect populations.

Pinus densiflora (Korean red pine) is widely distributed in East Asia and considered one of the most important species in Korea. In this study, the complete chloroplast genome of P. densiflora was sequenced by combining the advantages of Oxford Nanopore MinION and Illumina MiSeq. The sequenced genome was then compared with that of a previously published conifer plastome. The chloroplast genome was found to be circular and comprised of a quadripartite structure, including 113 genes encoding 73 proteins, 36 tRNAs and 4 rRNAs. It had short inverted repeat regions and lacked ndh gene family genes, which is consistent with other Pinaceae species. The gene content of P. densiflora was found to be most similar to that of P. sylvestris. The newly attempted sequencing method could be considered an alternative method for obtaining accurate genetic information, and the chloroplast genome sequence of P. densiflora revealed in this study can be used in the phylogenetic analysis of Pinus species.

2,3‐Butanediol (2,3‐BDO) is a promising bulk chemical owing to its high potential in industrial applications. Here, we engineered Klebsiella oxytoca for the economic production of 2,3‐BDO using mixed sugars from renewable biomass. First, to improve xylose consumption, the xylose transporter gene (xylE) was integrated into the methylglyoxal synthase A (mgsA)‐coding gene loci, and the engineered CHA004 strain showed much faster consumption of xylose than wild‐type (WT) strain with 1.4‐fold increase of overall sugar consumption rate. To further improve sugar utilization, we performed adaptive laboratory evolution for 90 days. The evolved strain (CHA006) was evaluated by cultivating it in the media containing single‐ or mixed‐sugars, and it was clearly observed that CHA006 has improved sugar consumption and 2,3‐BDO production than those of the parental strain. Finally, we demonstrated the superiority of CHA006 by culturing in two lignocellulosic hydrolysates derived from sunflower or pine tree. Particularly, in the pine tree hydrolysate containing xylose, glucose, galactose, and mannose, the CHA006 strain showed much improved consumption rates for all sugars, and 2,3‐BDO productivity (0.73 g L−1 hr−1) increased by 3.2‐fold compared to WT strain. We believe that the engineered CHA006 strain can be a potential host in the development of economic bioprocess for 2,3‐BDO through efficient utilization of mixed sugars derived from lignocellulosic biomass. In the biorefinery process, lignocellulosic biomass has been an important feedstock which can provide fermentable sugars, but poor utilization of mixed sugars by microbial hosts has been a limitation. Here, through adaptive laboratory evolution, we engineered Klebsiella oxytoca that can efficiently utilize mixed sugars derived from hydrolysates of pine tree and sunflower. The engineered strain would be served as a potential cell factory to establish a more economical and sustainable bioprocess for the production of 2,3‐butanediol and other value‐added chemicals.

The use of trees for biomonitoring of mercury (Hg) and other atmospheric pollutants is of increasing importance today. Leaves from different species have been the most widely used plant organ for this purpose, but only pine bark, and not leaves, was used to monitor Hg pollution. In Almadén (South Central Spain), the largest cinnabar (HgS) deposits in the world have been mined for over 2000 years to obtain metallic Hg and this activity has caused the widespread dispersion of this toxic element in the local environment. A strip of pine trees, 2750 m in length, adjacent and to the South of the mining town has been studied in order to evaluate pine tree needles as monitors for Hg contamination in this heavily polluted area. The study involved the collection of pine tree leaves from several discrete sites along the strip, as well as samples from other nearby locations, together with soil samples and monitoring of atmospheric Hg in the area during both the day and night. Leaves and soils were analyzed for total Hg concentration by means of atomic absorption spectrometry; the leachable fraction of soil Hg was also analyzed by the CV-AFS technique. The results indicate that soils from the investigated area were not directly affected by mining related pollution, with low total Hg levels (3–280 mg kg −1 ) found in comparison with the nearby Almadén metallurgical precinct and very low leachable Hg contents (0.27–59.65 mg kg −1 ) were found. Moreover, pine tree needles have a low uptake capacity, with lower THg levels (0.03–6.68 mg kg −1 ) when compared to those of olive trees in Almadén. However, pine needles do show significant variability with regard to the distance from the source. Gaseous Hg exhibits a similar pattern, with higher levels close to the source, especially during night time (225 ng m −3 ). A multiple linear regression analysis (MLRA) revealed that gaseous Hg in the nocturnal period is the prime factor that influences the amount of Hg uptake by pine tree needles. This finding makes pine needles a promising candidate to biomonitor gaseous Hg on a local or regional scale worldwide. Almadén pine tree needles have been exposed to a number of different Hg sources, including the primary one, namely the old mine dump, and secondary sources such as polluted roads or illegal urban residual waste. The secondary sources cause some minor discrepancies in the model established by the MRLA. The biomonitoring capacity of pine needles needs to be evaluated in areas far from the source. The process involved in gaseous Hg uptake by pine needles appears more likely to involve sorption in the external part of the needle than uptake through stomas, thus making this process strongly dependent on high atmospheric Hg concentrations.

Biomonitoring studies have enormous benefits providing a fruitful and cost-efficient means of measuring environmental exposure to toxic chemicals. This study collected ambient air and pine tree components, including needles and 1-year-old and 2-year-old branches, for one year. Concentrations, potential sources and temporal variations of atmospheric polycyclic aromatic hydrocarbons (PAHs) were investigated. In general, lower concentration levels were observed in the warmer months. Ambient PAHs pose a serious public health threat and impose a need for calculating cancer risks. It was also intended to define the best tree component reflecting the ambient air PAHs. The consideration of the representative tree component minimizes the unnecessary laboratory processes and expenses in biomonitoring studies. The coefficient of divergence (COD), diagnostic ratio (DR) and principal component analysis (PCA) were employed to specify the PAH sources. As a result of the DR and PCA evaluations, the effect of the industrial area has emerged, besides the dominance of the pollutants originating from traffic and combustion. The results have shown that pine needles and branches were mainly affected by similar sources, which also influenced air concentrations. Inhalation cancer risk values were also calculated and they varied between 1.64 × 10−6 and 3.02 × 10−5. A potential risk increases in the colder season depending on the ambient air PAH concentrations.

Rainfall interception is an important process of the water cycle that can have significant influence on surface runoff and groundwater storage. Since rainfall interception measurements are rare and time consuming, rainfall interception estimation can be made indirectly using different meteorological variables. Experimental data of rainfall interception for birch and pine trees was measured at an experimental plot located in an urban area of Ljubljana, Slovenia in this study. A copula model was applied to predict the rainfall interception using meteorological variables, namely air temperature and vapour pressure deficit data. The copula model performance was compared to some other models such as decision trees, multiple linear regressions, and exponential functions. Using random sampling, we found that the copula model where Khoudraji-Liebscher copula functions were used yielded slightly smaller root mean square error (RMSE) and mean absolute error (MAE) values than other tested methods (i.e., RMSE and MAE results for birch trees were 24.2% and 18.2%, respectively and RMSE and MAE results for pine trees were 25.0% and 19.6%, respectively). The results demonstrate that the copula-based proposed method and other tested models could be used for the prediction of rainfall interception at the considered plot and in the wider surroundings. Furthermore, these models could also be applied for the prediction of rainfall interception for these two tree species in other locations under similar vegetation and meteorological conditions.

Determining physiological mechanisms and thresholds for climate-driven tree die-off could help improve global predictions of future terrestrial carbon sinks. We directly tested for the lethal threshold in hydraulic failure – an inability to move water due to drought-induced xylem embolism – in a pine sapling experiment. In a glasshouse experiment, we exposed loblolly pine (Pinus taeda) saplings (n = 83) to drought-induced water stress ranging from mild to lethal. Before rewatering to relieve drought stress, we measured native hydraulic conductivity and foliar color change. We monitored all measured individuals for survival or mortality. We found a lethal threshold at 80% loss of hydraulic conductivity – a point of hydraulic failure beyond which it is more likely trees will die, than survive, and describe mortality risk across all levels of water stress. Foliar color changes lagged behind hydraulic failure – best predicting when trees had been dead for some time, rather than when they were dying. Our direct measurement of native conductivity, while monitoring the same individuals for survival or mortality, quantifies a continuous probability of mortality risk from hydraulic failure. Predicting tree die-off events and understanding the mechanism involved requires knowledge not only of when trees are dead, but when they begin dying – having passed the point of no return.