Thuja Research Articles

Unveiling the Dynamics of Canopy Transpiration: A Novel Model Integrating Stomatal and Aerodynamic Resistance in Semi-Humid Forests

Canopy–atmospheric water vapor output resistance (gs) is a key parameter in researching forest canopy transpiration. It is important for quantifying the water vapor exchange in forest ecosystems. However, the method by which gs is determined has been controversial, and it cannot precisely represent water vapor exchange. This study aimed to develop a model to quantify the water vapor resistance between the canopy and the atmosphere in Platycladus orientalis (P. orientalis) forests using sap flow and meteorological factors monitoring data. The resistance model was constructed using the relationship between canopy stomatal resistance (gc) and aerodynamic resistance (ga) from the mechanism perspective, and sap flow data and measurements of meteorological variables were used to model the stomatal and aerodynamic resistance of the canopy. The results indicate that the canopy-atmospheric water vapor output resistance was closer to the measured values and showed a unimodal curve in the diurnal scale, and this change could provide more accurate measurements of tree transpiration. At the same time, the canopy-atmospheric water vapor output resistance was strongly influenced by wind speed and PAR when 0.2 m/s < u < 0.4 m/s (R2 = 0.871, p < 0.01). The stomatal and aerodynamic resistance were also both strongly influenced by wind speed, with the proposed model achieving a high degree of fit (R2 = 0.949, p < 0.01), providing a new tool for analyzing forest transpiration. This research provides a new perspective and technical reference for clarifying the mechanism of forest canopy water output.

Larvicidal and adulticidal activity of irradiated Thuja orientalis essential oil by gamma radiation for controlling Culex pipiens

Larvicidal and adulticidal activity of irradiated Thuja orientalis essential oil by gamma radiation for controlling Culex pipiens

Chemical Constituents, Antioxidant, and Enzyme Inhibitory Potentials Supported by In-Silico Studies of the n-Hexane Extract and Essential Oil of Platycladus orientalis (L.) Franco Leaves.

Platycladus orientalis leaves are widely used in traditional medicine to treat different ailments. In the present study, the volatile constituents were obtained by n-hexane extraction and hydrodistillation. Comprehensive metabolomic profiling was performed using GC-MS analysis. Furthermore, in vitro antioxidant potential and enzyme-inhibitory activity were assessed and supported by in silico profiling. Results revealed the predominance of monoterpene hydrocarbons in the hydrodistilled volatile oil (42.30%) followed by oxygenated sesquiterpenes (32.10%); with cedrol as the main component. Diterpenoids (49.70%) and sesquiterpene hydrocarbons (13.43%) were the major components of the n-hexane extract; with vulgarol A, a diterpene alcohol, as the major constituent. The volatile oil demonstrated significantly higher antioxidant potential across all assays, including ABTS and DDPH scavenging activity, CUPRAC, and FRAP assays. However, the n-hexane extract demonstrated broad inhibitory effects against butyrylcholinesterase, tyrosinase, α-amylase, and α-glucosidase enzymes, supported by molecular docking study and predictive ADME profiling. Therefore, it may be concluded that the n-hexane extract is a viable option for treating dysregulated enzyme conditions. In addition, the potential use of volatile oil in the pharmaceutical industries and management of oxidative stress can be inferred. These results warrant further studies to validate the therapeutic potential of the volatile oil and the n-hexane extract.

Antibacterial and antifungal activities of Platycladus orientalis leaf extract-mediated Fe2O3 and Ce-doped Fe2O3 nanoparticles

Green synthesis of nanomaterials harnesses naturally occurring materials, including plant extracts, to offer environmentally friendly alternatives to conventional biomedicine, agriculture, and other field applications. This study explores the green route to Fe2O3 and cerium-doped Fe2O3 (Ce-doped Fe2O3) nanoparticles synthesized for the first time using the leaf extract of Platycladus orientalis. The synthesized nanoparticles were characterized for their structural, morphological, chemical, and optical properties. The hematite phase of Fe2O3 nanoparticles with spherical morphology was obtained. The introduction of Ce as a dopant into Fe2O3 increased the lattice strain of Ce-doped Fe2O3 nanoparticles (0.51%) compared to pristine Fe2O3 (0.46%) even though the size of both nanomaterials was similar. Compared to pristine Fe2O3 nanoparticles, Ce-doped Fe2O3 nanoparticles also demonstrated enhanced antimicrobial and antifungal activities against Escherichia coli, Enterococcus faecalis, Listeria monocytogenes, Penicillium chrysogenum, Aspergillus niger, and Mucor mucedo. The green-synthesized Ce-doped Fe2O3 nanoparticles possess potential for application in biomedical and environmental fields based on their relevance to human health and food safety, diversity in microbial characteristics, and potential for resistance to conventional treatments.

Platycladus orientalis Leaf Extract Promotes Hair Growth via Non-Receptor Tyrosine Kinase ACK1 Activation.

Platycladus orientalis is a traditional oriental herbal medicinal plant that is widely used as a component of complex prescriptions for alopecia treatment in Eastern Asia. The effect of PO on hair growth and its underlying mechanism, however, have not been demonstrated or clarified. In this study, we investigated the hair-growth-promoting effect of PO in cultured human dermal papilla cells (hDPCs). Platycladus orientalis leaf extract (POLE) was found to stimulate the proliferation of hDPCs. POLE with higher quercitrin concentration, especially, showed a high level of cellular viability. In the context of cellular senescence, POLE decreased the expression of p16 (CDKN2A) and p21(CDKN1A), which resulted in enhanced proliferation. In addition, growth factor receptors, FGFR1 and VEGFR2/3, and non-receptor tyrosine kinases, ACK1 and HCK, were significantly activated. In addition, LEF1, a transcription factor of Wnt/β-catenin signaling, was enhanced, but DKK1, an inhibitor of Wnt/β-catenin signaling, was downregulated by POLE treatment in cultured hDPCs. As a consequence, the expression of growth factors such as bFGF, KGF, and VEGF were also increased by POLE. We further investigated the hair-growth-promoting effect of topically administered POLE over a 12-week period. Our data suggest that POLE could support terminal hair growth by stimulating proliferation of DPCs and that enhanced production of growth factors, especially KGF, occurred as a result of tyrosine kinase ACK1 activation.

Influence of soil organic carbon fractions on the soil priming effect under different vegetation restoration modes

AbstractThe soil priming effect is a key mechanism influencing carbon (C) cycling processes between the forest soil organic carbon (SOC) pool and the atmosphere. Different vegetation restoration modes have different SOC pool compositions, and it is not clear whether such differences affect the soil priming effect. Therefore, we selected soil from six typical vegetation restoration modes Platycladus orientalis (PO), Pinus sylvestris (PS), Quercus acutissima (QA), shrub (SH) and wasteland (WL) in the soil and rocky mountainous areas of northern China and measured the soil properties, microbial communities, microbial necromass carbon (MNC), SOC fractions and the soil priming effect. The SOC content decreased in the order of PO (21.33 g kg−1), PS (22.00 g kg−1), QA (13.67 g kg−1), SH (13.33 g kg−1) and WL (10.33 g kg−1), and the trends of the mineral‐associated organic carbon (MAOC) and fungal necromass carbon (FNC) content were the same as those of the SOC content. The soil priming effect was greater in both forests and shrublands than in wastelands, with the greatest effect occurring in PO forests, where the soil priming effect reached 159.91 mg CO2‐C kg−1 soil after 30 days of incubation, which was 1.4 times greater than that in WL. The soil priming effect was mainly determined by the difference in MAOC content. In addition, the soil C/N ratio and bacterial community diversity also indirectly affected the soil priming effect by influencing the soil MNC and SOC fractions. Overall, afforestation increased the SOC content, fungal necromass contribution and mineral conservation, increasing the soil priming effect. This theoretical foundation supports the enhancement of SOC sequestration capacity by implementing various modes of vegetation restoration in the future.

Soil Carbon Accumulation Under Afforestation Is Driven by Contrasting Responses of Particulate and Mineral‐Associated Organic Carbon

AbstractAfforestation is widely believed to sequester carbon (C) in soil. However, the effect of afforestation on soil organic C (SOC) accumulation is still debated due to the contrasting features of particulate and mineral‐associated organic C (POC and MAOC). We conducted a field investigation of 144 paired sampling sites by comparing afforested and non‐afforested lands to investigate the POC and MAOC dynamics after afforestation across the Danjiangkou basin in subtropical China, where forests are dominated by Platycladus orientalis, Quercus variabilis and Pinus massoniana. The average contents of SOC, POC, and MAOC were significantly increased by afforestation; however, POC and MAOC responded differently to afforestation type. All afforestation types promoted the POC content, and MAOC also showed positive responses to afforestation except that afforestation with P. massoniana from shrubland significantly reduced the MAOC content. With increasing SOC content, the POC grew at a faster rate than MAOC at high SOC levels. Afforestation hindered the growth rate of POC, while it promoted the growth rate of MAOC as SOC accrued, which potentially obscured the distinct patterns of C accumulation triggered by afforestation. The variation partitioning suggests that, under afforestation, microbial traits had a higher contribution to both POC and MAOM variations compared with non‐afforested land. These results suggest that the robust buildup of microbial biomass due to increased plant C input following afforestation could contribute to soil C accumulation by promoting microbial necromass.

Effects of plantations on rainfall redistribution in a rocky mountain area of North China

AbstractRainfall redistribution plays a crucial role in the water cycle. However, the main factors affecting the redistribution of rainfall remain uncertain. We chose three different plantations—cork oak (Quercus variabilis Bl.), oriental arborvitae (Platycladus orientalis L.) and black locust (Robinia pseudoacacia L.)—to investigate the role of plantations in rainfall redistribution and to determine the main factors influencing rainfall redistribution. The results indicated that cork oak exhibited the highest stemflow (0.34%) and the lowest canopy interception (12.58%), whereas black locust had the lowest stemflow (0.21%), and oriental arborvitae displayed the greatest canopy interception (32.8%). Under different density conditions for cork oaks, the stemflow was highest (0.39%) in low‐density forests with 750 trees ha−2 and lowest (0.34%) in medium‐density forests with 1100 trees ha−2. Meanwhile, the highest canopy interception (17.68%) was observed in high‐density forests (1300 trees ha−2), while the lowest interception rate (9.22%) was found in low‐density forests. The main factors affecting rainfall redistribution and their contribution rates were as follows: bark roughness index (35%), wind speed (18.6%), tree species (14.2%), diameter at breast height (11.2%), stand density (9.6%) and rainfall amount (5.4%). Our findings suggested that structural characteristics of trees are the primary factors affecting rainfall redistribution. Planting cork oak in the rocky mountain regions of North China is recommended because of its substantial stemflow production, particularly under low‐density growth conditions. Therefore, this study has significant guiding implications for the selection of afforestation tree species in similar rocky mountain areas globally.

Characteristics of forest understory herbaceous vegetation and its influencing factors in biodiversity hotspots in China

Forest ecosystems, especially within biodiversity hotspots, heavily rely on the often-overlooked understory herbaceous communities (USHC) for their structural integrity and ecological functions. Because of their modest stature, these communities have garnered insufficient attention from researchers. Therefore, in this study attention is focused on USHC, which attempts to fill this research gap. To achieve this, we established 105 sample plots in 2022 within forest ecosystems situated in the biodiversity hotspot of southwest China. Our investigation unveiled a rich biodiversity tapestry, identifying 424 plant species from 108 families and 284 genera. Notable were the 217 herbaceous species identified in the understory layer, representing 67 families and 163 genera. These understory herbaceous species accounted for 51.2 % of the overall species count. Through a detailed analysis, the sample plots were categorized into eight distinct communities using a two-way indicator species analysis. These communities exhibited diverse variations in species composition, diversity, biomass, and nutrient characteristics. Notably, community I (Eucalyptus robusta Smith + Rubus corchorifolius L. f. + Alternanthera philoxeroides (Mart.) Griseb.), V (Camptotheca acuminata Decne + Rubus parkeri Hance + Iris tectorum Maxim), VIII (Platycladus orientalis (L.) Franco + Viburnum dilatatum Thunb. + Cyclosorus interruptus (Willd.) H. Ito) stood out for their exceptional species diversity and productivity. Moreover, correlation analyses highlighted the substantial impact of topographic and soil factors on USHC. Altitude, soil water content, and total carbon content emerged as the primary determinants of species diversity. Biomass demonstrated close associations with total soil carbon and nitrogen. Furthermore, the nutrient characteristics displayed significant correlations with soil nutrient contents. These findings underscore the critical importance of prioritizing USHC attention in forest conservation and management strategies within biodiversity hotspots. The implications strongly advocate for the inclusion of these communities in planning and decision-making processes, emphasizing their pivotal role in maintaining structural and functional diversity in ecosystems.

Characteristics of deep soil layer water deficit under different artificial vegetation types of the Loess Plateau, China

AbstractSoil water is a crucial factor for the growth of vegetation and sustainable development in water‐limited areas. After large‐scale vegetation restoration on the Chinese Loess Plateau, understanding the relationship between vegetation and deep soil moisture has become a crucial focus in current research. In this study, artificial forest (Pinus tabulaeformis [PT], Robinia pseudoacacia [RP] and Platycladus orientalis [PO]), apple orchard (AO), secondary forest (SF) and farmland (FL) were selected as the research objects, and grassland (GL) as the control, using soil‐drilling techniques. We systematically monitored the soil water content of 0–10 m soil layer over two hydrological years, and explored the effects of different vegetation types on soil water deficiency. The results showed that: (1) The deep soil water various significantly among different vegetation types. Compared with GL, the soil water content in all forest land was generally lower, and this difference became more pronounced in deeper soil layer (>7 m), which indicating the depth of the influence of vegetation on soil water has reached 10 m. (2) The mean soil water deficit size (SWDS) values of PT (0.14), RP (0.17), PO (0.07), AO (0.15), SF (0.10) and FL (0.27) in 0–1 m were all positive, indicating that surface soil water had accumulated during more than half of the sampling periods. In the 2–10 m soil layer, mean SWDS was negative in all vegetation types except in FL, leading to soil desiccation. SWDS was found to fluctuate with soil depth. (3) SWDS was affected by a combination of soil properties and vegetation growth. Our results indicate that the current afforestation model could lead to the deficiency of deep soil water. Therefore, it is imperative to make reasonable vegetation structure according to the available local soil and water resources in future vegetation allocation and management.

Increased soil bacteria-fungus interactions promote soil nutrient availability, plant growth, and coexistence

Tree species and interkingdom relationships in the belowground metacommunity are key factors in determining soil microbial diversity and community composition. However, how bacterial-fungal interactions mediate soil nutrient and plant growth remains largely unexplored in the coniferous forests. Here, we selected three types of naturally growing coniferous forests on the Loess Plateau—pure stands of Platycladus orientalis, mixed stands of Platycladus orientalis and Pinus tabuliformis, and pure stands of Pinus tabuliformis—to compare the differences in soil properties, microbial diversity and community composition, soil enzymatic activity, and plant growth conditions across these stand types. We found that tree species mixing significantly alters soil microbial community diversity and composition, increasing the positive associations between bacteria and fungi. Compared to pure stands, mixed stands exhibit significantly higher bacterial diversity, whereas fungal diversity shows no significant difference. Additionally, available soil nutrients (ammonium nitrogen and available phosphorus) are significantly increased in mixed stands, along with their associated soil enzymatic activities. The partial least squares path model suggests that higher bacterial diversity enhances bacterial-fungal positive interactions, increasing the relative abundance of ectomycorrhizal fungi and the decomposition rate of organic matter in mixed stands, thereby boosting soil nutrient availability and plant growth. These results highlight the importance of positive bacterial-fungal associations for soil nutrient availability and plant growth, deepen the understanding of the role of soil microbial interactions in mediating plant species coexistence. Most importantly, our results implied a stable coexistence of the pioneer P. orientalis and the late successional species P. tabuliformis in the Loess Plateau region and provided a microbiological interpretation.

Antibacterial and Antibiofilm potential of Thuja orientalis L. extract targeting cariogenic Enterococcus faecalis ATCC 29212: A combined in-vitro, in-silico study, and cytotoxicity screening

ObjectivesIn this study, we explored the efficacy of methanolic extract of Thuja orientalis (TOME) as a novel antibacterial and antibiofilm agent against a cariogenic bacterium, Enterococcus faecalis ATCC 29212. DesignAntibacterial susceptibility studies were conducted and surface morphology analysis was performed using field emission scanning electron microscopy (FESEM). Antibiofilm activity was evaluated through both qualitative and quantitative biofilm inhibition assays and validated by microscopic analysis. In-silico molecular docking studies were conducted using the EDock server. The effectiveness of TOME was substantiated by biofilm model on dentin discs and cytotoxicity towards the HaCaT cell line was assessed using the MTT assay. ResultsTOME exhibited significant bactericidal activity with minimum inhibitory concentration of 12.5mg/mL and additionally, it effectively compromised bacterial cell wall integrity. Qualitative, quantitative and microscopic studies depicted the inhibition of biofilm formation. TOME significantly impacted the production of extracellular polymeric substance and extracellular DNA. Molecular docking studies identified beta-caryophyllene as a potent inhibitor of the Enterococcal surface protein (Esp). Biofilm model depicted the reduction of bacterial load on dentin discs. Additionally, TOME showed reduced cytotoxicity on HaCaT cells, indicating its potential as a safe therapeutic agent. ConclusionThese findings highlight TOME's promise for developing novel treatments for dental infections and biofilm-associated diseases. Further research should focus on isolating and characterizing the active compounds within TOME, particularly beta-caryophyllene, to elucidate their precise mechanisms of action.

Nothophoma spp. causing leaf blight of ancient Platycladus orientalis

Ancient Platycladus orientalis holds significant ecological, landscape, historical, and cultural value. In northern China, leaf blight has significantly impacted the growth and ornamental value of ancient P. orientalis. In this study, 26 blight leaf samples of ancient P. orientalis were collected in Beijing, China. Phylogenetic analysis based on the concatenated internal transcribed spacer (ITS), β-tubulin (tub2), and RNA polymerase second largest subunit (rpb2) DNA sequence data combined with fungal morphological characteristics revealed three taxa of Nothophoma, i.e. N. platycladus, N. spiraeae, and N. juglandis. Of which, N. platycladus is a species new to science. Koch’s postulates indicated that all these three species of Nothophoma could cause leaf blight of P. orientalis.

Response of Fuel Characteristics, Potential Fire Behavior, and Understory Vegetation Diversity to Thinning in Platycladus orientalis Forest in Beijing, China

Objective: Active fuel management operations, such as thinning, can minimize extreme wildfire conditions while preserving ecosystem services, including maintaining understory vegetation diversity. However, the appropriate thinning intensity for balancing the above two objectives has not been sufficiently studied. Methods: This study was conducted to assess the impact of various thinning intensities (light thinning, LT, 15%; moderate thinning, MT, 35%; heavy thinning, HT, 50%; and control treatment, CK) on fuel characteristics, potential fire behavior, and understory vegetation biodiversity in Platycladus orientalis forest in Beijing using a combination of field measurements and fire behavior simulations (BehavePlus 6.0.0). Results: A significant reduction in surface and canopy fuel loads with increasing thinning intensity, notably reducing CBD to below 0.1 kg/m3 under moderate thinning, effectively prevented the occurrence of active crown fires, even under extreme weather conditions. Additionally, moderate thinning enhanced understory species diversity, yielding the highest species diversity index compared to other treatments. Conclusions: These findings suggest that moderate thinning (35%) offers an optimal balance, substantially reducing the occurrence of active crown fires while promoting biodiversity. Therefore, it is recommended to carry out moderate thinning in the study area. Forest managers can leverage this information to devise technical strategies that simultaneously meet fire prevention objectives and enhance understory vegetation species diversity in areas suitable for thinning-only treatments.

Exacerbated Tree Growth Decline of an Old Platycladus orientalis Forest after Rapid Warming at the Northern Edge of the Taihang Mountain of China

Old trees are irreplaceable conservation resources with numerous ecological and socio-cultural values. While many forests have experienced significant declines under recent climate warming, the risk of growth declines in old trees remains unknown. Here, we tackle this problem by dendrochronological studies of 30 old trees in a Platycladus orientalis forest at the northern boundary of the Taihang Mountain of China. We examined annual growth trajectories of trees at individual level and discovered four severe growth decline events over the last 150 years, including the periods of 1894–1899, 1913–1919, 1964–1967 and 2004–2018. The most recent growth decline event lasted for 15-year and involced 50% to 75% of the old trees. This decline was unprecedented in both its extent and duration. Furthermore, the growth–climate relationship of these old trees has changed since 1990. Before 1990, tree growth was significantly correlated with minimum winter; after 1990, tree growth became significantly correlated with the self-calibrating Palmer Drought Index. These results suggest that warming-induced droughts after 1990 could be the primary driver of the recent growth decline. If climate warming continues and drought stresses intensify, the old trees may face an increased risk of growth decline and even mortality.

Detoxification Mechanism of Hinokitiol by Alternaria alternata and Its Application in Agricultural Antifungal Control.

Alternaria alternata is a common plant pathogen that can infect crops and reduce their production. In this work, an antagonism experiment between A. alternata and the essential oil of arborvitae (Platycladus orientalis) was performed, and it was proven that A. alternata had developed resistance to this plant-derived fungicide. A. alternata facilitated the biotransformation of hinokitiol (1), the main antifungal compound in the essential oil of arborvitae, into (R)-2-hydroxy-β-methylbenzeneethanol (2), which does not have antifungal activity against A. alternata. This biotransformation is an unusual ring-contraction reaction that was verified to be catalyzed by P450 enzyme hydroxylation and Baeyer-Villiger oxidation. In addition, the P450 enzyme inhibitors 1-aminobenzotriazole and piperonyl butoxide effectively prevented the destruction of the hinokitiol structure by A. alternata, and the combined use of these P450 enzyme inhibitors significantly increased the antifungal activity of hinokitiol. This work provides a theoretical reference for the further development of botanical fungicides.

Investigation into the hydrogen inhibition mechanism of Platycladus orientalis leaf extract as a biodegradation inhibitor for waste aluminum-silicon alloy dust in wet dust collectors

This study investigates the risk of hydrogen explosion caused by waste metal dust encountering water in wet dust collectors. It proposes using renewable plant extracts to suppress hydrogen evolution from aluminum-silicon (Al-Si) alloy dust, aiming to achieve intrinsically safer production. Platycladus orientalis leaf extract (POLE) was prepared using water as a solvent. Hydrogen inhibition experiments, material characterization, and theoretical calculations were conducted to evaluate the effect of POLE on waste Al-Si dust. The inhibition experiments demonstrated that POLE exhibits excellent inhibitory performance. At a POLE concentration of 2.0 g/L, the hydrogen inhibition efficiency reaches 97.71 % after 22 h, with a reaction rate constant of 8.9708 × 10−5, approaching zero. This efficiency remained stable over 5 days. POLE formed a uniform, dense protective film on the Al-Si dust surface, with a contact angle of 99.23°. FTIR spectra revealed absorption peaks corresponding to POLE functional groups and Al-O bonds, indicating that successfully adsorption of POLE through both physical and chemical interactions. Finally, theoretical calculations were performed to further explain the hydrogen inhibition mechanism of POLE, supplementing and confirming the characterization data. This study inhibited hydrogen production from waste dust, offering a new approach to enhancing the hydrogen production rate from recycled Al scraps.

Evaluating the Efficacy of Plant Extracts in Managing the Bruchid Beetle, Callosobruchus maculatus (Coleoptera: Bruchidae).

An estimated 2000 plant species have been employed for pest control worldwide. The use of these botanical derivatives is thought to be one of the most cost-effective and sustainable options for pest management in stored grain. The present study was designed to assess the efficacy of five plant extracts viz; Nicotiana tabacum L., Nicotiana rustica L., Azadirachta indica A. Juss., Thuja orientalis L., and Melia azedarach L. against Callosobruchus maculatus L. Plant species extracts were applied at six different concentrations, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replications. The phytochemical analyses of ethanolic extracts of five plant species showed variable amounts of phytochemicals i.e., alkaloids, flavonoids, saponins, diterpenes, phytosterol, and phenols. Total phenolic and flavonoid compounds were also observed. The efficacy of A. indica was highest, characterized by the lowest infestation rate (16.65%), host seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). In contrast, T. orientalis was found to be the least effective against C. maculatus, with the highest infestation rate of 25.60%, host seed weight loss of 26.73%, mean oviposition of 117.17, and adult emergence rate of 82.01%. Probit analysis was performed by estimating LC50 and LC90. The toxicity percentages of N. tabacum (LC50 = 0.69%, LC90 = 14.59%), N. rustica (LC50 = 0.98%, LC90 = 22.06%), and A. indica (LC50 = 1.09%, LC90 = 68.52%) were notable in terms of the lower LC50 and LC90 values after the 96-h exposure period against C. maculatus. Repellency was assessed by using the area preference and filter paper method. The repellency of C. maculatus on plant extracts increased with the increasing dose and time, such that it was the highest after 48 h. Likewise, at a 3% concentration, A. indica demonstrated 100.00% (Class-V) repellency followed by N. tabacum (96.00%, Class-V), N. rustica (74%, Class-IV), M. azedarach (70.00%, Class-IV), and T. orientalis (68.00%, Class-IV). Based on the findings of this study, we recommend integrating N. rustica, N. tabacum, A. indica, and M. azedarach for effective management of C. maculatus and highlight the potential of these plant species in the formulation of new biocidal agents.

Assessing the phenological state of evergreen conifers using hyperspectral imaging time series

Phenology is a reliable indicator of vegetation condition and ecological changes in the environment. Plant Spectral Phenology (PSP) offers the potential for the development of automated, rapid, and wide-area vegetation monitoring systems. The spectral characteristics of plants (vegetation) are employed as metrics of PSP, which can be sensed both proximally and remotely. A key objective is to undertake a comparative analysis of the results of PSP versus those of phenology based on visual observations. The resolution of this issue is of paramount importance for the coordination of phenological studies at diverse levels (ground, surface, and remote), thus ensuring the continuity of phenological studies conducted prior to the advent of PSP. This issue is particularly pronounced in the case of evergreen conifers. The present study focuses on four evergreen conifers: Thuja occidentalis, Platycladus orientalis, Pinus sylvestris and P. nigra subsp. pallasiana. Hyperspectral imaging was performed under laboratory conditions using a Cubert UHD-185 hyperspectral camera. Concomitantly, phenological observations were conducted. The spectral time series yielded 79 chlorophyll-sensitive and carotenoid-sensitive Vegetation Indices (VIs), which were then used to construct double logistic functions. A significant proportion of the VIs exhibited a high degree of correctness with regard to the aforementioned functions, as indicated by the value of R2 exceeding 0.7. The values of the principal stages of seasonal development of evergreen conifers, namely the Start of Season (SOS), End of Season (EOS), Position of Peak value (POP) and Length of Season (LOS), were calculated using double logistic functions. These stages were matched to the phenological phases of development of the experimental plants. The values of SOS, EOS, POP and LOS varied significantly depending on the VIs used as a metric as well as the evergreen conifers. The lowest variability by metrics is observed in SOS, while the maximum is observed in EOS and POP. The results obtained may be of importance for the choice of criterion for the comparison of PSP with phenology based on visual observations and the most suitable VIs for these purposes.

Effects of dietary supplementation with medicinal plant mixtures and immunostimulants on the immune response, antioxidant capacity, and hepatopancreatic health of Chinese mitten crab (Eriocheir sinensis).

This study aimed to evaluate the efficiency of tea polyphenols (TP) and medicinal plant mixtures (Astragalus membranaceus + Lonicera japonica, Rheum officinale Bail + Scutellaria baicalensis + Platycladus orientalis) combined with astaxanthin (AST), benzoic acid (BA), and yeast complex on the health status of Eriocheir sinensis. A total of 630 crabs (male crabs: 41.51 ± 1.63 g; female crabs: 47.27 ± 0.79 g) were randomly distributed into seven groups with three replicates (male: female, 1:1). These crabs were fed as follows for 8 weeks: basal diet (M1), M2 (M1 + 100 mg/kg TP), M3 (M1 + 2.0 g/kg A. membranaceus + 20 g/kg L. japonica), M4 (M1 + 2.5 g/kg R. officinale Bail + 1.5 g/kg S. baicalensis + 1.0 g/kg P. orientalis), and M5, M6, M7 (M2, M3 and M4 with 600 mg/kg AST +1.0 g/kg BA + 20 mg/kg yeast complex added, respectively). The results showed that the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), and lysosome (LZM) in the hemolymph were significantly increased in M5, M6, and M7 (P < 0.05), and the highest phagocytosis index (PI) and LZM activity were observed in M7 of female crabs. Moreover, the antioxidant indicators superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) of hepatopancreas were also significantly improved in M5, M6, and M7 (P < 0.05), while the malondialdehyde (MDA) contents showed an opposite trend. Furthermore, a morphological examination also showed the improved histological structure of hepatopancreas in M7, especially as seen in the clear lumens, no vacuolation, and integrity of the basal membrane of the hepatopancreatic tubule. Taken together, these results suggested that 2.5 g/kg R. officinale Bail, 1.5 g/kg S. baicalensis, and 1.0 g/kg P. orientalis in combination with 600 mg/kg AST, 1.0 g/kg BA, and 20 mg/kg yeast complex could improve the non-specific immunity, antioxidant capacity, and hepatopancreatic health of E. sinensis.