Evergreen Research Articles

Transcriptome Analysis Revealed the Regulatory Mechanism of DIMBOA Affecting Early Somatic Embryogenesis in Dimocarpus longan Lour.

Dimocarpus longan Lour. is an evergreen tree of the genus Longan in the Sapindaceae family, native to tropical and subtropical regions. Longan embryonic development is closely related to fruit set and fruit quality. An in-depth study of the mechanism of longan embryonic development could therefore contribute to the development of the longan industry. DIMBOA is the principal compound representing benzoxazinoids (BXs), and is closely linked to auxin biosynthesis and signal transduction. Auxin is one of the crucial hormones for inducing somatic embryogenesis (SE) in plants. Previous research has shown that DIMBOA promotes morphogenesis in the early somatic embryogenesis of longan, but the specific regulatory mechanism has not yet been clarified. To elucidate the molecular mechanism by which DIMBOA affects early somatic embryogenesis in longan, we chose longan embryogenic cultures grown under 0 mg/L DIMBOA as the control group (the check, CK), and longan embryogenic cultures grown under 0.1 mg/L DIMBOA as the treatment group (D) to be analyzed by transcriptomic sequencing. A total of 478 differentially expressed genes (DEGs) are detected in check vs. D, of which 193 are upregulated and 285 are downregulated. These DEGs are significantly enriched in the biosynthetic and metabolic functions of various substances such as vitamin B6 (VB6) biosynthesis, phenylpropanoid pathways, and carbohydrate metabolism. DIMBOA affects SE processes in longan via TFs, including MYB, ZF, bHLH, LBD, NAC, WRKY, etc. After DIMBOA treatment, the expression of most of the key genes for IAA synthesis was significantly downregulated, VB6 content was significantly reduced, and H2O2 content was significantly increased. Therefore, it is suggested that DIMBOA directly or indirectly affects the H2O2 content through the VB6 metabolic pathway, thereby regulating the endogenous IAA level to modulate the early SE morphogenesis of longan.

How do aboveground and belowground functional traits correlate with the demography of tree seedlings regenerated after landslide disturbances?

ABSTRACT Trait-based plant ecology is commonly used to study plant demography in forests, especially after disturbances. However, how functional traits affect the demography of regenerating seedlings after landslides remains largely unknown. This study conducted a 2-year monitoring of Abies sachalinensis (evergreen species) and Acer mono (deciduous species) seedlings dominantly regenerating in artificial landslide areas in northern Japan. We investigated the correlations between intraspecific variations in functional traits and two demographic properties (growth and mortality). We found that growth of evergreen tree seedlings was correlated with functional traits related to leaf and root construction costs and light capture capacity. However, there were no significant correlations between mortality and the functional traits for either species in the post-landslide forests. Our results emphasize the importance of both aboveground and belowground functional traits in understanding vegetation recovery after landslides. This work suggests that the intraspecific trait-demography relationships can vary depending on the demographic properties in post-landslide forests.

Exploring the relationship between khat chewing behaviour and psychological well-being among students of Jazan University

Background: Khat, a well-known natural stimulant from the Catha edulis plant, a flowering evergreen tree or large shrub of the Celastracea family is taken in few parts of southern province. Being adjacent to Yemen, Khat chewing is a common habit among the population in the Jazan region. khat eating is associated with many health ailments like depression, stress anxiety. Objectives: 1. To estimate the prevalence of depression, anxiety and stress in khat chewers 2. To assess the psychological disorders in khat chewers. Methodology: A cross-sectional study (survey) conducted and sample size collected with pre designed questionnaire. Data entered in Microsoft excel and processed in SPSS version 23 and the results tabulated. Univariate and multivariate analysis with multilogistic regression done. Results: Majority of participants were males and were 21 years old or younger. Notable difference identified between urban (40%) and rural (60%) and this difference was identified as potential distinction in the psychological behaviour of the students. Odds ratio was found to be high in males and in >21-year-old students when compared with females. GPA showed significant difference when observed with psychological status. GPA scores less than 3.75 were found to have more psychological disturbances than GPA>3.75. Interquartile range among depression, anxiety and stress higher among khat chewers when compared with non-khat chewers and the difference found to show high statistical significance. (P<0.01). Conclusion: Khat chewing in this area found to be significantly high in students so continuous health education shall be the priority for the policy makers

Planted Forests in China Have Higher Drought Risk Than Natural Forests.

To improve the environment and mitigate climate change, China has implemented ambitious projects for natural forest protection and expanded planted forests. However, increased climate variability has led to more frequent and severe droughts, exacerbating the decline of these forests. The drought risk of planted forests is rarely assessed by considering both resistance and resilience, and comparative analyses between natural and planted forests are lacking. Here, we compared drought resistance and resilience in natural and planted forests across China using satellite observations from 2001 to 2020 to understand which forests were at higher risk of drought. The results showed that planted forests exhibited lower drought resistance and resilience compared to natural forests, particularly in subtropical broad-leaved evergreen forests and warm temperate deciduous broad-leaved forests. Moreover, drought resistance in planted forests significantly increased, while resilience decreased during 2011-2020 compared to 2001-2010, suggesting a shift in the strategies of planted forests to cope with drought stress. The higher drought risk in planted forests compared to natural forests was mainly attributed to lower forest canopy height and poorer soil nutrients, which limited resistance, and lower canopy height and severe drought characteristics (severity, duration, and frequency), which reduced resilience. These results underscore the higher potential risk of drought exposure in planted forests. To mitigate future drought impacts on planted forests under climate change, enhanced management strategies, including the preservation of natural forests and augmentation of structural diversity in planted forests, are imperative.

Impact of silicon nitride nanoparticles on soil organic carbon dynamics in subtropical evergreen forest ecosystems of China: An incubation study.

Ensuring the stability of soil organic carbon (SOC) is vital for effective long-term carbon storage in forest ecosystems. While nanoparticles (NPs) have shown the potential to enhance SOC stability and reduce cumulative carbon mineralization rates (CCMR) in agricultural soils, their effects on forest soils remain largely unexplored. This study addresses this gap through an incubation experiment that evaluated the impact of silicon nitride nanoparticles (Si3N4-NPs) at varying concentrations [control, 0mgkg-1 (NP0); 50mgkg-1 (NP1); 100mgkg-1 (NP2)] on SOC stability, CCMR, enzymatic activities, and microbial diversity across three forest ecosystems in the Dinghushan region of Guangdong, China: coniferous forest (CF), mixed conifer-broadleaf forest (MCBF), and monsoon evergreen broadleaf forest (MEF). The results revealed that Si3N4-NP application at the NP2 concentration significantly reduced CCMR by 40.82% compared to the control (NP0). Moreover, NP2 substantially decreased the activities of key soil enzymes: β-glucosidase by 13.81%, N-acetylglucosaminidase by 32.62%, cellobiohydrolase by 59.12%, and phenol oxidase by 26.40%, relative to NP0. The NP2 treatment also enhanced total SOC retention by 24.62% compared to NP0. Within SOC fractions, NP2 significantly impacted the less labile (C3) and non-labile (C4) fractions, which increased by 46.83% and 57.84%, respectively, compared to NP0. Meanwhile, the very labile C (C1) and labile C (C2) fractions showed non-significant changes. Furthermore, the Si3N4-NP applications induced distinct shifts in bacterial (Actinobacteriota) and fungal (Ascomycota) microbiomes, which correlated significantly with CCMR and total SOC. These findings indicate that Si3N4-NPs improve SOC stability and reduce mineralization in forest soils. However, field-scale validation is essential to assess the long-term impacts of Si3N4-NPs on microbial communities and overall ecosystem functioning. This study highlights the significance of NP concentration and forest type in developing effective strategies for SOC management to mitigate climate change.

Assessing and optimizing the potential for climate change mitigation and carbon sequestration in urban residential green spaces: energizing sustainable cities

IntroductionUrban green spaces play a crucial role in mitigating climate change by sequestering atmospheric carbon dioxide. This study aimed to evaluate the carbon sequestration potential of common plant species in urban residential areas and provide recommendations for optimizing green space design and management.MethodsThe research was conducted in four residential areas of Nanjing, China, where key growth parameters of 20 plant species, including evergreen trees, deciduous trees, evergreen shrubs, and deciduous shrubs, were measured. The assimilation method was employed to calculate carbon sequestration per unit canopy area and for entire plants.ResultsThe results showed that the carbon sequestration capacities of different plant species and types exhibited significant differences, with p-values less than 0.05. In terms of daily carbon sequestration per unit canopy projection area, the ranking was as follows: evergreen trees > evergreen shrubs > deciduous trees > deciduous shrubs. For total plant carbon sequestration, the ranking was: evergreen trees > deciduous trees > evergreen shrubs > deciduous shrubs. Evergreen trees performed excellently in both carbon sequestration metrics, with the average daily carbon sequestration per unit canopy projection area and for the entire plant being 18.0024 g/(m2·d) and 462.28 g/d, respectively. The study also observed seasonal variations, with carbon sequestration rates being higher in autumn and summer compared to spring and winter. During the summer, the average daily carbon sequestration per unit canopy projection area and for the entire plant were 11.975 g/(m2·d) and 161.744 g/d, respectively, while in autumn, these values were 13.886 g/(m2·d) and 98.458 g/d. Seasonal variations were also observed, with autumn and summer exhibiting higher carbon sequestration rates compared to spring and winter. Additionally, CO2 concentrations were monitored across the four residential areas, providing insights into the spatial and temporal dynamics of carbon sequestration.DiscussionBased on the findings, optimization strategies were proposed, such as prioritizing the selection and integration of high-performing evergreen tree species in urban green space design and incorporating diverse plant types to enhance year-round carbon sequestration. This study contributes to the development of sustainable urban planning and landscape management practices, promoting the role of green spaces in mitigating climate change and enhancing urban resilience.

A note on Pterospermum obtusifolium Wight ex Mast. (Malvaceae), a rare endemic evergreen tree of southern Western Ghats, India

Pterospermum obtusifolium Wight ex Mast. is a rare, large, evergreen tree endemic to the southern Western Ghats. The authors have collected specimens from two locations in Courtallum, Sengottai Forest Division, Tenkasi District, Tamil Nadu. As detailed taxonomic account including fresh images are not available until now, they are provided in this paper for the first time.

Invasion of temperate riparian forests by Acacia dealbata affects macroinvertebrate community structure in streams

The riparian forest determines many of the stream characteristics such as physicochemical variables and the availability and quality of food resources for aquatic communities. In central Portugal, native mixed deciduous forests are being heavily invaded by Acacia dealbata, which is an evergreen and nitrogen-fixing tree species, but effects on stream benthic macroinvertebrate communities are unknown. We assessed invasion effects on macroinvertebrate communities by comparing streams flowing through native forests (native streams) and streams flowing through forests heavily invaded by A. dealbata (invaded streams), in central Portugal. We did not find major differences in macroinvertebrate abundance, total taxa richness or diversity between native and invaded streams, due to high variation among native streams. However, taxonomic structure of macroinvertebrate communities differed between stream types, with invaded streams showing lower percentage of sensitive taxa. Macroinvertebrate communities structure based on functional feeding groups also differed between stream types, with a tendency for higher abundance of shredders and scrapers/grazers and lower abundance of filter feeders in native than invaded streams, probably due to altered composition of leaf litter inputs and canopy cover within invaded streams. Our findings suggest that invasion by A. dealbata affect macroinvertebrate community mostly in terms of taxonomic and functional structure. Since A. dealbata is rapidly spreading in all southern Europe, this study highlights the importance of enhancing the comprehension of its impact on aquatic communities to identify ecological risks and formulate effective mitigation strategies.

Elucidation of Phytochemicals and Antidiabetic Activity of Methanolic Ex-tract of Piper betle Leaves on nSTZ-Induced Type 2 Diabetic Model Rats

Piper betle is an evergreen plant that has been claimed to possess various therapeutic properties including diabetes for a long period of time. The present study was undertaken to evaluate the antidiabetic effects of Piper betle (100% methanolic extract) on neonatal streptozotocin (nSTZ) induced type 2 diabetic (T2DM) model rats. P. betle methanolic extract preparation and phytochemicals screening test were done by following standard methods. Diabetes was induced in 48hrs rat pups by a single ip injection of STZ (90mg/kg bw). After three months, OGTT was done (glucose 2.5g/10ml/kg bw) to find out their glycemic status. Six normal and 18 T2DM Long Evans rats were chosen and divided them into four groups. Where group (i) was comprised of normal rats i) Normal water control (NWC); ii) Diabetic water Control (DWC), iii) Gliclazide (GT 20mg/5ml/kg bw) and iv) P. betle (1.25g/10ml/kg bw) extract treated groups respectively. In 28 days, experimental period groups (i) and (ii) received water orally (10ml/kg bw) respectively with a single feeding. 24 Blood samples were collected at the beginning by tail cut and cardiac puncture method was done at the end of the study under halothane anesthesia. Blood serum and dissected small portion of the liver were stored at -20˚C refrigerator for biochemical (fasting serum glucose, serum insulin, serum lipid profiles) and liver glyco-gen estimation. Statistical Analysis was done by using SPSS-16 software. Phytochemicals screening revealed that P. betle extract contain significant amount of tannins, flavonoids, phenols, and terpenoids. Oral consumption of P. betle showed that, a significant (P<0.01) reduction of FSG had been found when compared to the base line value. Moreover, while compared to the DWC a significant (P< 0.01) reduction of FSG has been found in P. betle treated group respectively. GT group also ameliorated FSG significantly (p<0.03) while compared to the base line value. Liver glycogen content was increased (24%) in P. betle treated rats when compared to the DWC group. Serum insulin level also increased significantly (P< 0.001) when compared to the baseline value. Furthermore, the consecutive treatment of P. betle resulted in a significant reduction of TG and Cholesterol (p<0.001 & p<0.02), a 10% decrease in LDL, and a significant increase in HDL (p<0.01). The findings of our study suggest that P. betle possesses significantly hypoglycemic and insulinomimetic properties due to the abundant sources of phytochemicals.

Plant root carbon inputs drive methane production in tropical peatlands

Tropical peatlands are carbon-dense ecosystems that are significant sources of atmospheric methane (CH4). Recent work has demonstrated the importance of trees as an emission pathway for CH4 from the peat to the atmosphere. However, there remain questions over the processes of CH4 production in these systems and how they relate to substrate supply. Principally, these questions relate to the relative contribution of recent photosynthetically fixed carbon, released as root exudates, versus carbon substrate supply from the slowly decomposing peat matrix to CH4 emissions within these ecosystems. Here, we examined the role of root inputs in regulating CH4 production inferred from soil emissions using a combination of in situ tree girdling, in situ13C natural abundance labelling via stem injections, and a 13CO2 labelling of transplanted plants of two contrasting plant functional types, a broadleaved evergreen tree, and a canopy palm. Girdling of broadleaved evergreen trees reduced CH4 fluxes by up to 67%. Stem injections of trees and palms with a natural abundance label resulted in significant isotopic enrichment of CH4 fluxes, reinforcing the link between root carbon inputs and peat CH4 fluxes. Ex situ13CO2 labelling of plants resulted in significant 13C enrichment of peat CH4 fluxes. Taken together, our results demonstrate for the first time that plant root exudates make a substantial contribution to CH4 production in tropical peatlands.

Evaluation of Antioxidant, Xanthine Oxidase-Inhibitory, and Antibacterial Activity of Syzygium cumini Linn. Seed Extracts

Syzygium cumini (L.) Skeels, commonly known as the Jamun or Indian blackberry, is a tropical evergreen tree native to the Indian subcontinent, and it belongs to the Myrtaceae family. This research aimed to assess the antibacterial properties of the extracts derived from S. cumini seed kernels and evaluate their total flavonoid content, total phenol content, total carbohydrate content, antioxidant capacity, and inhibitory effects on xanthine oxidase. Cold maceration was chosen for its ability to preserve thermolabile compounds and efficiently extract bioactive constituents with minimal energy and equipment requirement, with hexane and methanol employed as extraction solvents. The methanolic seed kernel extract of S. cumini showed the highest flavonoid (127.78 μg quercetin equivalent/mg dried extract vs. 21.24 μg quercetin equivalent/mg in hexane dried extract) and polyphenol content (153.81 μg gallic acid equivalent/mg dried extract vs. 38.89 μg gallic acid equivalent/mg in hexane dried extract), along with significant carbohydrate content (475.61 μg glucose equivalent/mg dried extract vs. 5.57 μg GE/mg in hexane dried extract). It also demonstrated potent antioxidant activity (IC50: 9.23 μg/mL; ascorbic acid: 5.10 μg/mL) and xanthine oxidase inhibition (IC50: 14.88 μg/mL), comparable to the standard drug allopurinol (IC50: 6.54 μg/mL), suggesting its therapeutic potential. Moreover, the methanolic extract of seed kernels exhibited strong antibacterial activity, with inhibition zones of 19.00 mm against S. epidermidis, higher than the standard antibiotic (gentamicin: 18.33 mm) against K. pneumonia (ciprofloxacin: 33.66 mm). The lowest minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.32 mg/mL and 0.52 mg/mL, respectively, were observed for the same extract against S. epidermis. In conclusion, this study demonstrated the remarkable antibacterial effects of S. cumini methanolic seed kernel extract against various pathogenic microorganisms as well as significant inhibitory effects on xanthine oxidase and antioxidant activity.

Chronic and infectious respiratory mortality and short-term exposures to four types of pollen taxa in older adults in Michigan, 2006-2017

IntroductionLevels of plant-based aeroallergens are rising as growing seasons lengthen and intensify with anthropogenic climate change. Increased exposure to pollens could increase risk for mortality from respiratory causes, particularly among older adults. We determined short-term, lag associations of four species classes of pollen (ragweed, deciduous trees, grass pollen and evergreen trees) with respiratory mortality (all cause, chronic and infectious related) in Michigan, USA.MethodsWe obtained records for all Michigan deaths from 2006-2017 from the Michigan Department of Health and Human Services (MDHHS). Deaths from infectious and chronic respiratory-related causes were selected using International Classification of Diseases (ICD-10) codes. Pollen data were obtained from a prognostic model of daily pollen concentrations at 25 km resolution. Case-crossover models with distributed lag non-linear crossbases for pollen were used to estimate associations between lags of daily pollen concentrations with mortality and to explore effect modification by sex and racial groups.Results127,163 deaths were included in the study. Cumulative daily high concentrations (90th percentile) of deciduous broadleaf, grass and ragweed were associated with all-cause respiratory mortality at early lags with e.g., a 1.81 times higher risk of all respiratory deaths at cumulative 7 day lag exposure to deciduous broadleaf pollen at the 90th percentile (95% confidence interval: 1.04, 3.15). Exposure to high concentrations of grass and ragweed pollens was associated with increased risk for death from chronic respiratory causes. No association was found for any pollen species with death from infectious respiratory causes though there was a positive but non-significant association of exposure to deciduous broadleaf and ragweed pollens. We found no evidence to suggest effect modification by race or sex.ConclusionsModelled exposures to high concentrations of pollen taxa were associated with increased all-cause and chronic respiratory mortality among older adults. Results suggest that pollen exposure may become more important to respiratory mortality as the temperatures increase and pollen seasons lengthen.

Combined Impacts of Climate and Tree Physiology on Mercury Accumulation in Tropical and Subtropical Foliage and Robust Model Parametrization.

Atmospheric elemental mercury (Hg0) assimilation by foliage contributes prevalently to the global atmospheric Hg0 sink in forests. Today, little is known about the mechanisms of foliar Hg accumulation and how climate factors and tree physiology interact to impact it. Here, we examined meteorological factors, foliar physiological traits, and Hg accumulation rates from leaf emergence to senescence in a tropical rainforest, tropical savanna, and subtropical evergreen broadleaf forest. Also, robust models for foliar Hg accumulation were parametrized. Generally, foliar Hg accumulation rate in subtropical evergreen forest was highest (16.4 ± 12.3 ng m-2 day-1), followed by the tropical rainforest (14.2 ± 9.8 ng m-2 day-1), and lowest in the tropical savanna (4.7 ± 4.9 ng m-2 day-1). Atmospheric relative humidity, stomatal conductance, and leaf photosynthesis are key drivers of spatial-temporal variations in foliar Hg accumulation. The canopy-structure-induced specific leaf physiological traits drive temporal variations in foliar Hg accumulation, and climate-controlled leaf physiological traits account for spatial variations among three forests. Finally, our robust models enable precise simulation of foliar Hg accumulation rates at both tree species and ecosystem scales facilitating particularly regional and global Hg transport and chemical models to quantify the vegetation's role as a sink for atmospheric Hg0 uptake.

Phylogeographic and genetic insights into Sinonychia martensi: an endemic cave-dwelling harvestman in Beijing

Caves are one of the most exciting environments on earth, often considered an evolutionary laboratory due to the suite of convergent adaptive traits (troglomorphisms) of organisms inhabiting them. Sinonychia martensi Zhang & Derkarabetian, 2021, is the first and only Travunioidea species recorded in China and is endemic to Beijing, being known from multiple caves. However, nothing is known regarding its phylogeographic or evolutionary history. In this study, we assessed the species boundaries of S. martensi from nine caves using morphological and molecular methods to elucidate its phylogenetic position and genealogical relationships. We also investigated the genetic diversity, population genetic structure and demographic history of S. martensi to clarify the population-level relationships and make inferences about historical phylogeography. The results indicate that the species from different caves all belonged to S. martensi but represent different populations. These populations exhibit strong population structure and low genetic diversity. Cave populations may share a common ancestor and multiple independent invasions to different caves. The diversification within S. martensi was likely driven by climate change and subtropical evergreen broadleaf forests associated with the middle Miocene. This study highlights the need for further conservation efforts and exploration in Beijing caves.

Assessing the seasonality of foliar nutrient concentrations in woody plants.

Seasonal variations in foliar nutrient concentrations are an important strategy of plants to adapt to different climates and availabilities of soil nutrients. Gaps in our knowledge, however, remain in both the seasonality of the concentrations of multiple nutrients in plant leaves and their spatial pattern on a large scale. We compiled data on foliar concentrations of nine essential nutrients (N, P, K, Ca, Mg, Fe, Mn, Zn, and Cu) in woody plants in China and evaluated the characteristics and latitudinal patterns of their seasonal variability (i.e., seasonality). Foliar concentrations of mobile nutrients (N, P, K, and Zn) in deciduous broadleaf woody plants decreased significantly during the growing season, but nonmobile nutrients (Ca and Mn) continued to accumulate. In contrast, the foliar nutrient concentrations in evergreen broadleaves and conifers generally showed no significant seasonal trend. The seasonality of foliar nutrient concentration was weaker for the nutrients with higher foliar concentrations, supporting the hypothesis of seasonal stability of high-demand nutrients. The seasonality of foliar nutrient concentration was stronger for deciduous than evergreen plants, while the effect of plant phylogeny was not statistically significant. The seasonality of foliar N and P concentrations increased with latitude in the deciduous broadleaf woody plants, but evergreen plants showed no significant latitudinal trend. The spatial patterns of seasonality for foliar N and P concentrations were significantly explained by climate and foliar habit. These findings improve our understanding of the seasonality of plant foliar concentrations of multiple nutrients as a strategy to adapt to varying climatic conditions.

Integrating ATAC-seq and RNA-seq to reveal the dynamics of chromatin accessibility and gene expression in regulating aril coloration of Taxus mairei.

Fruit coloration results from a complex process. Maire yew (Taxus mairei) is an evergreen tree with red, purple, and yellow fruits (arils). While significant progress has been made in understanding pigment biosynthesis in arils, the role of chromatin accessibility in color development remains less well understood. To gain deeper insights into the genetic and epigenetic factors involved, we employed RNA sequencing (RNA-seq) and assay for transposase-accessible chromatin sequencing (ATAC-seq). By integrating the results, we identified 723 differentially expressed genes (DEGs) with chromatin changes in P vs. R, including 312 up- and 411 down-regulated genes. In Y vs. R, we found 159 DEGs, with 97 up- and 62 down-regulated. KEGG enrichment analysis highlighted the flavonoid and carotenoid pathways as major contributors to color variation. When the arils turned purple, the expression levels of C4H, CHS, C3'H, F3'H, F3H, DFR, ANS, PSY, PDS, β-OHase, CYP97A3, and LUT1 were significantly up-regulated, while ZDS was down-regulated. The transition to yellow arils was characterized by the up-regulation of F3H, DFR, ANS, ZDS, CYP97A3, β-OHase, and LUT1, accompanied by the down-regulation of C4H, CHS, PSY, and PDS. Additionally, 27 transcription factors (TFs) were identified, including MYB, bHLH, and bZIP. These TFs may potentially influence variation in aril color by regulating downstream genes. In total, eight genes were selected for qRT-PCR validation, indicating the reliability of the transcriptome sequencing data. Our results provide in-depth information regarding the coloration of the arils in Maire yew. The study could provide insights for further genetic improvement in Taxus.

Leaf Photosynthetic and Respiratory Thermal Acclimation in Terrestrial Plants in Response to Warming: A Global Synthesis.

Leaf photosynthesis and respiration are two of the largest carbon fluxes between the atmosphere and biosphere. Although experiments examining the warming effects on photosynthetic and respiratory thermal acclimation have been widely conducted, the sensitivity of various ecosystem and vegetation types to warming remains uncertain. Here we conducted a meta-analysis on experimental observations of thermal acclimation worldwide. We found that the optimum temperature for photosynthetic rate (Topt) and the maximum rate of carboxylation of Rubisco (ToptV) in tropical forest plants increased by 0.51°C and 2.12°C per 1°C of warming, respectively. Similarly, Topt and the optimum temperature for maximum electron transport rate for RuBP regeneration (ToptJ) in temperate forest plants increased by 0.91°C and 0.15°C per 1°C of warming, respectively. However, reduced photosynthetic rates at optimum temperature (Aopt) were observed in tropical forest (17.2%) and grassland (16.5%) plants, indicating that they exhibited limited photosynthetic thermal acclimation to warming. Warming reduced respiration rate (R25) in boreal forest plants by 6.2%, suggesting that respiration can acclimate to warming. Photosynthesis and respiration of broadleaved deciduous trees may adapt to warming, as indicated by higher Aopt (7.5%) and Topt (1.08°C per 1°C of warming), but lower R25 (7.7%). We found limited photosynthetic thermal acclimation in needleleaved evergreen trees (-14.1%) and herbs (-16.3%), both associated with reduced Aopt. Respiration of needleleaved deciduous trees acclimated to warming (reduced R25 and temperature sensitivity of respiration (Q10)); however, broadleaved evergreen trees did not acclimate (increased R25). Plants in grasslands and herbaceous species displayed the weakest photosynthetic acclimation to warming, primarily due to the significant reductions in Aopt. Our global synthesis provides a comprehensive analysis of the divergent effects of warming on thermal acclimation across ecosystem and vegetation types, and provides a framework for modeling responses of vegetation carbon cycling to warming.

Autumn and winter air phytofiltration - Are plants able to biofilter air during peak pollutant emissions?

Air pollution is highest in winter. The high concentration of particulate matter (PM) and trace elements (TE) after the growing season is influenced by increased pollutant emissions, unfavorable meteorological conditions, and the low efficiency of air phytofiltration. Plants that can remove pollutants from the air during the growing season are leafless in autumn/winter, and therefore unable to capture PM/TE effectively. This study investigated the ability of nine species of leafy evergreen plants to accumulate PM (surface and in-wax PM; PM2.5 and PM10) and TE in autumn and winter. Plant material was harvested in November and December from the park in Wuhan, China. The amount of accumulated pollutants depended on the species. The shrubs (Loropetalum chinense, Pittosporum tobira, Rhododendron simsii) and grass (Ophiopogon japonicus), were more effective at phytofiltration of PM and TE per leaf area unit than the trees. However, to better understand the potential of plants to accumulate PM in relation to a unit of land area, the leaf area index (LAI) has to be considered. Ligustrum lucidum and P. tobira characterized by low LAI, despite having PM deposition comparable to other trees and shrubs, exhibited a markedly reduced efficacy of pollutants accumulation in relation to square metre of land they occupy. In contrast to the TE concentration in winter, PM deposition on plants did not always increase after the autumn, probably due to the park's low density of vegetation, PM resuspension by wind, and a decrease in the plants' physiological activity. Seasonal variations in pollutants accumulation among species were recorded during the autumn/winter. This study reinforces the need for biodiversity and higher-density urban greening to optimize post-growth air phytofiltration. A holistic, year-round air pollution mitigation strategy should be provided by incorporating more diverse evergreen plant species with complementary phytofiltering properties.

Assessment of Suitable Habitats, Fragmentation Analysis, and Ecological Corridor Identification for Sichuan Golden Snub-Nosed Monkey (Rhinopithecus roxellana) in Sichuan Province, Southwest China.

The Sichuan golden snub-nosed monkey (Rhinopithecus roxellana) was found to possess significant scientific and conservation value but faced multiple threats including habitat fragmentation and loss, human disturbance, illegal hunting, and the impacts of climate change on their habitat. To enhance habitat protection for this species, our study utilized field survey data and distribution records from protected areas to systematically evaluate spatial heterogeneity in suitable habitat distribution and habitat quality in Sichuan Province. Integration of 3S technology and ecological modeling allowed for a comprehensive assessment. We found that: (1) The potential habitat area for the species in Sichuan Province covered 78,470.47 km², with suitable and marginally suitable habitats occupying 28,301.36 and 50,169.11 km² respectively. Suitable habitats were predominantly found at elevations of 1600-3200 m, in areas with low population density and minimal human disturbance. (2) Suitable habitats within protected areas accounted for 42.7% of the total suitable habitat area, while marginally suitable habitats within protected areas comprised 24.8% of the total marginally suitable habitat area. (3) Vegetation types most utilized by the species, ranked from highest to lowest preference, were deciduous broadleaf forests, evergreen coniferous forests, evergreen broadleaf forests, mixed coniferous-deciduous forests, and shrublands. Evergreen coniferous forests exhibited the largest patch area and lowest fragmentation, whereas deciduous broadleaf forests showed higher fragmentation within protected areas. (4) Four potential ecological corridors were identified, connecting the Wujiao, Xuebaoding, and Baodinggou nature reserves. Strengthening the protection of suitable habitats and potential ecological corridors would enhance landscape connectivity, facilitating the effective utilization of suitable habitats by the Sichuan golden snub-nosed monkey. Our findings provided a scientific basis for future conservation and management efforts for the Sichuan golden snub-nosed monkey.

Landscape and conservation genetics of western black crested gibbons (Nomascus concolor) in China.

Despite decades of field study, very little is known about the molecular ecology of gibbons, particularly as it relates to their ability to disperse across degraded and fragmentary landscapes. The critically endangered western black crested gibbon (Nomascus concolor) has been reduced to a small, fragmented population with about 1300 individuals. In the largest population genetic study of free-ranging gibbons to date, we sampled 47 of these gibbons from 13 sites in China and generated 15 polymorphic autosomal microsatellite markers. We identify three population clusters of N. concolor in Yunnan centered in 1) the Wuliang and Ailao Mountains, 2) the Yongde Daxueshan Mountains, and 3) an isolated remnant near the border with Vietnam. Within the Wuliang Mountains, we identified four subclusters, three of which are bounded by high-altitude rhododendron forest, and one that is isolated from the main population by ~2 km of degraded forest and pasture. Least-cost path analysis and isolation by resistance modeling demonstrates that the population genetic distances among gibbons in Wuliangshan National Nature Reserve are significantly correlated with geographic paths that avoid use of high-altitude rhododendron forest in favor of evergreen broadleaf forest. Although these gibbons have likely undergone reductions in heterozygosity from recent consanguineous mating, we suggest that their active avoidance of inbreeding on the population level maintains higher than expected levels of genetic diversity. This research provides new insights into how gibbons interact with heterogeneous environments and expands our understanding of their molecular ecology and conservation genetics.