bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mutagenic Consequences of DNA Methylation within and across Generations
Authors: Hanson Haley E. , Liebl Andrea L.
Published: October 2022

DNA methylation is an epigenetic modification with wide-ranging consequences across the life of an organism. This modification can be stable, persisting through development despite changing environmental conditions. However, in other contexts, DNA methylation can also be flexible, underlying organismal phenotypic plasticity. One underappreciated aspect of DNA methylation is that it is a potent mutagen; methylated cytosines mutate at a much faster rate than other genetic motifs. This mutagenic property of DNA methylation has been largely ignored in eco-evolutionary literature, despite its prevalence. Here, we explore how DNA methylation induced by environmental and other factors could promote mutation and lead to evolutionary change at a more rapid rate and in a more directed manner than through stochastic genetic mutations alone. We argue for future research on the evolutionary implications of DNA methylation driven mutations both within the lifetime of organisms, as well as across timescales.
Advanced Image Analysis Methods for Automated Segmentation of Subnuclear Chromatin Domains
Authors: Johann to Berens Philippe , Schivre Geoffrey , Theune Marius , Peter Jackson , Sall Salimata Ousmane , Mutterer Jérôme , Barneche Fredy , Bourbousse Clara , Molinier Jean
Published: October 2022

The combination of ever-increasing microscopy resolution with cytogenetical tools allows for detailed analyses of nuclear functional partitioning. However, the need for reliable qualitative and quantitative methodologies to detect and interpret chromatin sub-nuclear organization dynamics is crucial to decipher the underlying molecular processes. Having access to properly automated tools for accurate and fast recognition of complex nuclear structures remains an important issue. Cognitive biases associated with human-based curation or decisions for object segmentation tend to introduce variability and noise into image analysis. Here, we report the development of two complementary segmentation methods, one semi-automated (iCRAQ) and one based on deep learning (Nucl.Eye.D), and their evaluation using a collection of A. thaliana nuclei with contrasted or poorly defined chromatin compartmentalization. Both methods allow for fast, robust and sensitive detection as well as for quantification of subtle nucleus features. Based on these developments, we highlight advantages of semi-automated and deep learning-based analyses applied to plant cytogenetics.
Modeling Climate Effects on Site Productivity of Plantation Grown Jack Pine, Black Spruce, Red Pine, and White Spruce Using Annual/Seasonal Climate Values
Authors: Sharma Mahadev
Published: October 2022

Site index (SI) is a commonly used measure of forest site productivity and is affected by climate change. Therefore, climate effects on site productivity were analyzed and modeled for jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (Mill.) B.S.P.), red pine (Pinus resinosa Ait.), and white spruce (Picea glauca (Moench) Voss) plantations using annual/seasonal values of climate variables. Jack pine and black spruce trees were each sampled from 25 plantations (sites), and red pine and white spruce trees were sampled from 30 and 31 plantations, respectively, from across Ontario, Canada. Stem analysis data collected from 201 jack pine, 211 black spruce, 90 red pine, and 93 white spruce trees were used in this study. To analyze and model climatic effects on site productivity, parameters of the stand height models were expressed in terms of climate variables. A nonlinear mixed-effects modelling approach was applied to fit the stand height models. Climate effects on site productivity was evaluated by predicting stand heights in three areas (the central, eastern/southeastern, and western parts of Ontario) for the period 2021 to 2080 under three emissions trajectories (representative concentration pathways (RCP) 2.6, 4.5, and 8.5 watts m−2). Climate effects on site productivity depended on tree species and location. For jack pine, climate effects were positive and pronounced only in western Ontario under all emissions scenarios. The effects were negative and mild after breast height age (BHA) 50 in central Ontario for black spruce. Similarly, the effects were negative and more pronounced at all areas after BHA 35 for red pine. On the other hand, for white spruce the effects were negative and highly pronounced from a young age under all scenarios, mainly in the southeast. For all species except for jack pine, climate effects were more pronounced under RCP 8.5 than the other two scenarios.
Comparing the Structure, Function, Value, and Risk of Managed and Unmanaged Trees along Rights-of-Way and Streets in Massachusetts
Authors: Suttle Ryan , Kane Brian , Bloniarz David
Published: October 2022

Trees provide numerous benefits in urban areas, including improving stormwater retention and filtration, removing gaseous and particulate pollutants from the air, sequestering atmospheric carbon, and reducing ambient temperature. However, trees also pose risks in urban areas. Trees growing near overhead electrical utility lines cause a large proportion of electrical power outages. To mitigate this risk, arborists frequently and sometimes severely prune trees near overhead utilities for clearance and to reduce the likelihood of failure. Ostensibly, urban trees distant from utility lines are not pruned as frequently or severely. This study aimed to (i) assess factors related to both individual trees and the sample populations of trees growing near and away from overhead utility lines, and (ii) determine whether those factors differed between the two groups. In total, 200 utility easement plots and 200 non-utility control plots were distributed in Eversource Energy’s distribution territories, encompassing 2361 trees in total. Diameter at breast height (DBH), crown height and spread, percent crown missing, percent twig dieback, and likelihood of failure were gathered for each tree in the study. These variables were compared individually among study groups, and used as inputs to calculate estimated ecosystem service delivery using USFS iTree Eco v6. Overall, trees in control plots were larger and delivered more ecosystem services, per tree, than trees in utility plots. However, on a population level, trees in utility plots were more populous and delivered more aggregate ecosystem services than those in control plots. Although the aesthetics of utility tree pruning is often debated, there were no differences in likelihood of failure ratings between trees in control and utility plots. These findings may help to frame trees near overhead utility lines, commonly seen as risks or eyesores, as valuable green infrastructure and community assets.
STPM_SAHI: A Small-Target Forest Fire Detection Model Based on Swin Transformer and Slicing Aided Hyper Inference
Authors: Lin Ji , Lin Haifeng , Wang Fang
Published: October 2022

Forest fires seriously destroy the world’s forest resources and endanger biodiversity. The traditional forest fire target detection models based on convolutional neural networks (CNNs) lack the ability to deal with the relationship between visual elements and objects. They also have low detection accuracy for small-target forest fires. Therefore, this paper proposes an improved small-target forest fire detection model, STPM_SAHI. We use the latest technology in the field of computer vision, the Swin Transformer backbone network, to extract the features of forest fires. Its self-attention mechanism can capture the global information of forest fires to obtain larger receptive fields and contextual information. We integrated the Swin Transformer backbone network into the Mask R-CNN detection framework, and PAFPN was used to replace the original FPN as the feature fusion network, which can reduce the propagation path of the main feature layer and eliminate the impact of down-sampling fusion. After the improved model was trained, the average precision (AP0.5) of forest fire target detection at different scales reached 89.4. Then, Slicing Aided Hyper Inference technology was integrated into the improved forest fire detection model, which solved the problem that small-target forest fires pixels only account for a small proportion and lack sufficient details, which are difficult to be detected by the traditional target detection models. The detection accuracy of small-target forest fires was significantly improved. The average precision (AP0.5) increased by 8.1. Through an ablation experiment, we have proved the effectiveness of each module of the improved forest fire detection model. Furthermore, the forest fire detection accuracy is significantly better than that of the mainstream models. Our model can also detect forest fire targets with very small pixels. Our model is very suitable for small-target forest fire detection. The detection accuracy of forest fire targets at different scales is also very high and meets the needs of real-time forest fire detection.
Exploring the Role of Forest Resources Abundance on Economic Development in the Yangtze River Delta Region: Application of Spatial Durbin SDM Model
Authors: Zhang Qian , Tang Decai , Boamah Valentina
Published: October 2022

With the data of 41 cities, including urban and rural areas in the Yangtze River Delta (YRD) region from 2007 to 2019, this paper mainly uses the spatial econometric method to analyze the impact of forest resource abundance in the YRD region on economic development under the background of carbon neutrality. Direct effects, indirect effects, and total effects are further decomposed. The main conclusions are as follows. (1) The abundance of forest resources in the YRD has a U-shaped non-linear effect on economic development, and the curse of forest resources will gradually form forest resource welfare with economic improvement. (2) The phenomenon of economic convergence exists in the YRD region. (3) The spatial effect of forest resource abundance on economic development is non-linear, and the increase in greenery and carbon reduction should be moderately reasonable. (4) The abundance of forest resources can also promote the development of green total factor productivity. The research in this paper complements the existing literature and provides a reference for policymakers.
Influence of Eucalyptus Plantation on Soil Organic Carbon and Its Fractions in Severely Degraded Soil in Leizhou Peninsula, China
Authors: Zhong Jundi , Pan Ping , Xiao Shenghong , Ouyang Xunzhi
Published: October 2022

Effective vegetation restoration plays an important role in maintaining and improving soil nutrients and can promote the fixation of soil organic carbon (SOC) and its fractions in degraded soil areas. To understand the influence of Eucalyptus plantation on SOC and its fractions in severely degraded soil in Leizhou Peninsula, China, vegetation restoration with Eucalyptus (RE: Eucalyptus–shrub ES, Eucalyptus–grass EG, and Eucalyptus–Dicranopteris ED) was chosen as the research object, and natural vegetation restoration without Eucalyptus (RNE: shrub S, grass G, and Dicranopteris D) nearby was used as the control group. SOC and its fractions in different vegetation types were compared and analyzed after sample plot surveys and sample determination, and the driving forces of SOC and its fractions were discussed. SOC, dissolved organic carbon (DOC), microbial biomass carbon (MBC), easily oxidized organic carbon (EOC), and particulate organic carbon (POC) in RE were significantly different from those in RNE, increasing by 194.4%, 36.3%, 111.0%, 141.6%, and 289.9%, respectively. The order of SOC, EOC, DOC, MBC, and POC content in RE was ES > EG > ED. SOC and its fractions were positively correlated with leaf litter cover and biomass, and soil organic matter. SOC, total nitrogen, available nitrogen, total phosphorus, available phosphorus, and enzyme activities were negatively correlated with microbial diversity but were not significantly correlated with soil bulk density and microbial richness. Structural equation modeling analysis results showed that soil enzyme activity was a direct driving force of SOC and its fractions. The input of carbon sources from leaf litter and soil properties were indirect factors that affected SOC and its fractions by affecting microbial characteristics and enzyme activities. Thus, planting Eucalyptus in harsh environments, where natural restoration is difficult, can be an effective measure for early vegetation restoration.
Study on Synergistic Characteristics of Accumulation Landslides Supported by Arbor Species
Authors: Jiang Tong , Li Longfei , Xue Lei , Huang Kun , Zhao Jindi , Wang Lijin , Wan Li , Ding Hao
Published: October 2022

Vegetation slope protection is widely used in slope support engineering as an ecologically friendly support method. There has been a lot of research on herbs and shrubs slope protection, but less on arbor slope protection. Using accumulation landslides as a research subject, a series of physical model tests of arbor slope protection were conducted, using a combination of various monitoring technologies and 3D printing technology that can produce realistic root models. The slope protection effect of arbors and the synergistic characteristics of accumulation landslides were explored using a preliminary analysis. We found that, with the support of arbor roots, (1) the peak-start stage, second peak stage, variable attenuation stage, and linear attenuation stage were the four stages of the anti-sliding force curve. The peak value of anti-sliding force on a slope with root protection increased, and the time it took to reach the peak value increased dramatically. Furthermore, after attaining the peak value, the degree of anti-sliding force attenuation was diminished. (2) The slope displacement showed a downward trend. Moreover, the coefficient of variation of displacement curves in different parts decreased, and slope integrity was enhanced. (3) The degree of slope crack growth diminished, resulting in an arch stress area and improved anti-sliding capacity. (4) There was an apparent “synergetic” tendency in the evolution process of accumulation landslides. Furthermore, the anti-sliding force and displacement curves in different parts had a good correspondence.
Drought Offsets the Potential Effects of Nitrogen Addition on Soil Respiration and Organic Carbon in Model Subtropical Forests
Authors: Zhu Yu-lin , Lin Xue-ping , Huang Yun-peng , Tang Xing-hao , Fang Xiong , Yi Zhi-gang
Published: October 2022

Nitrogen (N) deposition is increasingly aggravating and has significant impact on the processes of forest soil carbon (C) cycling. However, how N deposition affects forest soil C cycling processes in the scenario of future drought-frequent climate is still unclear. Therefore, we conducted a 2.5-year experiment at two levels of N addition treatments (control and N addition) and three levels of moisture (well-watered: ca. 80% of field capacity, moderate drought: ca. 60% of field capacity, severe drought: ca. 40% of field capacity) to investigate the impact of N addition, drought, and their interaction on soil respiration (Rs) and soil organic carbon (SOC) content. The results showed that N addition significantly increased Rs and SOC content, and severe drought decreased Rs and SOC content. In a well-watered condition, N addition significantly increased annual mean Rs, but in moderate drought and severe drought condition, N addition did not obviously affect Rs. In the control group, severe drought significantly decreased annual mean Rs by 61.5%, and decreased SOC content in 0–10 cm and in 10–20 cm by 3.0% and 1.6%, respectively. However, in the N addition group, moderate drought and severe drought significantly decreased annual mean Rs by 27.6% and 70.5%, respectively. Meanwhile, compared to the well-watered condition, severe drought significantly decreased SOC content in 0–10 cm and in 10–20 cm by 12.4% and 11.9% in the N addition group, respectively. Severe drought also decreased aboveground and belowground biomass, fine root biomass, MBC, and specific respiration in N addition group. The Rs and SOC content were positively correlated with aboveground biomass, belowground biomass, and fine root biomass. These results suggest that under future global change scenarios, severe drought might offset the promotive effects of N deposition on soil respiration and C sequestration in the young subtropical forest. Moreover, the N deposition may enhance the suppressive effect of drought on soil respiration and C sequestration in the future.
Water Transport Characteristics of Multiple Structures of Xylem Vessels in Magnolia
Authors: Xu Tianyu , Zhi Shuteng , Su Yanru , Li Zonglei , Zheng Ennan
Published: October 2022

The multiple structures of xylem vessels in Magnolia provide stable and efficient water transport channels. The structural parameters of xylem vessels were studied in wood sections and in macerated materials. The results showed that the xylem vessels of Magnolia contained a helical thickening structure and a pit structure of a secondary wall, and the end walls had a scalariform perforation plate. The helical thickening and scalariform perforation plate increased the flow resistance of the vessel, and the pit structure decreased the flow resistance of the vessel. There was a close positive correlation between the flow resistance of the vessels and the helical width, the helical height, the thickness of the scalariform perforation plate, the number of holes in the scalariform perforation plate, the length of the pit canal, and the pit spacing. In addition, there was a negative correlation between the flow resistance of the vessels and the helical spacing, the pit vertical diameter, and the pit domain length. Among these structural parameters, the helical height, the number of holes, and the length of pit canal had a greater influence on the flow resistance. The pit structure caused the vessel to produce radial water transport. The radial transmission efficiency increased with the increase in the pit domain length. With no pit membrane in the pit structure of Magnolia, the radial transmission efficiency would be between 43.99% and 53.21%.
Comparative Morphological, Anatomical and Physiological Analyses Explain the Difference of Wounding-Induced Agarwood Formation between Ordinary Agarwood Nongrafted Plants and Five Grafted Qi-Nan Clones (Aquilaria sinensis)
Authors: Li Xiaofei , Cui Zhiyi , Liu Xiaojin , Hong Zhou , Zhang Peng , Xu Daping
Published: October 2022

Agarwood is the dark resinous heartwood of injured ordinary Aquilaria sinensis (OA). Recently, some new clones of A. sinensis (Qi-Nan) that intensively produce high-quality agarwood were selected and cultivated by grafted clonal seedlings. However, very little is known about their agarwood formation mechanism, and it is unclear whether the current method of distinguishing Qi-Nan from OA by observing its leaf apparent morphology is scientifically reliable. In this study, the differences between OA and Qi-Nan clones in agarwood formation and their correlation with morphological, anatomical and physiological characteristics were investigated in two types of A. sinensis trees. After the mechanical injury, agarwood yield and essential oil content in agarwood of Qi-Nan were significantly higher than that of OA. There was no significant difference in leaf shape parameters between Qi-Nan and OA, but Qi-Nan showed higher specific leaf weight, total leaf chlorophyll, leaf nitrogen content and net photosynthetic rate. A xylem anatomical analysis showed that Qi-Nan had significantly smaller vessel wall thickness, greater ray cell wall thickness and larger interxylary phloem area than OA. Moreover, Qi-Nan had a greater consumption of non-structural carbohydrates than OA. Agarwood yield and oil content in agarwood showed significantly positive correlations with leaf photosynthetic capacity, the wall thickness of xylem ray cell, interxylary phloem area, starch utilization rate of trees, and a significantly negative correlation with the wall thickness of xylem vessel of trees. In brief, Qi-Nan has a stronger photosynthetic basis to supply more carbon sources, a more efficient xylem structural basis for agarwood production and a higher carbon source utilization rate, leading to a higher agarwood yield and oil content. It is not reliable to distinguish Qi-Nan from OA simply by observing leaf apparent morphology.
Review on the Phase Change Materials in Wood for Thermal Regulative Wood-Based Products
Authors: Sulaiman Nurul Syuhada , Mohamad Amini Mohd Hazim
Published: October 2022

Wood is an excellent building material or component that has been used all over the world. The rise in energy consumption worldwide, particularly in the building sector, has led to the development of diverse methods to overcome this problem. Embedding phase change material, PCM, into the wood has been researched as one of the most effective alternatives of controlling the thermal loads of wood, as it can store and release latent heat energy at a specific temperature range. Due to increasing interest, this article reviews the PCM in wood, including some research on the recent efforts that has been made by other researchers regarding this topic. This article also provides insight into problems associated with the wood and wood-based products incorporated with PCM. From the three groups of PCM, namely organic, inorganic, and eutectic mixture, the organic and eutectic mixture were most commonly chosen and successfully impregnated into wood structure. Carbonization and delignification can help to increase the stabilization of the PCM in wood. Adding PCM to wood sometimes decreases its strength, thus balancing between the thermal regulative performance and other industrial requirements needed to fabricate a fully functional thermal-regulative wood.
Spatiotemporal Changes in Leaf Area and Carbon Sequestration of Terrestrial Vegetation in China over the Last Two Decades
Authors: Hu Qingfeng , Gong Enjun , Wang Zhihui , Zhang Jing , Liu Wenkai , Feng Feng
Published: October 2022

Spatio-temporal change characteristic in leaf area index (LAI), gross primary productivity (GPP), total leaf area and total carbon sequestration of terrestrial vegetation at different geographic regions, provinces and land cover change types over China during 2000–2018 were clarified, respectively. The net increase in total leaf area and carbon sequestration over China from 2000 to 2018 is 1.7491 × 106 km2 and 1957.36 TgC, and Southwestern part contributes the most with a contribution of 25.3% for leaf area and 20.1% for carbon sequestration, respectively. The overall contribution of northern provinces to enhanced carbon sequestration capacity is greater than that of southern provinces, with a maximum for Inner Mongolia, even though southern provinces have a much higher leaf area increase. The annual increase rates of LAI and GPP in returning cropland to forest–grassland and artificial restoration of forest–grassland are higher than that of self-rehabilitation of rapid growth stage for planted young vegetation. However, due to self-rehabilitation of forest–grassland has the largest area percentage of 59%, it contributes the most to the increases of leaf area and carbon sequestration among different land cover change types, except for northeastern China, where improved farmland productivity is a dominant factor. It should be noted that the leaf area and carbon sequestration exhibit upward trends in urbanized areas over China. whereas slight increasing and even negative trends are also observed in southwestern, southern, and eastern China (e.g., Shanghai), where artificial surface construction occupied more cropland during urbanization processing. Compared with climatic factors, LAI is the dominant factor influencing GPP increases over China since 2000, and gradually weakened coupling relationship between LAI and GPP is observed from north to south. For climatic factors, GPP is dominantly affected by precipitation in northern parts and by solar radiation in southern parts.
Effect of Different Peat Substitute Substrates on the Growth and Quality of Seedlings of Handroanthus chrysanthus (Jacq.) S.O. Grose
Authors: Zhang Peijian , Zhang Guowu , Shang Xiuhua
Published: October 2022

With the depletion of peat resources, local agricultural and forestry wastes represent potential seedling substrate materials. We investigated the effects of mixed substrates supplemented with peat replacements, such as decomposed eucalyptus bark, coconut bran, and carbonized rice husk, on the growth of Handroanthus chrysanthus (Jacq.). We screened suitable organic substrates for the production of seedlings of H. chrysanthus to provide a theoretical basis for its scientific cultivation. The proportions of 15 types of substrates were determined by using simplex center-of-gravity mixing. The physical properties of different mixed substrates were studied, and the growth, biomass, root development, and photosynthesis of seedlings were analyzed. The quality of seedlings was comprehensively evaluated, and the optimal substrate ratio was obtained through regression analysis. Substrate compositions had significantly different effects on growth, biomass, root morphology, and photosynthesis. The results of these single-index analyses were corroborated by using principal component analysis. Adding decomposed eucalyptus bark was beneficial to the growth of seedlings, whereas coconut bran and perlite restricted growth. The results show that decomposed eucalyptus bark can replace peat as a container seedling substrate. The substrate formula can be used to provide technical support and a theoretical basis for the scientific cultivation of high-quality light matrix seedlings of H. chrysanthus.
Online Measurement of Outline Size for Pinus densiflora Dimension Lumber: Maximizing Lumber Recovery by Minimizing Enclosure Rectangle Fitting Area
Authors: Ji Min , Zhang Wei , Wang Guofu , Wang Yong , Miao Hu
Published: October 2022

This paper proposes a non-contact, online, rapid, and non-destructive measurement method of Pinus densiflora S.et Z. (Pinus densiflora) dimension lumber based on an algorithm of maximizing lumber recovery by minimizing the enclosure rectangle fitting area. The method takes the full influence of multiple factors, such as the difficulty in measuring large-size dimension lumber, conveying deflection, etc. into account. Image splicing, object and background segmentation, and lumber size measurements are carried out. Compared to other current algorithms, it can decrease the measurement errors and improve measurement efficiency. The problems of slow image segmentation, large-size lumber measurement, and conveying deflection are solved. Through measurement tests and error analysis, the measurement accuracy of the lumber size can reach 0.8 mm/m. This method meets the requirements of high-speed lumber production and lays the foundation for the development of a lumber detection and evaluation system.
Increased Soil Bacterial Abundance but Decreased Bacterial Diversity and Shifted Bacterial Community Composition Following Secondary Succession of Old-Field
Authors: Yang Wen , Cai Xinwen , Wang Yaqi , Diao Longfei , Xia Lu , An Shuqing , Luo Yiqi , Cheng Xiaoli
Published: October 2022

Plant secondary succession is a very effective approach for the rejuvenation of degraded ecosystems. In order to comprehend alterations and driving mechanisms of soil bacterial communities under secondary succession of old-field and reveal their subsequent impacts on the decomposition and accumulation of soil organic carbon (SOC) and nitrogen (SON), we investigated changes in soil bacterial communities following ~160 years of old-field succession on the Loess Plateau of China through analyses of quantitative polymerase chain reaction (qPCR) and Illumina MiSeq DNA sequencing of 16S rRNA genes. Our results revealed that subsequent to secondary succession of old-field, soil bacterial abundance progressively increased, while bacterial richness and diversity significantly decreased. Principal component analysis and Bray–Curtis similarity index showed that bacterial community composition gradually shifted following old-field succession. Specifically, the relative abundances of Proteobacteria, Rokubacteria, and Verrucomicrobia progressively increased, while Actinobacteria and Firmicutes slightly decreased following old-field succession. The most enriched of Proteobacteria (e.g., Rhizobiales, Xanthobacteraceae, Gammaproteobacteria, Bradyrhizobium, Rhizobiaceae, and Mesorhizobiur) were found in a climax forest, while Chloroflexi and Gemmatimonadetes had the lowest relative abundances. Further, the most enriched members of Actinobacteria, including Geodermatophilaceae, Frankiales, Blastococcus, Micrococcales, Micrococcacea, Propionibacteriales, Nocardioidaceae, Nocardioide, and Streptomycetaceae, were exhibited in the farmland stage. Our results suggested that secondary succession of old-field greatly modified soil bacterial communities via the transformation of soil nutrients levels, altering plant biomass and soil physiochemical properties. Soil bacterial community composition was transformed from oligotrophic groups to copiotrophic Proteobacteria following old-field succession, which may promote SOC and SON accumulation through increasing the utilization of labile organic carbon (C) and nitrogen (N), while decreasing decomposition of recalcitrant organic C and N from the early- to late-successional stages.
Targeted Metabolomics Reveals Impact of N Application on Accumulation of Amino Acids, Flavonoids and Phytohormones in Tea Shoots under Soil Nutrition Deficiency Stress
Authors: Gong Xuejiao , Li Lanying , Qin Lin , Huang Yingbo , Ye Yulong , Wang Min , Wang Yingchun , Xu Yaqiong , Luo Fan , Mei Huiling
Published: October 2022

The abundant amino acids and flavonoids in tea crucially contribute to its particular flavor and many health benefits. The biosynthesis of these compounds is significantly affected by carbon and nitrogen metabolism, which is regulated by the nitrogen conditions in the soil. However, exactly how N-starved tea plants use N absorbed from the soil for the biosynthesis of amino acids, flavonoids, and phytohormones is still little known. Here, tea plants that were deficient in nitrogen owing to long-term non-fertilization were subjected to a higher N application (300 kg/ha) or lower N application rate (150 kg/ha) as well as organic or inorganic N. The levels of 30 amino acids, 26 flavonoids, and 15 phytohormone compounds were analyzed using ultra-high-performance liquid chromatography quadrupole mass spectrometry (UPLC-Q-MS/MS). It was found that a continuous lack of fertilization generated a minimal availability of soil N; as a result, the yield and the theanine and soluble sugar contents were greatly decreased, while the accumulation of seven flavonoid compounds (e.g., epigallocatechin, vitexin, and genistein) increased notably. The levels of theanine, glutamate, and aspartate significantly increased with the supply of N, whereas multiple amino acids, such as alanine, phenylalanine, valine, etc., decreased, indicating that the absorption of nitrogen is preferentially used for the biosynthesis of theanine and glutamate-derived amino acids by a N-starved tea plant. Meanwhile, the changes in the accumulation of flavonoids in tea shoots with various N supplies clarified that a lower N application rate has a negative influence while higher N has a positive effect on the synthesis of flavonoids in a N-starved tea plant. In addition, following N supply, the N-deficient tea plant accumulated ABA (Abscisic acid), SA (Salicylic acid), JA (Jasmonic acid), CKs (Cytokinins), and ACC (1-Aminocyclopropanecarboxylic acid), at 2.03, 1.14, 1.97, 1.34, and 1.26 times, respectively, as high as those in a tea plant with normal fertilization. Furthermore, we performed the correlation network analysis among amino acids, flavonoids, and phytohormones. Its result confirmed that glutamate, aspartate, and hydroxyproline showed a significantly positive correlation with 8, 11, and 8 flavonoid compounds, respectively. Cis-OPDA (cis-12-oxo-phytodienoic acid) was also significantly negatively correlated with eight flavonoid compounds (e.g., naringenin, myricetin, and quercetin). Collectively, our tests suggested that a lower N application promotes the biosynthesis of the theanine and amino acids involved in theanine synthesis, thus inhibiting the accumulation of other amino acids, while greater N application promotes flavonoids in a N-starved tea plant.
Striking a Balance between Livelihood and Forest Conservation in a Forest Farm Facility in Choma, Zambia
Authors: Wang Lanhui , Mondela Champo Lasford , Kuuluvainen Jari
Published: October 2022

Charcoal production is an essential energy source and income source for many people in low-income countries, such as Africa. Charcoal production is also associated with deforestation—a global issue that significantly affects the environment and ecosystems. Therefore, promoting strategies that can balance forestry protection and people’s livelihoods in low-income countries is critical. This study investigated the factors affecting Zambia’s rural households’ participation in the natural regeneration (NR) program—the program initiated by the Forest and Farm Facility program (FFF) of the United Nations Food and Agricultural Organization (FAO) in Zambia in 2015. Using household survey data collected from Choma District in Southern Zambia, this study used descriptive statistical analysis and a logit model to detect the factors that affect the use of the NR program. The results indicate that charcoal production enhances the livelihoods of rural households when forest conservation is reconciled with household income and forest-management methods that abandon traditional practices. Participation in the NR program seems to be mainly driven by household income. The results indicated that the relationship between forest-resource utilization and conservation in Choma is encouraging. The implementation of the Forest and Farm Facility program is recommended to be spread to other communities to improve both livelihoods in local communities and forest conservation.
Comparative Transcriptome Analysis to Identify Candidate Genes Related to Chlorogenic Acid and Flavonoids Biosynthesis in Iridaceae
Authors: Han Guijun , Bai Guoqing , Wu Yongpeng , Zhou Yafu , Yao Wenjing , Li Long
Published: October 2022

Iris (Iridaceae) is one of the most widely admired ornamental plants. It has been used mainly in medicine due to the high concentration of chlorogenic acid (CGA), flavonoids, isoflavones, lignans, and other compounds in its rhizomes. In iris, the gene functions related to CGA and flavonoids biosynthesis are still unclear. In this study, we compared the I. germanica rhizome with a high accumulation level of CGA but a low accumulation level of flavonoids, and the I. pallida rhizome with a low accumulation level of CGA but a high accumulation level of flavonoids at the transcriptome and metabolome levels. A total of 761 metabolites were detected, including 202 flavonoids and 106 phenolic acids based on metabolome profiling. In total, 135 flavonoids were highly accumulated in I. pallida, including three flavanols, 51 flavonoids, 12 flavonoid carbonosides, 31 flavonols, and 21 isoflavones. Based on single-molecule long-read sequencing technology, 94,461 transcripts were identified in iris. Expression analysis indicated that the high accumulation level of C4H and 4CL in I. germanica were essential for CGA accumulation, while CHS, DFR, ANS, ANR, LAR, and 3GT were essential for flavonoids biosynthesis in I. pallida. Many transcription factors such as transcript_83288 (MYB), transcript_57970 (WRKY), and transcript_77465 (WRKY) act as regulators, playing important roles in these biological processes. Our findings provide new insights into the molecular mechanisms associated with the biosynthesis and regulation of flavonoids and CGA in the iris rhizome, and highlight the usefulness of an integrated approach for understanding this process.
Restoration Strategies for Three Dacrycarpus dacrydioides (A.Rich.) de Laub., Kahikatea Remnants in Hamilton City, New Zealand
Authors: Rogers Hannah C. , Clarkson Bruce D.
Published: October 2022

Identifying appropriate restoration strategies is vital for successful urban remnant restoration, but projects often lack consistent methods that distinguish them. In New Zealand, there are unique opportunities to restore depleted Dacrycarpus dacrydioides (A.Rich.) de Laub. (kahikatea, white pine) semi-swamp forest remnants in numerous urban centres. To assess potential restoration strategies for three kahikatea remnants in Hamilton City, we compared their physical features, native vascular species composition, age structures, life forms and epiphytes with a notional reference site (Te Papanui). Numerous native vascular species gaps are revealed among Te Papanui (66 species), Totara Park (40 species), Hillcrest Park (15 species) and Grove Park (nine species). Age structure analyses suggest that Hillcrest Park comprises the oldest kahikatea population, with an average age of 82 years, followed by Grove Park (70 years), Te Papanui (60 years) and Totara Park (32 years). A native floristic analysis of thirteen life forms found that Te Papanui contains the most (11), followed by Totara Park (eight), Grove Park (six) and Hillcrest Park (five). Despite the abundance of invasive plants at Totara Park, its high-water table and favourable humid, sheltered conditions support more epiphytes (nine) than Te Papanui (six), Hillcrest Park (one; Pyrrosia eleagnifolia), and Grove Park (none). Epiphytes absent from Te Papanui found at Totara Park may be due to the loss of the once abundant tree fern and host, Dicksonia squarrosa (whekī). Totara Park requires careful manipulation of troublesome weeds, whereas Hillcrest Park and Grove Park necessitate buffer extensions and native understory plantings. This study provides a simple framework that uses biophysical differences among urban remnants and a reference site to reveal suitable restoration strategies that could guide other urban restoration projects regionally and nationally.
Determination of Leaf pH without Grinding the Sample: Is It Closer to the Reality?
Authors: Chen Jiashu , Liu Sining , Hou Yufei , Luo Yan , Han Wenxuan
Published: October 2022

This study recommends a non-grinding measurement method of leaf pH which can reduce the destructive interference to the measured fresh-leaf pH values. To verify the accuracy of this method, we measured leaf pH with the non-grinding and grinding method and further assessed the dilution effect on leaf pH in the grinding process. Compared with the non-grinding method, the grinding method significantly increased the measured pH value; leaf pH increased with decreasing leaf–water ratio in the procedure of the grinding method, but gradually stabilized. The grinding effects of severe physical damage and thereafter oxidization of leaf samples, and the dilution effects according to the Debye–Hückel limiting law and acid-base ionization theory, may both contribute to the increased leaf pH measured with the grinding method. Thus, leaf pH measured with the non-grinding method was expected to be much closer to those of leaf sap in vivo and be more suitable to indicating the dynamic variation or instant response of leaf pH to the environmental changes. Finally, considering that non-significant difference had been proved in the measured leaf pH between dried, frozen, refrigerated, and fresh ground samples, a conversion equation was provided to facilitate mutual conversion of the results with non-grinding fresh samples (y) against those with grinding dried samples (as representative) (x): y = 1.097x − 0.722.
Impact of Silica Addition on Alleviating Cadmium Stress: Case Studies of Three Afforestation Tree Species Seedlings in Southern China
Authors: Wang Ziyang , Jin Shaofei , Su Yi , He Dongmei , Wang Yunxiang , Chen Yifei , Lin Chenlei , Liao Xiaoli , Zheng Dexiang
Published: October 2022

Cadmium (Cd) stress is becoming an increasing menace for plants, inducing a series of negative effect. Silicon (Si) plays an important role in mitigating Cd stress in plants. Here, we conducted a one-year experiment with three kinds of tree species seedlings (Schima superba, Chinese sweetgum, Chinese fir) and five levels of Cd treatments (0 mg·kg−1, 6 mg kg−1, 12 mg kg−1, 24 mg kg−1, 36 mg kg−1) with or without 1 g kg−1 Si addition to investigate the mitigation effect of Si on woody plants. The results in this study showed that Cd stress triggered morphological and physiological changes, inhibiting the growth of the three kinds of tree species seedlings. Low concentrations of Cd treatment stimulated the biomass production of Schima superba and Chinese sweetgum seedlings, whereas the biomass production of Chinese fir was not stimulated by Cd treatment. The stimulatory effects were also observed in the antioxidant enzyme (SOD, POD, CAT) activities of the three kinds of seedlings. The MDA contents decreased with the rise of Cd treatments. Soil pH decreased under Cd stress. BCF values of different fractions were observed to increase with the rise of Cd treatments, except for the leaf BCF value of Chinese sweetgum. The root−to−stem TF values of all increased compared with the control, while the root-to-leaf TF values were observed to decrease. Si addition enhanced the growth of the three kinds of tree species seedlings, inducing the increase of heights, ground diameter, leaf morphological parameters, biomass production, the content of chlorophyll and the activities of antioxidant enzymes. Treatment with Si significantly decreased the Cd concentration in different fractions of the three kinds of seedlings. Soil pH increased after treatment with Si. The BCF values for Si-treated plants were all observed to be lower than the non-Si-treated ones. However, the addition Si did not affect the root-to-stem and root-to-leaf TF values in the three kinds of seedlings.
Analysis of Volatile Aroma Compounds and Sensory Characteristics Contributing to Regional Style of Red Wines from Hexi Corridor Based on Sixteen Grape Varieties/Clones
Authors: Zang Xiaomin , Du Qing , Qu Rui , Ye Dongqing , Lu Yao , Liu Yanlin
Published: October 2022

Hexi Corridor is an excellent region for high-quality wines in China, but the characteristic and style of red wine from this region is unclear. To elucidate the regional style of red wines from Hexi Corridor, the aroma properties of red wines made from 16 different varieties/clones of grapes were comprehensively analyzed using HS-SPME-GC-MS, sensory evaluation, odor activity value method, and partial least squares regression analyses. We identified 52 aroma compounds and found that floral and black berry provided a good reference for shaping red wine style and selecting related varieties in Hexi Corridor region. Ethyl caproate, (Z)-3-hexen-1-ol, ethyl 9-decenoate, and hexyl alcohol, which were the characteristic aroma substances of Hexi Corridor red wines, had positive effects on the floral aroma of Merlot, Cabernet Sauvignon, Pinot Noir, and Malbec wines. Hexyl alcohol and (Z)-3-hexen-1-ol also contributed to the black berry and spice aromas, while isobutyl acetate opposed the expression of these aromas of Malbec and Cabernet Franc wines. These results showed that the sensory characteristics of floral and black berry are of vital significance in shaping the red wine style of Hexi Corridor, among which ethyl caproate, (Z)-3-hexen-1-ol, ethyl 9-decenoate, and hexyl alcohol are important contributors.
q-PCR Methodology for Monitoring the Thermophilic Hydrogen Producers Enriched from Elephant Dung
Authors: Saripan Khamanitjaree , Mamimin Chonticha , Imai Tsuyoshi , Sittijunda Sureewan , Reungsang Alissara
Published: October 2022

This study aims to create a quantitative polymerase chain reaction (q-PCR) methodology for monitoring the hydrogen-producing mixed cultures enriched from elephant dung using alpha-cellulose as a carbon source through five generations of repetitive sub-culture. The enriched thermophilic mixed cultures from the fifth cultivation cycle gave the highest hydrogen yield of 170.3 mL H2/g cellulose and were used to generate hydrogen from sawdust. Clostridium sp. and Thermoanaerobacterium sp. were the dominant bacteria in thermophilic mixed cultures with high hydrogen yield, according to polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE). q-PCR primers Chis150F and ClostIR, TherF and TherR, and BacdF and BacdR were developed to amplify the 16S rRNA genes of Clostridium sp., Thermoanaerobacterium sp., and Bacillus sp., respectively, for the quantification of hydrogen-producing bacteria in biohydrogen fermentation. Similar q-PCR analysis of Clostridium sp., Thermoanaerobacterium sp., and Bacillus sp. 16S rRNA gene amplification during hydrogen production from cellulose and sawdust revealed increasing gene copy number with time. The molecular approaches developed in this study can be used to monitor microbial communities in hydrogen fermentation processes efficiently.
Effects of Different Forage Types on Rumen Fermentation, Microflora, and Production Performance in Peak-Lactation Dairy Cows
Authors: Guo Cheng , Wu Yaqi , Li Shengli , Cao Zhijun , Wang Yajing , Mao Jiang , Shi Haitao , Shi Renhuang , Sun Xiaoge , Zheng Yuhui , Kong Fanlin , Hao Yangyi , Xu Xiaofeng
Published: October 2022

Forages are vital in maintaining the dietary structures of ruminants, and reducing their costs is important for improving dairy production efficiency. Thus, this study investigated the effects of dietary forage types on dry matter intake, production, rumen fermentation, and the microbial profile in peak-lactating cows. Eight cows (600 ± 25 kg) with days in milk (60 ± 10 days) were assigned to four groups using a replicated 4 × 4 Latin square design: OG (oat hay + alfalfa hay + corn silage + concentrate), CW (Leymus chinensis + alfalfa hay + corn silage + concentrate), AS (alfalfa silage + oat hay + corn silage + concentrate), and AC (alkali-treated corn straw + alfalfa hay + corn silage + concentrate). The ruminal butyrate acid concentration was lower in the OG group than in the AS and AC groups post-feeding (12 h; p < 0.05). Ruminal NH3-N content was higher in the AS group than in the AC and CW groups post-feeding (9 h; p < 0.05). The percentage of ruminal Oscillospira and unknown microbes was higher in the CW group than in the other groups (p < 0.05). The total rumination time and rumination time per dry matter intake of AC were significantly higher than those of the other groups (p < 0.05). Milk lactose content in the AS group was highest among the groups (p < 0.05), and milk fat content was higher in the OG group than in the CW group (all p < 0.05). Overall, our results suggested that the butyrate acid content of forage from oat hay in rumen fermentation was significantly lower than that of calcium oxide and alfalfa silage sources when the dietary nutrition level was similar. The diet derived from L. chinensis increased the number of fibrillation helices related to fiber-decomposing bacteria and simultaneously increased unknown strains. Forage derived from alfalfa silage tended to increase milk protein levels. Alkali-treated corn straw could significantly increase the total rumination time and unit dry matter rumination time of dairy cows, which plays an important role in maintaining rumen health. The rational use of low-quality forage has broad prospects in China.