Objective: By analyzing the niche characterization of tree functional types (TFTs) in a central subtropical karst forest, we can infer the differences in resource utilization and interspecific competition among different TFTs, providing theoretical guidance for vegetation restoration and reconstruction in karst areas. Method: Based on plot surveys in the subtropical karst evergreen-deciduous broadleaved mixed forest in central subtropical China, the 40 tree species were selected and classified into different functional types according to canopy height, population size, shade tolerance, and seed dispersal mode. The niche characterization of the tree species in different functional types were analyzed by measuring niche breadth and niche overlap index. Result: The niche breadths of tree species in the karst forest are generally low, with the ranking of common species > occasional species > rare species, and there are significant differences among them. The niche breadths of gravity dispersed species are significantly lower than those of animal dispersed and wind dispersed species, while there are no significant differences in niche breadths between different TFTs with different shade tolerance and canopy height. The niche overlaps among the 40 tree species are also low, with significantly higher overlap between common species compared to occasional and rare species, and significantly higher overlap for overstory species compared to understory species. Light demanding species have significantly higher overlaps compared to shade tolerant species, while gravity dispersed species have significantly lower overlaps compared to animal dispersed and wind dispersed species. The overlaps between common and occasional species are significantly higher than those between common and rare species, as well as those between occasional and rare species. The overlaps between animal dispersed and wind dispersed species are significantly higher than those between animal dispersed and gravity dispersed species, as well as those between wind dispersed and gravity dispersed species. However, the overlaps between mid-tolerant and shade tolerant species are significantly lower than those between light demanding and mid-tolerant species, as well as those between light demanding and shade-tolerant species. Conclusion: Most tree species in the subtropical karst evergreen and deciduous broad-leaved mixed forest occupy relatively small niche spaces and may have lower interspecific competition. The differences in niche breadth and overlap among different TFTs may be closely related to habitat heterogeneity and species trait differences. When conducting vegetation restoration in degraded habitats, the composition and structure of the community should be reasonably constructed based on the niche characterization of different TFTs, thereby promoting recovery of forest vegetation.

Objective: The objective of this study was to assess the influence of leaf traits on the litter production and litter turnover period in subtropical China. This study was aimed to provide scientific basis for the rational selection of tree species in afforestation to improve soil fertility after successive reforestation of Cunninghamia lanceolata. Method: We studied the annual litter productions and their turnover periods under 3-year-old young afforested land, which were established on the sites after clear-cutting of Cunninghamia lanceolata plantations. The regression relationships between leaf traits and litter production/turnover period were established by measuring leaf functional traits (specific leaf area, leaf dry matter content, nitrogen content, etc.) and leaf litter quality (leaf litter C/N ratio, tannin content, soluble sugar content, etc.). Result: Among 17 tree species, Mytilaria laosensis had the highest litter production (6.67 t·hm^?2a^?1), and C. lanceolata had the lowest litter production (0 t·hm^?2a^?1). Alnus trabeculosa leaf litter had the shortest turnover period (0.09 a). Michelia maudiae leaf litter had the longest turnover period (1.09 a). The litter production increased with the increase of specific leaf area and decreased with the increase of leaf nitrogen content. The litter turnover period increased with the increase of leaf litter C/N ratio and tannin content, decreased with the increase of leaf litter max water retention capacity. Conclusion: In subtropical young afforested land, leaf functional traits effect the litter production and leaf litter traits effect the turnover period. Meanwhile, Cunninghamia lanceolata plantations has lower litter production return to soil in subtropical young afforested land. In the management of subtropical artificial forest, it is necessary to consider planting trees with higher specific leaf area and litter maximum water holding capacity, lower litter tannin content and carbon nitrogen ratio, so as to improve the return amount and forest litter turnover and improve the soil fertility of degraded plantations.

Objective: A quantitative acknowledge on the spatial variation and scale effect of soil organic carbon (SOC) content provides basis to accurately and conveniently estimate the average SOC content of the whole slope, comprehensively understand the status of soil resources and the ecosystem carbon cycle, and propose high-quality soil management programs. Method: Three adjacent typical slopes formed by the project of returning farmland to forestland were selected in the small watershed of Zhongzhuang within the semi-arid loess hilly region of Ningxia. After multiple sample points were set up in succession from the top to the foot on slopes, the land use, vegetation characteristics and site conditions were investigated, the surface soil samples (0-20 cm) were collected to test the SOC content, and the slope aspect difference and slope position variation were analyzed. Taking the horizontal distance or relative distance from slope top as the independent variable, the slope scale effect was quantitatively described by the slope moving average of the surface SOC content as the dependent variable, and the ratio of the surface SOC content of any point on the slope to the average value of the slope as the dependent variable to realize the scale from ‘point’ to ‘slope’. Result: The surface SOC content had obvious slope difference, position variation and scale effect in the study region. The average surface SOC content was the highest on the southern slope (7.60 g·kg^?1), followed by the eastern slope (6.42 g·kg^?1) and the western slope (5.65 g·kg^?1). However, the variation range of surface SOC content of the eastern slope (15.95 g·kg^?1) was the largest, followed by the western slope (11.34 g·kg^?1), and the smallest was the southern slope (9.72 g·kg^?1), indicating that the slope effect was the strongest on the eastern slope, followed by the western slope and the southern slope. The pattern of position variation in surface SOC content was roughly the same among the three slopes, which gradually decreased from the slope top, and tended to be stable after the horizontal distance from slope top reached 200, 150 and 280 m (relative distance were 0.73, 0.45 and 0.76), respectively. It was mainly due to the spatial distribution pattern of land uses (Upper part: natural slopes; Lower part: terraced fields), vegetation types (Upper part: forest and grass; Lower part: crops) and vegetation restoration years (Upper part: long time; Lower part: short time). For every 100 m increase in the horizontal distance from slope top, the moving averages of the eastern, western, and southern slopes increased ?3.40, ?2.50, and ?1.51 g·kg^?1, respectively. For every 0.1 increase in the relative distance from slope top, the moving averages increased ?0.96, ?0.75 and ?0.55 g·kg^?1, respectively. The quantitative relationships between the ratio of surface SOC content at different slope positions to the slope average in three slopes was well constructed with the increase of horizontal distance or relative distance from slope top (R²>0.7, P<0.001), then the value of slope average can be accurately and conveniently estimated from the data of any point on a slope. Besides, the surface SOC content measured at a relative distance of 0.4 from slope top was the most similar with as the average value of slope. Conclusion: The surface SOC content decreases first and then stabilizes from the top to the bottom of slopes in semi-arid loess hilly region, which closely relates to the spatial distribution pattern of land uses, vegetation types and restoration years. The slope variation characteristics and scale effect of surface SOC content can be quantitatively described by taking the increase of (relative) horizontal slope length as the scale variable, so as to accurately and conveniently estimate the average value of surface SOC content on a slope.

Objective: The aim of this study was to determine the relative contribution rate of environmental variables to forestland superficial landslide risk, to clarify the key vegetation factors affecting the superficial landslide risk and their disaster reduction range, and to reveal the coupling effect of vegetation and non-vegetation factors on the superficial landslide risk. This research can provide important theoretical support for landslide risk assessment and disaster mitigation decision. Method: Taking the forest land in Huaying Mountains as the research object,17 environmental variables were selected, and the MaxEnt model was used to determine the relative contribution rate of environmental variables to the prediction of superficial landslide risk of the forest land, the response changes of superficial landslide risk to various factors were analyzed based on the existence of vegetation factors. Result: 1) The ROC test results of the model accuracy showed that the simulation accuracy of the model was 0.887 without considering the vegetation factor, which reached a very accurate level of accuracy, while in the case of considering the vegetation factor, the simulation accuracy of the model was 0.915, which reached an extremely accurate level of accuracy, and the accuracy was improved by 3.1%. 2) The cumulative contribution rate of engineering geological rock group, forest volume, distance to fault, terrain relief, elevation, green-red vegetation index, plane curvature, and stand type to the prediction of superficial landslide risk reached 80%. Vegetation factors played an important role in the superficial landslide risk prediction, mainly reflected in forest volume, vegetation coverage, and stand type. 3) The existence of vegetation factors changed the response of superficial landslide risk to five variables including plane curvature, slope aspect, elevation variation coefficient, slope variable, and profile curvature. Vegetation factors weakened the superficial landslide risk caused by plane curvature, elevation variation coefficient, and profile curvature, and the reduction rates were 4.9%, 5.9%, and 8.1%, respectively. Vegetation factors aggravated the superficial landslide risk caused by slope variability, with an aggravating rate of 10.9%, and it had both positive and negative effects on the superficial landslide risk generated by the slope aspect, with the aggravation and reduction rates of 12.8% and 6.4%, respectively. Conclusion: Our results demonstrated that the MaxEnt model had high simulation accuracy for the simulation of superficial landslide risk of forest land, and it expressed the response of the superficial landslide risk to various influencing factors intuitively. When using this model to predict the superficial landslide risk of forest land, in addition to the conventional influencing factors such as geology, topography, landform, soil, etc., the vegetation factor was also a key environmental variable in the model simulation, which had an important contribution to the simulation accuracy. The existence of vegetation factors generally did not change the response trend of the superficial landslide risk to other influencing factors, but would have an important impact on the superficial landslide risk caused by the extreme values of some non-vegetation factors, showing a coupling effect, which might aggravate or weaken the superficial landslide risk.

Objective: This study is intended to explore whether and how slash pine (Pinus elliottii) nutrient acquisition and utilization strategies are effected by the initial planting (even-aged mixed) and replanting (uneven-aged mixed) of broad-leaved trees, in order to provide a scientific basis for management of the slash pine forests. Method: Our study was focused on slash pine, which are widely planted in the subtropical red soil hilly region of China. We conducted a long-term single-species and mixed experiment including three treatments (a 20 m×20 m plot per treatment) that pure slash pine plantation, mixed plantation of slash pine and Schima superba, mixed plantation of slash pine and S. superba (replanting S. superba for 14 years).At the age of 30 years and with similar site conditions, five 20 m × 20 m plots in each treatment were established.The rhizosphere soil, fine roots, twigs, fresh and senesced needles of slash pine standard trees were collected. The nitrogen (N) and phosphorus (P) in soil and plant organs were determined to evaluate the effects of different mixed methods on root nutrient capture, needles nutrient resorption and nutrient translocation, and to reveal the driving factors of nutrient acquisition strategies. Result: Initial and replanting broad-leaved trees increased the rhizosphere soil NH₄⁺-N and mineral N (MN) in slash pine (P<0.05). But there was no significant difference in nutrient contents between the initial planting and the replanting. Mixed broad-leaved trees increased the N and P concentrations of each organ in slash pine, and the mixed effect of the initial planting was better than that of the replanting. Slash pine had 14.04% and 46.16% higher root capture ability of N and P in the initial mixed plantation than the pure plantation, respectively. The needles N resorption efficiency in the initial mixed plantation significantly decreased by 6.07% compared with slash pine pure plantation, and the needles P resorption efficiency in the initial mixed plantation significantly increased by 15.49%. The lack of significant effect of broadleaf tree replanting on both root capture and needles resorption efficiency of slash pine because of the reduction in cost of roots nutrient capture compensating for the inhibition of root nutrient absorption. In addition, compared with pure plantation, the N translocation of transport roots to twigs and needles in the initial mixed plantation increased by 36.05% and 15.61%, respectively. And compared with pure plantation, the P translocation of transport roots to twigs and needles in the initial mixed plantation was decreased by 35.13% and 36.52%, respectively. There was no significant change in N translocation in the replanting of the mixed plantation, but the P translocation from transport roots to twigs and needles was 53.21% and 40.17% lower than that in the pure plantation. Conclusion: Mixed broad-leaved trees increased the nutrient content of rhizosphere soil and plant organs, and changed the nutrient acquisition strategy of slash pine in red soil hilly region.The initial planting promoted nutrient acquisition and utilization of slash pine with higher intensity than the replanting. In addition, the translocation process of nutrient in plants would shape the trade off between root capture and needles resorption.

Objective: Acid rain caused by sulfur dioxide and nitrogen oxide emissions harms the growth of trees in southern China, it is imperative to elucidate the long-term effects of acid rain in these southern acid rain areas on the radial expansion of various tree species. Method: In this study, Pinus massoniana and Machilus nanmu, the dominant tree species in Jinyun Mountain, were investigated with tree ring climatology 40 and 35 cores of Pinus massoniana and Machilus nanmu were collected respectively. The chronology of tree whorl width was established. And calculate the basal area lncrement. The chronology of tree ring width was established, and the increase of DBH cross-sectional area was calculated. The changes of tree growth and the response relationship between tree growth and acid rain factors in recent 20 years were analyzed. Result: 1) The overall representativeness of Pinus massoniana and Machilus nanmu standard chronology samples are 0.942 and 0.869 respectively. The overall representativeness, average sensitivity, first-order autocorrelation and interpretation of the first principal component of Pinus massoniana standard chronology are larger than those of Machilus nanmu. 2) Between 1961 and 2020, both Pinus massoniana and Machilus nanmu experienced growth inhibition, and the growth inhibition time of Pinus massoniana was longer than that of Machilus nanmu, but they all recovered after 2010. 3) The type of acid rain in the Jinyun Mountain gradually changed from sulfuric acid type to mixed sulfuric acid-nitric acid rain. Average temperature and precipitation are not the main limiting factors of tree growth in Jinyun Mountain in the past 20 years. The radial growth of Pinus massoniana and Machilus nanmu was significantly positively correlated with rainfall pH (P<0.05), significantly negatively correlated with rainfall SO₄^2? (P<0.05). Rainfall NO₃^? was significantly negatively correlated with the radial growth of Machilus nanmu (P<0.05), and rainfall NH₄⁺ was significantly negatively correlated with the radial growth of Pinus massoniana (P<0.05). 4) Multiple linear regression model shows that annual-scale rainfall SO₄^2? concentration and NO₃^? concentration had highly significant negative effects (P<0.01) on radial growth of Sargasso pine and Runner's briar, respectively, explaining 65.5% and 29.5% of the growth variance, respectively. which is the main limiting factor of tree growth in Jinyun Mountain. Conclusion: Acid rain SO₄^2? and NO₃^? are the main limiting factors for tree growth in the Jinyun Mountain area. There is great potential to use tree rings to study the effects of acid rain on tree growth.

Objective: This study aims to provide a theoretical basis for scientific management, effective protection and efficient utilization of germplasm resources, by investigating population structure of collection germplasm resources of Phoebe bournei with SSR markers, and constructing a core collection of the germplasm resources. Method: A total of 33 pairs of SSR primers were used to investigate the genetic diversity and genetic structure of 425 individual trees of P. bournei belonging to 218 subfamilies collected from 27 provenances of five provinces (autonomous region), including Fujian, Jiangxi, Hunan, Zhejiang, and Guangxi. Genetic diversity parameters such as number of observed alleles (N_a), effective number of alleles (N_e), observed heterozygosity (H_o), Shannon’s information index (I), Nei’s diversity index (H) were calculated by combined DateTrans1.0 and Popgene32 software. The genetic structure of nine populations was analyzed using STRUCTURE 2.3.4 software. The core collection was constructed by using the method of grouping and stepwise clustering with the minimum distance. The genetic diversity parameters were examined by t-test, to verify the validity of the core collection for P. bournei. Result: According to the geographical distribution of germplasm sources, 218 families can be divided into 9 populations. A total of 130 alleles were detected at 33 SSR loci, and the average number of effective alleles (N_e) was 2.159, the average observed heterozygosity (H_o) was 0.224, the average expected heterozygosity (H_e) was 0.477, and the Shannon information index (I) average value was 0.841, indicating that there was the moderate genetic diversity in the germplasm resources of P. bournei. Genetic structure analysis classified nine populations into three groups. From the 425 original germplasm resources of P. bournei, 85 core germplasms and 340 reserved germplasms were obtained through stepwise cluster sampling. The core germplasms accounted for 20% of the original germplasms, and the retention rates of its N_a, N_e, H_o, H_e, I, and H were 92.318%, 103.803%, 116.652%, 105.052%, 103.341%, and 104.664%, respectively. The t-test analysis showed that there was no significant difference in the genetic diversity parameters between the core germplasm and the original germplasm, indicating that the core germplasm was able to fully represent the genetic diversity of the original germplasm. Conclusion: The core germplasm collection preserves the genetic diversity information of the original collection, which removes the genetic redundancy. The results are beneficial to the effective protection and scientific utilization of P. bournei resources and lay a solid foundation for further breeding in P. bournei.

Objective: Tung tree is one of the four major woody oil tree species in China. The development of tung tree industry has certain strategic significance for improving China’s energy self-sufficiency. This paper aims to establish a new asexual reproduction technology system for tung tree seedlings with hypocotyle rootstocks grafting by studying the new technique of tung tree seedlings and hypocotyle grafting, so as to provide a new way for the future asexual reproduction of tung tree elite varieties. Method: The seedlings cultivated from Vernicia montana and Vernicia fordii seeds were used as rootstocks, and the current year-old semi-woody stem segments with buds of the offsprings of Vernicia fordii ‘Huatong No. 1’ were used as scions. The effects of different rootstock species, grafting methods, grafting film types, grafting periods, seedbeds and transplanting heights on the grafting success of the seedling rootstocks were investigated for two consecutive years, and the microscopic anatomical structure of wound healing after grafting was observed. Result: 1) Under favorable conditions of other external factors, the survival rate of tung tree grafting was more than 89.0% with V. montana and V. fordii seedlings as rootstocks, and there was no significant difference in the early growth between the two, but V. montana rootstocks was more beneficial to improve the resistance of tung trees. With the V. montana seedlings as rootstocks, the survival rate of split grafting with plastic film was 184.0% higher than that of aluminum foil, and the survival rate of split grafting with plastic film was 58.7% higher than that of jointing grafting. 2) The suitable length of the upper axillary buds, lower part axillary buds and petiole of scion was 1.0 cm, 3.0 cm and 0.5 cm, respectively, for grafting on tung tree seedling rootstock; the suitable incision length for rootstock splitting was 1.5 cm, the height of transplanting seedbed was 15 cm, the light transmission rate of the shade net was 25%, and the grafting union should be above the ground at the time of transplantation. 3) Different grafting periods had significant effects on the survival rate of tung trees by hypocotyle grafting. The survival rate of grafting in early June was 51.5% higher than that in mid-May, with significant differences (P < 0.05). The seedlings grafted in early June had better growth in the later period. 4) By observing the growth process of axillary buds and the anatomical structure of callus at the graft union, it was found that the wound was partially healed and the axillary buds began to expand after 10 days of grafting, and the axillary buds grew new leaves after 20 days. The wound healing degree of scion and rootstock was higher after 70 days, and it was necessary to remove the film to facilitate the growth of the grafted seedlings. Conclusion: The technology system of grafting of tung tree seedling rootstock is successfully established in this paper. In June, the overall survival rate of tung tree hypocotyle grafting with a large number of seedlings in the field can reach more than 70.0%, which provides a practical way for asexualized seedling breeding of tung trees in the future.

Objective: This study aims to establish a symbiotic system between Piriformospora indica and Rhododendron, in order to provide new ideas for improving the drought resistance of existing landscaping Rhododendrons. Method: A Rhododendron pulchrum cultivar, ‘Purple Butterfly’, commonly used in Chinese gardens was continuously irrigated with P. indica liquid for 6 times in a total of 30 days. A symbiotic system of P. indica and Rhododendron was established. The morphological and structural changes of Rhododendron plants colonized with P. indica were investigated, and the effects of P. indica on the drought resistance of Rhododendron and some related physiological and biochemical indexes were evaluated. Result: P. indica gradually colonized the Rhododendron root system after being irrigated with P. indica liquid for 4 times (on the 20^th d). The colonization rate reached 91.67% after being irrigated with P. indica liquid for 5 times (on the 25^th d) and 100% after being irrigated with P. indica liquid for 6 times (on the 30^th d). After 30 days of colonization, the fresh weight, dry weight and leaf area increased, the thickness of the upper and lower epidermis of the leaves decreased, the ratio of palisade tissue to mesophyll increased, leaf architecture became more compact and root cell area increased. With extension of drought stress time, the growth status of Rhododendrons colonized with P. indica was improved. After 20 days of drought stress, the survival rate was high. There were no significant differences in relative electrical conductivity, proline content, malondialdehyde content, and superoxide dismutase activity of leaves with the extension of drought time. The half lethal time was significantly prolonged, and the degree of stress was light. The drought resistance was significantly enhanced. Conclusion: R. pulchrum can establish a mutually beneficial symbiotic relationship with P. indica, thereby improving its resistance to drought stress. It is believed that P. indica can be used as a microbial agent to improve the drought resistance of Rhododendron.

Objective: The volatile components, aroma composition, and medicinal active substances in the wood of Populus koreana and Populus ussuriensis were analyzed, in order to improve the added value of poplar wood and provide a theoretical basis for the production of health-care poplar products. Method: Solid-phase microextraction was used to collect volatile substances in samples, and the collected samples were introduced into a gas chromatography-mass spectrometry (GCMS) for component separation and detection. The odor activity value of volatile organic compounds (VOCs) was calculated through the odor threshold and the relative content of the substance. All metabolites in poplar wood obtained from GCMS analysis were used to perform a query in the Traditional Chinese Medicine System Pharmacology (TCMSP) database, and the VOCs with oral bioavailability (OB）≥ 5% and drug-like (DL） ≥ 0.14 were selected as the main active ingredients. Relevant targets and related disease information of the identified metabolites were obtained through the database. Result: P. koreana wood had more VOCs, including aroma compounds and medicinal active ingredients, than P. ussuriensis wood. There were 18 and 16 VOCs that were detected in the wood powders of P. koreana and P. ussuriensis, respectively, including alcohols, alkanes, aldehydes, ketones, and esters. A total of 8 aroma compounds were retrieved from the volatile substances of P. koreana wood, including 7 key aroma compounds with aroma characteristics of butter, fragrance, fat, mushroom, and vanilla, and one potential aroma compound with resin, flower, and fragrance characteristics. However, only five aroma compounds were retrieved from the VOCs of P. ussuriensis wood, all of which were key aroma compounds. Besides the pleasant odor characteristics such as butter odor, grass odor, fat odor, flower odor, and green odor, the key odor compound of 2-hexanone in the wood of P. ussuriensis was more pungent. Further, P. koreana and P. ussuriensis wood shared some volatile metabolites, including 5 medicinal components of acetoin, hexanal, 4,6-dimethyl-dodecane, 3-octanone, and tetradecane. Four medicinal ingredients were found to be unique to P. koreana wood volatiles, which are 2,3-butanediol, 1-octyl-3-ol, 1-hexanol, and β-cedarene, while P. ussuriensis had two medicinal ingredients of pentadecaldehyde and 1-hexadecanol, of which 1-hexadecanol is an effective key component for human health. Conclusion: P. koreana wood volatiles have more aroma compounds and medicinal active ingredients. The key odor compound 2-hexanone in P. ussuriensis wood has a pungent odor and may be potentially harmful to the indoor environment and humans. P. koreana wood has a fresher aroma and contains more medicinal components that are beneficial to human health in volatiles. It can be used as a candidate tree species for health-care wood production. This study result provides a new direction for the selection and breeding of popular varieties.

Objective: The study aims to explore the pathogens of algal spots of Torreya grandis cv. ‘Merrillii’ and their biological characteristics, as well as screen efficient algicides, so as to provide scientific basis for controlling the disease. Method: The diseased leaves of T. grandis cv. ‘Merrillii’ were collected from the main planting areas in Zhejiang Province, and the algae were isolated from diseased leaves, and then identified by traditional morphological observation combined with molecular biological methods. The biological characteristics of the pathogenic algae were studied, and efficient algicides for controlling the disease were screened by laboratory virulence assay and the field control experiment. Result: 1) Three groups of synantectic pathogenic algae were isolated from algal spots, and they were identified as Desmodesmus armatus, Klebsormidium flaccidum and Tritostichococcus corticulus, respectively, based on the morphological characteristics and the SSU-ITS sequence analysis, all of which were newly reported pathogens of T. grandis cv. ‘Merrillii’. The culture conditions of the three alga species were similar, and they all grew well in BG-11 medium at 25 ℃ with an initial pH of 11 and a photoperiod of 12 h light/12 h dark. 2) With the mixed algae as the target, a laboratory toxicity assay showed that 12% copper rosinate suspension had the best algal killing effect, and the EC₅₀ was 8.33 mg·L^?1, which was significantly lower than other algicides （P<0.05）, followed by 33.5% copper quinoline suspension agent, 80% Bordeaux mixture, 20% thiophanate copper suspension agent and 45% lime sulfur mixture. The field control test showed that after 30 days of application, the control effects of 12% copper rosinate and 33.5% copper quinoline suspending agent were 78.11% and 71.62%, respectively. Conclusion: Three pathogenic green algae have newly been discovered from T. grandis cv. ‘Merrillii’ in Zhejiang Province, and the biological characteristics of the three alga species are similar. Laboratory toxicity assay and field control test show that 12% copper rosinate and 33.5% copper quinoline suspending agent have good control effect on algal spot of T. grandis cv. ‘Merrillii’.

Objective: In order to achieve more efficient and low-carbon intelligent manufacturing of mass customization furniture, it is necessary to implement more accurate intelligent production decisions on the basis of automated and continuous production, promote the production management from the traditional batch level to the part level, and carry out production scheduling based on the differentiated process time. By analyzing the key influencing factors of the NC (numerical control) drilling operation time, this paper constructs a mathematical model that can predict the NC drilling operation time of each part, so as to obtain more accurate operation time data before production, solve the practical problem of the missing operation time of custom furniture, and lay a solid data foundation for the part level production scheduling of custom furniture. Method: By conducting in-depth research around the actual manufacturing of custom furniture, starting from the operation logic of the NC drilling machining center, the paper analyzes the key influencing factors of the NC drilling operation time under different data conditions, collects more than 60 000 historical operation time data from the bottom of the equipment through MES (manufacturing execution system), constructs an analytic program to extract the key influencing factors, builds a three-layer artificial neural network model using the Mish activation function, and introduces momentum and learning rate attenuation algorithms to improve the model accuracy and operation efficiency. The prediction of the part level operation time in the NC drilling process of custom furniture is realized. Result: Under different data conditions, good prediction results are achieved based on artificial neural network, among which the prediction error rate of the average working time of the 9-dimensional variables extracted based on the NC program is 2.68%, which has the ability to predict the overall efficiency of the process. The mean absolute error of single part prediction results is 2.87 s, which is significantly better than the conventional linear regression model under the same data conditions, and has practical significance for guiding the part level accurate scheduling. Conclusion: By collecting a large amount of historical data through MES, constructing an analytic program, extracting the corresponding influencing factors, and building a three-layer artificial neural network based on the manufacturing big data, it is possible to accurately predict the part level operation time of NC drilling, thus laying a good data foundation for the optimization of equipment and process in the custom furniture manufacturing process, and promoting the practice of intelligent manufacturing in the field of custom furniture.

China has a wealth of bamboo resources, cutting-edge bamboo processing technologies, strong research and development capabilities, and strong international competitiveness. The bamboo industry is a green and promising sector of the Chinese economy that contributes significantly to the advancement of both economic growth and environmental protection. The conventional plastics sector is currently confronted with issues such a heavy reliance on non-renewable resources, excessive energy consumption, and significant environmental damage. Governments and groups around the world have introduced a number of “plastic ban” policies and initiatives to promote sustainable plastic alternatives in response to the expansion of the global economy and people’s rising concern for environmental protection. Bamboo presents a range of opportunities and options for the development of bamboo-based plastic substitutes because it is an eco-friendly, low-carbon, renewable, and degradable bio-based material with a variety of processing units, excellent material properties, and great processing selectivity and product designability. Bamboo-based plastic substitutes have steadily garnered regulatory, commercial, and consumer favor as an eco-friendly replacement. The Bamboo as a Substitute for Plastic Initiative was introduced in November 2022 by the Chinese government and the International Bamboo and Rattan Organization in an effort to reduce plastic pollution, combat climate change, and quicken the implementation of the UN 2030 Sustainable Development Agenda. In November 2023, 《The Global Action Plan for Bamboo as a Substitute for Plastic (2023—2030)》 was officially released. With the Bamboo as a Substitute for Plastic Initiative, China has made it clear that it is committed to protecting the environment, and various decision-making levels have been used to strongly encourage the development of the bamboo industry. This article analyzes the urgent need for and viability of alternative bamboo to plastic solutions based on the benefits of China’s bamboo resources and bamboo industry as well as the traditional plastic industry’s need for a green transformation. This paper focuses on the current state of typical key industry products like automotive parts, electric appliance shells, cooling tower tower packings, pipes and tubes, building decoration materials, and disposable tableware and their potential for bamboo as a substitute for plastic. Furthermore, the study proposes actionable recommendations, development trends, and future prospects for the adoption of bamboo as a substitute for plastic. This research seeks to provide some reference for the promotion and deployment of bamboo-based plastic alternative technologies and goods in China.

Climate change is an important aspect of global governance, assessing greenhouse gas emissions from human activities is key to address climate change, which has gained more and more attention by governments, scientific research institutions and enterprises all over the world. China has proposed a goal of carbon peak and carbon neutrality (“double carbon” goal). In this context, as a measure of greenhouse gas emissions, carbon footprint is becoming increasingly important. Evaluating the carbon footprint of wood and bamboo products is very important for China's wood and bamboo processing enterprises to implement the national“double carbon”goal, which plays an important role in promoting low-carbon and high-quality development. Research status of carbon footprint evaluation for sawn lumber, modified wood, wood-based panels and their products, glued laminated timber, cross laminated timber, and other wood and bamboo products were summarized. And the recent progress of evaluation methods was also analyzed. At present, life cycle assessment method is widely used to assess carbon footprint of wood and bamboo products globally. The standards for carbon footprint assessment are mainly ISO/TS 14067, GHG Protocol and PAS 2050. There is no international consensus on the assessment methods of biological carbon storage and its delayed carbon emission in wood and bamboo products, as well as the content of carbon footprint evaluation results. Due to the differences in wood and bamboo processing technology of different countries, the carbon footprint assessment results of the same product are significantly different. In addition, researchers often use different standards and hypotheses in carbon footprint evaluation, resulting in low comparability of the results for same product. Finally, we put forward four research topics which should be solved in the future: 1) In-depth study on the accounting methodologies of biological carbon storage and its delayed carbon emission to scientifically quantify the positive contribution of wood and bamboo products to climate change mitigation. 2) The formulation of international unified product category rules which is suitable for carbon footprint evaluation of wood and bamboo products, to further enhance the comparability of carbon footprint accounting results and promote the international mutual recognition of the results. 3) The establishment of a tracking system for the whole life cycle of wood and bamboo products is urgently needed to provide reference for the full life cycle carbon footprint assessment of wood and bamboo products. 4) Building a nationwide unified carbon emission factor database for China wood and bamboo industry, in order to provide fundamental data support for accurately measuring the carbon footprint of wood and bamboo products.