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Softwood cutting technology for Acer truncatum and physiological and biochemical analysis during rooting process WANG Yuxiao, ZHANG Bin, MA Qiuyue, FU Wei, KANG Zhen, ZHU Changhong, LI Shuxian JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 123-130.   DOI: 10.12302/j.issn.1000-2006.202208015 Abstract （2623）   HTML （67）    PDF（pc） （1786KB）（669）       Knowledge map    Save 【Objective】 In order to investigate the effects of different treatments on the rooting of softwood cuttings of Acer truncatum and find the best treatment method. We analyzed the relationship between changes in nutrient content, oxidase activity, and rooting of cuttings, and preliminarily explored the rooting mechanism of A. truncatum. 【Method】 Using rejuvenated A. truncatum trees and three-year-old A. truncatum mother trees as study materials, we conducted an analysis of the effects of growth regulators [indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) and a rooting solution], cutting positions (upper and lower parts), rejuvenation, and cutting time (June and September) on the rooting of A. truncatum. Furthermore, we examined the rate of root growth, callus formation, number of roots, root length, and other indicators of root development. Additionally, changes in nutrient contents (soluble sugar and soluble protein) and changes in oxidase activity [peroxidase (POD), polyphenol oxidase (PPO), and indole-3-acetic acid oxidase (IAAO)] were measured during the rooting process. 【Result】 The optimum IBA and NAA concentrations were 500 and 800 mg/L respectively, and the rooting rates were 59.3% and 52.7%, respectively. The optimal concentration for the rooting solution was a 1.43% volume fraction (70-fold) dilution, which achieved a rooting rate of 43.9%. Significant differences were observed among the three treatments, with all rooting indexes of cuttings treated with growth regulators performed better than those of the control. Additionally, the rooting effect of cuttings in June was better than that in September; the rooting effect of rejuvenated mother trees was better than that of 3-year-old trees; and the rooting effect of upper cuttings was better than that of lower cuttings. There were substantial differences observed following these treatments. During the rooting of the cuttings, the changes in the soluble sugar content following the treatment displayed a decreasing trend followed by an increasing trend. The soluble protein content, POD activity, and PPO activity initially increased and then decreased. However, the IAAO activity displayed a trend of decrease-increase-decrease. The control group exhibited a similar changing trend to that of the treatment group, but the peak time for the treatment group was 5-10 days earlier than that of the control. 【Conclusion】 The adventitious root formation of A. truncatum was categorized as a mixed rooting type. When the upper cuttings of rejuvenated mother trees were treated with IBA 500 mg/L, all rooting indexes were optimized, and the rooting rate peaked at 81.3%. Growth regulator treatment can improve the metabolism rate of nutrients and the synthesis process of related oxidase, and has a facilitative effect on the rooting of cuttings. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Advances in research of wildland-urban interface fires WANG Qiuhua, WANG Jin, LI Xiaona, MA Cheng, HONG Ruicheng, CAO Hengmao, GAO Zhongliang JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 1-10.   DOI: 10.12302/j.issn.1000-2006.202303047 Abstract （2424）   HTML （155）    PDF（pc） （1599KB）（4592）       Knowledge map    Save As the wildland-urban interface (WUI) becomes an increasingly important area of focus, the close relationship between human settlements and natural ecosystems such as forests has led to a high incidence of fires. Human activities play significant roles in the occurrence of fires in the WUI, and with rapid urbanization and the construction of forest cities, the complexity and severity of these fires have increased. This paper provides an overview of research progress on fires in the WUI, through literature analysis and case studies. At present, the concept of the WUI in China lacks clarity and standardization, highlighting the need for further research in this area. Future research should focus on expanding the database of interface fire cases and integrating satellite monitoring systems, video surveillance, and big data platforms to establish an early warning and monitoring system for the WUI. In addition, strengthening the research on fire behavior simulation and remote sensing monitoring, especially UAV fire behavior detection technology research on fire behavior simulations and remote sensing monitoring of WUI and unmanned aerial, remote-sensing monitoring and other new technologies will be crucial for providing effective solutions for fire prevention and control in the WUI. This will also contribute to the improvement of management measures, standards, and risk reduction strategies. Overall, the emphasis on new technologies and scientific research will provide a solid foundation for the management and reduction of fire risks in the WUI. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Conservation status and prioritization of rare and endangered plants in Jiangxi Wuyishan National Nature Reserve CHEN Lin, CAO Xiaomeng, PAN Tingting, LEI Ping, ZENG Lijian, LI Meng, YI Xiangui JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 39-47.   DOI: 10.12302/j.issn.1000-2006.202212017 Abstract （2350）   HTML （98）    PDF（pc） （1499KB）（1799）       Knowledge map    Save 【Objective】This research aims to determine the actual threat level and prioritize the conservation of rare and endangered plants in the Wuyishan National Nature Reserve in Jiangxi Province, provide a reference for the conservation of these plants in the nature reserve.【Method】Using the line transect method combined with historical literature, the endangered coefficient, genetic value coefficient, and species value coefficient were used to quantitatively analyze the conservation priorities of 113 rare and endangered wild plants in the Wuyishan National Nature Reserve in Jiangxi Province. The relationship between the rare and endangered plants of Wuyishan in Jiangxi Province and five adjacent areas, namely Wuyishan in Fujian Province, Tianmushan in Zhejiang Province, Lushan in Jiangxi Province, Wanchaoshan in Hubei Province, and Jinfoshan in Chongqing City, were compared using the Sorensen similarity coefficient.【Result】(1) There were 113 species of rare and endangered plants in the reserve, belonging to 47 families and 85 genera. Among these, there were 6 species classified as National Class Ⅰ, 15 species as National Class Ⅱ. 20 species were classified as Jiangxi Province Class Ⅰ, 11 species as Jiangxi Province Class Ⅱ, 55 species as Jiangxi Province Class Ⅲ, and 12 species endemic to Jiangxi. (2) According to the quantitative analysis of conservation priority, 17 species (15.04%) were assessed as first class, 41 species (36.28%) as second class, 54 species (47.79%) as third class, and 1 species (0.89%) as fourth class. (3) The similarity coefficient between Wuyishan in Jiangxi Province and the five adjacent areas were about 30%. However, Wuyishan in Jiangxi Province owned more rare and endangered plants (38 species) and a higher proportion of species per unit area (0.24), indicated a higher conservation value.【Conclusion】 The excellent habitats and abundant rare and endangered plants in Wuyishan in Jiangxi Province indicate a high conservation value. The assessment and classification of the 113 rare and endangered plants more accurately reflect their current situation in the Nature Reserve, providing a reference for effective conservation plans for threatened species. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Analysis of genetic diversity and construction of core collections of Korean pine (Pinus koraiensis) natural population YAN Pingyu, ZHANG Lei, WANG Jiaxing, FENG Kele, WANG Haohao, ZHANG Hanguo JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 69-80.   DOI: 10.12302/j.issn.1000-2006.202304035 Abstract （2237）   HTML （74）    PDF（pc） （2522KB）（1394）       Knowledge map    Save 【Objective】 Korean pine (Pinus koraiensis) is a valuable tree species that is distributed throughout northeastern China. Over the past century, human interference has led to a gradual decrease in the number of individuals and distribution of its natural population. Assessing the genetic diversity and building a core collection of natural Korean pine could provide a scientific basis for the effective conservation, management, and utilization of Korean pine germplasm resources. 【Method】 A total of five well-preserved natural populations of Korean pine in Hebei, Wuying, Xiaobeihu and Jixi in Heilongjiang Province and Lushuihe in Jilin Province in northeast China were studied. A combination of phenotypic data and molecular markers was used to construct the core collection. 【Result】 Molecular and phenotypic ANOVA results showed that the genetic variation of Korean pine natural populations mainly originated from inter-individual differences, which accounted for 96% and 72.84% of the total variation, respectively. The Jixi population was genetically distant from other populations, with an average Fst of 0.026 8. It also had a high genetic diversity, with Shannon and phenotypic diversity index values of 1.111 and 2.00, respectively. The population structure analysis showed that the five Korean pine natural populations had no obvious subpopulation structure. There were no significant changes in the genetic diversity of Korean pine populations among the different forest ages. Additionally, in the younger forest there was no evidence of heterozygous deletions or inbreeding. There was a broad correlation between needle traits and geographic factors, resulting in the phenotypic differentiation of Korean pine populations. 【Conclusion】 The Shannon and phenotypic diversity indexes of the core collection constructed by combining molecular and phenotypic markers with a 30% sampling ratio were 1.076 and 2.018, respectively, which was representative of the genetic status of Korean pine populations. This information can be used to better manage the germplasm resources of Korean pine and promote its protection and use. The genetic structure characteristics indicated a need to focus on in situ protection of the natural germplasm and to promote ecological recovery, germplasm protection, and use of Korean pine. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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An prediction of the potential distribution of suitable habitat for Grus leucogeranus using the MaxEnt model LIU Xiaoyan, ZHANG Zengxin, LI Jun, CHEN Juan, HUA Jun, PENG Ye, YAN Xin, QIU Jian JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 181-188.   DOI: 10.12302/j.issn.1000-2006.202303053 Abstract （2057）   HTML （56）    PDF（pc） （3409KB）（774）       Knowledge map    Save 【Objective】The middle and lower reaches of the Yangtze River basin are the most important wintering habitats for the Grus leucogeranus. However, in recent years, the distribution of suitable habitats for the G. leucogeranus in this area has been greatly altered by the combined effects of climate change and various other factors. Therefore, conducting research on the habitat suitability of G. leucogeranus in this area is of great significance for the protection and scientific management of this endangered species.【Method】In this study, based on the changes in the distribution of suitable areas of the G. leucogeranus wintering habitat in China, we used the Maximum Entropy Model (MaxEnt) to predict the potential suitable areas of the G. leucogeranus wintering habitat. The prediction was based on the G. leucogeranus distribution points, vegetation, topography, observed air temperature, precipitation, Global Climate Models (GCMs) data, and other various environmental factors.【Result】(1) The MaxEnt model proved highly effective in predicting the distribution of suitable habitats and assessing climate suitability for G. leucogeranus in their wintering grounds, with an AUC value of 0.978. The most influential environmental factors affecting the distribution of suitable habitat for G. leucogeranus were elevation, precipitation during the wettest month, slope, and NDVI. (2) The contemporary suitable habitat of the G. leucogeranus mainly distributed in the middle and lower reaches of the Yangtze River, with the the Poyang Lake being the most important high suitable area for the species. The medium and low suitable areas also mainly distributed around the the Poyang Lake. In addition, low suitable areas were found in the middle and lower reaches of the Yangtze River, along the coast of the Bohai Bay, and in the Haihe River, the Liaohe River, the Nenjiang, and the Songhua River basins. (3) Global climate model prediction results showed predictions indicate that the next 20 years, although the low suitable areas for G. leucogeranus during wintering is on the rise, the medium and high suitable areas generally decreasing. Among them, compared to the contemporary period, the medium suitable living area are projected to shrink by 2 500 to 25 700 km2, and the high suitable living area will shrink by 3 800 to 12 200 km2.【Conclusion】Different greenhouse gas emission scenarios will have different varying impacts on the distribution of G. leucogeranus. In the context of global warming, the wintering habitat of G. leucogeranus may shrink significantly, which will pose a serious challenge to the conservation of this rare species, and we should strengthen the research on G. leucogeranus habitat in the context of climate change, to provide data support for the conservation of G. leucogeranus and the management of their habitats. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Analyzing the genetic diversity of Nymphaea spp. based on SSR markers MAO Liyan, LI Huimin, LONG Lingyun, HUANG Qiuwei, TANG Yuwei, YU Yanping, HUANG Xinyi, TAN Xiaohui, NONG Xiaohui, ZHU Tianlong, LU Zushuang JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 57-68.   DOI: 10.12302/j.issn.1000-2006.202302029 Abstract （2040）   HTML （84）    PDF（pc） （2779KB）（1874）       Knowledge map    Save 【Objective】Nymphaea spp. (waterlily) are important aquatic flowers. The rapid development of the waterlily industry has led to challenges in identifying genetic backgrounds of newly introduced germplasms in a timely manner due to inadequate introduction management practices. This has resulted in issues such as mislabeling of seedlings and unclear parentage, hampering the effective utilization and innovation of waterlily germplasm resources. This study focuses on developing genome-wide SSR markers for conducting phylogenetic and genetic diversity analyses of waterlily species. These markers are intended to serve as a theoretical foundation for conserving and breeding waterlily germplasm resources.【Method】Based on the published complete genome sequence of waterlily, the SSR loci in 14 chromosome genes were analyzed using the micro satellite identification (MISA) tool. Subsequently, 150 pairs of SSR primers were designed with the assistance of Primer 3.0 software. Five native germplasms were chosen for PCR amplification utilizing the 150 primer pairs. Following PCR, SSR primers demonstrating high polymorphism were identified through agarose and denaturing polyacrylamide gel electrophoresis. The selected SSR primers were synthesized with fluorescent primers (FAM and HEX) before amplifying 147 waterlily samples via PCR. The resulting products were then assessed using capillary electrophoresis, and the raw data were analyzed using GeneMarker software. Fragment sizes at each allele site for every sample were compiled into a 0/1 matrix. Genetic diversity indices, cluster analysis, and principal component analysis were computed using Popgenen and NTSYS software toos.【Result】11 pairs of SSR primers exhibiting distinct bands and high polymorphism were carefully chosen following the analysis of agarose gel and polyacrylamide gel electrophoresis results. These selected primers were employed to evaluate the genetic diversity among 147 waterlilies. Capillary electrophoresis revealed the presence of 307 alleles. The polymorphism index (PIC) ranged from 0.46 to 0.60, average at 0.53. The effective allele number (Ne) rangedfrom 1.042 8 to 1.117 5, with an average of 1.071 8. Nei’s gene diversity index (H) ranged from 0.038 0 to 0.086 2, averaging at 0.056 2. The Shannon diversity information index (I) ranged from 0.085 6 to 0.163 8, averaging at 0.114 4. Cluster analysis indicated genetic similarity coefficients ranging from 0.781 8 to 0.993 5 among the 147 waterlilies, with an average coefficiency of 0.899 2. These waterlilies were classified into six groups based on a genetic similarity coefficient was 0.879 0. Principal coordinates analysis (PCoA) displayed results closely aligned with traditional morphological classification for the 147 waterlilies. The first, second and third principal coordinates accounted for 16.54%, 8.35% and 5.43% of the total genetic variation, respectively, comprising 30.32% altogether. The first coordinate was correlated with aroma formation and stamen development, the second with flowering time and environmental adaptability, and the third with flower types.【Conclusion】11 pairs of SSR primers displaying substantial polymorphism were chosen, demonstrating efficacy in distinguishing the genetic relationships among 147 waterlilies. These waterlilies were systematically categorized into six primary branches, with classification outcomes mirroring traditional morphology categorizations. The selected 11 pairs of SSR primers have potential utility in analyzing genetic diversity and identifying waterlily species. The SSR markers findings stand poised to offer a robust scientific foundation for germplasm collection, preservation, innovation, and the development of waterlily species. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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A study on photosynthetic characteristics and influencing factors of four kinds of garden trees in Zhengzhou LI Ximei, ZHAO Junjing, HUI Yi, HUANG Xin, GAO Chunyu, NIU Yaxuan, LIAO Xiaoyu, YU Chenyi JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 105-112.   DOI: 10.12302/j.issn.1000-2006.202402009 Abstract （2008）   HTML （76）    PDF（pc） （1721KB）（659）       Knowledge map    Save 【Objective】 Four common garden trees in Zhengzhou City, including Ligustrum lucidum, Magnolia grandiflora, Platanus orientalis and Styphnolobium japonicum, were selected as the study subjects. Our study provide a theoretical basis for the ecological construction of green space and the selection of tree species of Zhengzhou City from the perspective of physiological environment. 【Method】 Photosynthetic characteristics, leaf surface dust retention, and temperature and humidity of the growth environment were measured in different seasons to reveal the effects of physiological and environmental factors on net photosynthetic rate in the plants. Two-factor analysis of variance was used to compare the differences in photosynthetic characteristics of distinct species in different seasons. The interactions between different factors and their effects on plant photosynthetic rate were explored through generalized linear mixed models and structural equation models. 【Result】 There were significant differences in the net photosynthetic rate of the four garden trees in different seasons (P<0.05),and the net photosynthetic rate of Styphnolobium japonicum was significantly higher than that of other species. The net photosynthetic rate for each species was significantly higher in summer than in the other seasons. Physiological factors (stomatal conductance and transpiration rate) and environmental factors (dust retention and humidity) were significantly correlated with net photosynthetic rate (P<0.05). Humidity had the most significant direct and indirect effects on the net photosynthetic rate of plants and was the key environmental factor affecting plant photosynthesis. 【Conclusion】 The net photosynthetic rate of S. japonicum is higher than that of other tree species, and there is strong correlation between environmental and physiological factors of L. lucidum and M. grandiflora. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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The bird diversity spatial and temporal distribution patterns and its hotspot areas identification in Chengdu City REN Shichao, ZHANG Yinlong, CAO Mingchang, LIU Wei, QIAO Shufan, ZHU Xiaojing, LUO Kangning JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 189-196.   DOI: 10.12302/j.issn.1000-2006.202212039 Abstract （1963）   HTML （47）    PDF（pc） （2513KB）（1190）       Knowledge map    Save 【Objective】This study aims to explore the structural composition and spatial distribution patterns of bird communities in Chengdu, Sichuan, China, analyze the differences in bird diversity across various habitats and seasons, and identify bird hotspots to provide a basis for bird diversity protection in Chengdu and similar areas.【Method】In 2020, a survey of bird diversity was conducted across different seasons in 20 administrative districts of Chengdu using the line transect method and the sampling point methods. Species richness, Shannon-Wiener diversity index, Simpson index, Pielou evenness index, and community similarity coefficient were calculated to analyze bird diversity in Chengdu. Additionally, 41 key bird species were selected and categorized into raptorial birds, terrestrial birds, natatorial birds, and wading birds based on their ecological habits. The MaxEnt model was used to predict the potential habitats of key birds and identify bird biodiversity hotspots in Chengdu.【Result】A total of 261 bird species across 17 Orders and 62 Families were identified, including one species under national first-class key protection and 29 species under national second-class key protection. Among these, there are 99 species of resident birds, 61 species of summer migratory birds, 60 species of winter migratory birds, and 41 species of transient birds. The number of bird species and individuals, the Shannon-Wiener diversity index, the Simpson index, and the Pielou evenness index were highest in winter, followed by spring, autumn, and summer. Among the six habitats studied, forests (200 species) and wetlands (169 species) had the highest bird species counts. Urban land and wetlands had the highest number of individual birds and population sizes. Forest habitats exhibited the highest Shannon-Wiener diversity index and Simpson index, while urban land had the highest evenness index. The MaxEnt model predictions showed that the distribution of raptorial birds was significantly influenced by land cover type, distance from lakes, and distance from forests. Terrestrial birds distribution was largely affected by distance from forests, altitude, and settlement density. The distribution of waterbirds, including natatorial birds and wading birds, was heavily influenced by land cover type and distance from lakes. Chengdu’s bird diversity hotspots are primarily located in nature reserves, the Longmen Mountain Range, Chaoyang Lake, Longquan Mountain Forest Park, Sancha Lake, Xinglong Lake, Qinglonghu Wetland Park, and along the Minjiang and Tuojiang Rivers.【Conclusion】The rich bird diversity in Chengdu is closely linked to its natural environment, characterized by extensive forest areas, high spatial heterogeneity, and abundant food sources, making it a crucial habitat for birds. Although wetlands comprise only about 2% of the city’s land area, they rank second to forests in bird richness and should be a focal point in future bird biodiversity conservation efforts. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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The growth and photosynthetic characteristics of Acer truncatum seedlings in response to soil water and fertilizer coupling LI Panting, DU Manyi, WANG Yue, PEI Shunxiang, XIN Xuebing JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 113-122.   DOI: 10.12302/j.issn.1000-2006.202302008 Abstract （1893）   HTML （65）    PDF（pc） （1794KB）（808）       Knowledge map    Save 【Objective】 This research aims to investigate the growth and photosynthetic physiological characteristics of Acer truncatum seedlings in response to water-fertilizer coupling, and to analyze the optimal water-fertilizer combination for the growth of A. truncatum seedlings. 【Method】 One-year-old A. truncatum seedlings were subjected to varying water and fertilizer couplings in an orthogonal test design involving four factors and four levels of soil water content, nitrogen, phosphorus and potassium, resulting in 16 treatments. Growth indexes, relative chlorophyll content of the leaves SPAD values, photosynthetic characteristics, and light response curves were measured after the treatments. 【Result】 The growth indices generally increased firstly and then decreased with increasing fertilization amount. At a soil water content of 75%,1.2, 1.8 and 0 g/plant of N, P, K, respectively, the diameter and total biomass of the plant were significantly higher than those of other treatments. Suitable soil water and fertilizer coupling could significantly improve the height, ground diameter, and total biomass of A. truncatum seedlings. Moreover, there was no significant difference in the utilization ability of low light among different soil water and fertilizer coupling treatments, and nitrogen fertilizer had significant effects on the maximum net photosynthetic rate and light saturation point of A. truncatum seedlings. In addition, there was no significant difference in water use efficiency (WUE) between the different treatments for A. truncatum seedlings. The seedlings grew normally even under lower water conditions, such as 45% soil water content, and exhibited strong drought resistance. The effects of soil water and fertilizer on the growth of A. truncatum seedlings were ranked from high to low as nitrogen fertilizer > soil water content > potash fertilizer > phosphate fertilizer, based on a comprehensive scoring method. The optimal combination of water and fertilizer was 75% soil water content, with fertilizer comprising 1.2 g of nitrogen, 1.8 g of phosphorous, and 0 g of potassium per plant. 【Conclusion】 Water-fertilizer coupling had a significant effect on ground diameter and biomass of A. truncatum seedlings, but an insignificant effect on seedling height, while soil water content and nitrogen fertilizer also had a significant effect on the growth indexes of the seedlings. These findings provide a theoretical basis for the appropriate use of soil water and fertilizer in A. truncatum. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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The flowering phenology response of five early spring woody plants to the urban heat island effect in Nanjing SHI Lisha, WEN Shusheng, HUANG Xiaowan, HAN Qian, SHI Zhengyang JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 228-234.   DOI: 10.12302/j.issn.1000-2006.202208033 Abstract （1837）   HTML （39）    PDF（pc） （2686KB）（745）       Knowledge map    Save 【Objective】As an indicator of urban ecosystems, plant phenology can visually reflect the changes of ecosystem under the process of urbanization. In this study, we investigated the response pattern of flowering phenology of five common flowering woody species to the heat island effect in Nanjing, and provided data supplement for the response mechanism of vegetation phenology to the heat island effect in East China. 【Method】Based on Landsat 8 remote sensing data to invert the surface temperature of Nanjing, the urban heat island radio index (URI) was used to characterize the heat island intensity, and the combined with the flowering phenology observation data to quantitatively study the effect of urban heat island effect on the flowering phenology of plants.【Result】Nanjing showed a significant urban heat island effect. Heat island intensity ranking: central city > suburban area > remote suburban area. The sensitivity of the same plant to the heat island effect differed at different points. Among the five plants, Yulania denudata was the most affected by the heat island effect, with the flowering period advanced by four to 11 days and the flowering period duration shortened by up to 50%; Cercis gigantea, Malus halliana and Prunus yedoensis were affected to a similar extent and were at a medium level; Loropetalum chinense var. rubrum was the least affected, with the flowering period advanced by about two to four days and the flowering period duration shortened by about 19%. 【Conclusion】The heat island effect has a significant effect on the onset and duration of flowering periods of plants, and as the heat island effect increases, the onset, bloom and last flowering periods of plants tend to be earlier and shorter. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Induction and physiological regulatory mechanism of secondary flowering in Yulannia denudata CHEN Xiangbo, ZHANG Dongmei, FU Renjie, ZHANG Lang, SHEN Yamei, LUO Yulan, YIN Lijuan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 97-104.   DOI: 10.12302/j.issn.1000-2006.202301007 Abstract （1807）   HTML （84）    PDF（pc） （6803KB）（814）       Knowledge map    Save 【Objective】The aim of this study was to achieve the secondary flowering of Yulannia denudata through artificial induction and to explore the physiological regulation mechanism of flower bud differentiation and flowering induction in Y. denudata.【Method】Y. denudata plants were treated with nutrients and hormones. Flower buds were embedded in paraffin and sectioned to observe flower bud development, and endogenous hormone contents in flower buds at different stages were measured.【Result】Flower bud differentiation of Y. denudata began in early May when vegetative growth slowed down and was completed by early June. Secondary flowering within the same year was induced via treatment with exogenous hormones [6-benzylaminopurine (6-BA) and gibberellin A3 (GA3)] alone or in combination with nutrient applications [nitrogen (N), phosphorus (P), potassium (K) and sugars]. The secondary flowering rate ranged from 33% to 100%, with the maximum of 22 flowers per plant. During the maturation of flower bud differentiation, the levels of endogenous GA3 and abscisic acid (ABA) increased. The ABA content in flower buds decreased while breaking dormancy and flowering, whereas the content of endogenous auxins (indole-3-acetic acid (IAA) and methylindole-3-acetic acid (ME-IAA) increased. Flower buds treated with exogenous cytokinins had higher levels of ME-IAA, IPA, jasmonoyl-l-isoleucine (JA-Ile) and jasmonate (JA), while flower buds treated with exogenous gibberellins (GA3) had higher levels of endogenous trans-zeatin riboside (tZR), gibberellin A1 (GA1), and GA3. 【Conclusion】Exogenous hormones directly induce secondary flowering in Y. denudata without relying on nutrient treatments. Thus, different hormones may induce secondary flowering through various regulatory pathways. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Carbon dynamic simulation based on Biome-BGC model in mixed coniferous and broadleaved forest of Fengyang Mountain, Zhejiang Province HUANG Luyao, DU Shanfeng, JI Xiaofang, GUAN Xin, LIU Shenglong, YE Limin, JIANG Jiang JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 11-20.   DOI: 10.12302/j.issn.1000-2006.202211005 Abstract （1783）   HTML （123）    PDF（pc） （4196KB）（1226）       Knowledge map    Save 【Objective】This study aims to investigate the carbon dynamics of subtropical mixed coniferous and broadleaved forests in Fengyang Mountain, Zhejiang Province and their response to climate change. 【Method】The Biome-BGC model was used to simulate the net primary productivity (NPP), gross primary productivity (GPP), and net ecosystem productivity (NEP) in Fengyang Mountain from 1979 to 2018, to investigate the relationships between climate factors and NPP at different time scales. Pearson correlation analysis and quadratic function fitting were performed between climate factors and NPP at different temporal scales to explore the relationship and response patterns between NPP and major climate factors, and finally, different climate scenarios were applied to predict the carbon cycling trends in Fengyang Mountain in the next 100 years. 【Result】The average values of GPP, NPP and NEP of mixed coniferous and broadleaved forests in Fengyang Mountain for 40 years were 1 392.94, 451.25 and 16.21 g/(m2·a), respectively. Except for 1984, 2002, 2005, 2008 and 2010, which were carbon sinks and showed that the sensitivity of NPP to temperature change was the highest, and the increase of temperature in summer had a positive effect on the increase of NPP, while the increase of temperature in winter had a negative effect on NPP. To a certain extent, winter rainfall showed a positive effect on NPP, while summer precipitation showed a negative effect on NPP. The gross primary productivity of Fengyang Mountain forests in RCP2.6, RCP4.5 and RCP6.0 scenarios will keep increasing in the 21st century, and by 2100, the GPP of the studied forests in Fengyang Mountain under RCP2.6, RCP4.5 and RCP6.0 scenarios will reach 1 552.73, 1 660.30 and 1 960.41 g/(m2·a), respectively, and get increased 1.38%, 8.41% and 28.00% relative to the GPP in 2018. 【Conclusion】Overall, the forest ecosystem of Fengyang Mountain exhibited carbon sinks under normal conditions, but the cloudy and rainy summer weather in the mountainous area inhibited the increasing effect of temperature on carbon sinks to some extent. The future warming, increased rainfall and higher CO2 concentration simultaneously will favor the vegetation growth of mixed coniferous forests in Fengyang Mountain. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Growth variation and superior families early selection of Larix olgensis free-pollinated families WANG Jiaxing, YAN Pingyu, SUN Baifei, LIU Jinhong, FENG Kele, ZHANG Hanguo JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 81-89.   DOI: 10.12302/j.issn.1000-2006.202303014 Abstract （1778）   HTML （73）    PDF（pc） （1603KB）（715）       Knowledge map    Save 【Objective】 We investigated genetic variation and stability in growth characteristics across 40 free-pollinated families from four Larix olgensis seed orchards located in different regions, aiming to identify superior families. 【Method】 We analyzed progenies from four L. olgensis locations namely Hegang, Linkou, Yongji and Dagujia. The study involved single-point analysis of variance (ANOVA), multi-point multi-year ANOVA, genetic parameter analysis, stability analysis, and breeding value estimation on tree height and diameter at breast height (DBH) for trees aged 6-8 years to identify superior families. 【Result】 Single-point ANOVA results indicated significant differences in growth traits among families. Multi-point multi-year ANOVA revealed significant variations in the height of L. olgensis among families, locations, years, and their interactions. Genetic parameter analysis demonstrated that family heritability of height, ranging from 0.611 to 0.852 across sites, was greater than individual heritability, indicating strong genetic control. The phenotypic and genetic coefficients of variation at each site were 41.36% and 3.87%, respectively. Genetic gain in eight year height ranged from 23.35% to 38.89% at a 20% selection rate. Breeding value estimation identified high-yielding and stable families (CH309, CH349, HG5, BS349, and HG13) with an average breeding value of 0.528, an average height of 4.00 m (25.78% higher than that of the control), and an average stability parameter of 0.085, making them suitable for promotion in four locations. 【Conclusion】 L. olgensis exhibits rich genetic diversity in growth traits among families across different years and locations. The identified superior families are well-suited for cultivation in the three northeastern provinces and similar environments. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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The tailwater purification effectiveness of three aquatic plants and their subsequent physiological changes aquatic XIA Tongtong, WU Yongbo, PU Keyi, WANG Mingli JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 221-227.   DOI: 10.12302/j.issn.1000-2006.202304011 Abstract （1749）   HTML （42）    PDF（pc） （2174KB）（678）       Knowledge map    Save 【Objective】 This study aims to explore the effectiveness of hydrophytes in purifying tailwater from a sewage plant and the subsequent changes in their physiological characteristics. The results will provide a reference for the effective purification of tailwater and the selection of suitable hydrophytes for this task. 【Method】 Taking Schoenoplectus tabernaemontani, Typha orientalis and Iris pseudocorus as research objects, pot-control experiments were conducted to simulate the preparation of two different tailwaters, each characterized by different concentrations of contaminants. The removal effects on chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP), and the subsequent physiological characteristics of the three hydrophytes in the two different tailwaters were analyzed. 【Result】 The three types of hydrophytes all had strong removal effects for COD, TN and TP in tailwater. The COD concentration in tailwater decreased from 61.42-107.28 to 8.63-16.20 mg/L, the TN concentration decreased from 24.49-31.54 to 0.40-7.90 mg/L, and the TP concentration decreased from 2.11-3.43 to 0.05-1.00 mg/L. The antioxidant enzyme activity and relative conductivity of S. tabernaemontani and I. pseudocorus increased in the tailwater, while the peroxidase activity and relative conductivity of T. orientalis decreased significantly (P <0.05), and the catalase activity increased significantly (P <0.05). The chlorophyll content of all three hydrophytes in the tailwater decreased significantly (P <0.05), while the photosynthesis of S. tabernaemontani decreased in the tailwater with the higher concentration of contaminants. 【Conclusion】 Schoenoplectus tabernaemontani, T. orientalis and I. pseudocorus had significant removal effects on COD, TN and TP in the tailwater. The physiological metabolism of hydrophytes was affected following the exposure to the tailwater. It was concluded that S. tabernaemontani and T. orientalis can be planted together for purifying tailwater with low concentrations of contaminants, while I. pseudocorus can be used for the purification of severely contaminated tailwater. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Leaf phenotypic diversity analysis of holly germplasm resources WANG Xuejie, ZHOU Peng, HOU Sixuan, FANG Yanming, ZHANG Min JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 90-96.   DOI: 10.12302/j.issn.1000-2006.202302015 Abstract （1715）   HTML （83）    PDF（pc） （1949KB）（798）       Knowledge map    Save 【Objective】 This study aims to understand the leaf phenotypic diversity of holly (Ilex spp.) germplasm resources, elucidate the mechanisms behind this diversity, and support the introduction, cultivation and breeding of new varieties. 【Method】 We observed 18 phenotypic traits across 42 holly germplasm resources and analyzed the phenotypic variation using differential analysis, variance analysis, principal component analysis (PCA), and cluster analysis. 【Result】 There was significant variation in the leaf phenotypic traits among the holly germplasm resources, particularly in leaf area. The Shannon diversity index ranged from 1.00 to 2.03, indicating rich phenotypic diversity primarily due to interspecies variation. Correlation analysis showed a significant negative relationship between external leaf traits and anatomical traits. PCA identified four principal components, namely leaf length, tissue compactness, palisade tissue thickness, and stomatal density, that accounted for 85.20% of the variation, effectively capturing the overall characteristics of the holly plants. Cluster analysis grouped the 42 resources into four categories based on their leaf traits: large leaf with large petiole, small leaf with small petiole, medium leaf with hard serrations, and medium leaf with thin texture. 【Conclusion】 The study confirms substantial intrageneric phenotypic diversity in holly, driven predominantly by interspecies differences. External leaf traits were pivotal in phenotypic differentiation. The identified principal components, namely leaf length, compactness, palisade structure, and stomatal density, are crucial for classifying and identifying holly germplasm resources. Based on the leaf phenotypes, the resources were categorized into four distinct groups, providing a theoretical foundation for further classification, resource utilization, and breeding within the genus Ilex L. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Affecting factors analysis of functional diversity at different forest strata in an old growth forest community in Yachang Natural Reserve WANG Yaoyi, WANG Hongxiang, WANG Yongqiang, ZENG Wenhao, YE Shaoming JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 28-38.   DOI: 10.12302/j.issn.1000-2006.202208030 Abstract （1708）   HTML （103）    PDF（pc） （2573KB）（1958）       Knowledge map    Save 【Objective】 Functional diversity is crucial for forest biodiversity protection and maintenance of ecosystem stability. Exploring the characteristics and causes of functional diversity variation at different stratum levels will assist in understanding the maintenance mechanisms of biodiversity and plant community assembly processes. 【Method】 Leaf traits and environmental factors were collected from forest plot data from an 1.6 hm2 evergreen broadleaved forest in Guangxi Yachang Orchidaceae National Natural Reserve. K-means partitioning and Gaussian kernel density estimation were used for stratification. The direct and indirect effects of species diversity and environmental factors (light, topography, and soil) on functional diversity were explored in different forest strata using structural equation models. 【Result】 The diversity indices of the understory were greater than those of the canopy (P<0.05). Species diversity had a significant direct impact on all four functional diversity indices in the understory layer, whereas only the functional richness index (FRic) and quadratic entropy (RAOQ) indices were affected directly by species diversity in the canopy layer (P<0.05). A significant indirect effect (β = 0.278, P<0.01) of canopy openness on FRic index and a direct effect (β = -0.593, P<0.01) of canopy openness on functional evenness index (FEve) were found for understory trees. Topographic factors affected canopy functional diversity. Specifically, there was a relatively significant direct effect of aspect on FEve (β = -0.420, P<0.01) and RAOQ (β = -0.300, P<0.05) indices for canopy trees. Soil factors mainly affected the functional diversity of different forest layers through species diversity. Soil total phosphorus, available phosphorus, alkaline hydrolysis nitrogen, and available potassium content had a greater effect on the functional diversity of the understory, whereas soil total potassium content affected the FRic and RAOQ indices of the canopy. 【Conclusion】 There were marked differences in the characteristics of functional diversity at different forest stratum in the study area. Functional diversity was mainly affected by species diversity, canopy openness, and soil nutrients of understory plants, whereas topographic factors determined the functional diversity of the canopy layer. This study reveals the effects of biological and abiotic environmental factors on functional diversity across different forest layers and expands the understanding of the diversity of vertical stratification. The findings provide a further reference for biodiversity protection in natural forests. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of long-term nitrogen and phosphorus additions on soil organic carbon storage and its components in a subtropical forest CHEN Leiru, WEN Zhengyu, XU Xiaoniu, YIN Ruoyong, GAO Yu JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 139-146.   DOI: 10.12302/j.issn.1000-2006.202301001 Abstract （1704）   HTML （64）    PDF（pc） （2319KB）（828）       Knowledge map    Save 【Objective】The aim of the present study is to simulate the effects of long-term nitrogen (N) deposition on soil organic carbon (SOC) and organic carbon storage in subtropical forests with phosphorus (P) limitation to investigate the effects of active SOC and soil organic nitrogen (SON) components on organic carbon storage under long-term N addition, as well as to provide the basis for soil carbon (C) sequestration capacity and sustainable management of subtropical forest ecosystems.【Method】In an evergreen broad-leaved forest of Zhawan Nature Reserve, Qimen County, Anhui Province, two sites were selected, the middle slope and flat ridge, for the present study. Three different N and P addition treatments were designed at each site as follows: control (CK, N and P addition of 0 kg/hm2 per year), N addition (N, N addition of 100 kg/hm2 per year), and N+P addition (N+P, N addition of 100 kg/hm2 and P addition of 50 kg/hm2 per year). There were three replicate plots of 30 m × 15 m for each treatment, with a total of 18 sampling plots. In October 2020, soil samples were collected from the 0-40 cm layer in each plot to determine SOC content, SOC storage, active SOC fraction, SON fraction, and other basic physicochemical properties. The collected soil samples were divided into two parts. One part of the soil sample was naturally air-dried, crushed, and passed through a 0.25 mm sieve for the determination of soil SOC and total nitrogen (TN) content. The other part of the soil sample was treated differently to determine soil SOC, SON fraction, and other physicochemical properties to investigate the effect of long-term simulated N deposition on the organic carbon storage capacity of subtropical forest soils, as well as the effects of SOC and SON fractions on organic carbon storage. 【Result】Compared to the CK treatment, N and P additions did not significantly change the SOC content and storage, but it significantly reduced the soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents. Correlation analysis showed that SOC storage was significantly and positively correlated with most soil physical and chemical properties but significantly and negatively correlated with pH and bulk density. Linear regression analysis demonstrated that particulate organic carbon (POC) and particulate organic nitrogen (PON) explained 75.4% and 71.7% of the effects on SOC storage, respectively, while MBC and MBN explained 26.0% and 49.3% of the effects on SOC storage, respectively. There was no significant relationship between dissolved organic carbon (DOC) and SOC storage, and DOC explained 11.4% of the effects on SOC storage.【Conclusion】Long-term N and N+P additions significantly reduce the C and N contents of soil microbial biomass and may be detrimental to SOC stocks, with POC and PON having the greatest impact on SOC storage. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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The allocation mechanism and optimization strategies of carbon emission allowance in China under Carbon Peak and Neutrality Goals GUO Chunyan, QIN Tao, SONG Xiaoxiao JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (3): 1-13.   DOI: 10.12302/j.issn.1000-2006.202404015 Abstract （1650）   HTML （749）    PDF（pc） （2499KB）（303）       Knowledge map    Save 【Objective】The establishment of the national carbon market represents a significant institutional innovation for reducing greenhouse gas emissions through market mechanisms and promoting green and low-carbon development. It also serves as a crucial policy instrument for advancing the achievement of the carbon-peak goal and the carbon-neutrality vision. The scientific, fair, and reasonable allocation of carbon emission quotas lies at the core of the carbon trading process. This study analyzed the allocation of carbon emission quotas within the carbon trading system based on the current situation and proposed optimization strategies to offer references for the development of China’s carbon trading market.【Method】Adopting the research path of “status quo-problems-countermeasures”, this study employed methods such as literature review, case summarization, and comparative analysis. It analyzed the quota allocation models of major international carbon markets, summarized the current status and main problems of China’s carbon emission quota allocation mechanism, and puts forward relevant suggestions for future mechanism and strategy optimization.【Result】(1) From an international perspective, the practical experiences of major markets in carbon emission quota allocation were summarized. For instance, setting appropriate emission-reduction targets and flexible adjustment mechanisms in the carbon market, building sufficient confidence in participation and a stable price mechanism, as well as establishing a sound and perfect market mechanism and supporting legal system, provided valuable insights and references for the orderly implementation of a combination of free and paid carbon emission quota allocation methods.(2) From a domestic perspective, the current situation of China’s carbon emission quota allocation was summarized. With the development of China’s carbon trading market, certain achievements have been made in carbon emission quota allocation, including the gradual optimization of the tier-by-tier total quota amount, the progressive expansion of the covered industry scope, the diversification of allocation principles, and the gradual transition of the allocation mode from free to paid. Nevertheless, there are still numerous issues to be addressed, such as the need to improve the top-level design, the relative simplicity of the allocation method, the lack of stimulation of market vitality, and the necessity to enhance supporting measures.【Conclusion】Based on the current situation and future development trends of China’s carbon emission quota allocation, it is essential to strengthen the overall planning and top-level design of allocation, promote the progressive development of allocation, establish a scientific and reasonable trading ecosystem, improve laws, regulations, allocation methods, market mechanisms, and other supporting measures, and promote the market-based empowerment and optimization of the carbon emission quota allocation strategy. This will offer solution paths and model references for the development of China’s carbon trading market and the effective realization of carbon-emission-reduction targets. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Construction of natural landscape system in Jiangsu Province based on spatial distribution characteristics and ecological space identification TANG Xiaolan, CHEN Yalin, CHEN Qing, SONG Tianrui JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 156-164.   DOI: 10.12302/j.issn.1000-2006.202208010 Abstract （1643）   HTML （57）    PDF（pc） （3727KB）（742）       Knowledge map    Save 【Objective】 This study aims to comprehensively protect, rationally develop as well as effectively utilize natural scenic resources and alleviate the fragmentation, islanding and uneven distribution of natural resource landscapes in Jiangsu Province.【Method】 Using ArcGIS spatial analysis technology, the spatial distribution characteristics of natural landscape resources in Jiangsu Province were obtained from the Nearest Neighbor Index (NNI) and results of the kernel density analysis and accessibility analysis. Also, based on the double evaluation' of the land and space planning and the natural environment of Jiangsu Province, an ecological protection evaluation, including evaluations of the ecosystem services and ecological sensitivity, was conducted. Based on the evaluation results, the ecological space of Jiangsu Province was delineated. The above results are superimposed with the corresponding physical and human geographical characterizations of Jiangsu Province. 【Result】 The distribution and regional differences of protected areas of natural landscape resources in Jiangsu Province were revealed, which provided a realistic basis for the selection of natural landscape patches, corridors and advantageous regions. Nine natural landscape patches, seven natural landscape corridors and two natural landscape dominant areas in Jiangsu Province were delineated. Also, a natural landscape system in Jiangsu Province was formed based on natural landscape resources dominated by patches, corridors and substrates. 【Conclusion】 The landscape system applied the spatial concept to the study of landscape resources. This approach helps to strengthen the connection between protected areas of natural landscape resources, improve the integration and optimization of resources, create a landscape pattern more suitable for the protection and development of natural landscape resources in Jiangsu Province, and provide effective guidance for the protection and construction of natural landscape resources in Jiangsu Province and a scientific basis for reasonable development and utilization. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Effects of litter decomposition of Cunninghamia lanceolata and Schima superba on soil carbon contents, nitrogen contents and enzyme activities in Cunninghamia lanceolata plantations ZHOU Mengtian, LIU Li, FU Ruoxian, LI Xiaogang JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 131-138.   DOI: 10.12302/j.issn.1000-2006.202304024 Abstract （1614）   HTML （60）    PDF（pc） （2560KB）（820）       Knowledge map    Save 【Objective】Litter regression can affect the soil carbon and nitrogen cycle, which is an important process of sustainable management and soil fertility maintenance in Chinese fir(Cunninghamia lanceolata)plantations. The changes in soil carbon content, nitrogen content, and enzyme activity under the treatment of adding C. lanceolata and Schima superba litter were analyzed to provide the basis for nature-approximating transformation and stand management of C. lanceolata plantations.【Method】In the present study, 30-year-old C. lanceolata plantation soil was treated with C. lanceolata litter (S), S. superba litter (M), and a mixture of C. lanceolata and S. superba litter (mixed at a m (S):m (M)=5:1, SM). After 60 days of incubation, the content of ammonium nitrogen ( {\mathrm{NH}}_4^{+}-N), nitrate nitrogen ( {\mathrm{NO}}_3^{-}-N), soil organic carbon (SOC), water soluble organic carbon (WSOC), hydrochloric acid hydrolyzed organic carbon (HHOC), alkaline-hydrolyzable organic carbon (AHOC), recalcitrant organic carbon (ROC), and enzyme activities (β-glucosidase(GC); β-N-acetylglucosaminidase(NAG); polyphenol oxidase(PPO); and leucine aminopeptidase(LAP)) in the soil were measured in the different treatments. The relationship among soil carbon content, nitrogen content, and enzyme activity in different treatments was analyzed, and the effects of different litter on soil carbon content, nitrogen content, and enzyme activity in C. lanceolata plantations were evaluated.【Result】The degree of humification in the soil treated with mixed litter was increased compared to the soils treated with either litter alone. In the single litter treatment, the degree of humification with S. superba treatment was low, and the proportion of soil recalcitrant organic carbon (ROC) was relatively higher. After 15 and 30 days of incubation, the soil GC, NAG and PPO enzyme activities with C. lanceolata litter were significantly higher than those with S. superba litter. The decomposition of mixed litter significantly improved soil GC and NAG enzyme activities. The results of redundancy analysis and correlation analysis showed that soil AHOC content was significantly positively correlated with soil GC enzyme activity. NAG enzyme activity was positively correlated with soil WSOC content and negatively correlated with {\mathrm{NH}}_4^{+}-N content, while PPO enzyme activity was negatively correlated with {\mathrm{NO}}_3^{-}-N content and positively correlated with ROC and HHOC contents (P<0.01).【Conclusion】The addition of different litters significantly affects the soil carbon content, nitrogen content, and enzyme activity in C. lanceolata plantations. Compared to the addition of S. superba litter, the addition of C. lanceolata litter results in a higher soil humification degree, as well as higher enzyme activities related to the carbon and nitrogen cycle. Further, the addition of both C. lanceolata and S. superba litter is more beneficial in improving the degree of soil humification, soil carbon invertase activity, and nitrogen invertase activity compared to the addition of either litter alone, thus ultimately benefitting the soil carbon and nitrogen cycle of C. lanceolata plantations. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Estimation of habitat suitability and climatic distribution change of Pegaeophyton scapiflorum based on the MaxEnt model LI Ruilan, FAN Jinya, ZHAO Qian, LI Tingju, WANG Chenghui, DING Rong, GU Rui, ZHONG Shihong JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 173-180.   DOI: 10.12302/j.issn.1000-2006.202302003 Abstract （1590）   HTML （43）    PDF（pc） （3241KB）（768）       Knowledge map    Save 【Objective】 Pegaeophyton scapiflorum can be found mainly in the high altitudes of the Qinghai-Xizang Plateau in China, and the traditional surveys are difficult to implement. This study explored the dominant climatic factors that limit the distribution of P. scapiflorum in China and simulated its suitable distribution areas. The goal was to provide a theoretical basis for the investigation and protection of wild resources of P. scapiflorum. 【Method】 This study was based on 88 distribution sites and eight environmental factor variables of P. scapiflorum in China. The MaxEnt model was employed to predict the changes in its potential habitat. Additionally, the possible influence of climatic change under the extremely pessimistic representative concentration pathways scenarios RCP 2.6, RCP 4.5 and RCP 8.5 for the 2050s and 2070s were estimated. A comprehensive analysis of the main environmental factors affecting the distribution of P. scapiflorum was conducted. 【Result】 (1) The prediction accuracy of the MaxEnt model was high, and the AUC was 0.887. The prediction showed that P. scapiflorum is mainly located in the Qinghai-Xizang Plateau currently. The highly suitable areas were mainly distributed in the Kailas Range, Himalayas, southern valley of Xizang, Qaidam Basin, Nyainqêntanglha Mountains, Tanggula Mountains, the southern section of the Aemye Ma-chhen Range, the northern part of the Songpan-Ganzi Plateau, and Hengduan Mountain. The total suitable area of the potential geographical distribution of P. scapiflorum was approximately 310 × 104 km2, including 80.81 × 104 km2 of highly suitable areas. (2) The main environmental factor variables affecting the potential geographical distribution of P. scapiflorum were geomorphology, temperature, and precipitation, among which dem, isothermality, and annual precipitation aere the key environmental factors. (3) Under different climate change models, the suitable habitat will be reduced by 24%-28% compared with the present situation by 2050s and 2070s. The highly suitable area would be downgraded to the medium or low suitable area to significantly reduce or even disappear, and the distribution center of P. scapiflorum tended to migrate to the westward and higher altitudes. 【Conclusion】 Study results are an important reference for the conservation, sustainable development, and utilization of wild resources and artificial cultivation of P. scapiflorum. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Physiological regulation of 6-BA on late growth of Pseudostellaria heterophylla MA Julin, QIU Lingling, XIE Yinfeng, LÜ Qian, MA Yingli, LIANG Wenchao JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (1): 137-144.   DOI: 10.12302/j.issn.1000-2006.202303007 Abstract （1568）   HTML （9）    PDF（pc） （1712KB）（298）       Knowledge map    Save 【Objective】This research aims to investigate the effects of exogenous growth regulator 6-BA on the growth and physiology of Pseudostellaria heterophylla at the late growth stage and to provide a theoretical basis for efficient cultivation of P. heterophylla.【Method】 Different concentrations of 6-BA (0, 20, 40, 60 mg/L) were applied to the leaves in mid-May to determine the effects of 6-BA on root tuber growth, the antioxidant enzyme system, and the photosynthetic characteristics of P. heterophylla. 【Result】 (1) Compared to the control (CK), the root length, root diameter, fresh root yield, biomass per plant, dry weight of the aboveground part, and dry weight of the underground part of P. heterophylla in each 6-BA treatment group were significantly increased, with the 60 mg/L treatment showing the most pronounced effect. The fresh root yield and biomass per plant increased by 35.41% and 41.60%, respectively, compared to the CK, and these differences were statistically significant (P < 0.05). (2) The 6-BA treatment with an appropriate mass concentration significantly increased the activities of SOD and POD, as well as the chlorophyll and carotenoid contents in P. heterophylla leaves during the experiment. It also effectively mitigated the rising trend of MDA content and the declining trend of photosynthetic pigments. (3) The Pn, Gs, and Tr of P. heterophylla increased to varying degrees while Ci decreased, effectively alleviating the "nap" phenomenon of photosynthesis caused by non-stomatal restriction. The 60 mg/L treatment had the most significant effect. The daily mean, peak, and trough values of Pn increased by 51.76%, 41.24%, and 64.47%, respectively. (4) Compared to the control, the chlorophyll fluorescence parameters Fv/Fm, Fv'/Fm', ΦPSⅡ, and qP in each 6-BA treatment group increased to varying degrees during the experiment, while the NPQ value decreased. (5) The φPo, ψo, φEo, EABS/CSm, ETRo/CSm, EETo/CSm, and cPIabs significantly increased, while φDo and EDIo/CSm decreased with 6-BA treatment at an appropriate mass concentration (60 mg/L). These results indicated that the 6-BA treatment enhances the efficiency of PSⅡ light energy absorption, allocation, and utilization, as well as leaf-specific activity, alleviating the photoinhibition caused by excess excitation energy. 【Conclusion】 The 6-BA treatment at an appropriate mass concentration effectively enhances the antioxidant activity and photosynthetic performance of P. heterophylla leaves at the late growth stage, promoting growth and increasing root yield. The improvement in photosynthetic performance is related to enhancing antioxidant activity and PSⅡ photochemical activity in the leaves. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Research on the ecological compensation mechanism and standards for Qianjiangyuan-Baishanzu National Park YAO Hongwen, WANG Shihong, ZHU Chenghao, LI Zuohui, CHENG Linghong, LIAN Jihe, LIN Jie JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 21-27.   DOI: 10.12302/j.issn.1000-2006.202309044 Abstract （1557）   HTML （94）    PDF（pc） （1433KB）（934）       Knowledge map    Save 【Objective】The study aims to establish a sound ecological compensation standard, which will provide a sustainable and stable financial guarantee for the construction of national parks. 【Method】 Taking the Qianjiangyuan-Baishanzu National Park as an example, this study calculated the upper and lower range of the national park compensation standard by comparing the difference values of provincial public welfare forests inside and outside the national park with regulating services and opportunity cost losses. 【Result】 Considering the value of forest ecosystem regulation services and opportunity cost losses comprehensively, the value of provincial public welfare forests within the national park reached 47 237.01 yuan/(hm2·a).Among them, the value of provincial public welfare forests regulating service function was 45 672.53 yuan/(hm2·a), which was 13 306.25 yuan/(hm2·a) higher than outside the scope, and the value of each regulating service was higher than that outside the implementation area. The opportunity cost loss of public welfare forests within the national park was 1 564.48 yuan/(hm2·a), which still showed a gap of 841.48 yuan/(hm2·a) compared with the current highest compensation standard of 723 yuan/(hm2·a) of the provincial public welfare forests. 【Conclusion】 At present, there was still a large gap between the ecological compensation standard implemented in Qianjiangyuan-Baisanzu National Park and that calculated based on the regulating service unit area and opportunity cost. In the future, we suggest that the compensation standard be gradually increased year by year, taking into account the actual development needs of the National Park. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Distribution patterns of ant species in southeastern Yunnan Province YANG Lin, ZHU Huiqin, XU Zhenghui, ZHANG Xinmin, ZHOU Xueying, XU Guolian, LIU Xia JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 204-210.   DOI: 10.12302/j.issn.1000-2006.202211035 Abstract （1553）   HTML （41）    PDF（pc） （2570KB）（1189）       Knowledge map    Save 【Objective】The study aimed to investigate the patterns and laws of ant species distribution, including the habitat, vertical distribution, foraging patterns and nesting sites in southeastern Yunnan Province, provide a scientific basis for biodiversity cataloging and protection in this area.【Method】The distribution patterns of ant species in southeastern Yunnan Province were investigated using the plot-sampling method, and the data were counted using the harvesting frequency method. The Pearson correlation between the altitude and species richness of the ants was analyzed using the SPSS 26 software. 【Result】 A total of 197 species of ants, belonging to 64 genera and nine subfamilies under the Formicidae family, were recorded from five vertical zones in southeastern Yunnan Province. The majority of ant species inhabited different vegetation zones; however, a few ants, including Aphaenogaster schurri and Lasius himalayanus, inhabited only a single vegetation type. Of the 13 habitats, the ants (87 species) were most abundant in the middle-and low-altitude monsoon evergreen broadleaf forest, and least abundant (eight species) in the high-altitude Quercus semicarpifolia forest. The majority of ant species had a narrow ecological adaptation range, and the height difference in vertical distribution was less than 500 m. A few species of ants, including Ectomomyrmex javana, Nylanderia flavipes, and others exhibited a wide ecological adaptation range, and the height difference in vertical distribution was greater than 2 000 m. There were differences in the foraging zones and nesting sites of the majority of ant species. A few species, including Crematogaster osakensis, Formica cunicularia and Dolichoderus taprobanae, foraged and nested in multiple sites, and the species that foraged on the ground and nested in the soil were the most abundant. Correlation analysis revealed that the altitude and species richness were significantly negatively correlated at 0.01 level of significance. 【Conclusion】There are abundant resource for ant populations in southeastern Yunnan Province, and the distribution patterns of ant species in the region are primarily related to the altitude, types of vegetation, and adaptability. The species richness was found to be high in the middle-and low-altitude areas, which have a hot and humid climate, rich vegetation types, and sufficient food resources and nesting sites; however, the ants in the high-altitude areas inhabited fewer habitats and their species richness was low due to the cold climate and single type of vegetation. The study revealed that the functional characteristics of the ants determine their viability. The majority of ant species exhibited a strict environmental selection, and there were obvious differences in the distribution patterns of different species. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Precise genomic editing technology and its application in the improvement of woody plants JIANG Bo, AN Xinmin JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (1): 11-20.   DOI: 10.12302/j.issn.1000-2006.202402006 Abstract （1546）   HTML （32）    PDF（pc） （1995KB）（518）       Knowledge map    Save The rapid advancement of genome precision editing technologies has revolutionized our understanding of life’s mysteries. Central to these technologies is the capacity to precisely insert, delete, and substitute DNA sequences at designated genomic positions, facilitating the targeted modification of genetic information within living organisms. These technologies have become the cornerstone of research in the field of biology, from early explorations to the groundbreaking application of the CRISPR system, emphasizing the profound impact of scientific inquiry. The application of the CRISPR system has brought about a significant leap in genomic editing, catalyzing the emergence of more precise editing tools, such as base editors and prime editors, which have significantly enhanced the ability to edit genomes with precision. This milestone shift has already demonstrated tremendous potential in a wide range of fields, including agricultural improvement and disease treatment. The potential applications for gene editing technology are vast, especially in forestry and grass breeding. The CRISPR/Cas system can knock out multiple genes, offering high targeting efficiency, ease of design and operation, and low costs, making it widely applicable in crop genetic improvement. However, it is also associated with numerous limitations, which can be overcomed by new editing tools. As the technologies continues to advance, gene editing technology is expected to solve complex biological problems in the future, bringing more innovation and breakthroughs to human health and agricultural development. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Nitrogen, phosphorus contents and stoichiometric characteristics in different organs of three tree species in northeast China SUN Huizhen, LI Shan, LIU Shanshan, WANG Xingchang JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 147-155.   DOI: 10.12302/j.issn.1000-2006.202210003 Abstract （1467）   HTML （57）    PDF（pc） （1727KB）（739）       Knowledge map    Save 【Objective】The objective of this study is to investigate the nitrogen (N) and phosphorus (P) allocation patterns in the above- and below-ground organs of three different tree species in northeast China, namely Populus davidiana, Fraxinus mandshurica and Taxus cuspidata, and to provide theoretical insights into the trade-offs and allocation strategies of nutrient distribution among tree species.【Method】Mature individuals of P. davidiana, F. mandshurica and T. cuspidata were selected as research subjects. The N and P contents in aboveground organs, i.e., leaves, twigs and belowground organs, i.e., coarse roots, fine roots, were analyzed and the allocation ratios of N and P contents in the leaves, twigs and roots were calculated. Standardized major axis regressions were employed to examine the relationships of N and P elements between aboveground (belowground) organs of three tree species and the bidirectional nutrient transport of the same elements between aboveground and belowground organs.【Result】(1)The N and P contents in the leaves of P. davidiana and F. mandshurica were similar. However, the N and P contents in the leaves of these two species were significantly higher and lower, respectively, compared to T. cuspidata (P<0.05). The twigs of T. cuspidata exhibited the highest N and P contents, while F. mandshurica had the highest P content in coarse roots and N and P contents in fine roots. The N content in coarse roots was similar among the three species. (2)The ratios of N and P contents in leaves to twigs and leaves to coarse roots were the highest in F. mandshurica and P. davidiana, respectively, while the ratios of leaves to fine roots were the lowest in F. mandshurica. (3)For P. davidiana and T. cuspidata, the aboveground and belowground organs showed an allometric and isometric relationship respectively between N and P contents, with the scaling exponent in belowground being approximately half of that in aboveground. In contrast, F. mandshurica exhibited similar scaling exponents aboveground and belowground, both exhibiting significantly greater than 1 allometric relationship. For P. davidiana, the slopes of both aboveground and belowground P in both directions are half of the corresponding N values. For T. cuspidata, the slopes of P content in the upward direction were also half of the corresponding N values, and the downward N and P relationships were not significant. For F. mandshurica, the slopes of N and P content in the upward direction were similar, whereas in the downward direction, the P content slope was approximately 2/3 of N.【Conclusion】In contrast to P. davidiana and T. cuspidata, F. mandshurica tended to allocate N and P to metabolically active organs such as leaves and fine roots. The relationships between N and P in aboveground (or belowground) organs and N and P between above- and below-ground showed distinct coordinations for F. mandshurica compared to P. davidiana and T. cuspidata. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Changing features of habitat quality in Wuxi City based on InVEST model ZHAO Xiaoyu, WANG Yiming, HE Xu, LIU Xiaoyan, ZHANG Jiamin, DENG Yi, FENG Yao, CHU Lei, ZHANG Zengxin JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 165-172.   DOI: 10.12302/j.issn.1000-2006.202204066 Abstract （1466）   HTML （68）    PDF（pc） （2276KB）（719）       Knowledge map    Save 【Objective】 Based on 30 m of high-resolution land use data of Wuxi City in 2000, 2010 and 2018, the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model was used to reveal the changing features of habitat quality in Wuxi. Such information could provide a basis for ecological environment protection and restoration in Wuxi. 【Method】 Using the InVEST model, the habitat quality and habitat degradation degree of Wuxi during recent 20 years were simulated, and the relationship between the changes of land use, habitat quality and habitat degradation degree was analyzed by using the land use transfer matrix. 【Result】 In 2018, high-grade habitats in Wuxi accounted for approximately 31.11% of the city’s area, whereas the proportion of general grades was relatively higher, accounting for approximately 40.60% of the city’s area. The spatial distribution of habitat quality in Wuxi was various, with the high-grade habitats mainly distributed in Yixing City, Binhu District and other areas, while the low-grade habitats are predominantly located in the main urban area of Wuxi City and Jiangyin City. In the past 20 years, habitat quality in Wuxi has shown a significant degradation trend, of which the main urban areas of Wuxi such as Liangxi District and Jiangyin City have the most obvious degradation, whereas the degradation degree of Yixing City has not changed much. The changes of habitat quality and land use in Wuxi are inseparable, and among them, the construction land of Wuxi increased by approximately 12% from 717.40 km2 in 2000 to 1 291.40 km2 in 2018, and the area with increased construction land and the area where the quality of habitat decline is more obvious have good spatial consistency. 【Conclusion】 Degradation of habitat quality in Wuxi is closely related to the reduction of cultivated land area and the increase of urban construction land. Therefore, it is necessary to rationally use land, strictly control the scale of construction land, maintain the scale of ecological land use, and continuously improve the protection and restoration of wetlands. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Comprehensive effect of understory medicinal herb cultivation on individual volume growth in near-mature, mature and overmature Cunninghamia lanceolata forests YE Limin, XU Yuanke, ZHOU Yizhi, CHEN Zhenglu, WANG Yixiang, GE Hongli JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 48-56.   DOI: 10.12302/j.issn.1000-2006.202312027 Abstract （1463）   HTML （90）    PDF（pc） （2936KB）（832）       Knowledge map    Save 【Objective】 In the past, the understory planting was primarily conducted in young to middle-aged forests. However, with the advancement of public welfare forest development and the promotion of large-diameter timber cultivation, the issue of understory planting in mature stands has become an urgent research topic. This study aims to investigate the comprehensive effects of understory medicinal herb cultivation activities, including related shrubs cleaning up, land preparation, fertilization, routine care, and the growth of herbs, on the individual tree volume growth in mature Chinese fir (Cunninghamia lanceolata) forests. 【Method】 A total of 10 plots with understory planting of medicinal herbs and 10 plots without understory planting were established in mature Chinese fir plantations within Daji Forest Farm and Caoyu Pond Forest Farm, Jingning She Autonomous County, located in the southwestern part of Zhejiang Province. The medicinal herbs have been growing for a period of three years. One average tree from each plot was selected for wood analysis. The impact analysis of understory planting was conducted using a widely adaptable linear modeling approach, considering the annual growth measurements of volume, diameter, and height over the past three years. 【Result】 Under the simultaneous consideration of factors such as age, diameter at breast height, tree height, density, and site index, understory planting of medicinal herbs showed a significant promotional effect on individual tree volume growth. 【Conclusion】 With appropriate measures, understory planting can still significantly promote the volume growth of mature Chinese fir trees. However, this promotion is constrained by the age of the tree. The linear modeling approach is particularly suitable for analyzing data in situations where complexity exists and strict experimental control is not feasible. This method offers flexibility and provides reliable results. In small sample cases when using this method, it is necessary to perform a series of checks on the data to determine if the conditions are met in the course of modelling. Application of remedial measures to data that do not meet requirements. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Study on the morphological structure and anther abortion of Phyllostachys nigra flowers ZHOU Li, YAN Yingdan, LIU Jiaxin, WANG Sushuang, YANG Dejia, WANG Shuguang JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (1): 210-216.   DOI: 10.12302/j.issn.1000-2006.202308026 Abstract （1438）   HTML （11）    PDF（pc） （73078KB）（355）       Knowledge map    Save 【Objective】The flower morphological structure and anther abortion of Phyllostachys nigra are analyzed to explore the reasons for its low seed-set rate.【Method】The flower organs, mega- and microsporogenesis, as well as the development of male and female gametophytes, are observed through morphological examinations of the spikelets and paraffin sections using flower samples of P. nigra from the bamboo garden at the Southwest Forestry University. 【Result】The P. nigra inflorescence is a limited inflorescence, with the florets at the top blooming first, followed by the florets at the bottom. The spikelets cluster at the nodes of floral branches, with latent buds located at the base of the spikelets. The Ph. nigra florets are open, containing one palea, one lemma, three stamens, three lodicules, and one pistil. The lodicules are membranous and transparent, with well-developed cilia along the edges. The anther of P. nigra is approximately 8 mm long, containing four symmetrical sporangia. At the sporogenous cell stage, the anther wall consists of four layers: epidermis, endothecium, middle layer, and tapetum, from the outside to the inside. After anther maturation, two-celled or three-celled pollen grains are produced, and the anther wall comprises only two layers. The ovary is unilocular with parietal placentation, containing an anatropous ovule and three-lobed, feathery stigmata. 【Conclusion】Multiple abortions occur during the development of the stamens, which can be the key reason for the low seed-set rate of P. nigra. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Characteristics of fruit set and fruit sensory quality of blueberry hybrids with different ploidy level LI Xueling, LIU Ying, WU Wenlong, LYU Lianfei, ZHANG Chunhong, LI Weilin, CAO Fuliang JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (3): 41-51.   DOI: 10.12302/j.issn.1000-2006.202404027 Abstract （1385）   HTML （773）    PDF（pc） （2577KB）（233）       Knowledge map    Save 【Objective】In this study, 24 hybrids were made using blueberries of three distinct cultivation cultivar including Vaccinium corymbosum ‘O’Neal’, V. ashei ‘Pink Lemonade’ and V. ashei ‘Bonita’ as the male parent and three ploidy types of blueberries as the female parent. We aimed to investigate the differences in fruit setting and fruit sensory quality after pollinating these crosses. The results may provide some clues for proportion of pollination trees for cultivation and selection of breeding parents in hybrid breeding of blueberry. 【Method】Using the fruits from open pollination of the female parents as the control (CK), sensory quality indices of hybrid fruits from different crosses including fruit appearance parameters, contents of carbohydrates, antioxidant substances, and volatile compounds were evaluated.【Result】Hybridization compatibility between the three male parents and the rabbiteye blueberry cultivars ‘Vernon’ and ‘Briteblue’ was relatively low. Higher fruit set rate was solely found in the hybrid crosses with highbush types using ‘O’Neal’ and ‘Bonita’ as the male parents. After crossing with ‘O’Neal’, the single fruit mass of ‘Primadonna’ was decreased with a significant increase in fruit firmness. In addition, the fruit shape index of ‘Primadonna’ fruits pollinated by ‘Bonita’ increased significantly. Seed observatioin indicated that the hybrid crosses between blueberry ‘Pink Lemonade’ and three southern highbush cultivars all showed the relatively high fruit set rate, and hybrid seeds were not found in the hybrid fruits in the other crosses. Notably, the hybrid crosses between three male parents ‘O’Neal’, ‘Pink Lemonade’ and ‘Bonita’, and the rabbiteye type cultivar ‘Climax’ all revealed no seeds in the fruits. In comparison with each naturally open-pollinated female parent, the contents of sugar substances in the hybrid fruits of highbush types cultivars were significantly increased after the pollination of ‘O’Neal’ and ‘Bonita’. Especially, the solidity-acid ratios of the hybrid fruits of ‘Winsor’ and ‘Primadonna’ were extremely high after the pollination of ‘Bonita’. Further detection of aromatic substances demonstrated that there was a total of 59 volatile compounds in the fruits of all hybrid combinations. Although the types and contents of the volatile substances varied among the combinations, three main common substances, including linalool, caryophyllene oxide, and trans-2-hexenal were detected across almost all hybrid combinations. The content of linalool in the hybrid fruits of ‘Sharpblue’ was both significantly increased after pollination of ‘Bonita’ and ‘O’Neal’, while that of ‘Primadonna’ was significantly increased only after pollination by ‘O’Neal’. Espcecially, the content of trans-2-hexenal in the hybrid fruits of ‘Primadonna’ and ‘Sharpblue’ pollinated by ‘O’Neal’ was significantly higher than those of the naturally open-pollinated fruits. The volatile substances of the rabbiteye blueberry cultivar ‘Climax’ increased significantly after pollination by ‘Pink Lemonade’, and the substances of alkene type covered a relatively higher proportion. The content of total phenols and anthocyanins showed a similar trend in pollination combinations of different ploidy, with the highest content of total phenols and VC in the hybrid fruits of ‘Climax’ pollinated by ‘O’Neal’, and the content of anthocyanins in the fruit of ‘Primadonna’ and ‘Climax’ was relatively higher under natural open-pollination. 【Conclusion】Blueberries of different ploidy levels have a certain cross-compatibility for inter-ploidy hybridization, and the seedless fruit can be obtained in the crosses of the rabbiteye derived cultivar ‘Pink Lemonade’ and three southern highbush varieties. The solidity-acid ratios of hybrid fruits of most of the highbush cultivars were significantly increased after crossing with the rabbiteye cultivar ‘Bonita’. Especially, after crossing with the male parent ‘O’Neal’, the hybrid fruits of rabbiteye cultivar ‘Climax’ bore no seeds with the increase in the accumulation of antioxidant substances. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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A single tree leaf area prediction model in the Larix olgensis and Fraxinus mandshurica mixed forest WANG Yue, MIAO Zheng, HAO Yuanshuo, LIU Xin, DONG Lihu JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 235-245.   DOI: 10.12302/j.issn.1000-2006.202311012 Abstract （1370）   HTML （34）    PDF（pc） （2160KB）（590）       Knowledge map    Save 【Objective】 Using tree-level variables and single-tree competition indicators, a nonlinear mixed-effects model was used to construct a single-tree leaf area model of Larix olgensis-Fraxinus mandshurica, providing a theoretical basis for further research on stand productivity and canopy structure.【Method】 A total of 111 Larix olgensis plants and 113 Fraxinus mandshurica plants were selected from different mixing proportions of Larix olgensis-Fraxinus mandshurica mixed forest in Shangzhi City, Heilongjiang Province, and their leaf areas were measured. The whole subset regression method was used to establish a nonlinear single-tree leaf area prediction model for the two tree species. The contribution of each variable to the model was analyzed through the relative weight method. Simultaneously, the random influence of the sample plot on leaf area was considered, a mixed effect model was constructed, and the model was evaluated.【Result】 The optimal mixed effect model of larch single-tree leaf area considering random effects at the plot level was composed of PCR (crown ratio), DBH (diameter at breast height, DBH), and PHDH (ratio of forest tree height to the average height of dominant trees in the forest stand), including one random effect parameter. The R_{\mathrm{a}\mathrm{d}\mathrm{j}}^2 of the model was 0.89, root mean square error (RMSE) was 11.68 m2, mean deviation (ME) was -0.202 7 m2, mean absolute deviation (MAE) was 7.943 0 m2, and prediction accuracy (Pa) was 99%. The optimal mixed effect model of ash single-tree leaf area considering the random effect at the plot level consists of PCR, DBH, PHDH, and PCW (crown width), including one random effect parameter, The R_{\mathrm{a}\mathrm{d}\mathrm{j}}^2 of the model was 0.87, RMSE was 13.61 m2, ME was -0.281 7 m2, MAE was 9.397 6 m2, and Pa was 99%, all of which had good fitting effects. The relative weight calculation results showed that in the optimal model, DBH was the variable that has the greatest impact on the single-tree leaf area of Larix olgensis and Fraxinus mandshurica. 【Conclusion】 The mixed effect model considering the plot level improves the accuracy of predicting the leaf area of single trees of the two tree species. DBH is the variable that has the greatest impact on the leaf area of a single tree. It is necessary to consider tree competition variables in leaf area models of mixed forests. The model constructed in this study can provide technical support for accurately predicting the leaf area of single trees of Larix olgensis-Fraxinus mandshurica and can help with conducting in-depth research on the growth, development, and crown structure of the forest stand. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Correlation analysis and model construction of nut phenotype and kernel quality of early-fruiting walnuts (Juglans regia) LI Yang, ZHANG Yunqi, WEN Yue, ZHANG Suilin, CHEN Yonghao, QI Jianxun, ZHANG Junpei, HOU Zhixia JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (1): 119-127.   DOI: 10.12302/j.issn.1000-2006.202401005 Abstract （1311）   HTML （12）    PDF（pc） （5747KB）（281）       Knowledge map    Save 【Objective】There are correlations between phenotypic traits and fruit qualities. This study clarifies the relationships between nuts’ phenotypic traits and kernels’ qualities in early-fruiting walnuts from the Beijing-Hebei region, aiming to construct association models that provide a basis for preliminarily distinguishing nut qualities through phenotypic traits. 【Method】 The research focused on the superior genotypes of early-fruiting walnuts (Juglans regia) in the selection nursery at the Beijing Academy of Agricultural and Forestry Sciences. Nine nut phenotypic traits and four kernel qualities were measured during the fruit ripening stage. Based on these data, coefficients of variation, correlations, and variances were analyzed, and suitable regression models were constructed through fitting verification. 【Result】(1) The variation across 13 nut indices reaches a very significant level (P<0.01), with the coefficients of variation ranging from 5.43% to 28.63%. Except for sphericity, geometric average diameter, kernel yield, oil content, and protein content, the coefficients of variation for all other indicators exceed 10%. (2) Nut qualities exhibit intercorrelations. Oil content is closely related to the kernel yield and shows a significant positive correlation with soluble sugar content, but it is not closely related to starch or protein content. The protein and soluble sugar content demonstrate similar relationships with nut phenotypic traits, showing a significant negative correlation with nut size and dry weight and a significant positive correlation with volume kernel yield. Both are also significantly negatively correlated with starch content; the starch content is positively correlated with nut size and dry weight but negatively correlated with volume kernel yield.(3) Regression models are constructed based on the correlations between nut phenotypic traits and kernel qualities. There is a linear relationship between oil content and kernel yield, a parabolic relationship between soluble sugar content and volume kernel percentage, a linear relationship between starch content and nut volume, and a linear relationship between protein content and geometric average diameter. The models are validated by model fitting, with the difference between the predicted and actual values within the 95% limits of agreement (LOA) accounting for more than 95% of the total, demonstrating the models’ reasonableness and reliability. 【Conclusion】 Reliable regression models are constructed based on the close relationship between nut phenotypic traits and kernel qualities. These models can preliminarily distinguish nut quality and are helpful for the initial screening of suitable cultivars or strains. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of extreme climate on the distribution and potential habitat of Hyphantria cunea in China XUE Mingyu, HAO Dejun, ZHAO Xudong, GENG Yishu, HU Tianyi, XIE Chunxia JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (5): 197-203.   DOI: 10.12302/j.issn.1000-2006.202212010 Abstract （1309）   HTML （39）    PDF（pc） （2626KB）（743）       Knowledge map    Save 【Objective】This study aims to predict the potential habitat of Hyphantria cunea under extreme climate conditions in China. 【Method】The occurrence data of H. cunea were obtained. Contemporary and future bioclimatic variables and extreme climate index data were processed using ArcGIS and DIVA-GIS. Environmental variables with low correlation coefficients and high contribution rates were selected. These variables were input into MaxEnt to calculate the potential habitats of H. cunea for the contemporary period, 2021 to 2040, 2041 to 2060, and 2061 to 2080. The spatial changes in the habitats were expressed by the relative positions of the centroids of the habitats. 【Result】The maximum daily precipitation, warm spell duration index, percentage of nights when the minimum temperature is below the 10th percentile, and mean temperature of the wettest quarter were important variables affecting the distribution of H. cunea. The potential habitat of H. cunea was currently mainly distributed in eastern, northern, and northeastern China, as well as the middle and lower reaches of the Yangtze River. In the future, H. cunea might spread to southwest China, reaching Sichuan and Chongqing, with scattered distributions in Guangdong and Guangxi. 【Conclusion】The extreme precipitation is an important factor affecting the distribution of H. cunea. H. cunea is adapted to areas with stable climates. Predictions based on the extreme climate index indicate a risk that H. cunea will spread to southwest China in the future. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Effects of drought on the soil microbial biomass C, N, P ecological stoichiometric characteristics of poplar plantation ZHAO Ziwei, RUAN Honghua, YANG Yan, XIE Youchao, SHEN Caiqin, XU Yaming, CAO Guohua JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (3): 33-40.   DOI: 10.12302/j.issn.1000-2006.202311030 Abstract （1300）   HTML （762）    PDF（pc） （1552KB）（156）       Knowledge map    Save 【Objective】This study aimed to reveal the effects of drought on soil microbial biomass carbon (C), nitrogen (N), and phosphorus (P), as well as their ecological stoichiometric characteristics in poplar plantations. We also aimed to understand the soil C, N, and P biogeochemical cycles in poplar plantations under a future global drought scenario and provide a theoretical basis for the rational management of these plantations.【Method】Soil microbial biomass C (MBC), N (MBN) and P (MBP), along with their ecological stoichiometric characteristics (i.e., MBC/MBN, MBC/MBP, and MBN/MBP), and soil physicochemical properties, were examined in a poplar plantation (Populus deltoides) at Dongtai Forest Farm, Jiangsu Province, China. Three treatments were established in this study, control (CK), 30% throughfall reduction (D1), and 50% throughfall reduction (D2).【Result】(1) Soil MBC, MBN, and MBP were significantly reduced under drought conditions compared to the control, with reductions of 16.09%, 22.60%, and 32.49%, respectively, for the D2 treatment. Both MBC/MBN and MBC/MBP were significantly increased under drought conditions, with increases of 10.33% and 25.15%, respectively, in the D2 treatment, while soil MBN/MBP ratios did not change significantly. (2) Soil MBC, MBN and MBP showed significant seasonal variations, ranging from 344.67 to 500.12 mg/kg, 45.21 to 63.22 mg/kg, and 15.33 to 23.48 mg/kg, respectively. MBC, MBN, and MBP contents were lower in summer and fall than in winter and spring. In contrast, seasonal variations in MBC/MBN and MBC/MBP showed opposite trends to those of MBC, MBN, and MBP, while seasonal variations in MBN/MBP were not significant. (3) Compared with the control, drought treatments significantly reduced $\mathrm{NH}_{4}^{+}-\mathrm{N}$, dissolved organic carbon (DOC), available phosphorus (AP), and soil water content (SWC) by 68.81%, 32.77%, 29.87%, and 11.05%, respectively. Drought treatments increased soil pH and $\mathrm{NO}_{3}^{-}-\mathrm{N}$ content by 1.51% and 194.34%, respectively. Correlation analyses showed that soil MBC, MBN, and MBP had highly significant positive correlations with SWC and total nitrogen (TN) and significant or highly significant negative correlations with SOC, $\mathrm{NO}_{3}^{-}-\mathrm{N}$ content, and the total carbon to nitrogen ratio (C/N). Soil MBC/MBN, MBC/MBP, and MBN/MBP showed significantly or highly significant positive correlations with $\mathrm{NO}_{3}^{-}-\mathrm{N}$ and C/N and significant or highly significant negative correlations with SWC and TN content.【Conclusion】Drought significantly affected soil microbial C, N, and P and their ecological stoichiometric characteristics in poplar plantations, potentially altering the soil nutrient balance and cycling in these plantations. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Dynamic changes and driving forces of ecological environment quality in the source region of the Yangtze River from 1990 to 2020 WANG Tianhong, JIANG Fugen, LONG Yi, DENG Muli, SUN Hua JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (3): 110-118.   DOI: 10.12302/j.issn.1000-2006.202301017 Abstract （1299）   HTML （756）    PDF（pc） （2524KB）（116）       Knowledge map    Save 【Objective】Accurately and efficiently monitoring the spatio-temporal distribution characteristics of the ecological environment quality and its evolving trends in the source area of the Yangtze River is of great significance for maintaining the high-standard protection of the ecological environment. It also serves as a fundamental basis for formulating long-term and effective ecological protection and restoration strategies in the Sanjiangyuan region. The remote sensing ecological index (RSEI) has distinct advantages over traditional evaluation methods relying on single monitoring indices. It boasts rapid assessment capabilities, objectivity, high efficiency, strong visual interpretability, and reliable predictability. Nevertheless, the spatial resolution constraints and the complexity of data acquisition and processing in remote sensing images still present challenges to the large-scale and accurate evaluation of the RSEI.【Method】In this study, the Google Earth Engine (GEE) platform was utilized, with Landsat series images as the data source. Remote sensing images of the Yangtze River source area during the vegetation-growing season (from June to September) from 1990 to 2020 were obtained. Subsequently, long-time-series RSEI data were calculated. To comprehensively analyze the RSEI in the Yangtze River source area from 1990 to 2020, the coefficient of variation was applied to measure its stability, the Sen + Mann-Kendall (Sen + MK) trend analysis was used to explore the spatio-temporal change trends, the Hurst index was employed to predict future evolution, and the trend analysis method was adopted to identify the driving forces behind these changes.【Result】(1) From 1990 to 2020, the RSEI values in the Yangtze River source region were predominantly distributed within the range of 0.4-0.6. Geographically, the region exhibited a clear pattern where the RSEI values were higher in the eastern and southern parts and lower in the western and northern parts.(2) The average coefficient of variation of the RSEI in the source region was 6.52%. This indicates that the ecological environment in the eastern and western regions underwent relatively more pronounced fluctuations, while the central region remained relatively stable. Overall, the RSEI showed a slow oscillating trend, with an average annual growth rate of 0.004 7. Spatially, the RSEI presented an overall upward trend, and the area with improved ecological conditions accounted for 83.63% of the total study area.(3) The average Hurst index value of the RSEI in the source region was 0.53, implying that the future changes of the RSEI were more likely to be continuous rather than show anti-sustainability. The future ecological environment quality in the Yangtze River source region was expected to experience continuous improvement, yet the overall trend was relatively mild, and there still existed an underlying risk of degradation.(4) In the Yangtze River source region, the RSEI was positively correlated with air temperature, night-light index, and potential evapotranspiration. This reveals that both natural factors and human activities had a certain degree of influence on the enhancement of the ecological environment quality.【Conclusion】The integration of using GEE for remote sensing data acquisition and time-series data analysis has significant potential for rapidly and comprehensively monitoring the ecological environment quality on a large scale. This approach can offer valuable references and technical support for ecological monitoring and protection efforts in the Sanjiangyuan area, thereby contributing to the sustainable development of the regional ecological environment. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Comparison of pathogenicity and reproduction of Bursaphelenchus xylophilus in pine families with different disease resistance WANG Junwei, HU Longjiao, WU Xiaoqin JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (1): 21-27.   DOI: 10.12302/j.issn.1000-2006.202302017 Abstract （1251）   HTML （27）    PDF（pc） （1446KB）（393）       Knowledge map    Save 【Objective】 To explore whether the interaction of pine families with varying levels of disease resistance in the same plot with pine wood nematode (Bursaphelenchus xylophilus) under natural conditions affects the pathogenicity and reproduction of B. xylophilus, and to determine if the expression level of cytochrome P450 i.e. CYP family-related genes of B. xylophilus strains with noticeable differences in pathogenicity different after interaction with pine trees, the following study was conducted.【Method】This study monitored the gene pools of several families of Pinus densiflora and P. thunbergii, which were introduced from Japan previously in the lab. Field monitoring was conducted over several years, revealing significant differences in disease resistance among different pine families. Dead wood samples from each family in the pine tree gene pool were collected, and automated molecular detection was used to identify B. xylophilus. Nematode samples from five P. densiflora families and five P. thunbergii families, confirmed to have died from B. xylophilus, were isolated. A total of 10 B. xylophilus strains were obtained through monoheterotic in vivo culture, and their pathogenicity and reproduction were tested. The relative expression of two cytochrome P450 genes in four B. xylophilus strains with significantly different pathogenicity was detected by RT-qPCR. 【Result】The results indicated that in the same tree species within the same plot, the stronger the disease resistance of the pine families, the lower the reproduction rate of B. xylophilus strains obtained under monoheterotic living culture. Conversely, weaker disease resistance in pine families corresponded with higher reproduction rates of B. xylophilus strains. Inoculating each strain with 2-year-old P. thunbergii revealed that the pathogenicity test results of nematode strains obtained from diseased and dead trees of five P. thunbergii families were positively correlated with the resistance of pine families. The B. xylophilus strain JYK-34, isolated from the most resistant family (34), showed the highest pathogenicity. However, for P. densiflora families, there was no positive correlation between resistance and the pathogenicity of B. xylophilus. The B. xylophilus JYK-18, isolated from a highly resistant family (18), exhibited weak pathogenicity. Compared with the control B. xylophilus, the increased expression of two cytochrome P450 genes, BxCYP33C4 and BxCYP33C9, was positively correlated with the pathogenicity of the four B. xylophilus strains, namely JYK-34>JYK-17>JYK-18>JYK-31, after interacting with the P. thunbergii seedlings for 30 days. 【Conclusion】The differentiation in the reproduction of B. xylophilus was consistent among different disease-resistant families of P. densiflora and P. thunbergii. The pathogenicity of B. xylophilus isolated from pine trees with different resistance levels within the same plot in the resistant pine tree gene pool was not uniform, with different strains exhibiting varying pathogenicity. The cytochrome P450 genes BxCYP33C4 and BxCYP33C9 in B. xylophilus are involved in the interaction between B. xylophilus and pines and are also important genes related to the pathogenicity of B. xylophilus. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of drought on nitrogen uptake and distribution in Camellia oleifera root under nitrogen addition JIANG Xiaozeng, ZHU Yan, ZHOU Hengwei, HUANG Xingzhao, FU Longlong, WAN Fangfang JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (1): 95-102.   DOI: 10.12302/j.issn.1000-2006.202303015 Abstract （1239）   HTML （12）    PDF（pc） （1626KB）（362）       Knowledge map    Save 【Objective】This study investigates the growth response and nutrient utilization of the Camellia oleifera root system across different root orders under drought and nitrogen application. It aims to analyze how water and nitrogen affect root growth, nitrogen uptake, distribution and utilization, and to provide theoretical support for understanding the relationship between plant root architecture and nutrient strategies under climate warming. 【Method】 Two-year-old C. oleifera ‘Changlin 53’ trees were used. A pot experiment with 15N isotope tracing technology was conducted, setting two drought levels: normal irrigation (soil moisture content 75% ± 5%) and drought (soil moisture content 30%±5%). Two nitrogen application levels were used: no nitrogen and 15N-labeled ammonium nitrate (2.88 g/plant). After 75 days of drought treatment, the biomass, total nitrogen content, percentage of nitrogen from fertilizer (Ndff), and nitrogen use efficiency of roots of different diameter classes of C. oleifolia seedlings were measured. 【Result】 Under drought stress, there was a negative correlation between biomass and nitrogen content in grade 1-3, grade 5, and grade 6 roots, while a positive correlation was observed in grade 4 roots. Drought significantly affected 15N content and Ndff in all root diameter classes (P < 0.05). Drought inhibited 15N accumulation in all root diameter classes, with Ndff in grades 1-3 being most affected. Drought increased nitrogen distribution in roots, especially in grade 5 roots, which saw a 93.10% increase. However, the nitrogen use efficiency was inhibited to varying degrees across different root diameter classes. 【Conclusion】Nitrogen application increased root biomass and nitrogen allocation to coarse roots under drought but reduced fine root biomass and nitrogen accumulation. Drought significantly impacted the absorption, utilization, and distribution of fertilizer nitrogen in roots of all levels, enhancing nitrogen distribution, particularly in roots above grade 5, but inhibiting 15N absorption and utilization in roots of grades 1-4. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of different form quotients on prediction accuracy of individual tree volume of Larix gmelinii ZHANG Yijun, ZHANG Zipeng, JIANG Lichun JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (3): 95-102.   DOI: 10.12302/j.issn.1000-2006.202405028 Abstract （1215）   HTML （712）    PDF（pc） （1638KB）（102）       Knowledge map    Save 【Objective】This study took the Larix gmelinii in the Greater Khingan Mountains as the research subject. Based on breast height form quotient, normal form quotient, and ground form quotient, individual tree volume models incorporating different form factors were constructed. These models were then compared and analyzed against traditional one-variable and two-variable volume models, as well as the two-variable volume model for L. gmelinii in Northeast China.【Method】Based on the measured data of L. gmelinii, a series of breast height form quotients, normal form quotients, and ground form quotients at different heights of the trunk were introduced into the traditional volume model. One-variable and two-variable tree volume models with different form quotients were constructed, respectively, and variance functions were introduced to eliminate the heteroscedasticity in the fitting process of each volume model. The mean absolute error (MAE), root mean square error (RMSE), relative root mean square error (RMSE%), determination coefficient (R2), and Akaike information criterion (AIC) were used as evaluation indexes to fit and analyze each model.【Result】(1) The two-variable and three-variable models constructed with the introduction of the breast height form quotient at 50% relative tree height fitted best, with the three-variable tree volume model reducing the RMSE by 44.4% compared to the two-variable tree volume equation. (2) The three-variable volume model constructed by introducing the normal form quotient,at 50% of the relative tree height performed the best, reducing the RMSE by 23.1% compared to the two-variable volume model that incorporated the ground form quotient. (3) For the ground form quotient, the three-variable volume model achieved the best fit when the variable was set at 60% of the relative tree height, while the binary volume model performed optimally when the variable was set at 50% of the relative tree height. The three-variable volume model incorporating the ground form quotient reduced the RMSE by 32.5% compared to the two-variable volume model. (4) Compared to the two-variable volume equation for Larix gmelinii used in Northeast China, the three-variable volume model incorporating the breast height form quotient reduced the RMSE, MAE, and RMSE% by 62.85%, 65.02%, and 67.14%, respectively. The three-variable volume model containing the breast height form quotient reduced the RMSE by 60.41% compared to the traditional two-variable tree volume equations.【Conclusion】The form quotient is an important index of stem form, and the introduction of breast height form quotient, normal form quotient, and ground form quotient into the traditional volume models can improve the accuracy of predicting tree volume. The three-variable tree volume model has the best prediction effect with the introduction of the breast height form quotient. Therefore, it is recommended to use this model to predict the tree stem volume of L. gmelinii in the region in the future. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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A comprehensive evaluation of fruit characteristics of 46 blueberry cultivars ZHAO Huifang, ZHAO Fengyi, LIU Hongxia, WU Wenlong, WU Yaqiong, LI Weilin JOURNAL OF NANJING FORESTRY UNIVERSITY    2025, 49 (3): 52-62.   DOI: 10.12302/j.issn.1000-2006.202408010 Abstract （1190）   HTML （739）    PDF（pc） （2145KB）（271）       Knowledge map    Save 【Objective】This research aims to evaluate the fruit characteristics of 46 blueberry cultivars for selection and breeding purposes. 【Method】The fruit appearance, inner quality and sensory properties of 46 blueberry cultivars were investigated, then classified and evaluated by correlation, principal component and cluster analyses. 【Result】The northern highbush blueberry exhibited the largest fruit size, highest and acidity levels, and achieved the highest sensory score. The fruit of southern highbush blueberry was the smallest, with the lowest hardness and sensory score, the highest sweetness and total polyphenol content. The fruit of rabbit eye blueberry was larger than southern highbush blueberry, with the highest pericarp ratio and total anthocyanin content. Among appearance indices, the chromaticity a* of fruit with epicuticular powder removed exhibited the highest coefficient of variation (CV) at 2 926.91%, followed closely by the original fruit chromaticity a* at 370.96%. The CV of solid acid ratio (42.77%) was the highest among quality indices, followed by total anthocyanin content (39.78%), and the CV of sensory score was the lowest (<10%). Correlation analysis revealed that larger fruit size was associated with lower pericarp percentage and total polyphenol content. The acidity had the greatest effect on the solid acid ratio of blueberry fruits. Sensory evaluation indices, including appearance and comprehensive scores, showed significant positive correlations with fruit weight, transverse diameter, and longitudinal diameter, indicating that larger fruit size is a preferred characteristic in sensory evaluation. Cluster analysis showed that the 46 blueberry cultivars were divided into three types, among which the first type had the largest fruit with high hardness and acidity, the second type had the second-largest fruit with the highest sweetness, and the third type had the smallest fruit with high pericarp ratio, belonging to the processing type with high total anthocyanin and polyphenol content. Principal component analysis reduced the 11 appearance and quality indices to four principal components, explaining 75.217% of the total variance. Sensory evaluation revealed that, in addition to differences in size, sweet-sour balance and nutrient content, the 46 blueberry cultivars also varied in wax thickness, texture and fruity aroma, and seven large-fruit cultivars of ‘Primadonna’, ‘Millennia’, ‘Jewel’, ‘Chandler’, ‘Brigitta’, ‘Aurora’ and ‘Prolific’, 3 high sweetness cultivars of ‘Anna’ ‘Sweetheart’ and ‘Brightwell’, and four excellent taste cultivars of ‘Sunshine’, ‘Magnolia’, ‘Brigitta’ and ‘Beckyblue’ were selected. Comprehensive evaluation showed that sensory assessment results were largely consistent with principal component and cluster analyses. 【Conclusion】The 10 cultivars with large fruit size, high sweetness, crisp texture and rich aroma were ‘Prolific’, ‘Chandler’, ‘Sweetheart’, ‘Brigitta’, ‘Millennia’, ‘Beckyblue’, ‘Primadonna’, ‘Brigitta’, ‘Magnolia’ and ‘Pink Lemonade’, which were recommended for fresh consumption, and the 5 cultivars with high total anthocyanins and polyphenols content and high pericarp percent were ‘Gardenblue’, ‘Zhongzhi 4’, ‘Zhaixuan 4’, ‘Baldwin’ and ‘Centurion’, which can be used for processing blueberry products. These cultivars can also serve as parental materials for corresponding breeding objectives. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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A single tree segmentation method for street trees facing side-looking MLS point clouds YAN Yu, LI Qiujie, LI Weizheng JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (6): 166-174.   DOI: 10.12302/j.issn.1000-2006.202301018 Abstract （1176）   HTML （15）    PDF（pc） （6665KB）（363）       Knowledge map    Save 【Objective】Aiming at the problem of single tree segmentation of street trees in the investigation of street tree resources, a single tree segmentation method of street trees facing the side looking mobile laser scanning (MLS) point cloud was studied. The point clouds on both sides of the street scanned along the road direction were collected. A point cloud instance segmentation algorithm which can accurately implement single tree segmentation of street trees is established.【Method】The local features were extracted from the points in the point cloud, and the local features were input into the street tree point cloud detector to identify the street tree point cloud in the point cloud. For the identified street tree point clouds, the density-based spatial clustering of applications with noise (DBSCAN) was used to cluster the street tree clusters and filter out the street tree point clouds. The trunk point cloud of each street tree cluster was extracted, and several tree clusters were obtained using DBSCAN algorithm. The number of tree clusters contained in each street tree cluster was counted. For street tree clusters containing multiple trunk clusters, the method of vertical slicing and vertical cutting was used to divide the cluster into multiple single tree. The method of combining DBSCAN and K-nearest neighbor (KNN) was used to segment a single street tree in fine order to obtain the final tree segment result. The point cloud data on both sides of the street were collected, and three sets of experiments were carried out: street tree point cloud detector training, fine segmentation accuracy test and algorithm comparison.【Result】The accuracy rate, recall rate and F1 score of the street tree segmentation method facing side-looking MLS point cloud were 0.970 4, 0.951 0 and 0.960 6, respectively, which were superior to the two existing methods of first recognition and then segmentation.【Conclusion】The proposed method can accurately segment street trees in MLS point cloud, and save labor cost for street tree resource investigation. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）