Latest Articles

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes/issues, but are citable by Digital Object Identifier (DOI).
Study on the population density and activity rhythm of wild boar in Longyou County, Zhejiang, China
LI Yuying, CHEN Xiangxiang, YING Yishan, YI Lixiao, ZHU Lihong, YING Jianping, LIN Xiaoyue, ZHANG Min
, Available online  doi: 10.11833/j.issn.2095-0756.20240170
Abstract:
  Objective  By investigating the population density and activity rhythm of wild boars (Sus scrofa) in Longyou County of Zhejiang Province, this study is aimed to research the accurate countermeasures in wild boar prevention and control, and to provide exemplary monitoring and evaluation work from theory and practice to methodological application at the county level.  Method  Firstly, with the employment of infrared camera technology, a total of 1 308 independent and valid photographs were obtained from January 2021 to August 2023. Then the population density was estimated using a random encounter model, and the activity rhythm of the wild boar in the studied area was also investigated using the kernel density estimation method.  Result  The population density of wild boars in Longyou County ranged from 0.957 to 1.291 head per square kilometer with the total estimated population of wild boars in the county being approximately 417 to 563 considering suitable habitat areas and the number of wild boars decreasing from the southern mountainous areas, the northern mountainous areas to the central regions. In terms of habitat selection, the wild boar population preferred coniferous forests (relative abundance index IRA=38.45%), mixed coniferous and broad-leaved forests (IRA=24.39%), and the elevation range of 1 100 to 1 300 m (IRA=57.25%). With significant density data observed at 17:00 in all four seasons, daily activity rhythms are similar in spring and winter, exhibiting a unimodal pattern while in summer, the daily activity rhythm is bimodal, with the main peaks occurring around sunrise and sunset and there is no significant fluctuation in the daily activity rhythm in autumn and the population exhibited a highly significant seasonal migration behavior along the altitudinal gradient (P<0.01).  Conclusion  The distribution of wild boars in Longyou County exhibits significant spatial heterogeneity, while their activity rhythms are also influenced by factors such as altitude and season which can provide direct scientific evidence for the formulation of wild boar control policies in Longyou County and serve as a reference for estimating wild boar density and studying activity rhythms at the county level. [Ch, 2 fig. 4 tab. 29 ref.]
Fabrication and controlled release characteristics of whey protein-alginate dialdehyde microcapsule
YANG Ye, WU Shaping, WANG Kaijun, WU Changling, LIU Xingquan, WU Fenghua, WANG Peng
, Available online  doi: 10.11833/j.issn.2095-0756.20240243
Abstract:
  Objective  This study used whey protein (WPI) and alginate dialdehyde (ADA) to prepare WPI-ADA copolymer microcapsules, and the interactions between WPI and ADA and their effects on the controlled release of curcumin in the microcapsules were investigated to provide a theoretical basis for the development of the encapsulation system of curcumin.   Method  WPI-ADA copolymers were prepared using a wet-heat method, and the interaction between WPI and ADA was explored through analysis of grafting degree, browning intensity, and infrared spectroscopy. The effects of different proportions of copolymers on the emulsion were studied in terms of particle size, zeta potential, and rheological properties. The influence of copolymers on microcapsules was investigated using X-ray diffraction, thermogravimetric analysis, and the release characteristics of curcumin.   Result  The results indicated that the optimum mass ratio of WPI and ADA for preparing microcapsules was 1:3. Grafting degree, browning intensity and Fourier transform infrared spectroscopy (FTIR) analyses confirmed the formation of conjugates. Driven by covalent binding, the particle size of WPI-ADA emulsion decreased from 415.4 nm to 325.9 nm, and the microcapsule encapsulation efficiency increased from 83.9% to 95.4%. Additionally, WPI-ADA copolymer microcapsules exhibited good thermal stability. In vitro simulated digestion experiments demonstrated that WPI-ADA copolymer microcapsules exhibited certain controlled release capabilities, extending the time for maximum curcumin release from 12 hours to 24 hours in simulated gastric fluid and intestinal fluid.   Conclusion  Under covalent interaction, WPI-ADA copolymers can improve the physicochemical properties and curcumin release properties of microcapsules, and can be used to modify the microcapsule system and the delivery of hydrophobic active substances. [Ch, 8 fig. 1 tab. 27 ref.]
Impact of industrial organization models on the value realization of non-timber forest products
WANG Danting, ZHU Zhen, YANG Hong, SHEN Yueqin
, Available online  doi: 10.11833/j.issn.2095-0756.20240297
Abstract:
  Objective  This study aims to explore the impact of various industrial organization models on the value realization of non-timber forest products and their mechanism of action, and to clarify effective pathways for the value realization of material-based ecological products.   Method  Based on the survey data of 811 farming households from 7 counties (cities) in Zhejiang Province in 2022, this study empirically analyzed the impact of different industrial organization models on the value realization of non-timber forest products, as well as the role of regional public brands in this process.   Result  Both horizontal cooperation (cooperative + farmer) and vertical collaboration (company + farmer) models had significant positive effects on the value realization of non-timber forest products. Mechanism verification showed that regional public brands played a mediating role in the value realization process of non-timber forest products by industrial organizations. Heterogeneity tests revealed that the premium effect of non-timber forest products sold by farmers with small operation scale and through the Internet was more significant.   Conclusion  Industrial organizations can facilitate the value realization of non-timber forest products by promoting farmers’ participation in regional public brands. Therefore, it is suggested that while improving the organization degree of farmers, it is necessary to strengthen the construction of regional public brand and optimize sales channels. [Ch, 6 tab. 35 ref.]
Hydrological effects of litter layers in different forest types in the Bashang region
YU Along, WEN Hui, CONG Richun, HOU Meijuan, LI Hanzhi
, Available online  doi: 10.11833/j.issn.2095-0756.20230535
Abstract:
  Objective  This study, with an investigation of the water conservation capacity of litter layers in different forest types in the Bashang region, an important water conservation functional area in the Beijing-Tianjin-Hebei region, is aimed to provide a basis for the restoration, management and improvement of water and soil conservation in this region.   Method  With four types of forests, including Larix gmelinii var. principis-rupprechtii (PL), Betula platyphylla (NP), Populus davidiana and B. platyphylla mixed forest (NBP), L. gmelinii var. principis-rupprechtii and B. platyphylla mixed forest (PBL), selected as research objects in the Heping Forest Farm in Zhangjiakou City, field investigations and indoor immersion methods were employed to measure the ecological hydrological indicators of litter layers.   Result  (1) The thickness of litter layers in different forests ranged from 32.0 to 62.0 mm, with the PBL mixed forest having the thickest litter layer, followed by PL forest, NBP mixed forest, and NP forest. (2) The maximum water holding rate, maximum retention rate, and effective retention rate of litter layers were higher in NP forest and NBP mixed forest than PBL mixed forest and PL forest, with NP forest having the highest values of 231.15%, 207.60%, and 172.94%, respectively, and PL forest having the lowest values of 208.92%, 170.29%, and 138.95%, respectively. (3) The biomass, maximum water holding capacity, maximum retention capacity, and effective retention capacity of litter layers in the four types of forests ranged from 8.27 to 23.33 t·hm−2, 18.96 to 49.71 t·hm−2, 16.73 to 39.05 t·hm−2, and 13.90 to 31.56 t·hm−2, respectively, and the general trend was PL>PBL mixed forest>NBP mixed forest>NP forest. (4) The water holding capacity of litter layers in the four types of forests showed a logarithmic function relationship with the immersion time (R2>0.94) while the water absorption rate showed a power function relationship with the immersion time (R2>0.92).   Conclusion  The water absorption performance of litter layers per unit mass in PL forest was weaker than that in NP forest, but when considering the biomass, the total water holding and retention capacity of PL forest was significantly higher than NP forest, indicating a strong comprehensive water conservation capacity. [Ch, 5 fig. 3 tab. 38 ref.]
Challenges and countermeasures in implementing carbon labeling for agricultural products
HUANG Wei, ZHANG Hongying, XIAO Xiangze, LIN Lang, WANG Cheng
, Available online  doi: 10.11833/j.issn.2095-0756.20240373
Abstract:
The implementation of carbon labeling for agricultural products can promote precise and efficient carbon reduction in agricultural sector, support the realization of agricultural ecological value, innovate agricultural income models, and enhance domestic and international market competitiveness. China started late in this respect compared with foreign countries, with insufficient guidance from the top, and it was necessary to accelerate the implementation process. Difficulties existing in the implementation process of carbon labeling for agricultural products were analyzed. On the one hand, the carbon footprint accounting capacity for agricultural products was weak. Due to incomplete accounting standards and the weak data base, the accounting results were incomplete and inconsistent and comparability was low. On the other hand, there was insufficient driving force for the implementation of carbon labeling for agricultural products. Factors such as limited awareness, ability, and motivation of agricultural producers, weak willingness of consumers to pay, and lack of established standards and systems all contributed to limited credibility of accounting and certification results, and funding and other elements of security were not guaranteed. The main paths for promoting the application of carbon labeling for agricultural products were discussed, such as speeding up the development of accounting standards, consolidating the data base, promoting international mutual recognition of standards, data, and results, so as to enhance the capacity of carbon footprint accounting. Then, sound carbon labeling system should be established, including certification system and factor support system. Finally, the promotion of carbon labeling should be intensified by developing green consumption scenarios and providing technical support. [Ch, 2 fig. 1 tab. 45 ref.]
Effect of iron-modified biochars on soil nutrients and bioavailability of As and Pb
MAO Haonan, YANG Xing, LU Kouping, WU Jiasen, WANG Hailong
, Available online  doi: 10.11833/j.issn.2095-0756.20240171
Abstract:
  Objective  To investigate the effects of raw and iron-modified biochar on the nutrient content and bioavailability of arsenic (As) and lead (Pb) in con-contaminated agricultural soil.   Method  An experiment using rice potted in soil mixed with 2% raw Ficus microcarpa biochar (FMB) and Polyferric Sulfate (iron)-modified biochar (Fe-FMB) was conducted, no biochar soil as control. We measured soil nutrient availability, soil enzyme activity, rice biomass and As and Pb concentrations in various plant organs at different growth stages. The bioavailable As and Pb in the soil were determined using the NH4H2PO4 and DTPA extraction methods, respectively.   Result  The results indicated that, compared to the control, Fe-FMB significantly enhanced the availability of nutrients such as phosphorus (P) and silicon (Si) in the soil and significantly altered the distribution of Si forms in the soil, primarily increasing the content of amorphous silicon (by 25.2%) and iron-manganese oxidized silicon (by 11%). Fe-FMB was more effective in immobilizing soil As, reducing it by 37.9% compared to the control, while original biochar (FMB) was more effective for soil Pb immobilization, reducing it by 24.9%. Application of Fe-FMB led to a 67.2% reduction in As content in rice grains as compared to the control. Furthermore, Fe-FMB significantly increased the activities of leucine aminopeptidase, acid phosphatase, and catalase, with maximum increases of 121.1%, 99.1%, and 33.2%, respectively. Pearson’s correlation analysis showed that soil enzyme activity was significantly related to pH and As availability, indicating that biochar application can regulate soil enzyme activity by influencing soil pH and As bioavailability.   Conclusion  While F. microcarpa biochar is effective in remediating soils contaminated with Pb only, it is not suitable for the treatment of soils co-contaminated with As and Pb. On the other hand, iron-modified biochar shows a better prospect for remediating soils co-contaminated with As and Pb. [Ch, 8 fig. 2 tab. 39 ref.]
Floral substances and daytime release rhythms of 3 Chimonanthus species
HU Guiting, YANG Liyuan, REN Guangbing, ZHAO Hongbo
, Available online  doi: 10.11833/j.issn.2095-0756.20240266
Abstract:
  Objective  Flower fragrance is an important characteristic of ornamental plants, which is very crucial for plants reproduction. This study aims to reveal the biosynthesis and release mechanism of floral substances in Chimonanthus, and to provide a solid theoretical basis for the utilization and development of Chimonanthus resources.   Method  Headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used to identify and analyze floral substances of 3 Chimonanthus species, including C. praecox, C. salicifolius and C. nitens.   Result  A total of 44 floral substances were identified in 3 Chimonanthus species, among which 19, 23 and 18 substances were identified in C. praecox, C. salicifolius and C. nitens respectively. The floral substances of alcohols and esters were the highest in C. praecox, while the content of alkenes was the highest in the floral substances of C. salicifolius and C. nitens. The daytime release rhythms of floral substances in 3 Chimonanthus species were different. The floral substances of C. salicifolius and C. nitens in the morning, noon and afternoon were different, but the floral substances of C. praecox changed little. Phylogenetic analysis showed that C. salicifolius and C. nitens were more closely related than C. praecox.   Conclusion  The floral substances of C. salicifolius and C. nitens are similar, which caters to the phylogenetic relationship between them. In view of the special low-temperature flowering environment of C. praecox, the interaction between pollination insects and floral fragrance may be the reason for the uniqueness of floral substances. [Ch, 3 fig. 3 tab. 35 ref.]
Spatiotemporal evolution law and driving factors of carbon emissions in planting industry in Zhejiang Province
LI Wenhan, LIU Feiyang, ZHANG Meng, GU Lei, ZHOU Guomo
, Available online  doi: 10.11833/j.issn.2095-0756.20240156
Abstract:
  Objective  The aim is to explore the spatiotemporal evolution law and influencing factors of carbon emissions in planting industry in Zhejiang Province, in order to develop a carbon sequestration and emission reduction plan and promote low-carbon and green transformation of planting industry in Zhejiang Province.  Method  Based on the energy input data of planting industry in Zhejiang Province, the carbon emission coefficient method was used to assess the spatiotemporal evolution of carbon emissions of planting industry in Zhejiang Province from 2006 to 2021. Combined with Logarithmic Mean Weighted Divisia Index(LMDI), the driving factors of carbon emissions changes in planting industry were analyzed, and the grey prediction model was used to predict the carbon emissions of planting industry from 2022 to 2040.  Result  (1) From 2006 to 2021, the overall carbon emissions from planting industry in Zhejiang Province showed an upward trend followed by a downward trend, with an annual variation rate of −1.80%, and a total cumulative carbon emission of 129 million tons. Between 2006 and 2012, carbon emissions slowly increased and then sharply decreased after reaching a peak in 2012, with an average annual decline of 2.94%. (2) The carbon emissions from planting industry in Zhejiang Province showed a distribution pattern of high in the central region and low in the north and south. Hangzhou, Jinhua and Taizhou in the central region were the main carbon emitting regions, accounting for 39.86% of the province’s carbon emissions. (3) The improvement of planting industry efficiency and the optimization of regional industrial structure played a promoting role in carbon reduction, and the improvement of economic development level, the increase of population size, and the optimization of agricultural production structure were the driving factors that caused the increase in carbon emissions, among which the level of economic development was the dominant factor affecting the changes in carbon emissions, accounting for 41.58% of the total carbon emissions change. (4) LMDI decomposition model prediction results showed that the carbon emissions from planting industry in Zhejiang Province would continue to decline from 2022 to 2040, and the carbon emissions in 2040 would decrease to 37.20% of those in 2021. Among them, Hangzhou, Jiaxing, Shaoxing and Jinhua would have the largest decline.   Conclusion  Planting industry in Zhejiang Province has achieved carbon peak. To ensure a continuous decline in carbon emissions in the future, we should focus on optimizing agricultural production technology and adjusting industrial structure, applying chemical fertilizers rationally, improving planting efficiency, reducing energy consumption, and speeding up modernization of green agriculture, so as to accelerate the achievement of carbon neutrality goal. [Ch, 4 fig. 2 tab. 37 ref.]
Health evaluation of Populus euphratica forest in Dali Yabuyi Oasis in the hinterland of the desert
CUI Chuandeng, SHI Qingdong, LI Xiang, SHI Haobo, WAN Yanbo, LI Dinghao
, Available online  doi: 10.11833/j.issn.2095-0756.20240148
Abstract:
  Objective  The widespread degradation of Populous euphratica forests seriously threatens the ecological security of oases in arid zones. Therefore, mapping the health of P. euphratica forests is important for their sustainable management.   Method  The P. euphratica forests in Dali Yabuyi Oasis in the desert hinterland were taken as the object, and based on the field survey of 68 typical sample plots in the region, 17 indexes were selected from the aspects of forest productivity, forest community structure and habitat factors, and the health evaluation index system and health evaluation model applicable to the P. euphratica forests in the region were constructed by using the principal component analysis and the cluster analysis method, the forest health indexes were calculated, and the health of the P. euphratica forests in the region was comprehensively evaluated.   Result  (1) the overall forest health of oasis P. euphratica forests was poor, with 29.4% in an unhealthy state, 33.8% in a medium-healthy state, 30.9% in a sub-healthy state, and 5.9% in a healthy state. Groundwater burial depth, total nitrogen, depression, Simpson’s index, and Shannon-Wiener’s index were the main factors affecting forest health. (2) In the P. euphratica forests of Dali Yabuyi Oasis, the forest health index of deep groundwater burial depth is significantly lower than that of shallow and medium groundwater burial depth (P<0.05), and the forest health level is relatively low. Shallow groundwater burial depths have relatively high levels of forest health. Overall, the forest health indices of different groundwater depths: shallow groundwater depth (0.65)>medium groundwater depth (0.45)>deep groundwater depth (0). (3) Among the P. euphratica forests in different regions of the oasis, the forest health index of the P. euphratica forests in the north is significantly lower than that in the center and south, and the forest health level is relatively low. Forest health is relatively high in the south. Overall, the forest health index showed an increasing trend from the north, center to the south, and the forest health index in different regions: south (0.61)>center (0.58)>north (−0.01).   Conclusion  The overall health level of P. euphratica forests in the oasis is poor, the shallower the water table is, the higher the health index of P. euphratica forests is, and the health index shows a decreasing trend from the south, the center to the north in different regions. [Ch, 2 fig. 3 tab. 29 ref.]
Effects of abiotic stress treatments on the transcriptional activity of transposable element-derived TUCP in Phyllostachys edulis
ZHU Bailiang, DING Yiqian, ZHOU Mingbing
, Available online  doi: 10.11833/j.issn.2095-0756.20240195
Abstract:
  Objective  Transposable elements (TE), an essential component of eukaryotic genomes are prone to activation under stress when they account for over 63% of the Phyllostachys edulis genome. This study, with an analysis of the expression patterns of transcripts of uncertain coding potential (TUCP) from transposable elements under abiotic stress, is aimed to provide insights into the molecular mechanisms of TEs in stress resistance in Ph. edulis.   Method  First, bioinformatics techniques were employed to investigate the transcriptional characteristics and patterns of TE-TUCPs, and neighboring genes in Ph. edulis under 4 stress treatments: low temperature, high temperature, high salinity, and UV irradiation. Then the reliability of the differentially expressed TE-TUCPs, data derived from the transcriptome was validated using RT-qPCR.   Result  A total of 57 627 TE-TUCPs were identified from the transcripts of Ph. edulis under 4 stress treatments. These TE-TUCPs exhibited specific expression patterns in response to different abiotic stresses. High temperature, high salinity, and UV irradiation promoted differential expression of genes neighboring TE-TUCPs with transcriptional activity, whereas low temperature suppressed such differential expression.   Conclusion  TE-TUCPs were primarily derived from the Ty1/Copia and Ty3/Gypsy superfamilies. The expression potential of genes and that of nearby TE-TUCPs were mutually inhibitory and the transcription of TE-TUCPs was regulated by abiotic stress to modulate the expression of neighboring genes in response to stress. [Ch, 7 fig. 2 tab. 44 ref.]
Genetic variation of seed traits and SSR markers in femal Torreya grandis
LI Keyu, CHEN Rong, LIU Lian, CAI Xiaojun, JIANG Zhengchu, XIE Qiandan, YU Chenliang, YU Weiwu
, Available online  doi: 10.11833/j.issn.2095-0756.20240254
Abstract:
  Objective  This study is to investigate the seed traits of female Torreya grandis, analyze the genetic variation of the population based on SSR primers, and compare the differences in seed phenotype, quality, and genetic diversity between and within populations of T. grandis.   Method  Female T. grandis from Fuyang, Shengzhou, Lin’an, Jiande in Zhejiang Province and Mount Huangshan in Anhui Province were used as materials to compare the phenotypic traits of T. grandis leaves and seeds through variance analysis and principal component analysis. The genetic diversity of T. grandis was compared by SSR molecular markers using female T. grandis from Fuyang, Shengzhou, Lin’an, Chun’an and Mount Huangshan as raw materials.   Result  Analysis of seed traits revealed that there were significant individual differences (P<0.01) in 8 indicators: leaf quality, leaf shape index, seed mass, seed shape index, seed weight, kernel shape index, seed coat thickness, and shell thickness between and within populations. The relative fat content and soluble sugar content also showed extremely significant differences among populations (P<0.01), with fat content ranging from 29.36% to 42.35%, indicating rich variation in T. grandis seed appearance and kernel quality. SSR primer analysis showed that the mean Nei’s genetic diversity index (H) was 0.400, the mean Shannon’s information index (I) was 0.650, and the mean polymorphic information content (PIC) was 0.400. Chun’an population exhibited the highest genetic diversity (H=0.410, I=0.658), while Shengzhou population showed the lowest (H=0.369, I=0.565). 92% of the total genetic variation existed within the population.   Conclusion  There are genetic variations in the phenotype and quality of T. grandis between and within populations. The genetic diversity of Chun’an population is the highest, and the genetic variation within the population is greater than that between populations. [Ch, 2 fig. 11 tab. 26 ref.]
Effects of natural vegetation restoration after logging on soil organic carbon and its active components in Pinus massoniana secondary forests
HU Ao, ZHAO Yihui, WU Jilai, WU Yanping, LI Tongxin, YAN Yibo, YE Jianfeng, WANG Yixiang
, Available online  doi: 10.11833/j.issn.2095-0756.20240264
Abstract:
  Objective  The objective is to study the distribution characteristics of soil organic carbon (SOC) and its active components in Pinus massoniana forest affected by pine wilt disease, so as to reveal the influence mechanism of natural vegetation restoration after logging on soil carbon sink in P. massoniana secondary forest and provide scientific support for organic carbon pool management.  Method  From March to June 2023, in Yuhang District and Lin’an District of Hangzhou City, the undamaged P. massoniana forest was used as the control (ck), four vegetation restoration types were set up by using the space substitution time survey method: moderate logging restoration for 5 a (ML5), moderate logging restoration for 15 a (ML15), heavy logging restoration for 5 a (HL5) and heavy logging restoration for 15 a (HL15) to compare the variation characteristics of SOC, readily oxidizable carbon (ROC), particulate organic carbon (POC), microbial biomass carbon (MBC) and water-soluble organic carbon (WSOC) in different soil layers ( 0−10, 10−20, 20−40 cm ) of P. massoniana secondary forest under natural recovery after different logging intensities, and their relationship with soil physicochemical properties was analyzed to explore their mechanisms.   Result  (1) The content of SOC and its active components in each soil layer ranking from high to low were SOC, ROC, POC, MBC and WSOC, and the content decreased accordingly with the deepening of soil layer. The highest SOC content was 33.53 g·kg−1 in 0−10 cm soil layer of ML15, and the lowest WSOC content was 136.55 mg·kg−1 in 20−40 cm soil layer of ck. (2) Under the same logging intensity, the content of active organic carbon in soil of P. massoniana secondary forest increased with the increase of natural recovery years, among which the content of POC in each soil layer changed the most, and the content of POC in each soil layer of 15 a was over 2.6 times higher than that in each soil layer of 5 a. (3) The content of active organic carbon component in 0−10 cm soil layer of ML15 was the highest, and was significantly higher than that in ck (P<0.05 ). (4) The results of correlation analysis showed that there were significant positive correlations among active organic carbon components in soil and between active organic carbon components and \begin{document}${\mathrm{NO}}_3^- $\end{document}-N and NH4 + -N ( P<0.05 ).  Conclusion  Moderate logging has a significant promoting effect on SOC and its active components in P. massoniana secondary forest. The longer the natural recovery time of vegetation, the more favorable it is to increase the content of soil active organic carbon components. Moderate logging of P. massoniana pure forests and their natural recovery can promote soil carbon pool accumulation. [Ch, 3 fig. 3 tab. 46 ref.]
Carbon footprint assessment and emission reduction path analysis of 5 major bamboo shoot export products
DONG Linghui, MAO Fengcheng, ZHOU Yufeng, GU Lei, ZHOU Tianhuan, LI Zhengcai, ZHOU Guomo
, Available online  doi: 10.11833/j.issn.2095-0756.20240277
Abstract:
  Objective  This study aims to assess the carbon footprint of bamboo shoot products and explore their emission reduction potential, so as to promote low-carbon and high-quality development of the industry.   Method  Based on the field survey data from 2022 to 2023 in Lin’an District of Hangzhou City and Anji County of Huzhou City, Zhejiang Province, this study assessed the carbon footprint of 5 different types of bamboo shoot export products (seasoned bamboo shoots, hand-peeled bamboo shoots, dried bamboo shoots, boiled bamboo shoots, and fresh bamboo shoots) during the planting, production and distribution stages, identified carbon emission hotspots, designed emission reduction pathways, and calculated emission reduction based on scenario assumptions. The implied carbon emission and carbon emission intensity of bamboo shoot export products in China were estimated according to the export situation of bamboo shoot products in China from 2015 to 2023.  Result  (1) The carbon footprint of the 5 bamboo shoot products from large to small was as follows: seasoned bamboo shoot (1.387 4 kg·kg−1), hand-peeled bamboo shoot (1.010 7 kg·kg−1), dried bamboo shoot (0.927 4 kg·kg−1), boiled bamboo shoot (0.324 9 kg·kg−1), and fresh bamboo shoot (0.174 8 kg·kg−1). The carbon footprint composition analysis showed that the carbon emission hotspots of the 5 bamboo shoot products were mainly agricultural inputs, fresh shoot transportation, fresh shoot processing and additive inputs. (2) From 2015 to 2023, the average annual implied carbon emission of bamboo shoot exports in China was 1.848 2×105 t, with an average carbon emission intensity of 0.966 9 tons per 10 000 yuan. (3) The emission reduction scenario design based on carbon emission hotspots showed that the average decrease in carbon footprint of the 5 bamboo shoot products in 2023 was 20.15%.   Conclusion  There are significant differences in the carbon footprint of different types of bamboo shoot products. The implied carbon emissions of bamboo shoot products exported from 2015 to 2023 show a fluctuating downward trend. The comprehensive implied carbon emission intensity shows a fluctuating upward trend. The carbon emission hotspots of bamboo shoot products vary, and there is potential for further reduction in carbon footprint through emission reduction measures. [Ch. 2 fig. 7 tab. 36 ref.]
Leaf functional traits and their coupling relationships of woody plants with different life forms in the northern Dabie Mountains
XIA Jihui, YE Peixia, YANG Hai, ZHANG Shengquan, JIN Shanshan, ZHOU Mengli, YAN Dongfeng
, Available online  doi: 10.11833/j.issn.2095-0756.20240161
Abstract:
  Objective  This study aim to explore the variation of leaf functional traits among different life forms of woody plants on the northern edge of the Dabie Mountains, investigate the coupling relationship between indicators of leaf functional traits, and provide a basis for deciphering the response mechanisms of plants to climate change.   Method  Leaf functional traits of 30 common woody plants with different life forms (evergreen, deciduous, arbor, shrub) in Liankangshan National Nature Reserve on the northern edge of the Dabie Mountains were collected, and eight leaf functional traits including chlorophyll content, dry/fresh ratio, nitrogen content, phosphorus content, potassium content, nitrogen/phosphorus ratio, leaf area, and specific leaf area were determined. The leaf functional traits and their correlations of different life forms of woody plants were analyzed.   Result  There were certain differences in leaf functional traits among different life forms of woody plants, among which the average chlorophyll content, nitrogen content, phosphorus content, potassium content, leaf area, and specific leaf area of evergreen and deciduous trees showed significant differences (P<0.05). The average leaf area, nitrogen content, phosphorus content, potassium content, dry/fresh ratio, and nitrogen/phosphorus ratio of arbor and shrub showed significant differences (P< 0.05). There were certain correlations between some leaf functional traits, such as positive correlation between leaf nitrogen and phosphorus content and potassium content (P< 0.05), significant positive correlation between leaf nitrogen content and phosphorus content (P<0.05), positive correlation between leaf area and leaf nitrogen, phosphorus, potassium content (P<0.05), and positive correlation between specific leaf area and leaf nitrogen, phosphorus, potassium content (P< 0.05). The principal component analysis results showed that the leaf phosphorus, nitrogen, and potassium contents were important indicators of leaf functional traits, and the 30 woody plants could be classified into four functional groups based on the first and second principal components, with the contribution rates of 55.2% and 12.8% to the variation of plant leaf functional traits respectively.   Conclusion  There exists a certain pattern of variation in leaf functional trait indicators among different life forms of woody plants. Among them, leaf phosphorus, nitrogen, and potassium mass fractions are indicative indicators, and they are significantly positively correlated with leaf area. [Ch, 4 fig. 1 tab. 28 ref.]
Research progress on plant physiological morphology and light response mechanism in shaded environments
LIU Pei, WU Yufen, WANG Xiaofeng, WU Wenhui, GAO Yanhui, CHEN Donghong, SI Jinping, LI Cong
, Available online  doi: 10.11833/j.issn.2095-0756.20240187
Abstract:
Light is a crucial environmental factor affecting plant growth and development. It is of great scientific significance and application value to enhance plant yield and quality in agricultural production by improving its photosynthetic efficiency. In dense plant communities, lower plants receive less light energy due to the coverage of upper vegetation, so lower plants need to compete for more light energy to maintain growth. Plants have two strategies to obtain more light energy: shade avoidance syndrome (SAS) and shade tolerance response (STR). Research on SAS is relatively thorough, but there is a lack of in-depth research on STR. This paper provides an overview of how sunny plants adapt to lower light level by extending hypocotyl, petioles, stems and other physiological morphological changes in shaded environments. At the same time, shade tolerant plants respond to limited light conditions by exhibiting shade resistance characteristics such as promoting carbon acquisition, low phenotypic plasticity ability and improving stress resistance. Combined with the mechanism of shade avoidance response of sunny plants in response to low light environment through the interaction between hormones and light signaling pathways, the shade tolerance response mechanism of shade tolerant plants in shaded environments is studied, which involves both activating antagonistic factors to inhibit shade avoidance syndrome and improving the transcription activity of shade tolerance response genes to enhance low light adaptability. This review provides reference for research on the mechanism of different plants responding to low light environments, and proposes effective ways to improve the efficiency of plant light energy utilization, cultivate crop varieties with high light efficiency, and construct efficient forest ecosystems. [Ch, 3 fig. 61 ref.]
Effects of nitrogen application on nitrogen, phosphorus and potassium absorption and alkaloid accumulation in Fritillaria hupehensis
JIANG Li, GUO Kunyuan, CHEN Gang, CHENG Weishun, LUO Xi, WANG Suping, HUANG Xiang, DU Lei, ZHANG Guiyou, HONG Juan
, Available online  doi: 10.11833/j.issn.2095-0756.20240217
Abstract:
  Objective  This study aims to analyze the annual variation of the concentration and accumulation of nitrogen, phosphorus, and potassium in Fritillaria hupehensis bulbs, and explore the impacts of different nitrogen dosages on the accumulation of dry matter and alkaloids of F. hupehensis, so as to provide scientific basis for rational fertilization of F. hupehensis.   Method  F. hupehensis obtained from Xintang township, Enshi City, Hubei Province was used as the material. Under the conditions of 102.4 kg·hm−2 phosphorus pentoxide and 86.4 kg·hm−2 potassium oxide for both phosphorus and potassium fertilizers, 4 nitrogen fertilizer treatments were set up: no nitrogen fertilizer (N0), 58.0 kg·hm−2 nitrogen fertilizer (N1), 116.0 kg·hm−2 nitrogen fertilizer (N2), and 174.0 kg·hm−2 nitrogen fertilizer (N3). Samples were collected at seedling, flowering and harvest stages to determine the concentration of nitrogen, phosphorus, potassium and various alkaloids in the bulbs of F. hupehensis at different growth stages.   Result  The accumulation of dry matter, nitrogen, phosphorus, potassium, total alkaloid, verticine, verticinone, peimissine and hupehenine in F. hupehensis bulbs significantly increased with increasing nitrogen application (P<0.05), and all reached their peak at a nitrogen fertilizer application of 116.0 kg·hm−2. With the increase of nitrogen application, potassium to phosphorus ratio in F. hupehensis bulbs was less than 3.4 at seedling stage, while that during the flowering and harvesting periods was more than 3.4. Throughout the entire growth period, nitrogen to phosphorus ratio in F. hupehensis bulbs was less than 14.0, and nitrogen to potassium ratio was less than 2.1. During the seedling and harvest stages, the concentration of total alkaloid, verticine, verticinone, and hupehenine in F. hupehensis bulbs all decreased with increasing nitrogen application. During the flowering period, the concentration of verticine, verticinone and peimissine in F. hupehensis bulbs showed an increasing trend with the increase in nitrogen application. When the nitrogen fertilizer application amount was 116.0 kg·hm−2, the peak accumulation of total alkaloid, verticine, verticinone, hupehenine and peimissine in F. hupehensis bulbs were 56.50, 4.20, 12.73, 1.66, and 3.68 mg·plant−1, respectively. When the same amount of nitrogen fertilizer was applied, with the extension of growth period, except for peimissine, the concentration of all other alkaloids was the highest during the harvest period and the lowest during the flowering period. When the nitrogen fertilizer application amount was 116.0 kg·hm−2, the accumulation rate of verticine, verticinone and peimissine in bulbs decreased from flowering to harvest stage. The dry matter accumulation rate was relatively fast from seedling to flowering stage, and the accumulation ability of total alkaloids in the bulb during the flowering to harvest period was strong.   Conclusion  The amount of nitrogen fertilizer significantly affects the yield and quality of F. hupehensis. Excessive application of nitrogen fertilizer is not conducive to the accumulation of dry matter and alkaloids in bulbs. The accumulation of dry matter and alkaloids in bulbs of F. hupehensis at different growth stages is a dynamic process. Yield increase is predominant at vegetative growth stage, while alkaloids accumulation is dominant at productive growth stage. [Ch, 4 fig. 2 tab. 28 ref.]
Spatiotemporal evolution and regulation strategies of ecological risks in green space landscape in the water network area of southern Jiangsu
HUANG Xiaojie, DING Jinhua, WANG Daqing
, Available online  doi: 10.11833/j.issn.2095-0756.20240169
Abstract:
  Objective  This study aims to discuss the ecological risks caused by landscape fragmentation and habitat quality decline in green space in the water network area of southern Jiangsu Province under the background of rapid urbanization.   Method  Taking Kunshan City as an example, the land use data from 2000, 2010 and 2020 were selected, and the landscape pattern index was used to construct a landscape ecological risk assessment model. The spatiotemporal evolution characteristics of landscape ecological risks in green space of Kunshan City from 2000 to 2020 were analyzed, and green space control zones were defined based on the characteristics of landscape ecological risk level transfer and change.  Result  (1) From 2000 to 2020, the total area of green space in Kunshan City showed a continuous reduction trend, with a significant decrease in cultivated land, a total reduction of 20 203.11 hm2, accounting for 21.70%. The water area first slightly increased and then continued to decrease, with an overall decrease of 3813.66 hm2. The proportion of forest land and grassland was relatively small and stable. The area transfer matrix between land types of green space mainly showed a shift from arable land to construction land, reflecting the increasing interference degree of green space by artificial construction. (2) There were certain changes in the distribution of landscape ecological risks, mainly manifested as a shift from low risk level to higher risk level. The proportion of the highest and high risk areas increased by 8.10% and 6.61%, respectively, while the area of low and the lowest risk areas decreased by 8.25% and 9.73%, respectively. (3) Based on the characteristics of landscape ecological risk level transfer and change, the study area was divided into three types of control zones: key restoration zone, coordinated buffer zone and optimal utilization zone.  Conclusion  The landscape ecological risk of green space in Kunshan City shows an upward trend. There is a correlation between the transformation of green space land use type and landscape ecological risk, reflecting the increasing ecological pressure of green space under human construction activities. Green space zoning regulation strategies based on the spatiotemporal evolution characteristics of risks are proposed in this study. [Ch. 4 fig. 5 tab. 28 ref.]
Chloroplast genome of Phyllostachys edulis f. luteosulcata and comparison of chloroplast genome sequence of subspecies of Ph. edulis
LIU Xuan, ZOU Longhai, ZHOU Mingbing
, Available online  doi: 10.11833/j.issn.2095-0756.20240110
Abstract:
  Objective  This study aims to sequence, assemble, annotate, and analyze the chloroplast genome of Phyllostachys edulis f. luteosulcata. The research also involves comparing its chloroplast genetic information and phylogenetic relationships with those of other subspecies of Ph. edulis (moso bamboo).   Method  High-throughput sequencing data were used to assemble and annotate the complete chloroplast genome of Ph. edulis f. luteosulcata. Subsequently, we analyze the composition, codon preference, and repetitive sequences of the genome. Furthermore, sequence comparison and phylogenetic analysis were conducted to compare the phylogenetic relationships and genome sequence differences among different subspecies of moso bamboo.   Result  The chloroplast genome of Ph. edulis f. luteosulcata is a double-loop DNA of 139 678 bp in length containing 132 genes, including 85 protein-coding genes, eight ribosomal RNAs (rRNAs), and 39 transfer RNAs (tRNAs). The codon preference for this genome has an A/U base at the end. There are 49 repetitive sequences with the most common type being A/T and 55 SSR sites. Phylogenetic analyses constructed using the chloroplast genome sequences showed that Ph. edulis f. luteulosulcata is in a monophyletic branch together with other subspecies of Ph. edulis and is closely related to the original variety of Ph. edulis var. pubescens. The analysis of chloroplast genome sequence and coding gene characteristics showed that there were differences in the number and structure of coding genes and low degree of sequence variation among the subspecies of Ph. edulis.   Conclusion  This study is the first to comparatively analyze the chloroplast genomes of subspecies of Ph. edulis and reveals a degree of sequence variation in these subspecies of Ph. edulis. This variation information would be available for the identification and comparison of subspecies of Ph. edulis. [Ch, 5 fig. 2 tab. 27 ref.]
Soil moisture characteristics under the level benches and vegetation in loess area of western Shanxi Province
ZHU Hongsheng, ZHAO Jiongchang, CHI Jinming, WANG Zihan, WANG Liping, WANG Zhengze, YU Yang
, Available online  doi: 10.11833/j.issn.2095-0756.20240114
Abstract:
  Objective  This study, with an exploration of the effects of typical afforestation tree species and horizontal soil preparation measures on soil moisture dynamics in 0−180 cm soil layer in the loess region of western Shanxi Province, is aimed to provide a reference for vegetation restoration and comprehensive watershed management.   Method  Taking the level benches of typical engineering measures and the main afforestation tree species (Robinia pseudoacacia and Platycladus orientalis) in Caijiachuan watershed in the loess plateau region of western Shanxi as the research objects, the soil moisture was monitored in the growing season of 2019 (May − September), with a synchronous observation made of the soil moisture of natural slopes of R. pseudoacacia and P. orientalis using the paired experimental design before an analysis was conducted of the soil moisture characteristics under the comprehensive influence of different vegetation and level benches and the response process to rainfall events and the effects of typical engineering measures on soil moisture of different vegetation were evaluated.  Result  The changes of soil moisture before and after soil preparation with different vegetation types and level benches were closely related to the changes of rainfall and the average soil moisture decreased from level bench-P. orientalis (18.68%), slope-P. orientalis (16.19%), level bench-R. pseudoacacia (16.10%) to slope-R. pseudoacacia (15.42%). Compared with natural slope, level benches could increase the soil moisture of P. orientalis and R. pseudoacacia by 15.38% and 4.41% respectively and according to the vertical variation characteristics of soil moisture, level benches could significantly increase the depth of active layer and secondary active layer of soil moisture: the depth of horizontal active layer and secondary active layer of P. orientalis ranged from 0 to 80 cm, which was 33%, higher than that of P. orientalis slope while the depth of horizontal active layer and secondary active layer of R. pseudoacacia ranged from 0 to 140 cm, which was 40% higher than that of R. pseudoacacia slope.   Conclusion  The dynamic change of soil water content is closely related to rainfall, engineering measures and vegetation. Level benches is an effective engineering measure to carry out ecological restoration in small watershed of loess plateau, and the lifting effect of P. orientalis level benches (40%) is better than that of R. pseudoacacia level benches (33.33%). [Ch, 3 fig. 3 tab. 37 ref.]
Effects of Phyllostachys edulis expansion on soil microbial residue carbon accumulation in evergreen broad-leaved forests
SHAO Shuai, WANG Zhongqian, PAN Lingqiang, ZHENG Yunyou, ZHENG Xuli, TIAN Libin, XU Qiufang
, Available online  doi: 10.11833/j.issn.2095-0756.20230626
Abstract:
  Objective  This study is to reveal the dynamic changes of soil organic carbon (SOC) in evergreen broad-leaved forests during the expansion of Phyllostachys edulis in subtropical regions by affecting the accumulation of soil microbial residue carbon.   Method  Taking amino sugar, a biomarker of microbial residues, as the research object, this study investigated the succession sequence of the expansion of Ph. edulis in the state-owned forest farm of Lingfengsi in Anji, Zhejiang Province, namely, the accumulative effect of microbial residue carbon in surface soil (0−10 cm) of evergreen broad-leaved forest, Ph. edulis and broad-leaved mixed forest, and pure Ph. edulis forest, as well as the correlation characteristics with organic carbon.   Result  During the expansion of Ph. edulis, soil fungal residue carbon, bacterial residue carbon and microbial residue carbon all significantly decreased (36.76%, 35.13% and 40.32%, respectively), and the annual litter production indirectly affected SOC, fungi biomass, soil bacteria biomass and total microbial biomass, thereby affecting the cumulative effects of soil fungal residue carbon, bacterial residue carbon and total microbial residue carbon, respectively. There was no significant change in the ratio of fungal residue carbon, bacterial residue carbon and total microbial carbon residue to SOC in the early stage of Ph. edulis expansion (from evergreen broad. leaved forest to Ph. edulis and broad-leaved mixed forest), but in the late stage of expansion (from Ph. edulis and broad-leaved mixed forest to Ph. edulis forest), the ratio increased significantly.   Conclusion  The role of microbial carbon on SOC gradually increases during the expansion of Ph. edulis into evergreen broad-leaved forests. [Ch, 4 fig. 1 tab. 26 ref.]
Dynamic analysis of content and accumulation of mineral elements in branch-leaf mixture and seeds of Torreya grandis ‘Merrillii’ during the early growth stage
YE Shuyuan, ZENG Yanru, CAO Yongqing, TIAN Sukui, YU Weiwu
, Available online  doi: 10.11833/j.issn.2095-0756.20230583
Abstract:
  Objective  The objective is to explore the relationship between the content and accumulation of mineral elements in the branch-leaf mixture and seeds of Torreya grandis ‘Merrillii’ during the early growth stage of seeds, in order to provide a basis for scientific fertilization and improve the quality and yield of T. grandis ‘Merrillii’ seeds.   Method  (2+17) a T. grandis ‘Merrillii’ trees (2 a rootstocks and 17 a after grafting) were selected for experiment on Donghu campus of Zhejiang A&F University. Lateral branches (with leaves) and seeds of the second generation were collected from early March to early July, and the dynamic changes in nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), manganese (Mn) and copper (Cu) content and accumulation in branch-leaf mixture and seeds were analyzed.   Result  In the early growth stage of T. grandis ‘Merrillii’ seeds, there was no significant change in the transverse and longitudinal diameter of the seeds, dry and fresh weight, and moisture content of each fruit before early April. However, from mid April to mid June, the growth rate increased rapidly and then stabilized, and the accumulation of N, P, and K in branch-leaf mixture decreased while the accumulation and content of N, P, and K in seeds continued to increase, which indicated that N, P, and K in branch-leaf mixture were preferentially supplied to the growth of seeds. During the slow growth and flower bud differentiation stage, the demand for N, P, and K by seeds was relatively small, while during the rapid growth stage, the demand for N, P, and K by seeds increased. This phenomenon intensified with time. On a time scale, Ca gradually absorbed and accumulated in the branch-leaf mixture, while Ca content and accumulation in seeds decreased and ertremely decreased significantly. After the rapid growth period, the accumulation of Mg in seeds increased, while the accumulation and content of Mg in branch-leaf mixture decreased with the expansion of seeds. During the early growth stage of T. grandis ‘Merrillii’ seeds, the accumulation of Zn and Cu in branch-leaf mixture showed a decreasing trend, and the seed had a relatively small demand for Zn, Cu and Mn.   Conclusion  (1) The volume and moisture content of the fast-growing T. grandis ‘Merrillii’ seeds increase rapidly, and tend to stabilize after the filling period. (2) The content and accumulation of elements are closely related to the long-term growth of T. grandis ‘Merrillii’ seeds. To improve the quality of seeds, N, P and K fertilizers should be applied at the end of the slow growth period and the beginning of the fast growth period, along with an appropriate amount of trace element fertilizers such as Zn and Cu. Mg fertilizer should be applied after seed harvest. [Ch, 5 fig. 27 ref.]
Effects of manganese-modified biochar on accumulation of arsenic and lead in garlic and soil enzyme activity
WANG Ruiping, YANG Xing, GAO Yurong, LU Kouping, HE Lizhi, WU Jiasen, WANG Hailong
, Available online  doi: 10.11833/j.issn.2095-0756.20230584
Abstract:
  Objective  Soil heavy metal pollution is a common problem encountered in agricultural production activities, and how to effectively and synchronously passivate arsenic and lead in soil has become a research hotspot.   Method  Raw biochar was prepared from rice husks, and manganese-modified biochar was obtained through potassium permanganate. Pot experiments were conducted using garlic (Allium sativum) as an indicator plant to evaluate the effects of raw biochar and manganese-modified biochar at different application rates (10 and 30 g·kg−1) on the bioavailability of arsenic and lead in soil and soil enzyme activities.   Result  The application of different proportions and types of biochar significantly increased the content and pH of soil organic matter, available potassium and available phosphorus (P<0.05), while decreased the content of soil alkaline hydrolyzed nitrogen. The effect of manganese-modified biochar was more significant than that of original biochar. The application of 10 g·kg−1 manganese-modified biochar significantly reduced the content of available arsenic in soil by 11.5%, while 30 g·kg−1 manganese-modified biochar significantly decreased the content of lead in the extractable state of diethylenetriamine pentaacetic acid (DTPA) in soil by 28.3%. Compared with the control, the application of 10 g·kg−1 manganese-modified biochar increased the activities of β-N-acetylglucosamine glycase by 11.6%, and the application of 30 g·kg−1 manganese-modified biochar significantly increased the activity of acid phosphatase and β-glucoglycase by 9.8% and 37.7%, respectively. Meanwhile, the contents of nitrogen, phosphorus and potassium in garlic plants treated with manganese-modified biochar significantly increased (P<0.05), while the contents of arsenic and lead significantly decreased (P<0.05).   Conclusion  Manganese-modified biochar has significant potential in improving soil fertility and repairing arsenic-lead contaminated soil. [Ch, 8 fig. 1 tab. 52 ref.]
Impact and evaluation of different drying methods on the quality of Prunus mume flowers
CHEN Yingzhi, KONG En, LU Xinke, WANG Yiguang, DONG Bin, ZHAO Hongbo
, Available online  doi: 10.11833/j.issn.2095-0756.20240256
Abstract:
  Objective  The impact of different drying methods on the quality of dried Prunus mume flowers is to be studied and evaluated, so as to provide reference for maintaining the quality of dried P. mume flowers in drying process.   Method  4 different drying methods (hot air drying, microwave drying, compound drying and vacuum freeze-drying) were used to treat 8 P. mume flower cultivars (‘Dongfang Zhusha’ ‘Guhong Zhusha’ ‘Xiaohong Gongfen’ ‘Fenpi Gongfen’ ‘Fentai Yudie’ ‘Yueguang Yudie’ ‘Jiuguang Lve’ and ‘Suyu Lv’). Color difference, antioxidant capacity, and total flavonoid content were used as evaluation indicators to compare the impact of different drying methods on the quality of P. mume flowers. The entropy weight-coefficient of variation method was used for combined weighting to calculate the comprehensive score. The evaluation model was verified by the weighted proximation ideal solution sorting method and the optimal drying method was obtained.   Result  The color difference and shrinkage rate treated with vacuum freeze-drying were the smallest, less than 33.09 and 28.7%, respectively, and the total flavonoids, anthocyanins, and total chlorogenic acid mass fractions of the samples were the highest. The soluble protein mass fraction and antioxidant capacity of the materials treated with vacuum freezing and composite drying methods were the highest. The retention rate of volatile substances was the highest after composite drying, exceeding 50%. The comprehensive scores ranking from high to low was vacuum freeze-drying group, composite drying group, hot air drying group, and microwave drying group.  Conclusion  The mass fraction of active ingredients is the highest after vacuum freeze-drying, followed by composite drying. The quality of P. mume flowers is the best after vacuum freeze-drying and composite drying, which can be used for high-quality processing and mass production. [Ch, 8 fig. 6 tab. 29 ref.]
Comprehensive evaluation of spatial structure of four typical forest stands in Jinzishan state-owned forest farm
YUAN Zixin, GUO Qiuju, AI Xunru, YAO Lan, ZHU Jiang, WANG Lei, XIANG Qin
, Available online  doi: 10.11833/j.issn.2095-0756.20240162
Abstract:
  Objective  The objective is to comprehensively evaluate the spatial structure of four forest types in Jinzishan state-owned forest farm in Hubei Province, and determine the main factors affecting the forest stand structure in the region, so as to provide a theoretical basis for improving sustainable forest management level and forest quality.   Method  Based on the measured plot data of evergreen deciduous broad-leaved mixed natural forest, Cunninghamia lanceolata plantation, Cryptomeria japonica var. sinensis plantation and Liriodendron chinense plantation, forest spatial structure indicators such as uniform angle index, neighborhood comparison, mingling degree, and crowding degree were selected, and the unit circle comprehensive evaluation system was applied to comprehensively evaluate the four typical forest types.   Result  The proportion of random individual trees in different types was the highest, and the proportion of trees in different neighborhood comparison degrees was similar on the whole. The overall distribution of trees in the evergreen deciduous broad-leaved mixed natural forest was random [average value of uniform angle index (\begin{document}$\bar W $\end{document})=0.492], and the stand was well mixed [average value of mingling degree (\begin{document}$\bar M $\end{document})=0.747], but the growth advantage of trees was not obvious [average value of neighborhood comparison (\begin{document}$\bar U $\end{document})=0.497], the canopy was continuously covered [average value of crowding degree (\begin{document}$\bar C $\end{document})=0.941], and the resource utilization rate was high. Other plantations also showed a trend of random distribution (\begin{document}$\bar W $\end{document}=0.505−0.514) or slight cluster distribution (\begin{document}$\bar W $\end{document}=0.529), and the degree of mixing was low. Some trees showed certain advantages, especially in Cunninghamia lanceolata forests. Among the three types of plantations, the trees in L. chinense plantations were in a very dense state (\begin{document}$\bar C $\end{document}=0.768), while the stands of Cunninghamia lanceolata (\begin{document}$\bar C $\end{document}=0.557) and Cryptomeria japonica var. sinensis (\begin{document}$\bar C $\end{document}=0.563) plantations were in a relatively dense state, and there was still some growth space for trees. The comprehensive evaluation index of spatial structure showed that the state of evergreen deciduous broad-leaved mixed natural forest (0.600) was better than that of Cunninghamia lanceolata (0.583), Cryptomeria japonica var. sinensis (0.521) and L. chinense plantations (0.487).   Conclusion  There are differences in stand structure of different origins in the same region, and the spatial structure of evergreen deciduous broad-leaved mixed natural forest is better than that of Cunninghamia lanceolata, Cryptomeria japonica var. sinensis and L. chinense plantations. [Ch, 2 fig. 6 tab. 37 ref.]
Spatiotemporal evolution of forest carbon sink in Lishui City and its response to extreme precipitation
YANG Ningxin, MAO Fangjie, DU Huaqiang, LI Xuejian, SUN Jiaqian, ZHAO Yinyin, ZHENG Zhaodong, TENG Xianfeng, YE Fengfeng
, Available online  doi: 10.11833/j.issn.2095-0756.20240141
[Abstract](106) [HTML] (40) [PDF](10)
Abstract:
  Objective  The objective is to simulate and analyze the spatiotemporal evolution trend of forest net ecosystem productivity (NEP) in Lishui City, and reveal its response mechanism to extreme precipitation, so as to provide data support for spatiotemporal assessment of forest carbon sink potential in Lishui.   Method  The spatiotemporal pattern of forest NEP in Lishui from 1979 to 2079 was simulated under three climate scenarios (RCP 2.6, RCP 4.5, and RCP 8.5) by integrating plot survey, remote sensing observation and InTEC model. The spatiotemporal characteristics of extreme precipitation were analyzed and a structural equation model was constructed to explore the impact of extreme precipitation on NEP.   Result  (1) The frequency and intensity of extreme precipitation in Lishui during 1979-2015 showed an increasing trend. In the future climate scenario (except RCP 2.6), the extreme precipitation, frequency and intensity of RCP 4.5 and RCP 8.5 would continue to increase, with a higher trend of extreme precipitation events in areas such as Liandu District, Jinyun County and Jingning She Autonomous County. (2) Forest NEP showed an increasing trend from 1979 to 2015, with a growth rate of 20.18 g·m−2·a−1. From 2016 to 2079, forest NEP showed a downward trend under the three climate scenarios, but the total carbon sink showed an increasing trend, with the maximum NEP accumulation reaching 10.97 Pg. (3) From 1979 to 2015, extreme precipitation had positive effects on NEP, while it had negative impacts on NEP under the other two scenarios (RCP 4.5 and RCP 8.5) during 2016-2079, except for RCP 2.6 scenario under which extreme precipitation had no significant effect on NEP. However, extreme precipitation under RCP 8.5 had less impact on NEP than that under RCP 4.5.   Conclusion  Forests in Lishui demonstrate strong carbon sink capacity, and have high carbon sink potential under future climate scenarios. However, the impact of extreme precipitation on NEP should not be ignored. [Ch, 5 fig. 22 ref.]
Age effect on biomass distribution pattern and optimization of allometric growth equation in Eucalyptus urophylla×E. grandis plantations
CAO Haoyang, DU Apeng, XU Yuxing, ZHU Wankuan, HUANG Runxia, LIU Yusheng, WANG Zhichao
, Available online  doi: 10.11833/j.issn.2095-0756.20240180
[Abstract](102) [HTML] (36) [PDF](5)
Abstract:
  Objective  This study aims to analyze the biomass distribution pattern of Eucalyptus plantations at different ages, so as to provide theoretical basis and data support for accurate assessment of carbon storage and carbon sink in China’s Eucalyptus industry.  Method  Eucalyptus urophylla×E. grandis plantation in Leizhou Peninsula was taken as the research object. The whole-plant harvesting method was used to measure the biomass of various organs in 57 trees aged 1, 2, 3, 6 and 10. Using diameter at breast height (DBH), height (H), and diameter at breast height-tree height (DBH 2 H and DBHH) as independent variables, allometric growth models for organ biomass, aboveground biomass, and total biomass without and with age variables were established, respectively, to screen for the optimal model.   Result  The biomass of different parts of E. urophylla×E. grandis increased with age, but the proportion of each organ to the total biomass varied with age. The proportion of stem biomass increased with age, from 45.21% at 1 year old to 68.25% at 10 years old, whereas the proportion of branch and leaf biomass decreased with forest age, from 19.43% and 16.31% at 1 year old to 10.51% and 2.91% at 10 years old , respectively. The proportion of root biomass first increased from 19.05% at 1 year old to 25.21% at 3 years old, and then gradually decreased to 18.33% at 10 years old. The root to shoot ratio of E. urophylla×E. grandis ranged from 0.16 to 0.39. In selecting the optimal model for biomass of various organs, the model with DBH as the independent variable (without age variable) had better predictions for root biomass and total biomass than other models. The model with DBH 2 H plus age as independent variables had the best predictions for leaf biomass and aboveground biomass. The model with DBH, H, and age as independent variables had the best predictions for branch biomass. Regarding the prediction accuracy for stem biomass, there was no significant difference between the prediction models with DBHH and DBH 2 H plus age as independent variables, and both models could predict stem biomass well.   Conclusion  Forest age has significant impacts on the biomass allocation ratio of various organs in E. urophylla×E. grandis plantations. The prediction accuracy of branch, leaf, and aboveground biomass in E. urophylla×E. grandis plantations significantly improves if forest age is included in the allometric growth model. [Ch. 2 fig. 4 tab. 45 ref.]
Color change and physiological characteristics in Osmanthus fragrans Colour Group
JIN Xiaoyu, WANG Yiguang, ZHAO Hongbo, DONG Bin
, Available online  doi: 10.11833/j.issn.2095-0756.20240160
Abstract:
  Objective  This study, with an investigation of the classification of Osmanthus fragrans Colour Group and the changes of leaf color and related physiological characteristics during its growth, is aimed to provide theoretical basis for the classification, selection and improvement of Colour Group.   Method  With a total of 29 germplasm materials of Colour Group selected and classified by quantitative criteria and cluster analysis, two representative lines (‘Luocai 3’and‘Luocai 28’) were selected to observe the pigment distribution, component qualitative analysis, content determination and physiological index determination.   Result  Based on the cluster analysis at the stage of 30% leaf discoloration (S2), the cultivars were divided into two categories and three color series, namely the reddish brown series (the first subclass of Class Ⅰ), the orange brown series (the second subclass of Class I), and the purple pink series (the second subclass of Class Ⅱ). The anatomical structures of the two strains showed that anthocyanins were mainly distributed in the upper and lower epidermal cells of young leaves, and gradually decrease with leaf growth with the content of anthocyanins gradually decreasing, the content of chlorophyll continuing to rise and the content of carotenoids gradually increasing insignificantly. During the growth process of leaves, there was no significant pattern in the changes of soluble protein and soluble sugar content between the two, but they were relatively high in the S1 stage. The POD activity continued to increase, with‘Luocai 3’being higher than‘Luocai 28’ at each stage and the pH value of the leaves showed no significant change and remained within the acidic range.   Conclusion  Based on the leaf color parameters of the S2 period, a detailed color scheme division can be carried out for Colour Group. The color change of Colour Group leaves is mainly affected by the decrease in anthocyanin content and the increase in chlorophyll content, in which POD plays an important role. The difference between the reddish brown and orange brown series lies in the content and ratio of anthocyanins and carotenoids. [Ch, 7 fig. 1 tab. 29 ref.]
Effects of stand density on biomass and soil physico-chemical properties of Pinus tabuliformis forest in the loess area of western Shanxi
JIA Yajie, YANG Jianying, ZHANG Jianjun, HU Yawei, ZHANG Ben, ZHAO Jiongchang, LI Yang, TANG Peng
, Available online  doi: 10.11833/j.issn.2095-0756.20240571
Abstract:
  Objective  This study is in order to explore the effects of stand density on biomass and soil physicochemical properties in Pinus tabuliformis forests, for high-quality development and performance of the ecological service function.   Method  A 30-year-old P. tabuliformis forest in Caijiachuan watershed, Jixian County, Shanxi Province, was used as the research object, and the standard wood method was used to measure the biomass of individual plants and the overall biomass of the sample plots under the conditions of different densities, and the soil physicochemical properties were determined, so as to analyze the effects of stand density on the biomass of P. tabuliformis forest and soil physicochemical properties, and to determine their relationship by redundancy analysis (RDA) and Spearman’s correlation analysis.   Result  (1) The differences in stand biomass and total tree biomass between different densities were significant (P<0.05), and with the increase of stand density, stand biomass gradually decreased, and the total tree biomass had a peak at a density of 1 750 plants·hm−2; (2) The physicochemical properties of soil in forests of different densities differed significantly (P<0.05), with soil porosity being the highest at 1 750 plants·hm−2, reaching 52.38%, soil moisture content being the highest at 2 750 plants·hm−2, reaching 13.84%, and soil fertility being the best at a density of 1 750 plants·hm−2; (3) RDA and Spearman’s correlation analyses revealed that total soil porosity, organic carbon and quick-acting phosphorus were all highly significantly correlated with arbor biomass in the sample plots (P<0.01), and below-ground biomass was significantly affected by soil water content (P<0.05).   Conclusion  The stand density should be maintained at 1750 plants·hm−2 for the purpose of sequestering carbon and releasing oxygen and maintaining maximum productivity, and for the purpose of increasing the carbon sink capacity of the soil and improving fertility, and at 1 750−2 750 plants·hm−2 for the purpose of retaining soil and water and improving soil water retention properties. [Ch, 4 fig. 5 tab. 40 ref.]
Effects of precipitation pattern change on non-structural carbohydrates in different organs of Cunninghamia lanceolata seedlings
FU Xiaobin, CHEN Qi, LIU Yuanqiu, DUAN Tianze, WANG Lixing, PAN Yanle, KANG Wangchao, DENG Wenping
, Available online  doi: 10.11833/j.issn.2095-0756.20240253
Abstract:
  Objective  Frequent droughts caused by global temperature rise and precipitation pattern change have significant impacts on forest ecosystems, so information of plant water utilization and adaptation during and after droughts is crucial.   Method  The seedlings of Cunninghamia lanceolata were used as test material. A two-factor controlled experiment with 4 precipitation amount and 2 precipitation intervals gradients was set to investigate the response of non-structural carbohydrates (NSC) and related fractions content in different organs that suffer different precipitation amount and intervals.   Result  With the decrease of precipitation, NSC content of the seedlings showed an overall trend of firstly increasing and then decreasing in absorbing roots, transport roots, branches and leaves, and continuous decreasing in branches and trunks. C. lanceolata seedlings increased NSC content in transport roots, absorbing roots, leaves and branches, while hydrolyzed and converted the starch from the absorbing roots to soluble sugars to regulate intracellular water potentials; soluble sugars content showed an overall trend of continuous decreasing in transport roots and trunks, and an overall trend of firstly increasing and then decreasing in absorbing roots, leaves and branches; starch content of all organs showed an overall trend of firstly increasing and then decreasing. When precipitation was too low, C. lanceolata seedlings would consume NSC to preferentially meet the survival needs of absorbing roots, which led to a significant decrease of NSC content in transport roots, branches and twigs (P<0.05). When precipitation intervals increased, NSC content in leaves and transport roots of the seedlings increased significantly (P<0.05); soluble sugar content of leaves decreased significantly (P<0.05), and soluble sugar content of transported roots increased significantly (P<0.05).   Conclusion  To improve the survival of C. lanceolata plantation forests under changes in precipitation patterns, soil water content should be maintained at more than 50% of the average monthly precipitation in the local multi-year dry season, and watering intervals can be extended in areas with higher precipitation. [Ch. 3 fig. 1 tab. 51 ref.]
Response of bird diversity to environmental factors in recreational green spaces in Kunming
LI Lanying, GAO Min, YUAN Di, SHAN Xinyu, YI Kaiyuan, ZHANG Zhe
, Available online  doi: 10.11833/j.issn.2095-0756.20230604
Abstract:
  Objective  The objective of this study is to investigate bird communities in parks, roadside green spaces, and community green spaces in Kunming urban construction zone, analyze the differences in bird community composition across different recreational green spaces and their root causes, and explore the impact of urban green space environments on bird communities.   Method  From July 2021 to August 2022, birds were investigated in three types of recreational green spaces in Kunming City. Redundancy analysis and multiple linear regression were used to analyze the relationship between the diversity of resident birds and environmental factors during breeding and non-breeding seasons.   Result  (1) A total of 31 058 individuals in 176 species were recorded, belonging to 17 orders and 53 families, which included 1 species under national first-class key protection and 12 species under national second-class key protection. (2) Parks had the highest richness, abundance, and Shannon-Wiener diversity index of bird species, followed by roadside green spaces, and community green spaces had the lowest. However, the Pielou evenness index showed the opposite trend. (3) Redundancy analysis indicated that other internal environmental factors, except for the green space shape index, had a promoting effect on improving bird diversity. (4) Multiple linear regression showed the building index in buffer zones of 50 and 400 m was negatively correlated with bird diversity. The distance from the city center was positively correlated with bird diversity. The distance from Dian Lake was negatively correlated with bird diversity in roadside green spaces. The distance from the mountain was positively correlated with bird diversity in roadside green spaces, but negatively correlated with bird diversity in community green spaces.   Conclusion  In the future construction of recreational green spaces, it is necessary to reduce the impact of surrounding buildings on parks and roadside green spaces, increase heterogeneous landscape habitats, and focus on enhancing the richness of vegetation communities inside community green spaces. [Ch, 3 fig. 3 tab. 28 ref.]
Intra-annual growth and its response to climatic factors in four ring-porous wood species
XU Junliang, HOU Jiayu, WU Tong, ZHAI Lexin, LUO Pengfei, WEI Miao, ZHANG Yiping
, Available online  doi: 10.11833/j.issn.2095-0756.20240574
Abstract:
  Objective  The radial growth dynamics of xylem is considered one of the indicators of sensitivity to environmental change. Investigating the xylem formation is crucial to elucidate the relationship between trees growth and the climate.   Method  Microcore sampling and paraffin sections technology were used to monitor the intra-annual growth dynamics of xylem formation. We collected the microcores of Catalpa bungei, Cinnamomum camphora, Fraxinus chinensis and Koelreuteria paniculata every 7−10 d, and Gompertz model was used to fit the modeled value of cumulative radial growth.   Result  (1) Cambial activity began in early March and ended in mid-October. The duration of cambial activity was shortest for C. bungei [(189±14.6) d], and longest for C. camphora [(216±17.4) d]. (2) Four species finished the xylem differentiation in early November, and their maximum growth rate occurred in the middle of May. However, the widths of cumulative radial growth showed great variations among four ring-porous species which were from (5 807±2 192.9) μm for F. chinensis to (8 276±1 744.2) μm for C. bungei. (3) Additionally, temperature may be the main climatic factor influence the radial growth in study area. Both air temperature and surface ground temperature had a significantly positive correlation on the xylem growth increment for four ring-porous wood species (P<0.01). The positive correlation between precipitation and xylem growth was only in C. camphora (r=0.39, P<0.05). It may explained by the smallest diameter and area of vessel of C. camphora, which led to the trees were more sensitive to precipitation.   Conclusion  The radial growth of the four tree species in the local area is highly significantly positively correlated with air temperature. The response of the C. camphora plants to climatic factors is stronger than the other three ring-porous porous tree species. [Ch, 5 fig. 4 tab. 52 ref.]
Soil microbial diversity and its influencing factors in the habitat of rare plant Emmenopterys henryi in Jiulongshan, Zhejiang Province
LUO Zhengrong, ZHENG Weicheng, TANG Zhansheng, CAI Chenchen, CHEN Xubo, ZHENG Zihong
, Available online  doi: 10.11833/j.issn.2095-0756.20230532
Abstract:
  Objective  This study, with an investigation into the temporal and spatial changes of soil microbial diversity in the habitat of the rare plant Emmenopterys henryi and the main controlling factors of these changes, is aimed to provide reference for the protection and breeding of the rare species.   Method  High throughput sequencing technology was used to detect OTUs of bacteria and fungi in soil from 34 E. henryi dominated stands before an analysis was conducted of the effects of altitude, slope direction, soil nutrition, and characteristics of the tree communities on the diversities of soil bacteria and fungi.   Result  α diversity analysis indicated that: the mean of Shannon-Wiener index of bacterial communities was 5.87, and that of fungal communities was 0.98; the numbers equivalent of Shannon-Wiener index (H') decreased significantly with the increase of altitude (P<0.05) and increased significantly with the increased soil pH (4.62 − 5.83) (P<0.05); meanwhile, the numbers equivalent of Simpson index (D') was significantly and negatively correlated with the content of available potassium in soil (P<0.05); H' and D' of soil fungi firstly decreased and then increased with the increased altitude, and significantly decreased with the increased alkali-hydrolyzed nitrogen content in soil (P<0.05); meanwhile, there was a significant and positive correlation between D' and the basal area of the central E. henryi tree (P<0.05). β diversity analysis indicated that: the mean Sorenson index of bacterial communities was 0.39, with 70.2% contributions of species turnover component, and that of fungal communities was 0.72, with 85.1% contributions of species turnover component; the Sorenson indices of soil bacterial and fungal communities were both significantly spatial auto-correlated (P<0.05), and correlated with differences in soil nutrient content and tree species composition. The partial Mantel test results indicated that: the species turnover components of bacteria were significantly correlated with differences in soil nutrient content and tree species composition (P<0.05), while the species richness difference of soil bacteria was significantly correlated with the difference in sampling year (P<0.05); the species turnover components of fungi were significantly spatially auto correlated (P<0.05), and correlated with differences in soil nutrient content, while the species richness difference of fungi was significantly correlated with the differences in sampling year and the altitude (P<0.05).   Conclusion  Compared with other forests in China, the habitat of E. henryi in Jiulongshan boasts more diverse soil fungal, less diverse soil bacterial and higher spatiotemporal heterogeneity in soil microbial diversity. Altitude, soil alkaline nitrogen content, and the size of E. henryi tree are the main factors affecting α diversity of soil microbes, while soil physicochemical properties and the composition of tree communities are the main factors that influence β diversity of soil microbes. [Ch, 4 fig. 2 tab. 32 ref.]
Research on optimization of urban thermal environment ecological network based on MSPA and minimum cumulative resistance model
PAN Zhenhua, ZHOU Yuan, YAO Jing, NING Shunbin, LUO Yushu, WANG Manlin
, Available online  doi: 10.11833/j.issn.2095-0756.20230505
Abstract:
  Objective  The acceleration of urbanization leads to the change of urban underlying surface, serious landscape fragmentation, and continuous intensification of urban heat island effect, especially in the urban center where buildings and populations are highly clustered. The establishment of reasonable ecological network has become one of the important ways to improve the urban ecological environment.   Method  Based on the “source-sink” theory, this study used morphological spatial pattern analysis (MSPA) and landscape connectivity index to select the “source” and “sink” landscapes with good landscape stability and high connectivity as ecological sources in the study area. The minimum cumulative resistance model, gravity model and hydrological analysis module were used to construct and screen important ecological corridors in the study area, so as to establish a multi-level “source-sink” landscape network to alleviate urban thermal environment problems.   Result  The results showed that 24 core patches with important connectivity were selected as important ecological sources. There were 102 “source-source” corridors, 141 “source-sink” corridors, 325 “source-sink” corridors, 103 ecological nodes and 148 obstacle points. Through comprehensive superposition, the first-level compensation corridor was mainly composed of Minjiang River, Pihe River and other river channels, the second-level transport corridor was mainly distributed in the area with dense “sink” landscape, and the third-level action corridor was mainly distributed in the high-intensity construction area.   Conclusion  The optimization pattern of a multi-level ecological network based on the “source-sink” theory is an important measure for effectively mitigating the urban heat island effect. [Ch, 4 fig. 3 tab. 25 ref.]
Diversity characteristics of herbaceous species under Robinia pseudoacacia forest in different years
NAN Guowei, WANG Jinghui, QIN Shuying, HAN Lei, HE Xinyu
, Available online  doi: 10.11833/j.issn.2095-0756.20240128
Abstract:
  Objective  This study, with an investigation into the species composition and diversity index of herbaceous layer under Robinia pseudoacacia forests in the hilly gully region of the Loess Plateau, is aimed to explore the characteristics and main influencing factors of its diversity index, in order to provide reference for the practice of regional vegetation restoration.   Method  With the R. pseudoacacia forests of different years (7, 12, 22 and 45 years) in Zichang City selected as study subjects, the species composition of the herbaceous layer in the understorey of R. pseudoacacia forests of different years were investigated employing the “space instead of time” method and the plot survey method before an analysis was conducted of the main factors influencing the diversity index using redundancy analysis (RDA).   Result  (1) There were 55 species of herbaceous species in R. pseudoacacia forests of different years, belonging to 18 families, and their dominant species were mainly Asteraceae, Gramineae and Leguminosae, with the overall performance showing that the dominant species belong to a few families, while the subordinate species belong to most families; the Artemisia vulgaris, A. caruifolia and A. gmehinii have higher importance values; (2) The aboveground biomass of understory herbaceous in R. pseudoacacia forests increased with years, and planting years increased significantly the aboveground productivity of the herbaceous layer (P<0.05). (3) Ammonium nitrogen, soil organic carbon, soil moisture and total phosphorus were the main factors influencing the Margalef and Simpson index of species diversity as well as aboveground biomass of the understory herbaceous layer whereas total nitrogen, total phosphorus, ammonium nitrogen, and soil silt were the main factors affecting Shannon-Wiener and Pielou index.   Conclusion  The herbaceous layer of R. pseudoacacia forests in the study area showed different species diversity at different years. Artemisia plants showed great adaptive ability at different years, and species diversity indicators and biomass are significantly affected by soil moisture and nutrients. Therefore, it is important to focus on the balance of soil moisture and nutrients in future afforestation practices in the Loess Plateau region to enhance the stability and sustainability of plantation ecosystem development. [Ch, 2 fig. 2 tab. 31 ref.]
Growth of Acer truncatum seedlings in response to the seedling substrate with different kinds of biochar
CHEN Mengjie, LI Xiaoying, SU Xiaojuan, WANG Yiwen, WU Zeting
, Available online  doi: 10.11833/j.issn.2095-0756.20240109
Abstract:
  Objective  In order to study the effects of different kinds and amount of biochar on the growth and nutrition of Acer truncatum seedlings, the better biochar and its application amount are selected to provide a theoretical reference for the scientific application of biochar in A. truncatum seedlings.   Method  The seedlings were used as experimental objects, and pot experiments were carried out. Conventional light substrate without biochar was taken as the control (ck1). 3 types of biochar (rubber biochar, rice husk biochar and bamboo biochar) with addition of 30.0, 50.0 and 70.0 g·kg−1 were set up. The growth, biomass, photosynthetic index, root morphology and nutrition of the seedlings under different treatments were determined. The principal component analysis and membership function analysis of the seedlings were used to comprehensively evaluate the indicators and explore the best biochar and addition proportion.   Result  The growth, biomass, root morphological index, photosynthetic index and nutrient content of the seedlings were all promoted by adding biochar to the substrate, the effect of rice husk biochar on seedling height, stem diameter, photosynthetic index and root morphology was better than that of bamboo biochar and rubber biochar. 50.0 g·kg−1 rice husk biochar addition proportion was the best for root growth of seedlings, compared with ck1, the total root length, total root surface area, total root volume and average root diameter increased by 98.79%, 110.22%, 175.00% and 37.50%, respectively. 70.0 g·kg−1 rice husk biochar addition proportion had significant effects on chlorophyll, net photosynthetic rate, stomatal conductance, and transpiration rate, compared with ck1, which increased by 50.00%, 221.76%, 200.00% and 146.91%, respectively. The evaluation index of seedlings with 50.0 g·kg−1 rice husk biochar was the highest (0.665), which was the best amount of biochar.   Conclusion  The addition of biochar to the the substrate could promote the absorption and utilization of nutrients in A. truncatum seedlings. It is suggested that 50.0 g·kg−1 rice husk biochar should be preferentially selected when adding biochar to A. truncatum seedling substrate. [Ch, 3 fig. 4 tab. 31 ref.]
Extraction of DBH and height of Pinus yunnanensis individual trees by combining backpack laser scanning and unmanned aerial vehicle laser scanning
XU Shanshan, LI Changchun, ZHANG Chao
, Available online  doi: 10.11833/j.issn.2095-0756.20240107
[Abstract](107) [HTML] (44) [PDF](10)
Abstract:
  Objective  This study aims to explore the advantages of acquiring three-dimensional point cloud of forests based on backpack laser scanning (BLS) and unmanned aerial vehicle laser scanning (ULS) technology, and use LiDAR360 MLS and LiDAR360 software to realize accurate measurement of single tree diameter at breast height (DBH) and tree height, meanwhile, determine the optimal method for individual tree segmentation and extraction.   Method  Taking 6 circular plots of Pinus yunnanensis natural pure forest with a radius of 15.0 m in Luomian Township, Fumin County, Yunnan Province as an example, the iterative closest point algorithm (ICP) was employed to fuse BLS and ULS point cloud. LiDAR360 MLS and LiDAR360 software were used to denoise, classify, normalize, segment individual trees and extracted DBH and tree height of individual trees from the point cloud data. The correlation between measured values and estimated parameters was established by linear fitting, and the estimation effect of DBH and tree height was evaluated.   Result  Compared with LiDAR360 based on elevation information for classification, LiDAR360 MLS based on deep learning for classification was more in line with reality in the number of tree extraction. The tree extraction results from BLS and fusion point cloud were consistent, and the recall rate reached 100%. ULS performed single tree segmentation through seed points, with accuracy, recall, and F-measure of 94.59%, 88.98%, and 91.70%, respectively. However, due to canopy connectivity, there existed some under-segmentation and over-segmentation. The determination coefficient (R2) and root mean square error (ERMSE) of DBH extraction based on BLS were 0.904 and 2.046 cm, respectively. R2 and ERMSE extracted by tree height were 0.791 and 1.173 m, respectively. The fusion point cloud was affected by discrete points around the trunk, and the DBH extraction effect was relatively poorer than BLS. R2 and ERMSE were 0.881 and 2.284 cm, respectively. However, the information of canopy and understory of fusion point cloud was more complete, and the estimation accuracy of tree height was higher than that of BLS, with R2 and ERMSE values of 0.933 and 0.812 m, respectively.  Conclusion  Due to differences in working principles, ULS and BLS technologies each have their own advantages in acquiring point cloud from the canopy and understory. The combination of ULS and BLS can achieve a complementary effect, which can reflect the forest spatial structure more precisely, and realize the high-precision extraction of DBH and tree height. [Ch, 5 fig. 3 tab. 28 ref.]
Effects of river sediment as the main substrate on the growth and physiological indexes of Agrostis stolonifera ‘PENN A-4’
XIA Honglei, WANG Lei, FANG Chaochu, WANG Minyan, LIU Wanpeng, SHEN Cheng, ZHANG Jin
, Available online  doi: 10.11833/j.issn.2095-0756.20240157
Abstract:
  Objective  The dredging sediment from rivers, lakes, reservoirs and ponds can be used for the production of high-economic value landscape plants such as turf, which can not only solve the problem of occupying cultivated farmland and destroying top soil layer, but also solve the treatment and disposal problem of organic solid waste such as sediment.   Method  Based on the mixed material design and the principle of maximum consumption of river sediment, the proportion of the three raw materials, namely sediment, biogas residue, and biochar, was set to be 50%≤sediment≤100%, 0≤biogas residue≤50%, and 0≤biochar≤10%, respectively, totaling 13 treatments. Meanwhile, cultivated soil was set as the control, and the growth indicators (biomass dry mass, chlorophyll, root activity) and physiological indicators (soluble sugar, malondialdehyde, antioxidant protective enzymes) were measured to explore the feasibility and suitability of planting Agrostis stolonifera ‘PENN A-4’ with the substrate of river sediment as the main material instead of the traditional cultivated soil.   Result  Compared with the control, the dry weight of above ground part and underground part of A. stolonifera ‘PENN A-4’ significantly increased by 58.53% and 17.19%, respectively (P<0.05) and the root activity nearly doubled (P<0.01) when the proportion of sediment in the mixed substrate was 75.00%, the proportion of biogas residue was 20.00%, and the proportion of biochar was 5.00%, but the content of chlorophyll a and b in plants decreased by approximately 20.00% (P<0.01). In addition, the mixed substrate significantly increased superoxide dismutase activity (28.66%, P<0.01), but had no significant effect on the contents of soluble sugar and malondialdehyde, catalase activity and peroxidase activity in plants.   Conclusion  It is feasible to use river sediment as the main material, mixed with an appropriate proportion of biogas residue and biochar as a substrate instead of cultivated soil for A. stolonifera ‘PENN A-4’ planting. The mixed biogas residue can effectively increase the aboveground biomass and root vitality of the turf grass, while biochar can effectively increase the underground biomass of the grass. [Ch, 5 fig. 4 tab. 25 ref.]
Research advances on the plant ESCRT machinery regulation of stress responses
LI Juan, CAO Yueyinglun, SHI Linjuan, CHEN Bihui, TAN Yawei, GAO Yanli, CAO Wenhan
, Available online  doi: 10.11833/j.issn.2095-0756.20240166
[Abstract](185) [HTML] (140) [PDF](16)
Abstract:
Stress is one of the major reasons causing global crop yield decline. Under stress conditions, the intracellular protein trafficking needs to be adjusted rapidly to ensure the correct delivery of the associated cargo molecules via endomembrane system. The endomembrane system in eukaryotic cells contains diverse membrane-bound organelles, which are accurately and efficiently generated in a well-organized way. These organelles play essential roles in protein transport. The endosomal sorting complex required for transport (ESCRT) complex mediates the biogenesis of prevacuolar compartment/multivesicular body (PVC/MVB), facilitating the vacuolar trafficking of the ubiquitinated proteins. This review highlights the recent research on ESCRT machinery in plant stress responses, including the basic composition and function of ESCRT, and the regulatory role of ESCRT in plant abiotic stress (i.e. drought and salt stress) and innate immunity. To explore how ESCRT specifically recognizes and regulates stress response proteins, it will be helpful to construct a more precise ESCRT-mediated molecular regulatory network of stress responses. [Ch, 2 fig. 1 tab. 70 ref.]
Reviews
Difference of daily understory evapotranspiration under two water conditions in Larix principis-rupprechtii plantation
HAN Xinsheng, WANG Xiao, WANG Yanhui, LI Zhenhua
, Available online  doi: 10.11833/j.issn.2095-0756.20240251
Abstract:
  Objective  The purpose of this study is to explore the impact of soil moisture on the daily understory evapotranspiration in Larix principis-rupprechtii plantation, so as to provide a theoretical basis for understanding the mechanism of forest evapotranspiration adapting to climate change and developing plans for coordinated forest water management.   Method  Taking L. principis-rupprechtii plantation in Diediegou small watershed in semi-arid area of Liupan Mountain in Ningxia as the research object, two experiments (blocking precipitation or water-proof input, and natural precipitation input) were conducted. Soil moisture gradient was artificially increased, and the effects of environmental factors (air temperature, solar radiation intensity, precipitation, and so on) on the daily understory evapotranspiration under the two soil moisture conditions were analyzed.   Result  The daily understory evapotranspiration in August, September and October under natural precipitation condition was 67.06, 36.32 and 29.49 mm·d−1, respectively, which was greater than that under water-proof treatment (54.22, 20.07, and 11.35 mm·d−1). The daily understory evapotranspiration under the two water conditions was characterized by a gradual decrease, and the fluctuations under natural condition was greater than those under water-proof treatment. From August to October, the difference in daily understory evapotranspiration under both water conditions generally showed a wavy pattern of first increasing and then decreasing, while the ratio showed a gradually increasing wavy pattern. In August, September and October, the mean difference between natural evapotranspiration and water-proof evapotranspiration was 0.41, 0.54 and 0.59 mm·d−1, respectively, with ratios of 1.29, 1.91 and 2.74, respectively. As the potential evapotranspiration increased, the ratio of daily evapotranspiration difference to soil volumetric water difference under both water conditions gradually increased. The effect of soil moisture on understory evapotranspiration was small when the daily potential evapotranspiration was less than 3 mm·d−1, but increased when the daily potential evapotranspiration was more than 3 mm·d−1, and increased significantly when the daily potential evapotranspiration was more than 5 mm·d−1.   Conclusion  The factors affecting daily understory evapotranspiration are roughly the same under both water conditions. The difference lies in that the daily understory evapotranspiration under natural condition is more affected by precipitation, while that under waterproof treatment is more affected by soil moisture. Future study should focus on the influence of multiple soil moisture gradients on understory evapotranspiration difference. [Ch, 7 fig. 1 tab. 28 ref.]