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Advances in Remote Sensing Retrieval of Forest Aboveground Biomass REN Xiaoqi, HOU Peng, CHEN Yan Forest and Grassland Resources Research    2023, 0 (6): 146-158.   DOI: 10.13466/j.cnki.lczyyj.2023.06.018 Abstract （1100）   HTML （85）    PDF（pc） （1148KB）（6296）       Knowledge map    Save Forest aboveground biomass is one of the key indicators to reflect the status of forest ecosystem,which is of great significance to global climate change and China's carbon peak and carbon neutrality.With the rapid development and increasing maturity of remote sensing technology,it has become the main technical means for retrieving above-ground forest biomass in large areas.In this paper,the research progress of remote sensing inversion of forest aboveground biomass was discussed from two aspects through systematic review of relevant literatures at home and abroad.From the perspective of data source,it can be summarized as inversion methods of optical remote sensing data,synthetic aperture radar data and LiDARdata,and the effective information,advantages and limitations provided by each data source are expounded and analyzed.From the perspective of inversion model,it can be summarized as multiple regression model,machine learning algorithm and mechanism model,and the characteristics of different models are discussed and analyzed combined with practical application cases.Finally,this paper summarized the existing problems in the inversion of forest above-ground biomass by remote sensing,and prospected the direction and hotspots of forest above-ground biomass inversion by remote sensing in the future. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Habitat Suitability Assessment of Moose Based on Combined MaxEnt and HSI Model ZENG Haowei, LING Chengxing, ZHANG Jun, LIU Hua, ZHAO Feng, JIN Yue, LIU Shuguang, ZHANG Yutong FOREST RESOURCES WANAGEMENT    2023, 0 (4): 115-122.   DOI: 10.13466/j.cnki.lyzygl.2023.04.014 Abstract （700）   HTML （76）    PDF（pc） （3281KB）（3632）       Knowledge map    Save Moose is a national first-class protected animal in China.Studying the habitat quality of moose is a key step to protect moose population.In this paper,taking Heilongjiang Nanwenghe National Natural Reserve as an example,the habitat suitability of moose was evaluated using maximum entropy model(MaxEnt)and habitat suitability index(HSI)model.Moose distribution points data was gathered from unmanned aerial vehicle transect survey,the maximum entropy model was used to get the environmental factor contribution and single environment variable response curve,combined with natural geography of the Reserve,the evaluation model was set up based on the impact of different environmental factors on moose to evaluate the moose habitat suitability of reserve quantitatively.The results showed that altitude(20.3%),slope(11.4%)and distance from river(11.3%)were the main environmental factors affecting the habitat distribution of moose,while slope aspect,slope position and vegetation coverage had less effect on moose habitat.Moose prefer to live in forested area with low altitude,moderate slope,sunny slope,and prefer to live close to river,far away from human disturbance and in areas with high coverage.In the reserve,the area of high suitable habitat for moose is 424.6 km2,accounting for 18.5% of the total area.The area of low suitable habitat is 1 422.9 km2,accounting for 62% of the total area.The area of unsuitable habitat is 447.5 km2,accounting for 19.5% of the total area. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Main Results of the Fourth Rocky Desertification Survey in Karst Area and Analysis of Rocky Desertification Control Situation NING Xiaobin, WU Xiebao, HUANG Junwei, WU Houjian, LIU Wei, PENG Xi FOREST RESOURCES WANAGEMENT    2023, 0 (3): 9-14.   DOI: 10.13466/j.cnki.lyzygl.2023.03.002 Abstract （1591）   HTML （124）    PDF（pc） （972KB）（3146）       Knowledge map    Save The fourth rocky desertification survey in Karst area was based on the result of the third national land survey,while taking 2021 as the base year to comprehensively investigate the condition and change of the rocky desertification land China.This paper briefly introduced the basic situation of the fourth rocky desertification survey,the present situation and dynamic change of rocky desertification land,as well as analyzed the current situation of rocky desertification control,and put forward countermeasures and suggestions.The results showed that,the rocky desertification land area was 7.223 million hm2 by 2021.Compared with 2016,the net decrease of rocky desertification land area was 3.331 million hm2,while the average annual decrease was 0.666 million hm2.The main results indicating that the rocky desertification land in China presents the overall evolution direction of "area decreasing,degree reduction and ecological condition being stable ". Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Geographic Weighted Regression Model Combined with Remote Sensing for Estimating Forest Aboveground Carbon Storage of Songyang County ZOU Weimin, CHEN Chao, HUANG Lei, SONG Meixuan, LI Xuejian, DU Huaqiang FOREST RESOURCES WANAGEMENT    2023, 0 (4): 132-140.   DOI: 10.13466/j.cnki.lyzygl.2023.04.016 Abstract （611）   HTML （53）    PDF（pc） （5877KB）（2519）       Knowledge map    Save Aboveground carbon(AGC)is an important indicator of the basic characteristics of forest ecosystems and a theoretical basis for evaluating the functional structure and productive potential of forests.As one of the nine key forestry counties in Zhejiang Province,Songyang County has a very important ecological status,so the accurate estimation of forest AGC in Songyang County is an important reference value for the stability evaluation of forest ecosystems and forest management in Songyang County.However,Songyang County is dominated by medium and low hilly areas surrounded by mountains,and how to consider the influence of complex terrain on the temporal and spatial variation of AGC is an urgent problem to be solved to achieve accurate estimation of AGC in mountainous forests.Therefore,based on Landsat TM satellite imagery and forest AGC survey data in Songyang County,a geographically weighted regression model(GWR)combined with spatial variation characteristics was constructed to estimate forest AGC,and compared with the results of ordinary least squares(OLS),finally,the optimal model was selected to predict forest AGC and its spatial distribution in Songyang County.The results were asfollows:Texture information from Landsat TM satellite imagerywas important for predicting forest AGC in Songyang County;The GWR model accurately estimated the AGC and spatial distribution of forests in Songyang County,and improved the accuracy by 9% over the OLS model,with an R2 of 0.71.The total AGC of forests in Songyang County was 3.901×106 Mg,with an average AGC of 23.70 Mg/hm2,accounting for about 10% of the total AGC of forest vegetation in Lishui City,which had a relatively important position in serving regional ecological functions.The study will provide advanced technical tools for accurate estimation of forest AGC in Songyang County,as well as scientific data for evaluating the function of forest carbon sink in Songyang County. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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The Resource Status and Conservation Strategies of National Key Protected Wild Plants in China JIANG Yafang, TIAN Jing, LIU Zengli, MA Wei, SHAO Wei, BAI Ling FOREST RESOURCES WANAGEMENT    2023, 0 (4): 1-10.   DOI: 10.13466/j.cnki.lyzygl.2023.04.001 Abstract （1486）   HTML （87）    PDF（pc） （1248KB）（2321）       Knowledge map    Save Accurate data on the population and survival status of wild plant are the basis for the plant diversity conservation.The Regulations of the People's Republic of China on the Protection of Wild Plants make it clear that the wild plants administrative departments should periodically organize surveys of national key protected wild plants,and establish wild plants resource archives.Therefore,China launched the second national survey of national key protected wild plants in 2012.Based on the survey data,the population,community area and in situ conservation status of 283 species of national key protected wild plants in China are reported.Reasons for the changes of wild plant resources over the past 10 years are also discussed through comparative analysis between the first and second national survey of national key protected wild plants.In order to advance conservation and management of wild plants in China,several countermeasures and suggestions were put forward,including establishing a national platform for wild plant supervision and management,improving the plant diversity conservation system,and carrying out the wild plant rescue and conservation projects. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Biodiversity Conservation and Practice in National Wetland Park—A Case Study of Xixi National Wetland Park HU Xinting, YUAN Jun, CHENG Yonqquan, GUO Fengyi, YUAN Weiying, LI Gang, YANG Yongfeng Forest and Grassland Resources Research    2024, 0 (2): 133-140.   DOI: 10.13466/j.cnki.lczyyj.2024.02.016 Abstract （984）   HTML （21）    PDF（pc） （1015KB）（2108）       Knowledge map    Save China established its first National Wetland Park in 2005.As an indispensable component of wetland protection system in China,national wetland parks have significantly contributed to biodiversity conservation over the past two decades.This study examines the significant challenges national wetland parks face in current biodiversity conservation and outlines key strategies for biodiversity conservation planning.Taking Xixi national wetland parks as a case study,it demonstrates specific practices in biodiversity conservation,particularly in rare and endangered species conservation,watershed biodiversity demonstration and nature education.This study proposes strategies for the key directions of biodiversity conservation in national wetland parks,which include protecting and restoring the biological baseline resources of wetlands,wild plant and animal habitat restoration,establishing information system for wetland sensing and monitoring,and promoting scientific and rational utilization of biological resources.These strategies aim to facilitate the development of national wetland park and enhance the quality of wetland biodiversity conservation in the new era. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Spatio-Temporal Pattern Analysis of Vegetation NPP in Yunnan Province Based on Improved CASA Model QIAN Hui, ZHANG Chao, FAN Jinming, DENG Zaichun, ZHU Xiali, LI Chengrong Forest and Grassland Resources Research    2023, 0 (6): 120-128.   DOI: 10.13466/j.cnki.lczyyj.2023.06.015 Abstract （638）   HTML （16）    PDF（pc） （4149KB）（1942）       Knowledge map    Save Vegetation net primary productivity (NPP)is one of the indicators to measure the level of ecosystem productivity,it is of great significance to estimate it by using the combination of ecology and remote sensing.In this study,we applied the improved CASA model;based on the MODIS vegetation index product,meteorological data,and land cover data;estimated the vegetation NPP in Yunnan Province in 2000,2005,2010,2015,and 2020,and explored its spatial distribution characteristics using the Moran's I index,Getis-Ord Gi* hotspot analysis,and overlaying analysis with China's ecologically Functional Protected Areas in China were superimposed and analyzed.The results showed that:1)the vegetation NPP in Yunnan Province in the past 20 years showed a trend of decreasing and then increasing trend,with an average value of 822.98 gc/(m2 a);the monthly vegetation NPP reached the highest in summer and the lowest in winter;and among the different vegetation types,the evergreen broadleaf forests had the highest NPP values.2)The spatial distribution of vegetation NPP decreased from south to north in each year,and the global spatial autocorrelation Moran 's I index was greater than 0.7.The NPP hot spots were mainly located in the southwestern border of Yunnan,and the cold spots were located in the northwestern and central urbanization areas of Yunnan.3)NPP hotspot areas superimposed with ecological function reserve intersected in Xishuangbanna Ecological Function Reserve and Southwest Karst Ecological Function Reserve,and the superimposed area accounted for 23%~26% of the total area of hotspot areas in each year.The study shows that NPP in Yunnan Province has shown a fluctuating upward trend in the past 20 years,and the results can provide scientific references for vegetation monitoring and ecological environmental protection in Yunnan Province. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Study on Stand Spatial Structure of Typical Pinus massoniana Mixed Forest in Liping County of Guizhou Province YANG Shenjun, TAN Wei, CHEN Xinyu, TANG Jiajun, YANG Zejun, WU Yujie FOREST RESOURCES WANAGEMENT    2023, 0 (3): 105-114.   DOI: 10.13466/j.cnki.lyzygl.2023.03.014 Abstract （580）   HTML （6）    PDF（pc） （3320KB）（1731）       Knowledge map    Save This paper explored the spatial structure characteristics of typical mixed forests of Pinus massoniana in Liping County,Guizhou,and provided theoretical basis for the management and transformation of mixed forests in this area.Taking Pinus massoniana in the mixed forest in Liping County as the research object,the typical Pinus massoniana mixed forest in the study area was divided into 7 forest types based on the mixed tree species and proportion.The types were broad-leaved mixed forest with Pinus massoniana propotion of 40%(type A),50%(type B),70%(type C) and coniferous mixed forests mixed with Chinese fir with Pinus massoniana propotion of 30%(type D),50%(type E),70%(type F) and pure forests of Pinus massoniana(type G).The spatial structure of all types were analyzed using comprehensive evaluation indicators such as angular scale,diameter at breast height ratio,tree height ratio,mingling degree and spatial structure.The results showed that:1) The seven types of Pinus massoniana stands in the study area were all in a light aggregation distribution state,tending to a random distribution pattern;2) The Pinus massoniana in type F of the study area had a moderate height and diameter at breast height,while the Pinus massoniana in other types were subdominant in height and diameter at breast height;3) The mingling degree in the Pinus massoniana mixed forest in the study area was relatively high,usually above moderate mingling degree,while the pure forest of Pinus massoniana was in weak mingling degree and nearly zero mingling degree.4) The ranking of forest stand comprehensive evaluation was:Type A>Type D>Type E>Type B>Type F>Type C>Type G;5) There was no significant difference in the spatial structure of typical Pinus massoniana in the study area in terms of angular scale,ratio of diameter at breast height to size,and ratio of tree height to size.The differences in spatial structure were mainly influenced by the mingling degree.The mixed forest as a whole qas developing towards a top level community with random distribution,moderate competition among trees,and higher mingling degree,but it had not yet reached the level of natural top level community. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Forest Fire Risk Zoning Based on MaxEnt Model—A Case Study of Yantai Yellow and Bohai Seas New Area LI Jie, CHAO Bixiao, YAN Yuqian, JIANG Fan, ZHANG Dawei, SUN Yongkang, ZOU Quancheng Forest and Grassland Resources Research    2024, 0 (2): 8-16.   DOI: 10.13466/j.cnki.lczyyj.2024.02.002 Abstract （648）   HTML （25）    PDF（pc） （2259KB）（1657）       Knowledge map    Save Forest fires are sudden and destructive natural disasters influenced by various factors such as meteorology,terrain,vegetation,and human activities.The establishment of a forest fire risk zoning is essential for effective prevention and controlling forest fires,which is of great significance for carrying out related work in the future.As a machine learning method,MaxEnt has gained widespread domestic and international usage in predicting probabilities of occurrences and identifying zoning of forest fire risk due to its demonstrated high accuracy.Yantai Yellow and Bohai Seas New Area,located at the junction of Jiaodong Peninsula and Yellow and Bohai Seas has a developed economy,high population density,and significant human impact on forests,making it representative of forest fire prevention efforts in China.This study took Yantai Yellow and Bohai Seas New Area as an example and utilized MaxEnt to predict the probability of forest fire occurrence and delineate forest fire risk zoning based on historical fire incident data,as well as dominant environmental variables such as meteorology,topography,land cover types,and socio-economic factors.The research findings indicate that:1)Dominant tree species(group)and population density have significant impacts on forest fire occurrence;2)In Yantai Yellow and Bohai Seas New Area,the areas with high,medium,and general risk levels are similar in size.High-risk areas are mainly concentrated in the southwestern mountainous region,while general-risk areas are primarily found along the northeastern coast.Through verification,this study's results have shown a high level of accuracy and can provide a methodological exploration for subsequent national forest fire risk zoning. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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The Development Experiences of the Flower Industry in the Netherlands and Its Implications for China XIANG Yue, LIU Ping Forest and Grassland Resources Research    2024, 0 (4): 164-170.   DOI: 10.13466/j.cnki.lczyyj.2024.04.018 Abstract （693）   HTML （11）    PDF（pc） （1153KB）（1467）       Knowledge map    Save The flower industry,as a burgeoning sector that contributes to China's rural revitalization efforts,plays an important role in promoting economic prosperity,enhancing social well-being,and strengthening the construction of ecological civilization.It is currently at a key turning point,transitioning from high-speed development to high-quality development,while facing major challenges such as an incomplete industrial chain,weak quality supervision,low levels of scientific and technological innovation,and insufficient policy support.The Netherlands,as a global leader in the flower industry,offers advanced development practices and successful experiences that are highly relevant for promoting the sustainable growth of China's flower industry.This paper summarizes the current situation and successful experience of the Netherlands flower industry,and proposes development strategies for China's flower industry.By accelerating the optimization and upgrading of the flower industry,improving the quality management system,strengthening scientific and technological support,and enhancing government support,China's flower industry can achieve high-quality,sustainable development. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Characteristics and discussion on protection and management strategies of ancient and notable trees in China JIANG Chunying, SUN Zhichao, YU Shiyong, HOU Chuncai, YANG Xueqing Forest and Grassland Resources Research    2025, 0 (1): 6-16.   DOI: 10.13466/j.cnki.lczyyj.2025.01.002 Abstract （508）   HTML （112）    PDF（pc） （1447KB）（1331）       Knowledge map    Save To gain an in-depth understanding of the characteristics of ancient and notable tree resources in China,based on the data from the second national census of ancient and notable tree resources,this study analyzes the quantity,types,spatial distribution,growth characteristics,and health status of ancient and notable trees,and explores the multiple challenges faced by current protection management in terms of responsibility awareness,ownership management,ecological protection,and technological application.The results showed that there are a total of 5.0819 million ancient and notable trees in China,including 1.2213 million scattered ancient and notable trees,belonging to 2553 species of 608 genera in 157 families,mainly distributed in Northern China and southern regions.The ownership is mostly collective,with the majority being third-grade ancient trees.The tree height is concentrated between 10-20 m,the chest circumference is concentrated between 100-300 cm,and the crown width is concentrated between 5-20 m.There is a significant correlation between the growth potential of ancient trees and their growth environment.Under the current situation,in order to better protect ancient and notable tree resources,it is necessary to further optimize management strategies,implement graded and classified protection,improve financial support,establish a sound legal and educational system,and promote technological empowerment. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Survey and Analysis of Bird Diversity in The Erguna Wetland,Inner Mongolia WANG Qiyuan, JI Penghao, XUE Lei, GAO Runhong Forest and Grassland Resources Research    2024, 0 (5): 66-76.   DOI: 10.13466/j.cnki.lczyyj.2024.05.008 Abstract （853）   HTML （11）    PDF（pc） （1598KB）（1309）       Knowledge map    Save In the spring,autumn and winter of 2022,a survey of bird diversity was carried out in Erguna wetland by using line transect method and site sampling method. 1)A total of 14 139 birds and 115 species belonging to 19 orders and 40 families were recorded. 2)There were 78 species of Palaearctic,Holoearctic and Northeast type,accounting for 67.83% of the total species. 3)In terms of bird fauna,Palearctic species and widespread species are the main species,and in terms of resident types,summer migratory birds,resident birds and travelers are absolutely superior. 4)There are 39 species of protected birds,including 6 species under national priority protection,26 species under national secondary protection,24 species of birds listed in CITES Appendix II and 2 species listed in CITES Appendix I. 5)In terms of bird ecological types,songbirds had the largest number of species(57 species),but a small number(575),while swimming birds and wading birds had a total of 35 species(13 468 species),accounting for 95.25% of the total number of birds in this survey. 6)There were seasonal dynamic differences in bird community composition,with the highest Shannon-Wiener diversity index and Pielou evenness index in autumn and the lowest in spring,and the lower Sorensen index among different seasons. 7)The composition of bird community was greatly affected by habitat types. The Shannon-Wiener diversity index and Pielou evenness index were the highest in forest shrub,the lowest in farmland,and the Sorensen index among different habitat types was low. The results of the survey reflect the status quo of bird resources in Erguna wetland,and can provide a reference for the management and protection of birds in the reserve. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effect of Substrates and Exogenous Hormone on the Rooting of Air Layering of Berchemia floribunda(Wall.)Brongn. ZHAO Tian, WANG Yinchen, ZHOU Sixuan, ZENG Bing, YUAN Yang, DENG Mengqing, LIAO Yan, ZHANG Jinhua Forest and Grassland Resources Research    2024, 0 (2): 80-91.   DOI: 10.13466/j.cnki.lczyyj.2024.02.010 Abstract （474）   HTML （2）    PDF（pc） （1965KB）（1169）       Knowledge map    Save Berchemia floribunda(Wall.)Brongn.is a traditional precious tree species in China with functions as a nectar source,ornamental and medicinal source,and has good ecological and economic benefits.In order to optimize the optimal conditions for B.floribunda air layering propagation and to improve the vegetative propagation technology,the L9(34)orthogonal matrix experiment was performed to explore the effects of different substrate ratios,exogenous hormone types,exogenous hormone concentration and girdle width on rooting of its air layering,subordination function method and correlation analysis method were used to comprehensively evaluate various rooting indices,and the mechanism of these four factors on rooting explored.The results showed that a suitable substrate and exogenous hormone ratio can promote the formation of callus,along with an increase in various rooting indices.Variance analysis and range analysis indicated that the efficiency of air layering was affected by the substrate ratio,exogenous hormone and girdle width,substrates ratio and exogenous hormone types were the two most important factors.Based on a comprehensive evaluation and correlation analysis,it is concluded that the most favorable treatment condition for B.floribunda rooting is:perlite+peat+vermiculite(1∶1∶1)as substrates,NAA is used as an exogenous hormone types with a concentration of 400 mg/L,and the girdle width is 10 mm.Under this treatment,the callus induction rate is as high as (93.33±2.36)%,and the rooting rate is as high as(85.00±4.08)%,(9.67±0.47)days to form a callus at the wound site,(14.00±0.82)days start to take root,average number of first order roots[(15.44±0.51)roots],average length of first order roots[(7.13±0.25)cm],average diameter of first order roots[(3.03±0.21)mm],fresh weight[(3.29±0.05)g],dry weight[(0.67±0.04)g],root effect index(5.50±0.06),average subordinate function value(0.77)were the highest.The results of this study provide theoretical references and data support for establishing a rapid propagation system of B.floribunda and promoting its cultivation. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of Mixed Betula luminifera and Phyllostachys edulis with Different Proportions on the Growth of Cunninghamia lanceolata after Thinning SUN Kun, WU Dayu, SUN Honggang Forest and Grassland Resources Research    2024, 0 (2): 124-132.   DOI: 10.13466/j.cnki.lczyyj.2024.02.015 Abstract （687）   HTML （5）    PDF（pc） （1329KB）（1147）       Knowledge map    Save Scientifically reasonable mixed planting can restore soil fertility,enhance forest productivity,improve low-quality and low-efficiency forests,and achieve scientifically efficient management of Cunninghamia lanceolata plantations.By conducting forest thinning in Cunninghamia lanceolata plantations,mixed forests can be created with different proportions of Cunninghamia lanceolata and other species such as Betula luminifera or Phyllostachys edulis.This includes combinations with ratios of Cunninghamia lanceolata to Betula luminifera or Betula luminifera at 1∶1,2∶1,and 3∶1,respectively.The objective is to investigate the effects of mixed planting on the growth characteristics and functional traits of Cunninghamia lanceolata individuals.The results indicate that:1)Compared to pure forests,mixed planting increases the intensity of competition among trees.Additionally,the competition intensity between Cunninghamia lanceolata and Betula luminifera in mixed forests is lower than that between Cunninghamia lanceolata and Phyllostachys edulis.2)Mixed planting of Cunninghamia lanceolata with Betula luminifera and Phyllostachys edulis both increase the leaf area index(LAI)of Cunninghamia lanceolata.3)With the increase in Cunninghamia lanceolata retention density,the contents of available nitrogen,available phosphorus,and organic matter in the soil decrease.Compared to pure forests,mixed planting leads to a decrease of available nitrogen content in the soil but an increase in available phosphorus.4)As the retention density of Cunninghamia lanceolata increases,the individual tree volume of Cunninghamia lanceolata decreases,while the total stand volume increases in contrast.In Cunninghamia lanceolata mixed forests with Betula luminifera and Phyllostachys edulis,both the individual tree volume and the stand volume of Cunninghamia lanceolata are higher than those in pure forests of Cunninghamia lanceolata alone.In Cunninghamia lanceolata mixed forests with Betula luminifera,the individual tree volume and stand volume of Cunninghamia lanceolata are similarly greater than those in mixed forests with Phyllostachys edulis.5)The Hegyi competition index shows a highly significant negative correlation with the individual volume of Cunninghamia lanceolata(P<0.01);the individual volume of Cunninghamia lanceolata is significantly positively correlated with leaf area(P<0.05);available phosphorus is highly significantly positively correlated with individual volume and stand volume(P<0.01),and soil organic matter content is significantly positively correlated with stand volume(P<0.05).Based on the above findings,Cunninghamia lanceolata mixed forests with Betula luminifera are superior to those with Phyllostachys edulis in various aspects.Additionally,when the ratio of Cunninghamia lanceolata to Betula luminifera is 1∶1,it has the best promoting effect on the individual growth of Cunninghamia lanceolata,which is beneficial for cultivating large-diameter Cunninghamia lanceolata and improving stand quality.At the same time,attention should be paid to stand yield.When the ratio of Cunninghamia lanceolata to Betula luminifera is 3∶1,the stand volume of Cunninghamia lanceolata is maximized. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Spatial-Temporal Evolution Characteristics and Driving Influence Mechanism of Habitat Quality in Kuye River Basin YUAN Yuan, SHENG Yan, LIU Linfu, WANG Shuo, LI Juan, AN Li Forest and Grassland Resources Research    2023, 0 (6): 67-74.   DOI: 10.13466/j.cnki.lczyyj.2023.06.008 Abstract （473）   HTML （9）    PDF（pc） （3186KB）（1087）       Knowledge map    Save The Kuye River is located in the ‘ji’ bay in the middle reaches of the Yellow River.It is an important water supply section of the Yellow River.The quality of its habitat is related to the ecological security and people's well-being of the basin.Based on GIS technology,InVEST model and linear regression analysis method were used to reveal the spatial and temporal evolution characteristics of land use and habitat quality in Kuye River Basin from 2000 to 2020.The main driving factors of habitat quality change in Kuye River Basin were further explored.The results showed that :1)In 2020,the grassland area of Kuye River Basin decreased by 6.60 % compared with that in 2000,and the forest land area increased by 35.05 % compared with that in 2000.2)From 2000 to 2020,the Kuye River Basin was dominated by areas of medium and high habitat quality.The overall habitat quality was improved,and the habitat quality was reduced in some areas.3)From 2000 to 2020,the total output value of the secondary industry,the total industrial output value,the total population at the end of the year,the landscape separation index and the habitat quality index showed a significant negative correlation.It can be seen that the industrial development and human activities in the Kuye River Basin have a very significant impact on the decline of habitat quality in the study area. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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A Study on Forest Stand Spatial Structure Intelligent Optimization Based on Voronoi Spatial Unit LIU Xin, HUANG Lang, QING Dongsheng, LI Jianjun FOREST RESOURCES WANAGEMENT    2023, 0 (4): 27-35.   DOI: 10.13466/j.cnki.lyzygl.2023.04.004 Abstract （675）   HTML （27）          Knowledge map    Save Using the Voronoi method to determine the target tree and neighbourhood tree has the problems of inaccurate edge correction and uncertainty of threshold size,which are not conducive to the quantitative description of the spatial structure of forest stand.To address these problems,this study set all the forest trees in Voronoi units that are less than 0.5 m from the sample plot boundary line and incomplete as non-objective trees,and introduced a regulation threshold Rmax for the distance between the target tree and neighbourhood tree to correct the problem of unreasonable selection of target tree and neighbourhood tree in the processing of edge effects in Voronoi spatial units.Based on the modified Voronoi spatial unit,a multi-objective ecological harvesting scheme was constructed and intelligently optimized by an ant colony algorithm.The results showed that the fitness functions of the four sample plots,M4,M8,M14 and M17,which had relatively poor stand spatial structure conditions among the 20 sample plots before regulation,were improved by 0.72,0.92,0.93 and 0.86,respectively,after regulation by simulated harvesting,which proved that the scheme has a better effect on optimizing the spatial structure of forest stand,and can provide a supportive tool for forest management decisions. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Remote Sensing Inversion of Mangrove Biomass Based on Machine Learning HAO Jun, LYU Kangting, HU Tianqi, WANG Yunge, XU Gang Forest and Grassland Resources Research    2024, 0 (1): 65-72.   DOI: 10.13466/j.cnki.lczyyj.2024.01.009 Abstract （907）   HTML （41）    PDF（pc） （3014KB）（1012）       Knowledge map    Save Accurately investigating mangrove biomass is beneficial for evaluating the carbon sink potential of mangrove ecosystems.Based on field survey data,Landsat 8 remote sensing images and DEM data,22 feature variables were extracted to carry out remote sensing inversion of mangrove biomass in the Ximen Island,which used three machine learning methods:Random Forest(RF),Support Vector Machine model(SVM)and eXtreme Gradient Boosting(XGBoost).The results showed:1)Compared to the RF model and SVM model,the XGBoost model had a better estimation performance(R2=0.932,ERMS=0.514 t/hm2,EMA=0.313 t/hm2),which could more accurately estimate the mangrove biomass.2)Among the 10 important characteristic factors selected by Recursive Feature Elimination(RFE),the vegetation index has a relatively high importance in estimating mangrove biomass.3)The biomass inversion map of the XGBoost model,which is composed of 10 important characteristic factors,showed that the estimated mangrove biomass ranges from 9.138 to 29.229 t/hm2,which was similar to the findings of the field survey.It can be seen that the XGBoost algorithm shows good application capabilities in mangrove biomass.This research will provide a technical reference for the accounting of carbon storage in the Chinese mangroves. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Soil Moisture and Carbon-Nitrogen Content on the Productivity of Flat Stubble Caragana korshinskii Forest in the Northwestern Shanxi Sandstorm Region XUE Yue, ZHAO Fengxia, LI Yajie, JI Wenxia, MENG Dan Forest and Grassland Resources Research    2024, 0 (5): 56-65.   DOI: 10.13466/j.cnki.lczyyj.2024.05.007 Abstract （457）   HTML （10）    PDF（pc） （2992KB）（948）       Knowledge map    Save Since the implementation of the Three-North(i.e.,Northeast China,North China and Northwest China)Shelterbelt Forest Program,Caragana korshinskii forest has become a crucial ecological barrier for wind prevention and sand fixation in the northwestern Shanxi sandstorm region.Therefore,investigating the impact mechanisms of soil moisture and carbon-nitrogen content on the aboveground net primary productivity(ANPP)of Caragana korshinskii under stubble disturbance is vital for local artificial vegetation construction and regional ecological stability.In this study,flat stubble Caragana korshinskii in its first-year in the northwestern Shanxi sandstorm region was used as the research object.Independent sample T-tests,linear regression models,and random forest models were employed to study the changes in productivity of flat stubble Caragana korshinskii and the effects of soil moisture and soil carbon-nitrogen content at different radial distances and soil layers on this productivity.1)The ANPP of the un-flat-stubble Caragana korshinskii was significantly higher than that of the flat stubble Caragana korshinskii 20~<40 cm (P<0.01).Soil moisture content at depth and 0.25 m from the stem(R2=0.456,P=0.016),soil total nitrogen content at 40~<60 cm(R2=0.363,P=0.038)and soil moisture content at depth and 0.5 m from the stem(R2=0.465,P=0.015)were significantly positively correlated with the productivity of flat stubble Caragana korshinskii forest.2)The random forest model results indicated that the most important soil limiting factor affecting ANPP changes after stubble disturbance was soil moisture content at 20~<40 cm depth and 0.5 m from the stem.The study suggests that future management of Caragana korshinskii forests should focus on soil moisture and carbon-nitrogen content at 20~<60 cm soil depth in root-dense areas,particularly the response of soil moisture at the 20~<40 cm soil layer to ANPP.This approach will optimize the restoration strategy of Caragana korshinskii forests in the northwestern Shanxi sandstorm region and enhance the sustainability of the ecological functions of the Three-North Shelterbelt Program. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Analysis of Vegetation Cover Changes in Beijing from 2005 to 2020 YU Shiyong, XU Qian, YU Xiaofei FOREST RESOURCES WANAGEMENT    2023, 0 (3): 98-104.   DOI: 10.13466/j.cnki.lyzygl.2023.03.013 Abstract （1067）   HTML （24）    PDF（pc） （3716KB）（933）       Knowledge map    Save Based on NDVI data from 2005—2020,the spatial distribution characteristics,temporal distribution characteristics and spatio-temporal characteristics of vegetation were analysed using NDVI classification and difference analysis to reveal the spatio-temporal patterns of NDVI changes in Beijing,and to explore the reasons for the changes by analysing the vegetation cover changes in Beijing in the past 15 years.Through analysis,it is found that,the overall vegetation cover in the Beijing area is at a high level.From a regional perspective,the areas with very high NDVI mean coverage classes in Beijing from 2005 to 2020 were all located in the Jundu and Xishan mountain ranges.The vegetation coverage of Mentougou District,Huairou District,Yanqing District,Fangshan District,Changping District and Pinggu District was at the highest level in Beijing.In terms of time,the level of vegetation coverage changed significantly from 2005 to 2020,with the average annual NDVI value increasing from 0.659 0 to 0.756 6,an increase of 14.81%.The proportion of area with "very high" vegetation coverage increased from 5.31% to 47.79%,and the proportion of area with "low" vegetation coverage decreased from 5.91% to 1.25%.In terms of spatiotemporal change characteristics of vegetation,the area with obvious improvement and slight improvement accounted for more than 80%.Two "million mu afforestation" projects and mountain forest management were the main driving forces to improve the quality of vegetation coverage in Beijing. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Detection of Discolored Trees Caused by Pine Wilt Disease Based on Vegetation Index Method Using Terrestrial Ecosystem Carbon Inventory Satellite Data JIAO Quanjun, ZHENG Yanfeng, HUANG Wenjiang, ZHANG Bing, ZHANG Heyi, SHI Yimeng, WU Fayun, FU Anmin FOREST RESOURCES WANAGEMENT    2023, 0 (4): 123-131.   DOI: 10.13466/j.cnki.lyzygl.2023.04.015 Abstract （726）   HTML （14）    PDF（pc） （4853KB）（904）       Knowledge map    Save Pine wilt disease(PWD)is a forestry pest epidemic that poses a major threat to the survival ofpine trees.High-resolution satellite remote sensing is an effective approach for identifying PWD-infected pine trees.The Terrestrial Ecosystem Carbon Inventory Satellite(Goumang Satellite),which was launched on August 4,2022,has a four-band camera with a spatial resolution of more than 2m.The purpose of this paper is to investigate the vegetation index(VI)threshold approach for demonstrating PWD detection using Goumang Satellite multispectral data.Based on the multispectral characteristics of PWD discolored pine trees,an identification strategy based on two biomass-related and pigment-related VIs is proposed and a pine wilt disease index(PWDI)is designed.A test of PWD identification was conducted in Qixia City,Shandong Province.The results demonstrated that the double-VIs identification method outperformed the single-VI strategy,with the combination of PWDI and NDVI having the best PWD recognition capacity,with an overall accuracy of 84.5%,followed by the combinations of NWI-NDVI and NGRDI-NDVI.PWDI outperformed the other five examined VIs in terms of identification performance while using a single-VI method.This research demonstrates that the Goumang Satellite has a high potential for rapid and reliable detection of PWD discolored pine trees,and that the suggested double-VIs identification technique and the new PWDI can serve as a model for other comparable satellites used for PWD monitoring. Table and Figures | Reference | Related Articles | Metrics | Comments（0）