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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 （239）   HTML （14）    PDF （972KB）（539）       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

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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 （335）   HTML （44）    PDF （1248KB）（344）       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

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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 （188）   HTML （12）    PDF （3716KB）（270）       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

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Study on Tracing Pilot Work of China's National Park System MA Wei, LIU Zengli, WANG Zhichen, JIANG Yafang, TANG Xiaoping FOREST RESOURCES WANAGEMENT    2023, 0 (3): 1-8.   DOI: 10.13466/j.cnki.lyzygl.2023.03.001 Abstract （270）   HTML （39）    PDF （3035KB）（238）       Knowledge map    Save Since 2013,remarkable achievements had been made in the development of national parks in China.From the initial developement of national park system to the official establishment of the first batch of national parks and the release of the national park spatial layout plan,the leap from theory to practice had been realized.Our study focused on tracking the national park system pilots in China,sorting out and refining the pilot work at both the national level and pilot area level.By tracing the progresses of the pilot work of China's national park system,sorting out and refining the pilot work at both national and pilot area levels,comprehensively analysing and summarising the main achievements and lessons learnt at different stages of China's national park system pilot,recommendations that can be replicated and applied were put forward.In addition,we took Three-River-Source National Park as an example to trace the pilot study process to provide references for the establishment and management of national parks in China. Table and Figures | Reference | Related Articles | Metrics

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Dynamic Monitoring of Spartina alterniflora in Xiangshan Harbor Based on GEE and Random Forest LIANG Licheng, FU Xiaoqiang, ZHANG Bin, CHENG Guxun, LI Zuohui FOREST RESOURCES WANAGEMENT    2023, 0 (3): 38-45.   DOI: 10.13466/j.cnki.lyzygl.2023.03.006 Abstract （122）   HTML （7）    PDF （2259KB）（234）       Knowledge map    Save The large-scale invasion of Spartina alterniflora has endangered the ecological security of China's coastal area.Therefore,studying a fast and accurate algorithm for identifying Spartina alterniflora is particularly important for achieving dynamic monitoring within the region.Taking Xiangshan harbor as a research zone in this study,151 Spartina alterniflora and 140 non-Spartina alterniflora land patches were used as the training data set on the GEE platform.The index of NDVI,EVI,NDWI and BSI were extracted from the Sentinel-2 remote sensing image band information,and these indices were added to the remote sensing image data.Machine learning methods such as Support Vector Machines and Random Forests were used for identification and classification.By identifying and classifying Sentinel-2 remote sensing images from 2017 to 2022,dynamic monitoring of Spartina alterniflora within the study area was achieved.The research results showed that compared with SVM,the RF method had higher recognition accuracy for identifying Spartina alterniflora,and the overall recognition accuracy in 2022 reached 99.03% with a Kappa coefficient of 0.978 7.At the same time,the experimental results showed that the area of Spartina alterniflora in Xiangshan harbor has gradually decreased since 2017,indicating that the artificial intervention measures taken during this period were very effective.The dynamic monitoring and status analysis of Spartina alterniflora in Xiangshan harbor provided quantitative scientific data for the management of Spartina alterniflora,and have important reference value for formulating relevant prevention and control measures. Table and Figures | Reference | Related Articles | Metrics

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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 （88）   HTML （6）    PDF （5877KB）（215）       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

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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 （86）   HTML （6）    PDF （3281KB）（207）       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

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Evaluation and Optimization of Survey Methods for Ecological Factors about Wild Animals and Their Habitats YANG Xiao, HU Jiping, REN Kailei, RUAN Xiangdong FOREST RESOURCES WANAGEMENT    2023, 0 (3): 65-70.   DOI: 10.13466/j.cnki.lyzygl.2023.03.009 Abstract （169）   HTML （15）    PDF （998KB）（207）       Knowledge map    Save The field survey of the current ecological situation is the basis for the prediction and evaluation of ecological environment.However,the current field investigation methods focus on assessing the status of the ecological environment,and cannot accurately predict the potential impact of construction projects during construction and operation.Under the new situation of comprehensively strengthening the protection of wild animals,the paper innovatively introduced the concept of "relative value" for six indicators which were wildlife activity degree,species richness,the quantity of key national protected wild animals,habitat connectivity,vegetation coverage and the quantity of key national protected wild plants.Combining qualitative and quantitative technical measures,the optimization of the content,methods and data calculation methods of ecological status investigation were discussed.The optimized investigation method not only lays a foundation for the objective prediction of the potential impacts of construction projects on wildlife and their habitats,but also provides effective technical support for the early project approval and decision making.It also is of great significance to study how to coordinate the development of infrastructure construction with the protection of ecological environment. Table and Figures | Reference | Related Articles | Metrics

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Evaluation on Fire Risk Rating of Forest Stands in Wildland-Urban Interface—A Case Study of Guangzhou City LUO Dan, WANG Qingfei, CHAO Bixiao, LI Le, HAO Zezhou, LU Yuan, WANG Cheng, WU Ruichen, LIU Feipeng, PEI Nancai FOREST RESOURCES WANAGEMENT    2023, 0 (3): 56-64.   DOI: 10.13466/j.cnki.lyzygl.2023.03.008 Abstract （125）   HTML （7）    PDF （2042KB）（173）       Knowledge map    Save Forest fire risk assessment is the basis for fire prevention.Sixteen major forest stand types in Wildland-Urban Interface of Guangzhou City were studied,using terrestrial laser scanning data for precise,non-destructive analysis results to obtain forest stand characteristics and structural indicators.The fire risk of different forest stand types was comprehensively evaluated with 11 factors relating to the fire risk of forest stands via the analytic hierarchy process.The results showed that Eucalyptus forest(EF),Cunninghamia lanceolata forest(CLF) and Castanopsis chinensis forest(CCF) were classified as higher fire risk,specifically,EF with fire risk Class IV,CLF and CCF with fire risk Class III.The fire risk of mixed fir and broad forest,Acacia auriculiformis forest,Liquidambar formosana forest,Cinnamomum camphora forest,Schefflera heptaphylla forest,Castanea henryi forest,Machilus chinensis forest,Acacia auriculiformis forest,Elaeocarpus rugosus forest,Acacia confuse forest,Machilus nanmu forest and broadleaf mixed forest decreased in order.Among them,the mixed fir and broad forest had the highest fire risk in the secondary fire risk forest.The fire risk level of Schima superba forest was classified as Class I,with a low fire risk.By analyzing the stand characteristics and structure of medium and high fire risk forest types,targeted combustible material control and modifications were removed to reduce stand combustibility and to improve the efficiency of forest fire prevention. Table and Figures | Reference | Related Articles | Metrics

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FOREST RESOURCES WANAGEMENT    2023, 0 (4): 0-0.   Abstract （197）            Knowledge map    Save Related Articles | Metrics

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Assessment of Ecological Product Value and Financial Subsidy Scheme for Natural Hardwood Forests YU Songbai, SU Chenhui, ZHANG Hongai, LIU Daoping, LU Kangying, CHEN Shaolong Forest and Grassland Resources Research    2023, 0 (5): 29-39.   DOI: 10.13466/j.cnki.lczyyj.2023.05.004 Abstract （336）   HTML （11）    PDF （1144KB）（158）       Knowledge map    Save According to the operational data of natural hardwood forests in Guangdong Province,using the theories of forest resource asset evaluation and research findings on the value of natural forests,this study evaluated the existing and potential natural forests at different age points.The assessment measured the various ecological product values that can be realized through resource assetization and value monetization.Against the backdrop of the current Natural Forest Protection Project,government financial subsidies were proposed as the optimal approach to realizing the ecological product value of natural forests.This subsidy scheme encompassed several aspects,including compensation for increased economic conversion value of mountain forest prices with improved ecological efficiency,compensation or funding for operational losses resulting from selective cutting or cessation of logging,and subsidies for economic losses incurred due to mature,renewable timber that cannot be harvested due to restrictions.Based on the principle of opportunity cost,scientifically fair and equitable fiscal subsidy standards for selective logging or cessation of logging were proposed.A comparison with the current implementation standards revealed a significant inadequacy in the current standards,highlighting significant room for improvement.The proposed methodology of this study was scientific and provided technical references for formulating and revising policies on fiscal compensation for ecological benefits.It also offered theoretical support for the transfer and redemption of collective and individual natural forests in the construction of nature reserves.Additionally,this research provided practical guidance for the valuation of public ecological assets in nature reserves. Table and Figures | Reference | Related Articles | Metrics

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Forestland Grading Based on Forest Potential Productivity Evaluation Model and Its Application HUA Weiping, WU Jianwei, YU Liyao, WANG Yanan, WU Chengzhen, ZHUANG Chongyang, CHI Shangping, JIANG Xidian FOREST RESOURCES WANAGEMENT    2023, 0 (3): 29-37.   DOI: 10.13466/j.cnki.lyzygl.2023.03.005 Abstract （148）   HTML （12）    PDF （2884KB）（141）       Knowledge map    Save Forestland is an essential resource for forestry production.Scientific and reasonable classification of forestland grades can accurately and comprehensively reflect differences in forestland quality,providing a decision-making basis for government macro-control of the forestland market and strengthening forestland management.Taking standard stand volume as an evaluation element of forest potential growth power,we divided forestland quality grades and developed a forest potential productivity evaluation model related to forestland quality grading indicators.We estimated parameters using the LM-UGO method,evaluated model fitting goodness with fitting correlation coefficient,mean square error,sum of squares of residuals,and Chi-square test,and applied forestland quality grading to the forest resources in Wuyishan City and Wuyishan National Park as case studies.The results showed:1) The established forest potential productivity evaluation model had a correlation coefficient of 0.966,a mean square error of 1.726,a sum of squares of residuals of 286.095,and a Chi-square test value of 33.898.The weights of six forestland grading index factors including average annual temperature,average annual rainfall,thickness of humus layer,thickness of soil layer,slope,and slope position were 0.08,0.22,0.27,0.26,0.10,and 0.07 respectively.2) Based on the annual growth amount and average growth rate,the benchmark age for forestland quality grading was determined to be 20 years.3) In Wuyishan City and Wuyishan National Park,the proportions of grades 3 and 4 in forestland quality were relatively large,the proportion of grade 5 was 9.43%,grade 1 was the smallest,and the potential growth level of forestland was at a medium level.The area proportion of each grade was significantly related to altitude(topography),exhibiting a power function or polynomial relationship.Developing a forest potential productivity evaluation model related to forestland quality grading indicators can avoid the subjectivity problem of determining index factor weights by classical decision analysis methods such as the analytic hierarchy process and grey relational analysis method. Table and Figures | Reference | Related Articles | Metrics

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Discussion on Optimization of Natural Resource Asset Management System in National Park LING Wei, WANG Yaxuan FOREST RESOURCES WANAGEMENT    2023, 0 (4): 11-17.   DOI: 10.13466/j.cnki.lyzygl.2023.04.002 Abstract （187）   HTML （25）    PDF （1019KB）（141）       Knowledge map    Save Taking the reform of the national park management system as reference,this paper summarizes the management mode of national parks,reasonably divides the central and local powers,and establishes the work coordination mechanism and other reform experiences,and analyzes the problems existing in the natural resource asset management system,such as the unclear division of responsibilities between the owner and the supervisor,the "exercise of ownership" system and mechanism,and the unclear boundary between the central and local powers.In order to sort out and learn from the natural resource asset management models of the United States,Germany,Japan,Russia and other countries,we put forward four measures to improve thenatural resource asset management system of national parks,including strengthening the implementation of the "two unifications" responsibility,exploring the management of property rights system,improving the ecological compensation system,and improving the purchase service system. Table and Figures | Reference | Related Articles | Metrics

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Research on Evaluation of Elderly Healing Forest Wellness Base JIANG Xuwang, YU Shuhan, LI Yihui, ZHAN Liyu FOREST RESOURCES WANAGEMENT    2023, 0 (3): 71-79.   DOI: 10.13466/j.cnki.lyzygl.2023.03.010 Abstract （105）   HTML （5）    PDF （1031KB）（135）       Knowledge map    Save Based on the theory of healing environment and Maslow's hierarchy of needs,and combined with the characteristics of the elderly,the evaluation index system of elderly healing forest wellness base was established,which was composed of 4 primary indicators,23 secondary indicators and 29 tertiary indicators.The primary indicators were landscape resources,environmental quality,facility resources,team service ability and technology.Expert consultation and analytic hierarchy process were used to determine the importance and weight of indexes,and the evaluation grade was divided.Take Longqi Mountain forest wellness base,Geshikao forest wellness base and Mayan forest wellness base as cases,this paper made an empirical study on the three bases by means of questionnaire survey.Results showed that the evaluation index system was scientific and applicable.Longqi Mountain,Geshikao and Mayan forest wellness bases were all in the "comparatively suitable" level.Finally,targeted suggestions were made according to the shortcomings of the three cases,and from five aspects of policy guidance,improvement of evaluation standards,improvement of standing forest quality,strengthening personnel trainingand construction of aging facilities,suggestions were put forward to promote the integrated development of forestry and pension service industry. Table and Figures | Reference | Related Articles | Metrics

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Research on Ecotourism Standardization of Protected Areas ZHANG Bolin, QIAO Yongqiang, XU Wentong, TANG Xiaoping Forest and Grassland Resources Research    2023, 0 (5): 1-8.   DOI: 10.13466/j.cnki.lczyyj.2023.05.001 Abstract （131）   HTML （18）    PDF （1277KB）（134）       Knowledge map    Save Based on the relevant research in the field of ecotourism and analysis of the problems faced by the requirements and standardization in protected areas,the paper explained the framework and key points which the specification should focus on.According to the requirements of current policies and standardizations on the zoning of ecotourism,facility construction,recreation activities,activity management and monitoring and evaluation and other issues,the paper explained in depth that the standardization in protected areas is based on ecotourism zoning and activity control.It also stipulated corresponding content between zoning with infrastructure and service facility,and put forward relevant requirements suggestions for monitoring and management.When supplemented by supporting management measures,standardization could lead the ecotourism to a healthy development stage. Table and Figures | Reference | Related Articles | Metrics

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Analysis on the Spatial Distribution Characteristics of Representative Populations in Tropical Rainforest of Hainan WU Tingtian, CHEN Yiqing, CHEN Zongzhu, LEI Jinrui, CHEN Xiaohua, LI Yuanling Forest and Grassland Resources Research    2023, 0 (5): 133-141.   DOI: 10.13466/j.cnki.lczyyj.2023.05.016 Abstract （61）   HTML （1）    PDF （8815KB）（127）       Knowledge map    Save Representative populations play an innegligible role in ecological early warning and biodiversity conservation1.The assessment of endangered species is the key basis for the priority conservation of biodiversity,analysis on the distribution pattern of representative populations from the perspective of suitable survival area.The results showed that:1)There were 10~25 species of representative populations potentially distributed in most areas of the National Park of Hainan Tropical Rainforest,accounting for 83.86% of the total area.2)The distribution of representative populations was mainly affected by altitude and vegetation type.The overall number of species distribution showd a radiation state of decreasing distribution from high altitude to low altitude,from primary forest to secondary forest and plantation.3)The construction of the National Park of Hainan Tropical Rainforest already opened up the boundary between the original protected areas and greatly promoted the interconnection of the ecosystem.However,there were still large areas of high hotspots of endangered plants that have not been included in the core protected areas.Therefore,more attention should be paid to these areas.The survival status of representative populations directly reflected the current characteristics of tropical rainforest ecosystems to a large extent.The research results can provide reference and theoretical basis for the ecological planning and biodiversity protection of the National Park of Hainan Tropical Rainforest. Table and Figures | Reference | Related Articles | Metrics

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Single-Tree Crown Delineation in Plain Afforestation Areas Based on Mask R-CNN XING Yuanjun, WEN Kunjian, GUO Xiaoni, SONG Yabin, HU Zhongyue, JIANG Tengyu, HE Zijing FOREST RESOURCES WANAGEMENT    2023, 0 (3): 115-120.   DOI: 10.13466/j.cnki.lyzygl.2023.03.015 Abstract （131）   HTML （4）    PDF （5403KB）（125）       Knowledge map    Save This paper aims to investigate an automated approach for extracting spatial distribution and quantities of planted trees in plain areas by using of visible light imagery obtained from unmanned aerial vehicles.Specifically,the study focuses on analyzing afforestation patches located in Huailai,Zhangjiakou,Hebei Province.To achieve this,a manually constructed single-tree crown dataset was utilized to train and predict Mask R-CNN models with varying backbone networks(R50-FPN-1x,R50-FPN-3x,R101-FPN-3x),and their accuracies were compared on an independent test set.Results indicate that all backbone models were able to segment tree crowns in the afforested areas,with the R101-FPN-3x model achieving the highest accuracy of 75.33% and a recall rate of 73.23%.The results showed that the single tree segmentation method based on Mask R-CNN from UAV images could quickly and accurately detect single tree targets in afforestation areas automatically,and effectively segment single tree crown to map the crown contour,which could meet the needs of efficient investigation and monitoring in small and medium-sized plain afforestation areas. Table and Figures | Reference | Related Articles | Metrics

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Development of Tree Height-DBH Model for Cunninghamia lanceolata and Eucalyptus Robusta Based on Stand Dominant Height and Climatic Factors DU Zhi, CHEN Zhenxiong, Li Rui, LUO Chongbin, YANG Guojin, ZENG Weisheng FOREST RESOURCES WANAGEMENT    2023, 0 (4): 36-42.   DOI: 10.13466/j.cnki.lyzygl.2023.04.005 Abstract （187）   HTML （19）          Knowledge map    Save Based on the mensuration data of diameter at breast height(DBH)and tree height from 25 Plots of Cunninghamia lanceolata and 25 plots of Eucalyptus robusta in the annual monitoring and evaluation of national forest resources of Guangxi Zhuang Autonomous Region,the basic model with the highest simulation accuracy was selected from seven common tree height-DBH curve models,then stand dominant height and climate data were introduced to build generalized nonlinear models.The 10-fold cross-validation method was applied to test the models,and the estimation error of one-dimensional volume formula was evaluated.The results showed that:1)Among the traditional tree height-DBH curve models,Chapman-Richards model was the basic model with the highest accuracy;2)Compared with the basic model,the generalized nonlinear tree height-DBH model with stand dominant height and climate data had higher fitting accuracy.The determination coefficient(R2),mean prediction errors(MPE)and mean percent standard errors(MPSE)of Cunninghamia lanceolata model were 0.7976,0.58% and 13.91%,respectively,and those of Eucalyptus robusta model were 0.7207,0.62% and 11.58%,respectively;3)The volume calculated by the one-dimensional volume formula was quite different from the measured volume,especially the Eucalyptus robusta reach -13.51%,which exceeded the scope of forestry industry standards.It was worth noting that the relative error calculated by the binary volume formula and the generalized nonlinear tree height-DBH model is not above 0.5%.The generalized nonlinear tree height-DBH model of Cunninghamia lanceolata and Eucalyptus robusta can be well applied to practical production. Table and Figures | Reference | Related Articles | Metrics

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Characteristics of Suitable Communities of Hopea hainanensis, a Wild Plant with Extremely Small Populations in National Park of Hainan Tropical Rainforest LUO Wen, LI Yanpeng, XU Han, QIN Wenhao, LIU Daye, MO Shiqin FOREST RESOURCES WANAGEMENT    2023, 0 (4): 98-106.   DOI: 10.13466/j.cnki.lyzygl.2023.04.012 Abstract （96）   HTML （8）          Knowledge map    Save Hopea hainanensis is a national level Ⅰ key protected wild plant,and it also belongs to a wild plant with extremely small populations.It is urgent to conduct conservation research on Hopea hainanensis populations,because of the few adult trees in the wild and the severe recruitment limitation from seedling to sapling life stage.To understand the characteristics of suitable communities of Hopea hainanensis,7 sample plots of 20 m×20 m were set up in the primary forest and secondary forest in Jianfengling,Hainan.The similarities and differences in species composition,species diversity,importance value and niche width of Hopea hainanensis communities under the two habitat types were analyzed.The results showed that:1)A total of 294 species of woody plants belonging to 75 families and 168 genera were recorded in the suitable communities of Hopea hainanensis,with a large proportion of monotypic families,oligotypic families,monotypic genera and oligotypic genera.Lauraceae,Fagaceae,Rubiaceae and Symplocaceae are the dominant families in the Hopea hainanensis communities.2)There was no obvious dominant species in both the primary forest and the secondary forest,but the functional status of Hopea hainanensis was much stronger in the secondary forest.3)Hopea hainanensis showed a wide niche range in both primary forest and secondary forest,indicating that this species is more competitive for resources.In addition,the larger niche width in primary forest than that in secondary forest indicated that Hopea hainanensis is more adaptable to the environment of primary forest. Our results provide basic data for revealing the structure and development trend of the suitable community on Hopea hainanensis,which is of great significance for the restoration and protection of the wild plant with extremely small populations. Table and Figures | Reference | Related Articles | Metrics

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Experiments on Estimating Planted Forest Inventory Attributes Based on UAV-LiDAR Data ZHOU Mei, LI Chungan, YANG Chengling, LI Zhen FOREST RESOURCES WANAGEMENT    2023, 0 (3): 90-97.   DOI: 10.13466/j.cnki.lyzygl.2023.03.012 Abstract （130）   HTML （13）    PDF （6171KB）（113）       Knowledge map    Save To explore advanced,reliable,and feasible technical schemes for small-scale forest resource inventory and monitoring,unmanned aerial vehicle-based LiDAR (UAV-LiDAR) was tested for estimating and mapping forest inventory attributes.Thirteen UAV-LiDAR-derived metrics,which depict the three-dimensional structural aspects of the forest canopy and have clear forest mensuration and ecology significance,were used to construct 86 multiplicative power formulations consisting of 2~5 predictors for forest inventory attribute estimation by using a rule-based exhaustive combination.All the formulations were calibrated and validated using the sample plot data,and six optimal models were achieved.The results indicated that the coefficients of determination (R2) of the mean stand height,basal area,and volume estimation for the pine and eucalyptus planted forests were 0.616~0.853,the relative root mean squared errors (rRMSE) were 10.85%~18.79%,and the mean predictive errors (MPE) were 3.80%~9.72%.With its ability to accurately estimate and map forest attributes,UAV-LiDAR provides an innovative technological tool for small-scale forest resource inventory,and effectively overcomes many of the problems of conventional field measurements.However,there are still numerous technical issues that need to be further investigated in the application of UAV-LiDAR to forest resource inventory to improve accuracy and reduce inventory costs. Table and Figures | Reference | Related Articles | Metrics