Forest and Grassland Resources Research

Study on Tracing Pilot Work of China's National Park System

MA Wei, LIU Zengli, WANG Zhichen, JIANG Yafang, TANG Xiaoping

2023,(3): 1-8. doi:10.13466/j.cnki.lyzygl.2023.03.001

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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.

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

2023,(3): 9-14. doi:10.13466/j.cnki.lyzygl.2023.03.002

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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 ".

Identification and Gap Analysis of Priority Areas for Ecological Protection in Shennongjia of Hubei Province

ZHANG Ping, CHAO Bixiao, XIAO Yangping, WANG Li, LU Yuan, XU Jiannan, ZOU Shangbo, ZOU Quancheng

2023,(3): 15-20. doi:10.13466/j.cnki.lyzygl.2023.03.003

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Shennongjia of Hubei Province is rich in biodiversity and has high conservation value,which is highly irreplaceable worldwide.In order to more accurately protect important ecological resources in Shennongjia and improve protection efficiency,this study built an ecological protection priority area identification model for Shennongjia of Hubei Province,and conducted protection priority area identification and protection gap analysis for its regions.The results showed that the overall ecological value of Shennongjia in Hubei Province was relatively high,and the spatial distribution pattern of ecological protection importance was divided by provincial highway "318 - national highway 242 - provincial highway 318".The ecological protection importance in the north was significantly weaker than that in the south;The priority area for ecological protection in Shennongjia was mainly located in areas with high degree of naturalness and low human interference,including Taiyangping,Houziya,Shennongding,and other areas.However,there were still gaps in the protection of Liushuping in Zhuxi County,Hongyanzhai in Fangxian County,Heishayu in Shennongjia forest region,Huangqiya in Xingshan County,and Taihuang Mountain.The priority areas for ecological protection had basically been included in the management scope of natural protected areas and nature reserves,but there were still some gaps in protection.It is suggested that the opportunity of establishing Shennongjia National Park can be used to further integrate and optimize the regional nature reserve system,and improve protection efficiency on the basis of ensuring that areas with high ecological value are included in the protection scope.

Analysis of the Forest Ecosystem Services and Driving Forces in Natural Forest Protection Project Area in Yunnan Province

WANG Yihui, NIU Xiang, WANG Bing, SONG Qingfeng

2023,(3): 21-28. doi:10.13466/j.cnki.lyzygl.2023.03.004

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Based on the second-class survey data and ecological connection data of forest resources about Natural Forest Protection Project area in Yunnan Province in 1998 and 2020,and according to the China national standard of "Specification for Evaluation of Forest Ecosystem Service Functions",this study applies the distributed calculation method to evaluate the service functions of forest ecosystem,including soil conservation,nutrient accumulationn,water conservation,carbon sequestration and oxygen release,purification of atmospheric environment and biodiversity conservation in the Natural Forest Protection Project area in Yunnan Province,and explores the formation and growth mechanism of its ecological benefits.The study aims to clearly demonstrate the remarkable results of the Natural Forest Protection Project in Yunnan Province,to provide scientific basis and technical support for different regions to carry out forestry ecological construction projects scientifically,to adjust the direction of forestry development in time,to promote subsequent protection and development of natural forest resources,and to promote further protection and development of natural forest resources.The results show that:(1) From the perspective of time scale,the quality and value of forest ecosystem service functions in Natural Forest Protection Project area in Yunnan Province have shown an upward trend in the past 20 years.(2) In 2020,the total value of forest ecosystem services in Natural Forest Protection Project area in Yunnan Province was 917.189 billion yuan/a,of which the functional value of biodiversity conservation was 343.216 billion yuan/a,the functional value of water conservation was 231.108 billion yuan/a,and the functional value of purifying the atmospheric environment was 114.494 billion yuan/a,indicating that the forest ecosystem of Natural Forest Protection Project area in Yunnan Province plays an important role as the "green gene pool","green water reservoir" and "environmental purification oxygen bar bank".(3) From 1998 to 2020,the forest ecosystem service work of Natural Forest Protection Project in Yunnan Province was inseparable from the forest resource endowment and policy guidance,and under the combined influence of both mentioned above,the physical quantity and value of various forest ecosystem service functions showed an increase trend of different degrees.

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

2023,(3): 29-37. doi:10.13466/j.cnki.lyzygl.2023.03.005

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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.

Dynamic Monitoring of Spartina alterniflora in Xiangshan Harbor Based on GEE and Random Forest

LIANG Licheng, FU Xiaoqiang, ZHANG Bin, CHENG Guxun, LI Zuohui

2023,(3): 38-45. doi:10.13466/j.cnki.lyzygl.2023.03.006

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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.

Impacts of Land Use Changes on the Habitat of Asian Elephants in Simao District of Yunnan

JIN Yu, WANG Juan, YANG Yue, YANG Xiongwei, MA Huimin

2023,(3): 46-55. doi:10.13466/j.cnki.lyzygl.2023.03.007

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Based on the tracking and monitoring of Asian Elephants in Simao District of Yunnan Province during 2017 to 2020,and field survey for the land-utilization types in 2020,then combining with the background data of the third national-land survey in 2009 and 2019,this paper analyzed the correlation between land-utilization and Asian Elephant population distribution.The habitat suitability for Asian Elephant in Simao District were predicted and evaluated.The main results were as follows:1) Asian Elephant favoured to live in the regions where were 600~1 150 m of elevation,0°~20°of slope,northeast and southeast,close to the pond and river,less external interference.suitable habitat regions were only accounted for 14% with severe habitat fragmentation.2) From 2009 to 2019,the characteristics of land use type in Simao District were changed as follows:the areas for woodland,farmland and grassland were decreased and transfered into other types.While the land areas for plantation,construction and water storage were increased,plantation with an annual growth rate by 3.9%.Land use change was the main reason for decreased and fragmentation of the suitable habitat for Asian Elephant.3) The resaults of Asian Elephant monitoring during 2017-2020 showed that the activity frequency of Asian Elephant in the woodlands accounted for 54.9%.It indicated that woodland was an important place for the habitation of Asian Elephant.

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

2023,(3): 56-64. doi:10.13466/j.cnki.lyzygl.2023.03.008

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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.

Evaluation and Optimization of Survey Methods for Ecological Factors about Wild Animals and Their Habitats

YANG Xiao, HU Jiping, REN Kailei, RUAN Xiangdong

2023,(3): 65-70. doi:10.13466/j.cnki.lyzygl.2023.03.009

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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.

Research on Evaluation of Elderly Healing Forest Wellness Base

JIANG Xuwang, YU Shuhan, LI Yihui, ZHAN Liyu

2023,(3): 71-79. doi:10.13466/j.cnki.lyzygl.2023.03.010

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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.

Responses of Vegetation in Mu Us Sandy Land to Climate Change from 1982 to 2020

WANG Cuiping, HAN Xiaohong, WANG Haochen, YOU Jiaqi

2023,(3): 80-89. doi:10.13466/j.cnki.lyzygl.2023.03.011

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Mu Us Sandy Land belongs to the agro-pastoral staggered area in northern China,the ecological environment is fragile,and the vegetation growth is greatly affected by the climatic environment.Based on GIMMS NDVI3g.v1 from 1982 to 1999 and MOD13Q1 from 2000 to 2020,combined with the temperature and precipitation data of relevant meteorological stations,this paper discussed the spatiotemporal characteristics of vegetation growth and its response to climate change in Mu Us Sandy Land from 1982 to 2020 by using trend analysis,coefficient of variation,partial correlation analysis and Hurst index.The research results showed:1) The vegetation growth of Mu Us Sandy Land showed a continuous upward trend,with an increase rate of 1.3% per 10 a,with 2005 being the inflection point,and the vegetation growth being slow before 2005 and rapidly thereafter.2) The NDVI_average range of Mu Us Sandy Land was between 0.10~<0.41,and spatial distribution characterized by "low west and high east ",and the change trend was mainly increased,accounting for about 94.07% of the total area,of which a significant increase accounted for 57.43% and a very significant increase accounted for 30.14%;The spatial variation and stability of vegetation varied significantly,and the proportion of high fluctuation change area was 35.95%,and the bands were distributed in areas with strong vegetation growth at the southeast edge of sandy land.3) The positive correlation coefficient between NDVI and temperature in April,June and August was high,and the positive correlation coefficient between NDVI and precipitation from June to September was strong,and precipitation had a greater impact on the growth and development of sandy vegetation,and the co-directional characteristics of vegetation change were stronger than the reverse characteristics.4) The future change trend of Mu Us Sandy Land would be mainly continuous improvement and continuous degradation,with continuous improvement accounting for 51.49% of the total area and continuous degradation accounting for 46.49%.

Experiments on Estimating Planted Forest Inventory Attributes Based on UAV-LiDAR Data

ZHOU Mei, LI Chungan, YANG Chengling, LI Zhen

2023,(3): 90-97. doi:10.13466/j.cnki.lyzygl.2023.03.012

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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.

Analysis of Vegetation Cover Changes in Beijing from 2005 to 2020

YU Shiyong, XU Qian, YU Xiaofei

2023,(3): 98-104. doi:10.13466/j.cnki.lyzygl.2023.03.013

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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.

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

2023,(3): 105-114. doi:10.13466/j.cnki.lyzygl.2023.03.014

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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.

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

2023,(3): 115-120. doi:10.13466/j.cnki.lyzygl.2023.03.015

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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.

Resources and Growth Characteristics of Ancient Ficus microcarpa in Hainan

LIN Ling, CHEN Feifei, HUANG Chuanteng, HONG Wenjun, ZHANG Mengwen

2023,(3): 121-127. doi:10.13466/j.cnki.lyzygl.2023.03.016

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The study used a combination of literature collection and field plant investigation to conduct a systematic of and study ancient Ficus microcarpa resources in Hainan Province.The resource status,distribution pattern,and growth characteristics of ancient F.microcarpa were analyzed,and a tree age-height model was constructed to reveal the senescence mechanism of ancient F.microcarpa in Hainan,and to provide theoretical and practical basis for the daily maintenance management and rejuvenation of ancient F.microcarpa.The results showed that a total of 3 715 ancient F.microcarpa were recorded in Hainan Province,distributed in cluster.Haikou City and Lingao County had a higher distribution of trees,accounting for 48.7% of the total number of trees;the countryside is the main distribution area of Hainan ancient F.microcarpa,accounting for 92.84% of the total number of trees.Most of the ancient F.microcarpa also had good growth status and site conditions,and their age,diameter at breast height and height structure are normally distributed,and a logistic model equation of y=1.369/(1+7.053e^-2^.⁸⁵²^x)(R²=0.998) was fitted to represent the relationship between age and height of ancient Ficus microcarpa.The results of leaf physiological tests showed that the chlorophyll content and SOD enzyme activity of the normal plant of ancient F.microcarpa were higher than those of the weakened plant,but the MDA content was lower than that of the weakened plant,indicating that the chlorophyll content,SOD enzyme activity and MDA content of the plant can be used as one of the physiological indicators to determine the senescence of ancient trees.

Estimation of Pinus massoniana Index Based on Geostatistical Spatial Analysis

LI Cheng, TANG Daisheng, JIA Jianbo

2023,(3): 128-133. doi:10.13466/j.cnki.lyzygl.2023.03.017

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Based on the analytical data of 81 blocks of 100m² sample circles in the special forest survey of Chongqing,the nonlinear regression method was used to calculate the Pinus massoniana standing index,and based on the geostatistical analysis method,the optimal variogram model was selected for spatial interpolation estimation of the ground index,and the spatial distribution of the Pinus massoniana Standing Index was analyzed and the areas suitable for planting Pinus massoniana were identified.The preferred tree growth model is the Richards model,and the final mathematical model of the guide curve is H=141.898×[1-exp(-0.0006×t)]⁰^.⁶⁶⁶¹.The fitting results show that the Gaussian model is a preferred variogram model,and the ratio of gold value to the base value of Pinus massoniana variogram in the study area is 20.9%,which is less than 25%,indicating that the Pinus massoniana standing index in the study area has a strong degree of spatial correlation Spatial autocorrelation and spatial interpolation can be used to predict the ground index.The central region of the study area and the northeastern region had high site indexes.The area with a site index greater than 10.43 accounted for a large part,which was closely related to the average altitude,soil type and average precipitation in the study area.

Research on Carbon Storage Estimation of Cunninghamia lanceolata Plantation Based on LiDAR Technology

YAN Baoyin, JIANG Wenlong, FAN Junjun, XIANG Zheng, HUANG Jun

2023,(3): 134-139. doi:10.13466/j.cnki.lyzygl.2023.03.018

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In this study,the airborne LiDAR technology was used to investigate the stand factors of the Cunninghamia lanceolata plantation in Nanyuntai Forest Farm.Based on the survey results,the biomass and carbon storage were estimated using the biomass equation method combined with the carbon coefficient,in order to provide a basis for the management of Cunninghamia lanceolata' and the development of carbon sequestration and sink increase activities.The results indicate that 1) y=4.6642 $e 0.1237 x$ (R²=0.801 2) is the optimal inversion equation for diameter at breast height(DBH);2) The carbon storage of Cunninghamia lanceolata plantation increased with the increase of DBH class,and its aboveground carbon storage 4.31~72.79 t/hm²) was significantly higher than underground carbon storage 1.17~21.44 t/hm²),accounting for absolute advantage in the whole plant carbon storage(5.48~94.23 t/hm²);3) Comparing the multiple relationship of carbon storage of the whole plant among different DBH groups,the medium DBH group is 3.4 times of the small DBH group;The large DBH group is 2.68 times larger than the medium DBH group;The extra large DBH group is 1.89 times of the large DBH group,and the growth rate is gradually decreasing;4) From the distribution of carbon storage in different organs of Cunninghamia lanceolata,the carbon storage in the trunk and branches increases with the increase of DBH class,while the leaves decrease with the increase of DBH class.

Evaluation of Forest Ecosystem Service Function and Value in Huizhou City of Guangdong Province

XU Yun

2023,(3): 140-145. doi:10.13466/j.cnki.lyzygl.2023.03.019

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Based on the theories and methods of the "Specifications for Assessment of Forest Ecosystem Services"(GB/T 38582—2020) and the "Norm of Techniques for Valuation of Forest Resources Assets"(LY/T 2735—2016),and in combination with the survey and monitoring data of forest resources planning and design in Huizhou City,Guangdong Province,quantitative assessments were conducted on seven service functions and their values of forest ecosystems,including water source conservation,soil erosion prevention,carbon sequestration and oxygen release,atomospheric purification,forest protection,biodiversity conservation and forest recreation.The aim was to understand the forest ecological foundation in Huizhou City,and provide scientific basis for forest ecosystem zonation management,ecological conservation red line identificatin,fiscal transfers for ecological conservation,government ecological environment performance evaluation,ecological conservation and restoration projects,etc.The study shows that the forest ecological service value in Huizhou City is 44.138 billion yuan per annum,and the service function values are ranked in the following order:water source conservation>biodiversity conservation>carbon sequestration>soil erosion prevention and oxygen release>air purification>forest protection.Water source conservation and biodiversity conservation together account for 77.65% of the total value,and are the main service functions of forest ecosystems in Huizhou City.

Determination and Application of Reasonable Annual Forest Harvesting Volume Based on Simulation Calculation Method

CHEN Jingjing, CHAI Zongzheng

2023,(3): 146-152. doi:10.13466/j.cnki.lyzygl.2023.03.020

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The scientific measurement of reasonable annual harvesting volume of forests is the key to optimize forest structure and achieve sustainable development of forest resources.In this study,based on the forest resource survey data of Langfengguan state-owned forest farm in Guizhou Province,computer simulation was used to determine the reasonable annual harvesting amount of horsetail pine timber forest in this forest and compare it with the traditional formula method.The results showed that:1) the optimal managerial period and rotation period of 30 years were determined based on the simulation method,and the reasonable annual harvesting area was 19.88 hm² and the annual harvesting volume was 4 807.11 m³.2) During the simulation management in the next 30 years,the age group structure would be gradually stabilized,the proportion of middle-aged and near-mature forests would be gradually decreased,and the proportion of young and over-mature forests would be gradually increased.After the simulated management,the proportion of mature and over-mature forest area could be stabilized at 42.86%,and the age group structure would be ideally distributed.3) Compared with the traditional formula method,the simulation method has more scientific measurement mechanism,more flexible adaptability,more accurate measurement process and more objective measurement results.The use of simulation to determine the reasonable annual forest harvesting volume can provide a scientific reference basis for guiding forest management and realizing the sustainable use of forest resources.

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