北京城市森林林分结构对视觉形态质量的影响

doi:10.11707/j.1001-7488.LYKX20250210

摘要/Abstract

摘要：

目的: 探索北京城区林分的木本植物组成、林分物理结构对城市森林景观视觉质量的影响规律，拟进一步揭示林分结构与森林视觉质量关系的作用机制。方法: 在北京市六环内选取落在8条扇形样带内、2 km×2 km地理网格中面积为30 m×30 m的145块样地。通过主成分分析构建林分物理结构指数和物种组成结构指数，通过熵权法构建视觉形态性状指数，分析林分结构指标、结构指数对视觉形态性状指标、视觉形态性状指数的影响。结果: 树冠圆满度随着胸径组成多样性和树高组成多样性的增加而显著提高，随着树木空间占有度的提高而显著降低；偏冠度显著受平均树高、胸高断面积、Berger-Parker树种组成优势度的负影响，并显著受Margalef物种丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数的正影响，且随林分水平结构指数的提高而提高；平均树高较大或物种组成复杂度较高的林分，树冠伸展度显著降低；视觉形态性状指数随着树木空间占有度的提高而显著降低，与林分物种组成复杂度、物种组成优势度无明显关系。结论: 北京市六环内城市森林的视觉质量受林分结构复杂性的影响。其中，林分视觉形态性状指标显著受林分物理结构指标的影响，并在一定程度上受林分物种组成结构指标的影响，而林分的视觉形态性状指数主要受林分树木空间占有度的直接影响。林分物种组成结构指数对视觉形态性状指数的影响较低，很大程度上是因为林分物种组成结构指标与林分物理结构指标显著相关，即林分物种组成结构对城市森林视觉质量的影响是通过林分物理结构的影响而间接实现的。

关键词: 视觉形态性状, 视觉形态性状指数, 林分物理结构, 物种组成结构, 城市森林

Abstract:

Objective: This study investigates how the composition of woody species and the physical structure of urban forest stands in central Beijing influence the visual quality of urban forest landscapes, aiming to further elucidate the underlying mechanisms by which stand structure shapes forest visual quality. Method: 145 plots with area of 30 m×30 m were selected according to 2 km×2 km geographic grid which are included into 8 of the fan-shaped transects. Indices of stand physical structure and stand species composition were constructed by principal component analysis using data from stand structural indicators, and integrate index of visually morphological traits (II_VT) was constructed by entropy weight method using visually morphological trait indicators (VMT) data. Analyze the impact of stand structure indicators and structural indices on visual morphological trait indicators、visual morphological trait index. Result: Crown round degree (C_RD) was increased with DBH composition diversity and tree height composition diversity while it was decreased with degree of space occupation (D_SO). Moreover crown asymmetry degree (C_AD) was negatively affected by average tree height, total stand basil area and Berger-Parker index of dominant tree species (D_BP) significantly, but C_AD was positively affected by Margalef’s tree species richness, Shannon-Wiener index and Pielou evenness, and was increased with complexity of horizontal space (C_HS). Meanwhile crown extension range (C_ER) was significantly declined with increase of average tree height and complexity of tree species composition(C_SC). However the II_VT, which represented the overall VMT, was remarkably declined with enhancement of D_SO, and it was no significant correlations with complexity of tree species composition and dominant of tree species composition. Conclusion: Urban forest within the sixth ring road is influenced by complexity of stand structure. Visually morphological trait indicators were obviously shaped by stand physical structure indicators, and were partly determined by stand species composition indicators, while II_VT was mainly affected by D_SO. The lower effects of stand species composition index on II_VT were largely covered by the strong relations between stand physical structural indicators and species composition indicators. In other words, the stand species composition indirectly affects visually morphological quality through the stand physical structure of urban forest.

Key words: visually morphological traits, index of visually morphological traits, stand physical structure, stand species composition, urban forest

中图分类号:

S731.2

徐宇沛,郭璇,户佐佑,马冰倩,郭嘉欣,李阳,肖倩,董天心,徐程扬. 北京城市森林林分结构对视觉形态质量的影响[J]. 林业科学, 2025, 61(7): 220-230.

Yupei Xu,Xuan Guo,Zuoyou Hu,Bingqian Ma,Jiaxin Guo,Yang Li,Qian Xiao,Tianxin Dong,Chengyang Xu. Effects of Stand Structure on Visually Morphological Quality of Beijing Urban Forests[J]. Scientia Silvae Sinicae, 2025, 61(7): 220-230.

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城市森林结构指标计算公式及其含义"

指标名称 Indicators	计算公式 Model	含义 Description	文献 References
Margalef 物种丰富度指数Margalef species richness index （S_R）	$ {S}_{\mathrm{R}}=\dfrac{S-1}{\mathrm{ln}N} $	S为样地的乔木物种数量，N为样地所有乔木个体总数。S is the number of arboreal tree species， N is the total number of individuals of all arboreal tree species in the plot..	Magurran et al.， 2001
Shannon-Wiener 多样性指数Shannon–Wiener diversity index （H）	$ H=-\displaystyle \sum _{i=1}^{S}{p}_{i}\mathrm{ln}{p}_{i} $	P_i为样地第i个树种数量比例，S为样地的乔木物种数量。P_i is the number proportion of species i to all of arboreal trees in the plot， S is the total number of arboreal tree species in the plot.	Magurran et al.， 2001
Pielou 均匀度指数Pielou’s evenness index （E）	$ E=\dfrac{H}{\mathrm{ln}S} $	S为样地的乔木物种数量，H为Shannon-Wiener 多样性指数。S is the number of arboreal tree species in the plot， H is the Shannon-Wiener diversity index.	Magurran et al.， 2001
Berger-Parker优势度指数Berger–Parker dominance index （D_BP）	$ {D}_{\mathrm{B}\mathrm{P}}=\dfrac{{N}_{\mathrm{m}\mathrm{a}\mathrm{x}}}{{N}_{\mathrm{T}}} $	N_max为样地相对丰度最高的物种的丰度，N_T为总丰度。N_max is the abundance of the species with the highest relative abundance in the plot， N_T is the total abundance.	Magurran et al.， 2001
胸高断面积Basal area （G）	$ G=\dfrac{\displaystyle \sum _{i=1}^{N}{g}_{i}}{A} $	g_i为样地第i株林木的胸高断面积（m²），N为样地所有乔木个体总数，A为样地面积（m²）。g_i represents the cross area （m²） of the i tree at breast height in the plot，N is the total number of individuals of all arboreal tree species in the plot， A represents the area of the inventory plot （hm²）.	孟宪宇， 2006
平均胸径Mean diameter at breast height （$ \bar {D} $）	$ \overline{D}=\sqrt{\dfrac{\displaystyle\sum_{i=1}^ND_i^2}{N}} $	D_i为样地第i棵树的胸径，N为样地所有乔木个体总数。D_i is the DBH of the i^th tree in the plot.，N is the total number of individuals of all arboreal tree species in the plot.	孟宪宇， 2006
平均树高Mean tree height （$ \bar {H} $）	$ \bar {H}=\dfrac{\displaystyle \sum _{i=1}^{k}\bar {{h}_{i}}{G}_{i}}{\displaystyle \sum _{i=1}^{k}{G}_{i}} $	$ \bar {{h}_{i}} $为样地i径阶林木的算术平均高，G_i为样地i径阶林木胸高断面积之和，k为样地林木径阶数。$ \bar {{h}_{i}} $is the arithmetic average height of trees of each diameter class in the plot， G_i is cross area at breast height of trees in each diameter class in the plot， k is the number of diameter order in the plot.	孟宪宇， 2006
胸径组成多样性Diameter class diversity （H_DBH）	$ {H}_{\mathrm{D}\mathrm{B}\mathrm{H}}=-\displaystyle \sum _{j=1}^{m}{q}_{j}\mathrm{ln}{q}_{j} $	q_j为样地j径阶树木与所有树木的数量个数比例，m为样地林分径阶数。将胸径按照2 cm间隔进行分级，H_DBH主要反映城市森林中树木的水平空间异质性。q_j is the number proportion of j^th diameter class to all of trees in the plot. m is total number of diameter classes. We divided the diameter class by 2 cm interval. H_DBH mainly reflects horizontal spatial heterogeneity of trees in urban forest.	Ali et al.， 2016
树高组成多样性Tree height diversity （H_TH）	$ {H}_{\mathrm{T}\mathrm{H}}=\displaystyle \sum _{l=1}^{t}{r}_{\mathrm{l}}\mathrm{ln}{r}_{\mathrm{l}} $	按2 m间隔划分树木高度等级，r_l为样地第l个高度等级林木数量比例，t为样地树高的等级数量。H_TH主要反映森林中树木垂直结构的复杂性，体现了森林的垂直空间异质性。We divided the height class by 2 m interval. r_l is the number proportion of l^th height class to all of trees in the plot. t is total number of height classes in the plot. H_TH mainly reflects vertical spatial heterogeneity of trees in urban forest.	Ali et al.， 2016

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参考文献 0

	蔡丽丽, 徐程扬. 遥感技术在风景林景观质量评价中的应用研究进展. 林业科学, 2014, 50 (9): 145- 151.
	Cai L L, Xu C Y. A review on application development of remote sensing technology in landscape quality assessment of scenic forest. Scientia Silvae Sinicae, 2014, 50 (9): 145- 151.
	陈　瑜, 徐程扬, 李　乐, 等. 阔叶红松风景林单木景观质量评价与模型研究. 北京林业大学学报, 2014, 36 (5): 87- 93.
	Chen Y, Xu C Y, Li L, et al. Assessment and model research on scenic forest individual tree landscape quality in broadleaved and Korean pine mixed forests. Journal of Beijing Forestry University, 2014, 36 (5): 87- 93.
	崔　义, 刘海轩, 吕　娇, 等. 城市森林林内景观质量定量通用判别技术研究. 北京林业大学学报, 2020, 42 (12): 9- 23.
	Cui Y, Liu H X, Lü J, et al. General methods for quantitative assessment of in-forest landscape quality of urban forest. Journal of Beijing Forestry University, 2020, 42 (12): 9- 23.
	邓送求, 闫家锋, 王　宇, 等. 间伐强度对不同林分类型美景度的影响. 东北林业大学学报, 2010, 38 (3): 4- 7.
	Deng S Q, Yan J F, Wang Y, et al. Effects of thinning intensity on scenic beauty values of different types of stands. Journal of Northeast Forestry University, 2010, 38 (3): 4- 7.
	葛　楠, 李鸿祥, 曹　峰. 基于SBE-AHP法的河北塞罕坝森林公园植物景观质量评价. 中南林业科技大学学报, 2023, 43 (4): 182- 190.
	Ge N, Li H X, Cao F. Evaluation of the plant landscape quality of Saihanba Forest Park in Hebei based on the SBE-AHP method. Journal of Central South University of Forestry & Technology, 2023, 43 (4): 182- 190.
	贾艳红, 赵　军, 南忠仁, 等. 基于熵权法的草原生态安全评价: 以甘肃牧区为例. 生态学杂志, 2006, 25 (8): 1003- 1008.
	Jia Y H, Zhao J, Nan Z R, et al. Ecological safety assessment of grassland based on entropy-right method: a case study of Gansu pastoral area. Chinese Journal of Ecology, 2006, 25 (8): 1003- 1008.
	贾　娜, 史久西, 秦一心, 等. 森林色彩景观格局指数与色彩属性指标对观赏效应的影响. 林业科学, 2021a, 57 (2): 12- 21.
	Jia N, Shi J X, Xin Y X. et al. Influence of forest color landscape pattern indices and color attribute indicators on ornamental effect. Scientia Silvae Sinicae, 2021a, 57 (2): 12- 21.
	贾　娜, 闫　伟, 史久西, 等. 秋色叶树木树冠色彩特性对其观赏效应的影响. 林业科学, 2021b, 57 (11): 37- 48.
	Jia N, Yan W, Shi J X, et al. Influence of crown color characteristics on the ornamental effect of autumn-color trees. Scientia Silvae Sinicae, 2021b, 57 (11): 37- 48.
	韩文静, 张　昶, 王　成, 等. 珠三角地区冠层植物对森林色彩景观时空特征的影响. 西北林学院学报, 2025, 40 (1): 232- 243.
	Han W J, Zhang C, Wang C, et al. Influence of canopy plants on variation characteristics of forest color landscape in pearl river delta. Journal of Northwest Forestry University, 2025, 40 (1): 232- 243.
	黄　静, 孙新旺. 南京紫金山国家森林公园景观美景度评价及影响因素分析. 中南林业科技大学学报, 2024, 44 (11): 146- 154.
	Huang J, Sun X W. Landscape beauty evaluation and influencing factors analysis of Zijinshan National Forest Park in Nanjing. Journal of Central South University of Forestry & Technology, 2024, 44 (11): 146- 154.
	黄广远, 徐程扬, 毛　斌, 等. 基于灰色关联的北京城区景观乔木树种评价. 东北林业大学学报, 2011, 39 (11): 102- 104.
	Huang G Y, Xu C Y, Mao B, et al. Evaluation of landscape tree species in Beijing based on grey relation method. Journal of Northeast Forestry University, 2011, 39 (11): 102- 104.
	黄广远, 徐程扬, 朱解放, 等. 基于层次分析法和逼近理想解排序法的高校校园绿地景观评价. 东北林业大学学报, 2012, 40 (9): 113- 115, 123.
	Huang G Y, Xu C Y, Zhu J F, et al. Evaluation of green landscape in college campuses based on a combined AHP-TOPSIS method. Journal of Northeast Forestry University, 2012, 40 (9): 113- 115, 123.
	李　苹, 毛　斌, 许丽娟, 等. 密度、灌草盖度和树干形态对油松人工风景林林内景观指数的影响. 北京林业大学学报, 2018, 40 (10): 115- 122.
	Li P, Mao B, Xu L J, et al. Effects of density, shrub-herb coverage and trunk shape on the in-forest patch index of planted Pinus tabuliformis forests. Journal of Beijing Forestry University, 2018, 40 (10): 115- 122.
	李汝佳. 2017. 基于公众认知的徐州市园林树木个体美学特征研究. 徐州: 中国矿业大学.
	Li R J. 2017. Study on aesthetic characteristics of individual trees in Xuzhou City based on the public cognition. Xuzhou: China Mining University. ［in Chinese］
	刘叔成, 夏之放, 楼昔勇. 2010. 美学基本原理(第4版). 上海: 上海人民出版社.
	Liu S C, Xia Z F, Lou X Y. 2010. Basic principles of aesthetics (The fourth edition). Shanghai: Shanghai People’s Publishing House. ［in Chinese］
	刘思宇. 2023. 基于外部形态特征的长春市黄檗行道树单木美景度评价技术研究. 长春: 吉林农业大学.
	Liu S Y. 2023. Research on single-tree scenic evaluation technology of Phellodendron amurense road trees in Changchun City based on external morphological features. Changchun: Jilin Agricultural University. ［in Chinese］
	毛　斌, 彭立群, 李　乐, 等. 侧柏风景林美景度的林内色彩斑块非线性模型研究. 北京林业大学学报, 2015, 37 (7): 68- 75.
	Mao B, Peng L Q, Li L, et al. Non-linear scenic beauty model of scenic Platycladus orientalis plantations based on in-forest color patche. Journal of Beijing Forestry University, 2015, 37 (7): 68- 75.
	毛　斌, 徐程扬, 李　乐, 等. 人工油松风景林的林木分级技术. 林业科学, 2014, 50 (10): 49- 58.
	Mao B, Xu C Y, Li L, et al. Tree classification for Pinus tabulaeformis scenic plantation. Scientia Silvae Sinicae, 2014, 50 (10): 49- 58.
	孟宪宇. 2006. 测树学(第三版). 北京: 中国林业出版社.
	Meng X Y. 2006. Forest measurement (the third edition). Beijing: China Forestry Publishing House. ［in Chinese］
	欧阳勋志, 廖为明, 彭世揆. 天然阔叶林景观质量评价及其垂直结构优化技术. 应用生态学报, 2007, 18 (6): 1388- 1392.
	Ouyang X Z, Liao W M, Peng S K. Landscape quality evaluation and vertical structure optimization of natural broad leaf forest. Chinese Journal of Applied Ecology, 2007, 18 (6): 1388- 1392.
	孙姝亭, 陈美谕, 李　苹, 等. 北京市居民小区景观林林内景观质量评价研究. 西北林学院学报, 2016, 31 (5): 297- 305.
	Sun S T, Chen M Y, Li P, et al. Assessment on in-forest quality of landscape forest in residential area in Beijing. Journal of Northwest Forestry University, 2016, 31 (5): 297- 305.
	吴　鞠, 陈　瑜, 刘海轩, 等. 林分密度及混交度对长白山天然风景林树木形态的影响. 林业科学, 2018, 54 (12): 12- 21.
	Wu J, Chen Y, Liu H X, et al. Effects of stand density and mingling intensity on tree morphology in natural scenic forest in Changbai Mountain. Scientia Silvae Sinicae, 2018, 54 (12): 12- 21.
	薛永鑫, 南晓凡, 李献文, 等. 2024. 邻体竞争对城市森林微景观中针叶树视觉形态性状的影响. 生态学报, 44(11): 1-12.
	Xue Y X, Nan X F, Li X W, et al. 2024. Effects of neighborhood competition on visual morphological traits of coniferous trees in fine-scale landscapes of urban forests. Acta Ecologica Sinica, 44(11): 4758-4769. ［in Chinese］
	杨会娟, 于　泊, 车晓雨, 等. 塞罕坝机械林场林内景观质量评价研究. 林业资源管理, 2016, (3): 98- 103, 111.
	Yang H J, Yu B, Che X Y, et al. Study on scenic beauty of forest interior landscape in Saihanba Mechanized Forest Farm. Forest Resources Management, 2016, (3): 98- 103, 111.
	章志都. 2010. 京郊低山风景游憩林质量评价及调控关键技术研究. 北京: 北京林业大学.
	Zhang Z D. 2010. Quality assessing and key adjusting technologies for scenic-recreational forests in the lower mountains of suburban in Beijing. Beijing: Beijing Forestry University. ［in Chinese］
	周武忠. 2011. 园林景观美学(全国高等农林院校“十三五”规划教材). 北京: 中国农业出版社.
	Zhou W Z. 2011. Landscape aesthetics (13^th five-year plan textbook for national agricultural and forestry colleges). Beijing: China Agricultural Press. ［in Chinese］
	Ahmed S, Hilmers T, Uhl E, et al. Neighborhood competition modulates the link between crown structure and tree ring variability in monospecific and mixed forest stands. Forest Ecology and Management, 2024, 560, 121839. doi: 10.1016/j.foreco.2024.121839
	Ali A. Forest stand structure and functioning: current knowledge and future challenges. Ecological Indicators, 2019, 98, 665- 677. doi: 10.1016/j.ecolind.2018.11.017
	Ali A, Yan E R, Chen H Y H, et al. Stand structural diversity rather than species diversity enhances aboveground carbon storage in secondary subtropical forests in Eastern China. Biogeosciences, 2016, 13 (16): 4627- 4635. doi: 10.5194/bg-13-4627-2016
	Bartkowicz L, Paluch J. Morphological plasticity of six tree species with different light demands growing in multi-layered deciduous forests in Central Europe. European Journal of Forest Research, 2023, 142, 1177- 1195. doi: 10.1007/s10342-023-01584-7
	Bele A, Chakradeo U. Public perception of biodiversity: a literature review of its role in urban green spaces. Journal of Landscape Ecology, 2021, 14 (2): 1- 28. doi: 10.2478/jlecol-2021-0008
	Bruce H R, Buhyoff G J. The scenic beauty temporal distribution method: an attempt to make scenic beauty assessments compatible with forest planning efforts. Forest Science, 1986, 32 (2): 271- 286. doi: 10.1093/forestscience/32.2.271
	Cao Y J, Zhu J Y, Xu C Y, et al. Responses of visual forms to neighboring competition: a structural equation model for Cotinus coggygria var. cinerea Engl. Forests, 2021, 12 (8): 1073. doi: 10.3390/f12081073
	Carrillo-Angeles I G, Queijeiro-Bolaños M E, Malda-Barrera G X, et al. Aesthetic growth of a native tree species with desirable characteristics for urban green areas in arid and semiarid environments. Urban Forestry & Urban Greening, 2018, 33, 13- 15.
	Coverdale T C, Davies A B. Unravelling the relationship between plant diversity and vegetation structural complexity: a review and theoretical framework. Journal of Ecology, 2023, 111, 1378- 1395. doi: 10.1111/1365-2745.14068
	Forrester D I. Linking forest growth with stand structure: tree size inequality, tree growth or resource partitioning and the asymmetry of competition. Forest Ecology and Management, 2019, 447, 139- 157. doi: 10.1016/j.foreco.2019.05.053
	Guo P P, Su Y B, Wan W X, et al. Urban plant diversity in relation to land use types in built-up areas of Beijing. Chinese Geographical Science, 2018, 28, 100- 110. doi: 10.1007/s11769-018-0934-x
	Hao D Y. 2008. Content extraction, analysis, and retrieval for plant visual traits studies. Columbia: University of Missouri Columbia, USA.
	Hofmann M, Gerstenberg T, Gillner S. Predicting tree preferences from visible tree characteristics. European Journal of Forest Research, 2017, 136, 421- 432. doi: 10.1007/s10342-017-1042-7
	Jankovska I, Straupe I, Brumelis G, et al. Urban forests of Riga, Latvia-Pressures naturalness, attitudes and management. Baltic Forestry, 2014, 20 (2): 342- 351.
	Liu C, Wang T Y, Yuizono T. Assessing the landscape visual quality of urban green spaces with multidimensional visual indicators. Urban Forestry & Urban Greening, 2025, 106, 128727.
	Mao B, Gong L, Xu C Y. Evaluating the scenic beauty of individual trees: a case study using a nonlinear model for a Pinus tabulaeformis scenic forest in Beijing, China. Forests, 2015, 6 (6): 1933- 1948. doi: 10.3390/f6061933
	Magurran A E, Phillip D A. Implications of species loss in freshwater fish assemblages. Ecography, 2001, 24 (6): 645- 650. doi: 10.1111/j.1600-0587.2001.tb00526.x
	Nelson T, Johnson T, Strong M, et al. Perception of tree canopy. Journal of Environmental Psychology, 2001, 21, 315- 324. doi: 10.1006/jevp.2001.0223
	Penanhoat A, Ramirez N G, Aubry-Kientz M, et al. Effect of competition intensity and neighbor identity on architectural traits of Fagus sylvatica. Trees, 2024, 38, 1177- 1187. doi: 10.1007/s00468-024-02544-3
	Perles-Garcia M D, Kunz M, Fichtner A, et al. Neighbourhood species richness reduces crown asymmetry of subtropical trees in sloping terrain. Remote Sensing, 2022, 14, 1441. doi: 10.3390/rs14061441
	Qi J, Lin E S, Tan P Y, et al. Development and application of 3D spatial metrics using point clouds for landscape visual quality assessment. Landscape and Urban Planning, 2022, 228, 104585. doi: 10.1016/j.landurbplan.2022.104585
	Qi Z X, Duan J, Su H Y, et al. Using crowdsourcing images to assess visual quality of urban landscapes: a case study of Xiamen Island. Ecological Indicators, 2023, 154, 110793. doi: 10.1016/j.ecolind.2023.110793
	Trogisch S, Liuc X, Rutten G, et al. The significance of tree-tree interactions for forest ecosystem functioning. Basic and Applied Ecology, 2021, 55, 33- 52. doi: 10.1016/j.baae.2021.02.003
	Uria-Diez J, Pommerening A. Crown plasticity in Scots pine (Pinus sylvestris L.) as a strategy of adaptation to competition and environmental factors. Ecological Modelling, 2017, 356, 117- 126. doi: 10.1016/j.ecolmodel.2017.03.018
	Zhao J W, Xu W Y, Li R J. Visual preference of trees: the effects of tree attributes and seasons. Urban Forestry & Urban Greening, 2017, 25, 19- 25.

视觉形态性状指标 Visually morphological trait indicators	计算公式 Formula	含义 Description
偏冠度Crown asymmetry degree（C_AD）	$ C_{\mathrm{AD}}=\max\left(\dfrac{\mathrm{\mathit{W}_e}}{\mathrm{\mathit{W}_w}}；\dfrac{\mathrm{\mathit{W}_w}}{\mathrm{\mathit{W}_e}}；\dfrac{\mathrm{\mathit{W}_n}}{\mathrm{\mathit{W}_s}}；\dfrac{\mathrm{\mathit{W}_s}}{\mathrm{\mathit{W}_n}}\right) $	树冠半径偏离树木中心线（以树干基部点为准的垂直线）的最大程度。The maximum deviation of the crown radius from the vertical axis of the stem， referenced at the stem base.
树冠圆满度Crown round degree（C_RD）	$ {C_{{\mathrm{RD}}}} = {{{\mathrm{CW}}} \mathord{\left/ {\vphantom {{CW} {CL}}} \right. } {{\mathrm{CL}}}} $	反映树木冠幅和树冠长度之间的比例关系。该值越小，树冠越窄；该值越大，树冠越倾向于扁平。This metric reflects the proportional relationship between crown width and crown length. A smaller value indicates a narrower crown， whereas a larger value suggests a flatter， more spread-out crown shape.
树冠伸展度Crown extension rate（C_ER）	$ {C_{{\mathrm{ER}}}} = {{{\mathrm{CW}}} \mathord{\left/ {\vphantom {{CW} {TH}}} \right. } {{\mathrm{TH}}}} $	树冠直径与树高的协调程度。该值越大，表明树冠占有水平空间越多，侧方受挤压程度越小；该值越小，树冠水平方向生长受抑制越大，树冠越纤细。This metric quantifies the coordination between tree crown diameter and tree height. Higher values indicate greater horizontal space occupation by the crown and less lateral compression， whereas lower values suggest stronger suppression of horizontal crown expansion， resulting in a more slender crown form.

指标类型 Indicator type	指标名称 Indicator name	Axis1	Axis2	Axis3
林分物理结构指标 Stand physical structure indicators	每公顷胸高断面积Basal area per hectare（G）	0.601	0.624	0.130
	平均树高Mean tree height（$ \bar {H} $）	0.775	0.230	0.359
	平均胸径Mean diameter at breast height（$ \bar {D} $）	0.923	0.096	?0.044
	胸径多样性Diameter class diversity（H_DBH）	0.119	0.921	0.235
	树高多样性Tree height diversity（H_TH）	0.105	0.224	0.952

林分物种组成指标 Stand species composition indicators	Margalef物种丰富度Margalef species richness index（S_R）	0.906	0.134
	Shannon-Wiener多样性指数Shannon–Wiener diversity index（H）	0.943	0.125
	Pielou均匀度指数Pielou’s evenness index（E）	0.794	0.317
	Berger-Parker优势度指数Berger–Parker dominance index（D_BP）	?0.507	0.695

指标类型Type of indicators	指标名称Indicator name	平均值±标准差 Mean±SD	数值范围 Range of values	变异系数 Coefficient of variation（%）
林分物理结构 Forest stand physical structure	林分断面积Stand basil area（G）	9.49±8.61	0.13～61	90.80
	平均树高Mean tree height（$ \bar {H} $）	9.79±3.72	1.7～21.07	37.94
	平均胸径Mean diameter at breast height（$ \bar {D} $）	24.9±11.11	8.02～81.8	44.62
	树高多样性指数Tree height diversity（H_TH）	1.09±0.48	0～2.09	44.24
	胸径多样性指数Diameter class diversity（H_DBH）	1.77±0.55	0～2.61	31.15

物种组成结构 Species composition structure	Margalef丰富度Margalef species richness（S_R）	0.86±0.77	0～4.97	89.69
	Shannon-Wiener指数Shannon–Wiener index（H）	0.81±0.57	0～2.75	70.96
	Pielou均匀度Pielou’s evenness（E）	0.64±0.35	0～1	55.03
	Berger-Parker优势度Berger–Parker dominance （D_BP）	0.64±0.24	0.12～1	37.95

视觉形态性状 Visual morphological traits	偏冠度Crown asymmetry degree（C_AD）	1.95±0.97	1.16，6.29	49.75
	树冠圆满度Crown round degree（C_RD）	1.19±0.46	0.41，3.91	38.85
	树冠伸展度Crown extension rate（C_ER）	0.73±0.39	0.28，4.38	53.51

[1]	孙云浩,程南洋,沈文星. 长三角地区城市森林建设的空间关联及影响因素分析[J]. 林业科学, 2024, 60(5): 177-190.
[2]	刘鸣,乌尔里希·皮特扎卡,安德烈亚斯·罗洛夫,张德顺. 不同生境中多树种生长对干旱胁迫的敏感性评价——以德国萨克森州为例[J]. 林业科学, 2023, 59(11): 12-22.
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[5]	郝泽周,王成,裴男才,徐心慧,张昶,段文军,王子研. 深圳3处典型城市森林的春季生物声景多样性[J]. 林业科学, 2020, 56(2): 184-192.
[6]	刘海轩, 许丽娟, 吴鞠, 徐程扬. 城市森林降温效应影响因素研究进展[J]. 林业科学, 2019, 55(4): 144-151.
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[12]	朱耀军;王成;贾宝全;粟娟. 基于树冠覆盖的广州市中心区绿化格局分析[J]. 林业科学, 2011, 47(7): 65-72.
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[14]	康文星吴耀兴;何介南郭清和王卫文. 城市森林生态系统服务价值指标体系与评价方法[J]. 林业科学, 2008, 44(12): 129-134.
[15]	吴际友王旭军廖德志程勇侯伯鑫何才生. 冰冻雨雪灾害中城市森林抗雪压特性及评价[J]. 林业科学, 2008, 44(11): 59-64.