摘要: 目的深入剖析林分空间结构参数4元分布的生态意义，构筑基于相邻木关系的林分空间结构多样性综合评价指数，为制订有的放矢的森林结构调整策略提供理论依据、�/sec> 方法基于生物多样性概念，以参照树与其最近的4株相邻木组成的结构单元为对象，有机整合结构参数角尺度、混交度、大小比数和密集度的4元分布及结构单元树种数和林层数，运用遗传绝对距离公式、自然对数分别表达结构单元类型均匀性和丰富度，构造表达林分空间结构多样性测度指数，并运用长期定位监测样地数据进行验证、�/sec> 结果运用本研究提出的林分空间结构多样性指数（FSD）对处于不同气候带或不同起源的森林类型的空间结构多样性测度表明，锐齿栎天然林的FSD值（0.854）与阔叶红松林的FSD值（0.852）几乎相等，二者具有相似的空间结构多样性。侧柏人工林结构参数4元分布类型较多，高于锐齿栎天然林和红松阔叶林，但其空间结构多样性为3个林分类型中最低的（FSD = 0.382），主要原因是其垂直结构（FSD _v= 0.369）和水平结构（FSD _h= 0.562）多样性方面都比两类天然林低。结构单元中的平均树种数表现为天然林高于人工林，锐齿栎天然林�?.23，阔叶红松天然林�?.09，而侧柏人工林则为1.98，结构单元树种数能充分体现结构单元树种丰富程度、�/sec> 结论林分空间结构参数4元分布、结构单元树种数和林层数三者的有机整合是构造有效的林分空间结构多样性指数的基石。基于生物多样性概念提出的林分空间结构多样性指数FSD，既是对结构参数4元分布合适的量化表达，也是对结构参数4元分布生态意义恰当的诠释，更是对林分空间结构多样性的科学综合评价，能够测度出不同林分类型林分空间结构多样性的差异、�/sec>

关键诌�
• 林分空间结构/
• 结构参数N元分市�/a> /
• 结构单元树种�?/a> /
• 结构单元林层�?/a> /
• 林分空间结构多样�?/a>

Abstract: ObjectiveThe ecological significance of 4-variate distribution of stand spatial structure parameters was deeply analyzed and a comprehensive evaluation index of stand spatial structure diversity based on the relationship between adjacent trees was constructed to provide a theoretical basis for formulating targeted forest structure adjustment strategies. MethodBased on the concept of biodiversity, taking the structural unit which composed by reference tree and its nearest four adjacent trees as the object, organically integrate the 4-variate distribution of structural parameters of uniform angle index, mingling, neighborhood comparison and crowding, as well as the number of structural unit trees and forest layers, the genetic absolute distance formula and natural logarithm are used to express the evenness and richness of structural unit types, respectively, and the stand spatial structure diversity index was constructed. The validity of the index was verified by using the long-term positioning monitoring sample plot data ResultUsed the stand spatial structure diversity index (FSD) proposed in this study to measure the spatial structure diversity of forest types in different climatic zones or different origins show that the FSD values of Quercus alienavar. acutiserratanatural forest (0.854) and broad-leaved Pinus koraiensisforest (0.852) were almost the same, indicating that the two forest stands have similar spatial structural diversity. The 4-variate distribution types of Platycladus orientalisplantation was higher than other natural forest, however, its spatial structural diversity (FSD = 0.382) was the lowest in the three stand types, mainly due to its lower diversity in both vertical (FSD _v= 0.369) and horizontal (FSD _h= 0.562) structure than the two natural forest stands. The average number of tree species in the structural units was higher in natural forest than in plantation, with 4.23 in Quercus alienavar . acutiserrataforest, 4.09 in Pinus koraiensisforest, and 1.98 in Platycladus orientalisplantation. The number of tree species in a structural unit fully demonstrate species richness of the structural unit. ConclusionThe integration of the three numbers including 4-variate distribution of stand spatial structure parameters, the number of tree species and number of forest layers in structure unit, lays the foundation for constructing a valid spatial structure diversity index for forest stands. The stand spatial structural diversity index (FSD), based on the concept of biodiversity, is not only a feasible quantitative expression of the 4-variate distribution of structural parameters, but also is an appropriate interpretation of the ecological significance of the 4-variate distribution of structural parameters, and a comprehensive scientific evaluation of the spatial structural diversity of the stand. The index is able to measure the difference of stand spatial structure diversity of different stand types.

Key words:
• stand spatial structure/
• 4-variate distribution of structural parameters/
• number of tree species in structural units/
• number of stand layers in structural units/
• stand spatial structural diversity

�?nbsp; 1林木分布国�/p>

x,y代表样地的边长。圆圈的不同颜色代表树种，圆圈大小代表林木的相对大小；外框为样地大小，内框为分析区，外框与内框之间为缓冲区。x. y represents the side length of the sample plot respectively. The different colors of circles represent tree species, and the size of circles represents the relative size of trees; The outer frame is the sample plot size, the inner frame is the analysis area, and the buffer area is between the outer frame and the inner frame.

Figure 1.The distribution of trees

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�?nbsp; 2林分空间结构单元

i代表结构单元中的参照树，1�?�?�?分别代表参照树最近的4株相邻木、�i>irepresents the reference tree in the structural unit, and 1, 2, 3, and 4 represent the nearest four adjacent trees of the reference tree respectively、�/p>

Figure 2.Forest stand spatial structural unit

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�?nbsp; 3锐齿栎天然林结构参数四元分布

Figure 3.Quadrivariate distribution ofQuercus alienavar.acuteserratanatural forest

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�?nbsp; 4阔叶红松林结构参数四元分市�/p>

Figure 4.Quadrivariate distribution of broad-leavedPinus koraiensisforest

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�?nbsp; 5侧柏人工林结构参数四元分市�/p>

Figure 5.Quadrivariate distribution ofPlatycladus orientalisplantation

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 1林分概况

Table 1.Forest stand overview

样地代号 Sample plot code	林分类型 Forest type	样地位置	树种�?br/>Tree species	林层�?br/>Number of layers	林分断面�? (m2·hm�?) Basal area/ (m2·ha�?)	平均胸径 Mean DBH/cm	优势木高 Height of dominant trees/m	冠幅直径 Crown Diameter/m	密度/ (株·hm�?) Density/ (tree·ha�?)
A	锐齿栎天然林 Quercus alienavar. acutiserratanatural forest	甘肃小陇山百花林圹�br/> Baihua forest farm of Xiaolongshan, Gansu	33	2.7	26.91	18.5	16.1	3.98	1 006
B	红松阔叶枖�br/> BroadleavedPinus koraiensisforest	吉林蛟河东大坠�br/> Dongdapo of Jiaohe, Jilin	22	2.8	28.07	21.6	18.4	6.06	766
C	侧柏人工枖�br/>Platycladus orientalisplantation	北京九龙屰�br/> Jiulongshan Beijing	8	1.5	20.38	10.4	11.3	2.67	2 388

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�?nbsp; 2结构单元树种数及其占毓�/p>

Table 2.Number and percentage of tree species in structural units

结构单元 Structural units		红松阔叶枖�br/>BroadleavedPinus koraiensisforest			锐齿栎天然林 Quercus alienavar.acutiserratanatural forests			侧柏人工枖�br/>Platycladus orientalisplantation
树种�?br/>No. of tree species		结构单元�?br/>No. of structural units	结构单元比例 Percentage of structural units		结构单元�?br/>No. of structural units	结构单元比例 Percentage of structural units/%		结构单元�?br/>No. of structural units	结构单元比例 Percentage of structural units/%
1		17	2.62%		5	1.59		182	50.56
2		42	6.48%		9	2.86		84	23.33
3		88	13.58%		42	13.33		38	10.56
4		219	33.80%		112	35.56		32	8.89
5		282	43.52%		147	46.67		24	6.67
结构单元平均树种�?br/>Average number of trees species of structural unit		4.09			4.23			1.98

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�?nbsp; 3林分水平空间结构多样性评价指栆�/p>

Table 3.Indices of stand spatial structure evaluation

林分类型	结构单元类型 Type of structural unit (Ns)	结构单元平均种数 Average number of structural units ($ \bar s $)	结构单元林层数均� Average number of forest layers of structural unit ($ {\overline {Nc} } $)	结构单元均匀� Uniformity of structural unit (NSE)	结构单元丰富� Richness of structural unit (NSR)	结构单元树种丰富� Tree species richness of structural unit (SSR)	水平结构多样� Diversity of horizontal structure (FSDh)	垂直结构多样� Diversity of Vertical structural (FSDv)	林分空间结构多样� Stand spatial structural diversity (FSD)	林分空间结构多样性等� Grade of stand spatial structure diversity
锐齿栎天然林Quercus alienavar.acutiserratanatural forest	130	4.23	2.7	0.669	0.756	0.896	0.805	0.904	0.854	非常奼�br/>Very good
红松阔叶� Broad-leavedPinus koraiensisforest	129	4.09	2.8	0.558	0.755	0.875	0.766	0.937	0.852	非常奼�br/>Very good
侧柏人工�Platycladus orientalisplantation	134	1.98	1.5	0.641	0.761	0.424	0.562	0.369	0.382	较差 Inferior

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