胸径

BP模型在单木树高与胸径生长模拟中的应用

Application of BP Neural Network Model to the Simulation of Breast-height Diameter and Tree-height Growth

BP神经网络在林分平均胸径生长预估中的应用

Application of Back-Propagation Network to the Prediction of Stand Average Breast Diameter in Growth Progress

杉木人工林胸径的Weibull分布及其最优拟合研究

A Study on Weibull D.B.H. Distribution of Chinese fir Plantation and its Optimal Fitting

施肥处理的肥效指数达到286～1417，树高、胸径生长对P、N肥反应敏感；

The index of fertilizing effect of these treatments reached 2.86 ~ 14.17 . The growth of height , and basal diameter of Azadirachta indica young plantation were sensitive to P and N.

F3的平均树高只有7.22m，平均胸径更小（3.97cm），表现出明显的生长不正常。

On the contrary , the average height in the forest F2 was only 7.22 m and average diameter was even smaller ( 3.97 cm ) .

以湿地松人工林为研究对象，通过临时标准地调查测得4942株林木胸径（D）、冠径（E）；

The diameter ( D ) and crown ( E ) of 4 942 sample trees of Pinus elliottii collected from temporary sample plots was surveyed in this paper .

本文提出改进校正的方法。（10）空间分布格局的三种MonteCarlo检验方法中，基于最大胸径的MonteCarlo检验法较好。

( 10 ) Among three kinds of Monte Carlo test methods for spatial pattern , the one based on largest DBH is the best .

GM平均胸径还与坡位正相关；GM数量沿N→S的坡向梯度减少，而随坡度增大及坡形由凹转凸而增加；

The number of GM decreased as the slope exposure turned from N to S , as slope increased , and as slope shape turned from convex to concave .

林木胸径生长与土壤脲酶、微生物量C、有机C和PH呈极显著相关，土壤蛋白酶、过氧化氢酶和蔗糖酶与土壤PH值呈显著或极显著相关。

Soil PH with protease enzyme 、 catalase enzyme 、 invertase enzyme had very significant or significant correlation . The DBH with soil urea enzyme 、 MB-C 、 SOC and PH all had significant correlation .

地形要素对林隙高度和GM平均胸径的空间格局的贡献最大，分别达到75.9%和67.0%。

The contribution of topography induced variation is largest for the spatial variation of gap height and the average DBH of gap makers ( 75.9 % and 67.0 % respectively ) .

滇中云南松胸径和树高生长的GAM模型

GAM Model for Diameter and Height Growth of Pinus yunnanensis in Middle Regions of Yunnan Province

由预测产生的相对误差的大小，将原始数据划分为4种状态，分别写出胸径、树高、材积的四步概率转移矩阵p（i），建立灰色&马尔柯夫预测模型。

The original data were divided into 4 types according to the value of relative error , at the same time , transition probability matrix on DBH , tree height , volume was expressed respectively , the Grey-Markov forecasting model was also founded .

影响秆重的主要因子是年龄x1、壁厚x2、胸径x3和立竹密度x8，它们的因子负荷量均在50%以上。

The factors impacting on the stem weight are age ( x1 ), thick of stem ( x2 ), chest diameter ( x3 ) and density ( xs ) and their factor loadings are more than 50 % .

Weibull分布参数辨识改进及对浙江毛竹林胸径年龄分布的测度

The algorithm update of Weibull Distribution parametric identification and its application on measuring the distribution of diameter and age of Moso bamboo forests in Zhejiang Province , China

山杨根蘖苗稳定期指标是苗高2m，胸径1cm以上。

The index of root shoots seedlings in stationary phase is height 2 m , chest diameter 1 cm .

林分密度控制图是按照林分测树因子中的树高（H）、胸径（D）、蓄积（M）与立木密度（N）之间相互关系建立数学模型进行编制的。

The stand density control chart is worked out according to the mathematic model that is established on the basis of the relations between the tree height , diameter breast height , stock of the stand forest-mensuration factors and the stumpage density .

结果表明，长白山阔叶红松林25hm2样地内胸径≥1cm的木本植物共51个种，59158个活的个体。

The results show that there are 51 woody species and 59 158 living individuals .

AT是林分的总胸高断面面积：hB，和dB是抽样算得的具有平均胸高断面面积的树的高度和胸径；

HB and dB are respectively the height and breast diameter of the tree with average breast height cross-sectional areal dw is the average breast height diameter weighted by breast height cross-sectional area ;

但若中下颈部、上纵隔CT检查显示阴性，选择经左胸径路二野淋巴结清扫食管癌根治术，可明显减少术后并发症。

But effective radical operation on esophageal carcinoma through left thoracotomy to dissect lymph nodes in the thoracic and abdominal regions can be chosen when the CT image on the middle-lower cervical and upper mediastinum was negative , by which postoperative complications can be decreased distinctly .

利用Logistic方程对9个黑杨派杨树无性系的11年生林木的树高、胸径和材积的生长规律进行拟合，结果表明：利用Logistic方程拟合效果显著，相关系数皆在0.90以上。

Logistic equation was applied to fit growth rules of height , DBH and volume of 9 poplar clones at the age of 11 , the results showed that the fitting effect is remarkable and correlation coefficient all above 0.90 .

鉴于此，选取5个经验方程进行建模，结果显示，对于胸径和CI、RCI、RC1、RC2间的关系用双曲线和幂函数方程拟合较为适宜。

Thus , modeling by 5 empirical equations showed that using hyperboloid and power function fitting the relationships are quite good .

由此而导致林木生长缓慢，对于10年生赤桉林，F1的平均树高和平均胸径分别为9.46m和8.68cm；

As a result , the trees grew slowly . Take the ten-year-old forest ( Form Eucalyptus camaldulensis ) for example , the average tree height in the forest F1 was 9.46 m and the average diameter at breast height 8.68 cm ;

用Logistic生长方程拟合各解析木数据表明：胸径、树高和材积速生期分别出现在9～12,9～14和15～17年生左右。该林分尚属生长旺盛期。

Based on the DBH , the result from tree hight and timber volume data of analysis tree with Logistic increment equation showed that fast growing stage was 9-12 , 9-14 and 15-17 year-old for DBH , tree hight and timber volume respectively .

林隙特征对各地形因素梯度有显著的响应，其中扩展林隙面积、林隙高度、GM数量、种数以及平均胸径是反映地形影响的敏感指标。

Gap characteristics were shown to respond to gradients of a number of topographic factors : extended gap area , gap height , GM frequency and richness and average diameter at breast height ( DBH ) were all sensitive to the effects of topography .

在海拔600m位置，楠木种群的平均树高与胸径达最大值，楠木生长状况良好，长势旺盛。

At the altitude of 600m , the average height and diameter of Machilus and Phoebe population reach the maximum , where it also grows well and strong . 7 .

第二类（胸径≥20cm与树高≥6m）共1445株，其中大乔木1株、中乔木368株、乔木1076株；

The second category ( DBH ≥ 20cm and H ≥ 6 m ) has 1445 plants making up of one big arbor and 368 middle arbors and 1076 small arbors ;

群落中胸径≥3cm的个体密度为4284株／hm2，密度要比相邻的八宝山山地常绿阔叶林高。

The density of individuals ( DBH ≥ 3 cm ) in the forest was 4 284 / hm 2 , higher than that of the contiguous montane forest in Babaoshan Nature Reserve .

厚朴属于早期速生型树种，树高、胸径和树皮生长高峰期分别为3～10a，4～12a和6～14a。

The high-speed periods of tree height , DBH and rind were 3 ~ 10 , 4 ~ 12 and 6 ~ 14 years respectively .

河岸带森林群落建群种的个体年龄及其胸径关系呈现出显著正线性相关趋势，且其年龄结构沿海拔梯度也均呈现出倒J型分布。

The relationship between the individual age and DBH of the constructive species took on markedly positive linear correlation trend , and the age class structures all took on reversed " J " shape in the riparian forest communities along an altitudinal gradient , too .

合理的林分结构在450丛·hm-2时，丛立竹数为10株左右，胸径4～6cm。

With the optimal stand structure , when the stand density was 450 culms per hectare , the clumping living bamboo should be 10 culms with dbh 4-6 cm .