测树学实验指导及材料.docx

1、测树学实验指导及材料测树学实验指导及材料实习二 单木材积测定一、目的 掌握中央断面、平均断面求积式及区分求积式测算树干材积的方法。 二、仪器与材料 实习仪器为计算机，材料为各部位直径测定的样木汇总表(见表2-1)。表2-1 样木各部位直径高度(m)00.511.31.522.533.5直径(cm)17.116.315.714.914.513.613.113.112.8高度(m)44.555.566.577.58直径(cm)12.512.211.911.611.210.810.410.19.8高度(m)8.28.599.51010.51111.512直径(cm)9.79.69.398.88.58

2、.27.87.4高度(m)12.51313.51414.51515.51616.4直径(cm)7.16.56.15.24.542.91.10三、方法步骤（一）简单求积式1、平均断面积近似求积式将树干当作截顶抛物线体，小头直径为dn，大头直径为d0，木段长L，则材积V为：2、中央断面积近似求积式 式中：d1/2为中央直径.。（二）区分求积式将树干区分成若干等长或不等长的区分段，分别用简单求积式测算各分段材积，再把各段材积合计可得全树干材积该法称为区分求积法（区分段个数在5段以上）。在树干的区分求积中，梢端不足一个区分段的部分视为梢头，用圆锥体公式计算其材积。式中：梢头底端断面积；一梢头长度。 在

3、区分求积法中，常见的有中央断面区分求积式和平均断面区分求积式。2米为一个区分段长度计算实例如下表所示。表2-2 中央断面区分求积式实例胸径:20.3树高:13.6梢头木长度:1.6断面高(m)直径(cm)各区分段材积1200.0628318.80.0555515.90.0397713.70.0295912.40.0241118.50.0113126.1梢头木材积0.0016树干材积0.2245表2-3 平均断面区分求积式实例胸径:20树高:12.5梢头木长度:0.5断面高(m)直径(cm)各区分段材积022.6218.50.1339415.60.0919613.40.066489.90.043

4、6105.70.02051240.0076梢头木材积0.0002树干材积0.3642 利用表2-1 样木各部位直径材料，以1米和2米为一个区分段长度，分别用简单求积式和区分求积式测定树干材积，并计算胸高形数、实验形数和胸高形率。四、实习报告 实习报告包括上述各种方法计算结果，主要内容如下：1用中央断面区分求积式计算材积（各区分段长度取1米）；2用中央断面区分求积式计算材积（各区分段长度取2米）；3用平均断面区分求积式计算材积（各区分段长度取1米）；4用平均断面区分求积式计算材积（各区分段长度2米）；5胸高形数和实验形数（各区分段长度取1米用中央断面区分求积式计算的材积）；6胸高形率。实习三 树

5、高曲线模型研制一、目的 掌握数据法树高曲线模型研制技术，为研制其他模型如材积表的编制奠定基础。二、仪器与材料 实习仪器为计算机，材料为胸径树高测定数据，见表3-1，发邮件提供电子版实习材料。表3-1 胸径树高测定值样木号胸径树高样木号胸径树高样木号胸径树高样木号胸径树高1136.93918.112.47712.910.811524.419.72137.4401612.27813.79.611621.9193147.94116.411.6791411.511721.417.841310.84218.914.88013.910.411810.811513.211.24318.914.78113.7

6、9.911922.821.8613.210.94419.114.48212.39.81202322.7722.918.5452417.78326.22212122.723816.912.94624.117.88421.817.91228.99.191814.14724.117.68520.117.61237.97.91016.211.54811.38.88618.615.512425.710.11114.110.74912.610.98725.520.91251913.91215.212.85012.58.58823.916.612617.113.81312.810.95127.121.789

7、21.216.612712.58.61418.916.1522521.89023.518.812813.510.7151813.35327.621.19119.516.212914.39.9161914.95421.916.89214.810.213019.113.71723.314.95521.715.59314.610.21311813.71822.315.15619.213.79415.710.113215.7141919.512.5571411.49513.910.513317.7142014.811.25817.312.69618.116.213418.217.72113.79.95

8、917.512.39713.713.713516.415221513.36019.414.79812.88.213616.914.42315.211.56124.715.39919.114.713712.710.42415.512.1622014.110014.512.213812.19.82515.211.96313.18.8101149.613913.110.22611.610.16413.18.61021711.814024.118.3271212.16514.710.510313.210.314126.6202811.810.56633.918.410410.67.814227.420

9、.12921.220.36730.220.410512.88.21431610.63016.414.96826.119.110612.68.514423.218.13117.414.26940.322.610714.69.414516.612.43216.913703622.510811.210.414616.112.13316.313.87137.822.610911.69.714714.111.73416.212.7722417.211011.310.51481612.93516.212.47328.619.911110.98.614918.114.13622.320.17432.321.

10、4112119.415018.915.2372318.9753423.61131110.215120.114.33818.514.67631.426.711420.515.315217.615.3三、方法步骤 树木的树高生长与胸径生长之间存在着密切的关系，一般的规律为：树高随胸径的增大而增加，两者之间的关系常用树高一胸径曲线表示，把反映树高随胸径变化的曲线称为树高曲线。以胸径为自变量，树高为因变量建立的模型称为树高曲线模型。（一）、备选方程 胸径与树高的关系通常为非线性的，描述二者之间关系的方程很多，不同方程表达程度不尽相同，甚至差别很大。为了得到理想的树高曲线模型，本次实习采用多方程对比选优

11、法建模，用于拟合对比的备选方程如下表所示。其中：Y为树高，X为胸径，a、b、c为待定参数，用最小二乘法估计。表3-2 胸径与树高关系的备选方程方程号表达式1Y=a+bX2Y=aXb3Y=a+b/X41/Y=a+bX51/y=a+b/X6Y=aebx7Y=aeb/x8Y=a+bLnX9Y=a+bX+cX2101/Y=a+b/X+c/X211lnY=a+bX+c(lnX)212lnY=a+blnX+c(lnX)213lnY=a+blnX+c(lnX)214lnY=a+bX+c(lnX)15lnY=a+b/X+c/X2（二）、评价指标反映回归方程的拟合效果的常用指标为相关系数，为保证应用建模精度，有

12、必要再增加平均系统误差（S，简称系统误差）和平均相对误差（P，简称平均误差）作为评价指标，计算公式为：S= （1）P= （2）式中：、分别为树高实际值和用模型算出的理论值，n为样本数。（三）、分析评价 筛选方程时，相关系数越大越好，系统误差和平均误差越小越好，根据这三个指标对备选方程进行综合评价，选出最优树高曲线模型。四、实习报告 实习报告主要内容：1、胸径与树高关系的备选方程（表3-1）2、列出评价指标公式；3、树高曲线模型建模结果（表3-3）；4、写出分析评价过程及筛选出的最优树高曲线模型。表3-3 树高曲线模型建模结果方程号abc相关系数系统误差平均误差12345678910111213

13、1415实习四 二元材积表编制一、目的 掌握二元材积表编制技术，了解论文撰写方法。二、仪器与材料 实习仪器为计算机，材料为样木的胸径、树高、材积测定数据（见表4-1），发邮件提供电子版实习材料。表4-1 二元材积表编制样木材料序号胸径树高材积序号胸径树高材积序号胸径树高材积序号胸径树高材积16.670.00275214.9120.034310320.214.50.054815422.215.80.078727.29.30.00325316.111.50.034410421.616.90.05515523.418.80.079837.77.70.0065415.214.30.034810520.

14、113.90.05531563017.90.081148.49.70.00615517.815.30.035210619.314.90.055615721.418.30.081259.69.10.00775620.716.20.035610718.513.50.056115821.616.20.082361680.00775716.511.60.035810823.919.20.056215924.3160.0842710.29.50.01045817.213.40.036310920.415.50.056216021.219.80.0854810.59.50.01055924.615.60.

15、036411022.115.80.056316123.516.50.085791880.01096015.811.60.036811122.316.60.056916225.715.40.086410188.50.01096117.914.60.036911225.721.40.056916332.919.40.08691112.911.40.01186217.812.80.037311324.217.60.057316427.418.50.08871212.190.01196316.312.20.03751142417.50.057616527.718.80.089613187.50.012

16、56422.115.60.038411520.3170.058516625.719.80.09021411.510.80.01296517.512.50.038511623.318.10.058916728.525.50.090915208.50.01466623.513.50.04111722.316.50.060916826.9190.0931161210.60.01566717.415.50.041411820.317.30.061616924.416.80.0935172080.0168681814.50.042311927.615.50.062317029.1250.10071810

17、.410.20.01716925.516.40.042812023.217.80.062617122.115.50.1011914.111.20.01757025.815.90.043112119.3140.063117230.221.40.1028201211.60.0187119.813.50.043212224.418.40.063117323.7200.10542115.810.50.01937218.114.20.044112326.116.70.064217430.321.60.10612214.113.20.01977319.814.70.044512426.818.90.064

18、517531.225.80.106223208.50.0217421.219.10.045312522.2140.064817624.716.30.10752413.5100.02177525.816.80.045512623.313.60.065117729.123.80.10812514.312.60.02297618.815.50.045812721.2130.066717827.4220.11112612.69.50.02367717.413.60.046412820.814.40.06717927.217.30.11172714.1120.02417816.312.80.046612

19、926.917.50.067418025.8190.11212813.9110.02427916.214.30.046913021.7150.068218133.117.10.11662914.511.60.02498019.514.60.047213120.117.20.069318232.621.50.11813016.5130.02548124.416.10.047413223.717.80.070218336.323.70.12013112.911.30.02598226.317.20.047513323.817.50.070618431.122.10.12023216.212.90.

20、02688318.414.40.047813424.624.60.071118533.916.60.12213316.3180.02738418.115.30.04813521.718.20.071218631.3170.1221341412.80.02748521.9200.048213626.926.80.071318728.920.50.13043516.210.50.02798620.512.50.048313727.419.80.071818831.824.50.13213616.614.10.02838724.116.20.048613822.916.50.072118925.52

21、10.13583715.7120.02858821.414.70.048713930.818.20.072119030.520.60.13633816.912.70.038922.3210.048714025.918.40.072919136.322.80.14783916.614.80.03019018.214.20.048914123.717.80.07321922821.50.15084014.711.40.0305912216.60.04951422615.70.074619333.318.30.1513411411.70.03079220.917.50.049614322.9190.

22、074719430.6170.1524215.811.60.03079319.616.20.049814426.320.40.07519530.1220.15434313.3120.03089418.4140.05081452422.50.075219626.122.60.1574416.5150.03189518.6150.05114622.5160.075919735.6250.17474519.610.80.03229618.713.50.051314726.318.50.076119836.426.40.17934619.714.20.03269721.714.70.053514822.116.70.076419937.823.70.18414717.414.70.0329981812.80.053514926.418.50.076520032.926.70.19024815.711.3