杨树人工林立木生长量空间相关规律研究

为了使立木胸径测量装置得以用于全林蓄积变化量的动态监测,针对林地内树木代表性样点抽样方法问题,本文提出运用林地立木空间变异函数结合克里格插值的方法进行目标样点抽选.通过对林地实测数据进行分析验证,结果表明该方法有效；通过对立木空间变异函数分析,得出海拔方向是影响立木生长的主要因子,沿海拔方向胸径空间变程是240m,树高变程为360m,说明立木生长量个体间有很好的空间相关性；同时,经过对小于变程的不同参考样点距离进行克里格插值效果验证,得出0.3倍变程为最佳参考样点距离,能使树高预测误差小于2m,胸径预测误差小于1个径级.

STUDIES ON CORRELATION OF POPLAR ARTIFICIAL FOREST INCREMENT SPACE

In order to make the measurement of stumpage DBH(Diameter at breast height) device could be used practically in the dynamic monitoring Forest Growing Stock,according to the sampling study of proxy trees,this study is aiming at selecting target sample point combine stumpage’s spatial variation functions and Kriging interpolation method.Through the analysis of field test data in forest land,the results show that the method is effective;and through the analysis of spatial variation functions,we can obtain that altitude direction is the main factor to influence the growth of stumpage.Along the altitude direction diameter at breast height space variation is 240m,tree height variation is 360m,which show among the individual of forestry biomass has a good space correlation;after Kriging interpolation effect validation for less than variation’s different distance on reference sample point,and get that 0.3 times variation is the optimum distance which can make the forecast error on tree height less than 2m,and forecast error on DBH less than one diameter class.