森林调查中,不论采用哪一种调查方法,都不可能将调查总体实测。而多是采取抽样调查的方法,从总体内抽出一定数量的样木单元做为调查对象,用样本单元的数学期望值估计总体。样本单元数与总体单元数的比值,叫做抽样比。抽样比越大,估计值越接近实际,估计的 In the forest survey, no matter which survey method is used, it is impossible to survey the survey as a whole. Mostly take a sample survey method, a certain number of samples taken from the overall unit of wood as a survey object, the sample unit mathematical expectation estimates of the overall. The ratio of the number of sample units to the total number of units is called the sampling ratio. The larger the sampling ratio, the closer the estimate is to the actual estimate