Feasibility of estimating total stem volume and aboveground biomass from measurement on the largest trees in even-aged pure stands

Feasibility was tested of estimating the total stem volume and aboveground biomass from data of only the largest trees in even-aged pure stands. We ap plied a method of fitting a size-distribution function to data that exclude information of smaller individuals in a stand and compared the predicted s tem volume and aboveground biomass with those calculated with data of all l iving trees in the stand. The paired t test showed that the predicted value s of the total stem volume and aboveground biomass were not different (p = 0.05) from those observed even if only the largest 10% of the trees were us ed for estimation with the -3/2 power distribution. Results were similar wi th the beta-type distribution; however, data from at least the largest 30% of the trees in the stand must be included. Absolute values of the relative error of the predicted total stem volume or aboveground biomass were gener ally in the range 10-20%, indicating that the present method is accurate en ough to be used for calculation of these variables. However, there is syste matic bias in the predictions of the total stem volume and aboveground biom ass of a stand. Possible causes of the indicated biases and potential ways for improvement of the predictions were discussed.