%0 Research note
%T Empirical errors of small area estimates from the multisource National Forest Inventory in Eastern Finland
%A Katila, Matti
%D 2006
%J Silva Fennica
%V 40
%N 4
%R doi:10.14214/sf.324
%U https://silvafennica.fi/article/324
%X The precision of multisource national forest inventory (MS-NFI)  estimators and simple synthetic estimators based on NFI field data only  was assessed employing an independent inventory data set of several  small areas in Eastern Finland. There were seven test units of size 100  km<sup>2</sup> and three test units of size 1 km<sup>2</sup> for which a  systematic field sampling was carried out. The ‘improved’ MS-NFI method  yielded the most precise estimates for mean volume and mean volume of  pine and spruce: relative root mean square errors (RMSE<sup>*</sup>) were 5%, 12% and 15% for 100 km<sup>2</sup> test units and 13%, 27% and 40% for 1 km<sup>2</sup> test units respectively. The stratified MS-NFI method was best for  broad-leaved volume estimation. Synthetic estimation based on the NFI9  field plots post-stratified with coarse scale forest variable maps from  NFI8 resulted in RMSE<sup>*</sup>s comparable to those of the ordinary MS-NFI in areas of 100 km<sup>2</sup> for mean volume and mean volume of pine and spruce. The amount of  variation between the field inventory estimates for the test units  explained by the MS-NFI estimators remained the same or increased when  the size of the area increased from of 1 km<sup>2</sup> to 100 km<sup>2</sup> and up to 2000 km<sup>2</sup>.  The validation of the largest areas was made against the NFI9 field  inventory estimates for groups of municipalities in the study area.