The data that makes up the 1999 database have come from three sources as shown in Table 3. This reflects the commitment of the forest industry to having detailed forest resource information readily available. However, it is possible that some small-scale forest owners included in the database may change their management objectives. Areas currently intended to produce a harvestable timber yield may be left standing, for example to provide shelter or aesthetic appeal. Aggregated area data were checked at the territorial authority level against the 1998 NEFD area database to ensure variation was within acceptable limits.
Forest areas are sometimes mis-allocated between adjacent territorial authorities.
One way for users to minimise this problem is to aggregate data from adjacent territorial authorities, particularly where contiguous forest areas straddle territorial authority boundaries. The imputed new planting in each territorial local authority occurs in the same proportions as the new planting captured in the 1999 NEFD survey. The imputed new planting is made up of the same species proportions as the results to the 1999 NEFD surveys. Imputed new planting for radiata pine is assigned to the tending regimes in the same proportions as the postal survey results. The objective of the LCDB project is to produce a national spatial database which broadly describes vegetation cover.