Data input

Data variables

Two sets of data were entered into a spreadsheet program (Microsoft^� Excel 2000). The variables included in the first data set were:

Compartment number
Forest density class
Sample number
Elevation
Type of NTFP and its abundance
Tree species code
Dbh for trees above 15 cm in diameter
Timber quality
Crown form
Crown illumination
Competing vegetation

The second data set consisted of 1) to 4) in the first set plus:

Tree species code for trees
Diameter of trees between 5-15 cm dbh
Number of trees between 1.5 m height and 5 cm dbh

Data verification

The data in the spreadsheets were exported to S-Plus for Windows Version 6 Release 2 for data verification. Summary statistics (e.g. mean, median total sum) were produced for each variable as well as quartiles for continuous variables, and counts for categorical variables. If a variable exceeded logical consistencies, the raw data were checked, and if necessary ground checks were made to verify data accuracy.