STRATIFIED TWO-STAGE SAMPLING (SELF-WEIGHTED) FOR ASSESSMENT OF VILLAGE FOREST RESOURCES
Keywords:Sampling techniques, village forest resources, tree density, bamboo abundance, Bangladesh
The paper examines the suitability of Stratified Two-Stage Sampling (Self-Weighted) as a field sampling design in assessing village forest resources in Bangladesh. A study population of 900 households was formed consisting of 14 administrative units comprising of several local councils, each having a group of villages in the district of Chittagong in Bangladesh. The study concentrates on tree and bamboo resources as they contribute a major share of the village forest economy. Seven parameters defined under five variables were calculated for complete enumeration (total homestead area = 97 ha, total area of compact tree garden = 49 ha, total volume of trees = 9490 m3, total volume of compact trees = 8308 m3, total number of bamboos = 53 229, volume of compact trees per hectare = 170 m3 and number of households with bamboo plantation = 407). Stratified Two-Stage Sampling design was tested with collected field data using a computer. The parameters were estimated through the sampling technique using self-weighted method considering 250 sample households (estimated total homestead area = 78 ha, estimated total area of compact tree garden = 50 ha, estimated total volume of trees = 9432 m3, estimated total volume of compact trees = 8183 m3, estimated total number of bamboos = 53 546, estimated volume of compact trees per hectare = 165 m3 and estimated number of households with bamboo plantation = 413). The estimates were compared with the enumerated values on the basis of percentage standard error, percentage accuracy, percentage bias and 95% confidence level. The sampling design under the study was found to be a suitable inventory technique and is recommended for application in the field to assess village wood and bamboo resources in Bangladesh.