The forest inventory forms the foundation of forest planning and forest policy. The early designs of forest inventory in PNG was focused on timber production and were project based.Below are some of the basic Inventory practices done in timber resource assessments in the country.
All the potential timber areas have already been identified and are contained in the National Forest Plan and the Provincial Forest Plans. In this strategic planning stage, the Forest Resource Inventory Mapping System (FRIMS) is consulted. FRIMS provide consistent set of geographical information on the type and extent of forest resource and its current use by the forest industry. FRIMS consist of four types of data; logging concession information, constraints and land use, forest base/cover maps and base/topography. From this data, PNGFA can generate information such as boundaries, maps, forest types, inundated areas, etc. This information is then transferred on to appropriate map scale for laying of strip lines for sampling in the area of interest for purposes of forest inventory.
Reconnaissance generally is a survey of quality. It answers the question of whether it is worthwhile carrying more detailed forest surveys. Such a survey may be made either by examining aerial photographs/satellite imageries of the area; by walking through the area; or by establishing few plots in the area. Reconnaissance is conducted as an overall familiarization tour of the timber area. From this overall view the survey starting points and the general direction of survey lines are planned. Once the starting points are identified suitable landing sites are identified where field parties and cargo can be dropped off. The resource owners are also informed at this point of the inventory work that is planned to be executed in the area.
- Resource survey
This is the actual first level of survey that estimates the quantity of timber resource. This includes timber volume and species composition. Such surveys are made so that decisions can be made on whether the timber resource is viable or not for further development in terms of establishing a timber industry.
- Field Procedures
All forest inventories carried out so far are based on a systematic continuous line plot design, is most appropriate for inventory of tropical forest. A cross-section of the different forest types is also captured in the sampling. The information recorded in field sampling are Tree Enumeration, Tree Species, Diameter, Tree Height and other plot attributes. All is recorded in field books.
- Data Processing (FIPS)
All tree information contained in the field books from field survey are processed using Forest Inventory Processing System (FIPS) a computer programme that is used specifically for processing the data. Survey results are produced as printed output in variety of ways by the operator
- Survey Report
A report of the assessment is then made highlighting the field work, result of resource survey and recommendation on whether the timber resource in the forest area is adequate to support a viable timber project.