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Forest Inventory Section, Courtesy
of GFC
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Summaries of Valuation and Reconnaissance Surveys 1926-1950This phase of surveys used a modified version of the method used by Brandis in the teak forests of Burma at the end of the last century. Transects of 20 ö 30 metres were laid out in a systematic manner without stratification, usually based around access roads and navigable stretches of the countryâs many rivers and creeks. Sampling intensities were generally below 2.5%: the reconnaissance surveys are distinguished by their lower sampling intensities. Tree diameters were measured with calipers by 4 inch (10cm) class, though most of the summary information available only provides frequencies by species for all trees > 16 inches diameter (c. 41 cm), without individual diameter classes. A significant part of the interior was covered by these exercises, particularly when one considers the additional difficulties involved in field work in those days. D.B. Fanshawe summarised the tree frequency information from these valuation and reconnaissance surveys by seven main regions, presenting the resulting figures in Principal Timbers (1954). These figure (popularly called ãFanshaweâs Tablesä) have been a valued source of information for forestry companies, since they provide estimates of the frequencies of commercial sizes of important species by region. Though tree frequency information for the individual survey exercises was assembled in 1949, it appears that few copies of the resulting report were ever produced and the information was not widely available in this form. It is now reproduced here in electronic format, along with an index map. Presenting the results by area offers obvious advantages over the regional figures, which (as Fanshawe put it) are "averages of averages". Also of note is that the main forest concession boundaries are included in the index map to facilitate the pin-pointing of surveys relevant to individual forest concession holders. These concession boundaries must be considered approximate, since the small scale of the map does not allow them to precisely match their detailed legal descriptions. Although this forest survey information is still of great value to
forest managers and researchers alike,
In conclusion, for the purposes of forest management, the summaries provide useful baseline information, but this alone will not be adequate - it must be supplemented by....
For research purposes, there is wide scope for examining the distribution and density of individual species and/or species groups of interest across the range of areas surveyed. This information can also be examined in relation to other ecological, environmental, social or economic data. The original reports on most these surveys are available in GFC, though maps are only available for a limited number of these. The tables and the mapAn index map to the locations of the Valuation/Reconnaissance Surveys is provided. The number of each coloured survey area corresponding with the field of the same number in the down-loadable Excel file.Two worksheets are contained in this file; these are selected using the two labeled tabs at the base of the worksheet. The worksheets contain the same information, but the tree frequencies are expressed in two commonly used metric and imperial measures, respectively, i.e. a) Mean number of stems above 16 inches (c. 41cm) diameter per 100 hectares (=1 square km) b) Mean number of stems above 16 inches (c. 41 cm) diameter per 1000 acres The letterãpäin the table notes that the species was present within
the area, but that no large numbers were encountered within the transects
of sufficient size to be recorded.
To get a summary table for each area, Download MS Excel Zip File. The figures in these tables are expressed in the metric format, i.e. stems greater than 16 inches per 100 hectares (1 square km). In each of these tables, the species are presented in order of frequency, i.e. the most frequent species comes at the top of the list. Foresters may enjoy testing their knowledge of which species are most common in each survey area - make your prediction then just click on the area to find out what the survey found! |
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