Browsing by Author "Abdelsalaam, Ahmed Abdelsalaam"

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    Inventory procedure for teak forest projects
    (University of Dar es salaam, 1980) Abdelsalaam, Ahmed Abdelsalaam
    This research, undertaken at Mtibwa teak forest project, investigated: (1) Models to construct volume table for the project (2)Efficiency of four different designs to estimate volume per ha. These designs include: a) Circular plots (.01 ha) b) A sub sample selected with probability proportional to prediction from the plots (3P). c)Variable radius plots (sweeps) d) A sub samples selected with probability proportional to prediction from the sweep (3P). Among the different models tested, the following based on two parameters: diameter at breast height (dbh) and total height (h), for total over bark and under bark volume was recommended: V.C.T. or V. U. T = b1(dbh)2 +b2(dbh)2(h) +b3(h)2 +b4(dbh) (h)2. A three-parameter model gave similar results to the two-parameter model and, although the percentage error was a little less than for the two-parameter model, the latter was considered to be of greater advantage as it is cheaper and easier to use. Of the sampling designs tested: a) The circular fixed radius plots with all trees measured for h in order to predict volume was the least efficient design. b) The 3P sub samples from the circular plot gave the most efficient results. c) Sweeps were more efficient than fixed radius circular plots. They were nearly as efficient as a 3P sub sample from circular plots and they were more efficient than a 3P sub sample from sweeps. d) The 2P sub samples from sweeps were less efficient than sweeps in which all trees counted were measured for volume. Since sweeps gave results which were very near to the most efficient design, and they are an already known method and have other advantages, it was recommended as a design to be used in the teak project. Results obtained showed that 3P is a useful method. Research should be conducted and extended in other areas, and forestry staff should be trained so that they can become familiar with the method.