G. C. Pande , R. C. Jain

Abstract

Large scale plantations of Eucalyplus grandis have been raised in the high lands of Kerala and in the Nilgiris in Tamilnadu. The wood from these plantations will be mainly used for the production of pulp. Previous tables (A.N. Chaturvedi, Ind. For. Ree., Vol 12, No. 17) were based on the regression of volume on the variable D-H (D=diatmeter, and H=height of a tree). These tables were based on a measurement of 149 trees. The determination coefficient was quite high for this regression (0.99). Regression of, √V was further fitted on variable D (R²=O.97). A new analysis has been attempted, as (i) the number of trees measured now is 233 and the data naturally covers more trees of higher age classes and (ii) it was not considered worthwhile to restrict the fitting of regression to one variable only.

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G. C. Pande , A. N. Chaturvedi

Abstract

Relations between various crop parameters in Eucalyptus hybrid (Mysore Gum) plantations are given. The standing volume of pulpwood in these plantations can be readily estimated from measurements of basal area and crop height. Basal area is the most important factor that contributes towards standing volume.

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G. C. Pande

Abstract

In Eucalyptus grandis the number of plants planted varies greatly. The rate of growth in various localities has been also greatly different. There is mortality in earlier stages but later the number tends to stabilise. The problem was to arrive at an equation which would be based on number and top height. It was found that an equation earlier used by Steill (1961) gave good relults. The regression equations calculated are: Vo = - 74.684814 + 17.614124x + 2.131032x²; (R² =0.9314) & Vu = - 62.453599 + 13.488326x + 1.972164x²; (R² =0.9228) where x = top ht (m). (No. of stems ha)¹/6/10 and Vo & Vu are volumes (m²) over bark and under bark, per hectare, respectively. This equation has shown to be independent of rate of growth (quality). Based on this equation and top ht/age curves the values of volume and MAI, both o.b. & u.b., have been tabulated for various numbers. The numbers are the stabalised number in 5th year (or bave been assumed to have stabilised). Rotations of 9, 10 & 11 years have been suggested for quality I, II & III crops in E. grandis.

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G. C. Pande , R. C. Jain

Abstract

Large scale plantations are being raised in the country under the Five year plans. The main point of interest at any time is 'What is the volume of the crop?'. The direct measurement of volume is tedious and felling of sample trees may not be always possible. However two parameters viz. basal area (BA) of the crop and crop height (H) can be easily and quickly estimated. In the present study for E. grandis crops regressions of crop volume (both with and without bark) on the variable BA × H have shown very high determination coefficients. Tables have been given to estimate volume based on these parameters. It has been noticed that, although at 5% level of probability, the regression is independent of quality classes, at a lower level of probability it may become dependent on quality class. However, when the number per hectare (N) another easily estimable parameter-is added as an extra variable in the regression equation, there is not only considerable reduction in the residual sum of squares, the regression becomes definitely more independent of the quality. The regression equations so developed for volume (both outside & inside bark) are given and two tables are given for No.=800/ha and 1600/ha; other tables are not given but can be formed by using the equations.

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