Relationships Between Soil Properties and Red Pine Growth in Massachusetts
1961
Mader, Donald Lewis | Owen, D. F.
Results from a site study on 47 plots of plantation-grown red pine in Massachusetts indicate that growth is related to organic matter and nitrogen contents of the soil profiles and soil drainage class. Multiple regression of 5-year cubic foot volume growth per acre on total organic matter per acre of the solum and percent organic matter in the A horizon showed highly significant (1% level) partial and multiple regression coefficients. The regression accounted for 37% of the growth variability. The multiple regression coefficient for data on growth, log values for total nitrogen content per acre of the solum, and percent nitrogen in the A horizon from these plots also was highly significant, accounting for 35% of the variability in growth. Regression using height growth of dominants from 20 to 30 years of age, height of dominants at age 25, or volume per acre at age 25 as a measure of growth gave poorer correlations with organic matter and soil nitrogen than 5-year cubic foot volume growth per acre. A multiple regression equation relating eight soil factors to growth was highly significant accounting for 58% of the variability in growth and with highly significant partial regression coefficients for total nitrogen and drainage class. Organic matter, nitrogen, and drainage class appear to have some value in assessing site productivity although residual variability from other growth factors, or from error in sampling and analysis, is still appreciable resulting in prediction errors on the order of 10% of the average volume growth rate. Cubic foot volume growth gave better correlations with site factors than either total or periodic height growth.
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