The spatial variation of pH in the mor layer of some coniferous forest stands in northern Sweden
1989
Nykvist, N. | Skyllberg, U. (Sveriges Lantbruksuniv., Umeaa (Sweden). Inst. foer Skoglig Staandortslaera)
The spatial pH-variation is shown to be slightly decreasing when comparing different coniferous stands in northern Sweden with a 200 m2 respectively a 2 m2 sample plot within a stand. The result indicates that the pH-variation in the mor layer to a great extent is to be found in a plot less than 2 m2. The hypothesis of Hesselman (1926) and Bergholm et al. (1985) that few samples should be enough for a reliable pH-determination of a stand is questioned and critically discussed. The number of samples required to obtain a pH-determination with an accepted accuracy is discussed. The spatial pH-variation from the plots in the study suggest that approximately 12 samples are required to get a mean error of 2 % at 95 % confidence limits. But one should be aware of that, even with 12 samples, the difference between the highest and lowest value in a 2 m2 plot will be about 0.6 pH-units.
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