Chemical composition of interstitial water in decaying lodgepole pine bole wood

Abstract

The chemical composition of interstitial water in highly decayed lodgepole pine (Pinuscontorta ssp. latifolia) bole wood lying on the forest floor was sampled during the spring snow melt period in 1981 and 1982. The solutions were dominated by nutrient-rich organic compounds, with more than 95% of the dissolved total N and P occurring in organically bound forms. Relatively low C: N (45: 1) and C: P (280: 1) ratios for these organic compounds were 4- and 12- fold lower than C: N and C: P ratios for the solid phase, respectively, suggesting that they were preferentially mineralized by heterotrophic microorganisms. Subsequent rapid absorption by tree roots and microbes during the snow melt period probably was responsible for maintaining the low inorganic N and P concentrations that occurred. Presence of soluble polyphenols and carbohydrates, primary components of the lignocellulose wood substrate, suggest that the dissolved organic compounds resulted in part from the incomplete oxidation of organic matter decay products. Soluble organic ligands accounted for more than 65% of the solution charge balance. Although 80% of the dissolved organic carbon was acidic in nature, solution pH values were rather high (5.4), in part because of high concentrations of base cations.