Abstract

The bark of coniferous trees (BCT) is an essential component of the litter in boreal forests. The effects of temperature and mineral additives (N and P) on the rate of BCT decomposition (DecR), its constant (k), total loss of C–CO₂, and the changes in BCT chemical composition are assessed in a long-term (12 months) laboratory experiment with soil–bark substrates (SBSs) using three contrasting temperatures (2, 12, and 22°C) and sufficient moisture. The temperature coefficient (Q₁₀) for the mean DecR during the experiment varies from 1.1 to 2.5 depending on temperature range and SBS composition. The effect of temperature was the most pronounced during the first and second months of the experiment, explaining 47% of the DecR variation. At later stages of the experiment, the SBS composition affected by the addition of mineral N and P compounds is the key factor influencing the BCT decomposition; it explains 18–63% of the DecR variance. The maximum losses of C–CO₂ (158–187 g С/(kg bark), or 34–41% of the initial С content) are observed at 22°C. Irrespectively of the temperature, the most significant loss of ethanol-soluble compounds (56–64%) is recorded in the variant with the mineral N additive, whereas the cellulose content most significantly decreases (by 64–69%) in the variant with combined application of N and P and is almost independent of temperature. The loss of lignin was insignificant, amounting to only 3–12% of its initial content. The addition of mineral N and P is a key factor stimulating the BCT decomposition, considerably shortening the decomposition time and improving the quality of the resulting substrates.

中文翻译：

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温度，矿质氮和磷对腐烂过程和土壤-土壤基质组成的影响

摘要

针叶树的树皮（BCT）是北方森林凋落物的重要组成部分。长期评估温度和矿物添加剂（N和P）对BCT分解速率（DecR），其常数（k），C–CO _2的总损失以及BCT化学成分变化的影响。 （12个月）实验室实验，使用三个相反的温度（2、12和22°C）和足够的水分，对土壤-树皮基质（SBS）进行了测试。平均DecR的温度系数（Q ₁₀）根据温度范围和SBS组成，实验期间的温度在1.1到2.5之间变化。在实验的第一个月和第二个月，温度的影响最为明显，解释了47％的DecR变化。在实验的后期，受矿物N和P化合物的添加影响的SBS组成是影响BCT分解的关键因素。它解释了DecR方差的18–63％。C–CO ₂的最大损失在22°C下观察到（158-187 gС/（kg树皮），或初始С含量的34-41％）。与温度无关，在含矿物氮添加剂的变量中，乙醇可溶性化合物的损失最为明显（56–64％），而在组合使用的变量中，纤维素含量的减少最为明显（降低了64–69％）氮和磷的施用几乎与温度无关。木质素的损失微不足道，仅为其初始含量的3–12％。矿物N和P的添加是刺激BCT分解的关键因素，大大缩短了分解时间并提高了所得底物的质量。