Abstract

The dynamics of the content of water-soluble organic matter (WSOM) and its resistance to microbiological transformation in the Entic Folic Podzol of the postfire succession in the dwarf-shrub mountain tundra of the Khibiny Mountains are studied. A medium-intensity fire does not cause a statistically significant decrease in the soil WSOM content as compared to the reference plot. The activity of WSOM mineralization is mainly determined by the WSOM properties rather than by the microbial community. The dynamics of biodegradation is adequately described by a two-component first-order exponential model with a statistically significant existence of fast-mineralized (mean residence time, <1 day) and slow-mineralized (mean residence time, 33 to 111 days) pools. The maximum share of the fast pool is typical of the soil immediately after a fire and smoothly decreases during further postfire succession. During biodegradation, a biokinetic selection of the aromatic hydrophobic compounds most resistant to microorganisms is observed, while the simple nitrogen-containing components of WSOM are the first to be consumed by microorganisms.

中文翻译：

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战后演替期间基比尼山苔原土壤水溶性有机物的生化稳定性

摘要

研究了Khibiny山矮灌木山冻原上火演替后的Entic Folic Podzol中水溶性有机物（WSOM）含量的动态及其对微生物转化的抵抗力。与参考图相比，中等强度的火灾不会导致土壤WSOM含量有统计上的显着下降。WSOM矿化的活性主要由WSOM性质决定，而不是由微生物群落决定。两组分一阶指数模型充分描述了生物降解的动力学，该模型具有快速矿化（平均停留时间，<1天）和慢矿化（平均停留时间，33到111天）池的统计显着性。快速池的最大份额是发生火灾后立即出现的典型土壤，并在随后的继发演替过程中逐渐减少。在生物降解过程中，观察到了对微生物最有抵抗力的芳香族疏水化合物的生物动力学选择，而WSOM的简单含氮组分首先被微生物消耗。