Abstract Fire has considerable impact on vegetation and organic soils properties. As we observed that the differences between vegetation of burnt and unburnt areas on the rich fen are visible 11 years after the fire, we assumed that the post-fire changes are long lasting, yet limited exclusively to the burnt areas. In order to check this hypothesis we studied spatial differentiation of physical and chemical properties of soils, and productivity capacities of burnt and unburnt areas in the fen in Biebrza National Park. We took soil samples from the neighboring burnt and unburnt areas, from the depth of 0–30 cm and 30–50 cm. We analyzed 21 parameters of the soils including: pH, ash content, moisture, bulk density, exchangeable K, Na, Ca, available P, N-NH4+, N-NO3−, total N, C, K, Na, Ca, Mg, Fe, P; and calculated C:N, C:P ratios. Surface layer of the burnt soils differed significantly from the unburnt soils in respect of 17 out of 21 parameters. The most pronounced difference was observed for available phosphorous (on average 6 times higher for the burnt soils). The differences in the deeper layer were mostly insignificant. The burnt areas were also characterized by twofold higher plant productivity than recorded for the unburnt areas. The influence of fire on peaty soils was long lasting but mostly limited to the surface layer of the soils. In the case of particular soil features, the post-fire differences were modified by advanced muck formation (moorshing) processes in the unburnt areas. Since the fire led to long lasting increase of fertility, the recovery of fen vegetation is unlikely.

中文翻译：

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排水露天沼气对有机土壤的长期火灾影响

摘要 火灾对植被和有机土壤性质有相当大的影响。由于我们观察到在火灾发生 11 年后可以看到富沼上已燃烧和未燃烧区域的植被差异，因此我们假设火灾后的变化是持久的，但仅限于燃烧区域。为了验证这一假设，我们研究了别布扎国家公园沼泽中土壤物理和化学性质的空间差异，以及燃烧和未燃烧区域的生产力。我们从邻近的燃烧和未燃烧区域，从 0-30 厘米和 30-50 厘米的深度采集了土壤样本。我们分析了土壤的 21 个参数，包括：pH、灰分含量、水分、容重、可交换 K、Na、Ca、有效磷、N-NH4+、N-NO3−、总 N、C、K、Na、Ca、Mg ，铁，磷；并计算出 C:N、C:P 比率。在 21 个参数中的 17 个参数方面，燃烧土壤的表层与未燃烧土壤的表层显着不同。观察到有效磷的差异最显着（燃烧土壤平均高出 6 倍）。更深层的差异大多不显着。燃烧区域的植物生产力也比未燃烧区域的记录高两倍。火对泥炭土的影响是持久的，但主要限于土壤表层。在特定土壤特征的情况下，未燃烧区域的先进淤泥形成（系泊）过程改变了火灾后的差异。由于火灾导致肥力持续增加，沼泽植被不太可能恢复。