We determined the short‐ and medium‐term effects of prescribed burns on soil organic matter content and biological activity in grazing areas invaded by the shrub Echinospartum horridum (Vahl) Rothm. in the Pyrenees of Huesca (Spain). Soil samples were collected at 0–1, 1–2, and 2–3 cm depths in triplicate just before the burn, immediately after the burn (T0), and 1 and 5 years later (T1 and T5). We analysed the contents of total soil organic C and N, soil respiration, microbial biomass C, and β‐d‐glucosidase and acid phosphatase activities. Fire provoked an immediate high decrease in the contents of soil organic C (−40.2%) and N (−26.3%) in the first 3 cm, which were even lower at T5 (−50.3% and −46.5%, respectively). This can be explained as follows: (a) low incorporation of burned organic matter due to removal by wind and run‐off; (b) changes in microclimate increasing soil temperature and enhancing mineralization; and (c) a stimulating effect on decomposition due to the release of nutrients. Soil biological activity was affected at T0 in the first 3 cm (−49.3% glucosidase, −48.2% phosphatase, and −54.5% respiration rate). Microbial biomass C content was also affected by fire at T0 (−32.3%) but was close to its initial value at T5. The results suggest that these soils are particularly sensitive to fire. Adjusting the frequency and intensity of the burns is necessary to minimize their impact on the soil and to ensure the suitability of this management practice.

中文翻译：

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为牧场恢复而进行规定的燃烧后，表层土壤有机质的短期和中期演变以及生物学特性（西班牙，比利牛斯中部，泰拉）

我们确定了规定的烧伤对灌木刺E（Vahl）Rothm入侵的放牧区土壤有机质含量和生物活性的短期和中期影响。在韦斯卡（西班牙）的比利牛斯山脉。刚好在烧伤之前，烧伤之后立即（T0）以及1年和5年后（T1和T5）分别在0、1、2和2–3 cm深度处一式三份收集土壤样品。我们分析了土壤中总有机碳和氮，土壤呼吸，微生物生物量碳和β- d的含量葡糖苷酶和酸性磷酸酶活性。火灾引起头3 cm土壤有机碳（-40.2％）和N（-26.3％）的下降，在T5时甚至更低（分别为-50.3％和-46.5％）。可以解释如下：（a）由于风和径流的去除，燃烧有机物的掺入率低；（b）小气候的变化增加了土壤温度并增强了矿化作用；（c）由于释放养分而对分解产生刺激作用。在前3 cm的T0处，土壤生物活性受到影响（-49.3％的葡萄糖苷酶，-48.2％的磷酸酶和-54.5％的呼吸速率）。微生物生物量碳含量在T0（-32.3％）时也受到火灾的影响，但接近其在T5时的初始值。结果表明这些土壤对火特别敏感。