During wildfire season in the western US, fire retardant chemicals are dropped from aircraft in an effort to control the spread of fire. Fire retardant dropped on sites that are not actively burning results in exceptionally high soil nitrogen (N) and phosphorus (P) “fertilization” effect on wildland soils impacting terrestrial and aquatic ecosystems. Herein, we used microdialysis to evaluate the short-term spatiotemporal dynamics of soil inorganic N and ortho-P fluxes in response to wood pyrogenic carbon (PyC) on soils receiving fire retardant (Phos-Chek) in a 28-d column experiment. Retardant additions to soil induced dramatic increases in soil inorganic N and ortho-P flux rates. The addition of wood PyC to soils with retardant significantly and immediately reduced ortho-P flux rates at multiple depths (1, 5, and 10 cm) and reduced NH 4 + flux rates at 10 cm while retaining flux rates at 1 and 5 cm. These effects were observed throughout the course of the experiment and were more pronounced towards the end of the experiment. By d-28, PyC significantly reduced the NH 4 + , NO 3 − , and ortho-P accumulation on ionic resins at soil column bottoms by 50%, 52%, and 43%, respectively. The application of wood PyC may be effective at buffering excess nutrient fluxes from fire retardant and reduce short-term nutrient leaching in unburnt forest soils exposed to fire retardant.

中文翻译：

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阻燃剂和热解碳对土壤氮磷微尺度变化的影响

在美国西部的野火季节，飞机上会洒下阻燃化学品以控制火势蔓延。在不活跃燃烧的地方滴下阻燃剂会导致对影响陆地和水生生态系统的荒地土壤产生异常高的土壤氮 (N) 和磷 (P) “施肥”效应。在此，我们使用微透析来评估在 28 天柱实验中接受阻燃剂 (Phos-Chek) 的土壤上的土壤无机氮和邻磷通量的短期时空动态，以响应木材热解碳 (PyC)。向土壤中添加阻燃剂导致土壤无机氮和邻磷通量率急剧增加。将木材 PyC 添加到具有阻燃剂的土壤中显着并立即降低了多个深度的邻磷通量率 (1, 5, 和 10 cm) 并降低 10 cm 处的 NH 4 + 通量率，同时保持 1 和 5 cm 处的通量率。这些影响在整个实验过程中都被观察到，并且在实验结束时更加明显。到第 28 天，PyC 使土壤柱底部离子树脂上的 NH 4 + 、NO 3 - 和邻磷的积累量分别显着降低了 50%、52% 和 43%。木材 PyC 的应用可能有效缓冲来自阻燃剂的过量养分通量，并减少暴露于阻燃剂的未燃烧森林土壤中的短期养分浸出。和原磷在土柱底部离子树脂上的积累分别增加了 50%、52% 和 43%。木材 PyC 的应用可能有效缓冲来自阻燃剂的过量养分通量，并减少暴露于阻燃剂的未燃烧森林土壤中的短期养分浸出。和原磷在土柱底部离子树脂上的积累分别增加了 50%、52% 和 43%。木材 PyC 的应用可能有效缓冲来自阻燃剂的过量养分通量，并减少暴露于阻燃剂的未燃烧森林土壤中的短期养分浸出。