Phosphorus and Nitrogen Dynamics in Streams Associated With Wildfire: a Study of Immediate and Longterm Effects
Phosphorus and Nitrogen Dynamics in Streams Associated With Wildfire: a Study of Immediate and Longterm Effects
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与野火相关的溪流中磷和氮的动态：近期和长期影响的研究
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
C. N. Spencer
中科院分区：
文献类型：
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作者：
F. Hauer;C. N. Spencer
在野火期间和随后的五年期间收集流营养数据。取样来自野火内外的一系列成对流域。在长达一个月的野火的最初几天，磷和氮的浓度比背景水平增加了5至60倍，最高记录浓度高达135 μg/L可溶性活性磷，261 μg/L铵和61 μg/L硝酸盐。在同一时期，总磷和总氮分别增加到206 μg/L和349 μg/L。营养物浓度降至背景水平（受影响河流中可溶性活性磷为40 μg/L，硝酸盐>125 μg/L，浓度>对照河流中观察到的浓度的5倍。在高梯度流域，所有的营养物质都很容易被转移到溪流中，在火灾后的最初几年里，影响最显着。在不太陡峭的地形，可溶性活性磷浓度显着较高的火灾后3至5年，这也对应于相对较高的春季水文。相比之下，在火灾发生后的几年里，氮化合物在火灾冲击流中的浓度明显较高。我们属性这些差异的养分负荷率的结果是不同的动员机制的磷和氮和不同的土壤和地貌环境的流域排水由不同的流。
Stream nutrient data were collected both during a wildfire and over a subsequent five-year period. Sampling was from a series of paired watersheds located within and outside of the wildfire. Phosphorus and nitrogen concentrations increased from 5 to 60 fold over background levels during the first few days of the month-long wildfire with maximum recorded concentrations as high as 135 μg/L soluble reactive phosphorus, 261 μg/L ammonium, and 61 μg/L nitrate. Total phosphorus and total nitrogen during this same time period increased up to 206 μg/L and 349 mμg/L, respectively. Nutrient concentrations declined to background levels ( 40 μg/L soluble reactive phosphorus and >125 μg/L nitrate in impacted streams, concentrations >5 fold over those observed in control streams. In high gradient watersheds, all nutrients were easily transported to the streams with most notable impact during the early years after the fire. In less steep terrain, soluble reactive phosphorus concentrations were significantly higher 3 to 5 years after the fire, which also corresponded to relatively high spring hydrographs. In contrast, nitrogen compounds were observed to be significantly higher in concentration in fire impact streams in the years immediately following the fire. We attribute these differences in the rate of nutrient loads to be the result of the different mobilization mechanisms of phosphorus and nitrogen and the different soil and geomorphic settings of the watersheds drained by the different streams.