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长江上游水源涵养地高山森林溪流磷输出不仅是森林生态系统磷输出的主要形式,而且与下游水域环境密切相关,但对此人们一直缺乏必要的关注.因此,为了解森林溪流磷的最大输出潜力,于2013年8月中旬溪流流量较大的季节,调查了海拔3600~3700 m的高山森林18条溪流的磷输出及其从源头到尽头的变化特征.结果表明:在所选样地内,溪流中总磷储量为8120.1 mg,单位水体面积储量为5.4 mg·m-2,单位水体面积总输出量为150.3 kg·km-2·d-1,单位集水区面积总输出量为0.2 kg·km-2·d-1,集水区潜在年输出总量约为67.7 kg·km-2.溪流中总磷含量维持在检出限0.01~0.6 mg·L-1之间,所有溪流上游总磷含量和储量均明显高于下游;溪流尽头总磷储量仅为源头总储量的29.2%,尽头平均浓度为源头平均浓度的30.9%.这些结果表明,高山森林溪流具有明显的磷输出特征,但从源头到尽头的汇流过程中,溪流水体能显著降低总磷含量及储量,表现出明显的自净能力,这也是高山森林生态系统养分传输纽带的重要体现.
In order to understand the maximum output potential of phosphorus in forest streams, phosphorus output of alpine forest streams with water conservation in the upper reaches of the Yangtze River is not only the main form of phosphorus output in forest ecosystems, but also closely related to the environment of the downstream waters. However, , The phosphorus output of 18 streams in alpine forests at altitudes of 3600 ~ 3700 m and the characteristics of their changes from the source to the end of the river were surveyed in the season of high stream flow in mid-August 2013. The results showed that within the selected sample plots, The total phosphorus reserves were 8120.1 mg, unit water body area reserves were 5.4 mg · m-2, unit water area total output was 150.3 kg · km-2 · d-1, and unit catchment area total output was 0.2 kg · km-2 · d-1, and the potential annual output of catchment is about 67.7 kg · km-2. The total phosphorus content in the stream remained within the detection limit of 0.01-0.6 mg · L-1. Phosphorus content and reserves were significantly higher than those in the lower reaches.The total phosphorus reserves at the end of the stream were only 29.2% of the total source reserves and the average concentration at the end was 30.9% of the average source concentration.These results showed that the alpine forest streams had obvious phosphorus output characteristics, From the source to the end of the convergence process, streams water Can significantly reduce the amount of phosphorus and reserves, showed significant self-purification ability, which is also an important manifestation of alpine forest ecosystem nutrient transport ties.