FORMS OF SOIL PHOSPHORUS ALONG A NUTRIENT ENRICHMENT GRADIENT IN THE NORTHERN EVERGLADES
FORMS OF SOIL PHOSPHORUS ALONG A NUTRIENT ENRICHMENT GRADIENT IN THE NORTHERN EVERGLADES
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北部大沼泽地沿养分富集梯度的土壤磷形态
DOI：
10.1097/00010694-199509000-00004
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
C. Richardson
中科院分区：
文献类型：
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作者：
R. Qualls;C. Richardson
自 20 世纪 60 年代末以来，来自农业径流的约 60 MT y−1 磷流入佛罗里达州北部大沼泽地沼泽地区，形成了营养富集梯度。本研究的目的是确定 (i) 在过去 30 年中添加的磷和原生磷以什么形式储存，以及 (ii) 难以回收的形式是否是磷储存的主要形式。 2月、5月、8月和12月从养分流入源沿梯度在18个站点对泥炭土进行采样，然后依次提取磷。一般来说，沿梯度的磷浓度在进入沼泽内部约8至10公里处降至相对较低的浓度。腐殖质有机磷、残留不溶性有机磷、钙结合磷、交换性无机磷和铁/铝结合无机磷（仅在20至25厘米深度）的浓度均与距养分输入距离呈负相关，即富集区的浓度高出2至4倍。相比之下，表层土壤中微生物生物量 P 的浓度与距养分输入的距离无关，尽管变异性很大。由于富集区有更多泥炭沉积，因此所有形式的磷在富集区沉积速度都更快（快 1.8 至 8 倍，具体取决于形式）。泥炭中有机磷的沉积是储存养分流入中过量磷的最重要过程。在这些中性至微碱性（pH 7.2至7.9）泥炭土中形成钙结合磷也是最接近磷输入站磷沉降的重要机制。过量的磷富集已渗透到沼泽系统的大部分组成部分，包括有机和无机形式以及快速和缓慢循环形式。
About 60 MT y−1 of P from agricultural runoff have flowed into an area of the northern Everglades marshes of Florida since the late 1960s, creating a nutrient enrichment gradient. The objectives of this study were to determine (i) in what forms the added and native P have been stored over the past 30 years and (ii) whether forms that are resistant to recycling are the main forms of P storage. The peat soils were sampled at 18 stations along a gradient from the source of nutrient inflow in February, May, August, and December and were then subjected to sequential extraction of P. In general, the P concentrations along the gradient decreased to relatively low concentrations about 8 to 10 km into the interior of the marsh. Concentrations of humic organic P, residual insoluble organic P, Ca-bound P, exchangeable inorganic P, and Fe/Al-bound inorganic P (only at the 20 to 25-cm depth) were all correlated negatively with distance from the nutrient input, i.e., they were 2 to 4 times higher in the enriched area. In contrast, concentrations of microbial biomass P in the surface soil were not correlated with distance from the nutrient input although variability was great. Because more peat is accreting in the enriched area, all forms of P are accreting faster (1.8 to 8 times faster, depending on the form) in the enriched area. Deposition of organic P in the peat was the most important process storing excess P from the nutrient inflows. Formation of Cabound P in these neutral to slightly alkaline (pH 7.2 to 7.9) peat soils was also an important mechanism of P deposition at the stations closest to the phosphorus input. The excess P enrichment has permeated most components of the marsh system, including organic and inorganic forms as well as rapidly and slowly cycling forms.