Potassium and phosphorus additions modify the response of Sphagnum capillifolium growing on a Scottish ombrotrophic bog to enhanced nitrogen deposition
Potassium and phosphorus additions modify the response of Sphagnum capillifolium growing on a Scottish ombrotrophic bog to enhanced nitrogen deposition
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DOI：
10.1016/j.apgeochem.2007.03.002
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发表时间：
2007-06-01
影响因子：
3.4
通讯作者：
Crossley, A.
中科院分区：
文献类型：
--
作者：
Carfrae, J. A.;Sheppard, L. J.;Crossley, A.
本研究报告的影响，湿还原与氧化氮的泥炭藓capillifolium原位反应：建筑，化学和F-v/F-m。氮输入增强现实的治疗方案下，在一个独特的实验，在苏格兰边境，英国，接收，历史上和目前，低污染物沉积的湿地沼泽生态系统。从2002年（6月）开始，以16 kg和64 kg N ha（-1）a（-1）的比例施用铵（NH 4Cl）和硝酸盐（NaNO 3）处理，有或没有钾和磷（K2 HPO 4），以1：14的比例提供P：N。这些湿处理应用于三个重复在现场收集的降水，作为“真实的时间”应用于大，13米（2）的地块。在2003年6月至2004年5月的研究期间，降雨量在几个月内很低，使水分胁迫的影响得以观察。高氮输入降低了分枝数和光合有效物质长度，在地下水位较低时影响更为明显，但氮素形态对分枝数和光合有效物质长度的影响不明显。在氮形态重要的地方，氧化态氮的效果不如还原态氮的效果好。研究结果进行了讨论，在目前的知识沿着与关键的N负荷和管理方案的影响，沼泽地，以抵消升高的N沉积的不利影响。这些结果提供了进一步的证据，K和P的添加到N污染的沼泽可以改善直接的，至少在短期内对泥炭藓的N沉积的负面影响。(c)2007爱思唯尔有限公司保留所有权利。
This study reports the impacts of wet reduced versus oxidised N on in situ responses of Sphagnum capillifolium: architecture, chemistry and F-v/F-m. Nitrogen inputs were enhanced under realistic treatment scenarios in a unique experiment on an ombrotrophic bog ecosystem in the Scottish Borders, UK, receiving, historically and currently, low pollutant deposition. Ammonium (NH4Cl) and nitrate (NaNO3) treatments were applied from 2002 (June) at 16 kg and 64 kg N ha(-1) a(-1) with or without K and P (K2HPO4), provided in a 1: 14 ratio of P:N. These wet treatments were applied to three replicates in precipitation collected at the site, as 'real time' applications to large, 13 m(2) plots. A high application frequency > 100 events was achieved and the maximum spray concentration was 4 mM. Over the study period June 2003-May 2004 rainfall was low over several months enabling the effects of water stress to be looked at. Branching and the length of photosynthetically active material were reduced by the high N input and the effect was more pronounced when the water-table was low, but the form of N was not important. Where the N form was important the effects of oxidised N were less favourable than those of reduced N. The findings are discussed in relation to current knowledge along with implications for critical N loads and management options for bogs to counteract the detrimental impact of elevated N deposition. These results provide further evidence that additions of K and P to N-polluted bogs can ameliorate the direct, negative impacts of N deposition on Sphagnum at least in the short-term. (c) 2007 Elsevier Ltd. All rights reserved.