Effects of Long-Term Nitrogen Addition and Atmospheric Nitrogen Deposition on Carbon Accumulation in Picea sitchensis Plantations
Effects of Long-Term Nitrogen Addition and Atmospheric Nitrogen Deposition on Carbon Accumulation in Picea sitchensis Plantations
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DOI：
10.1007/s10021-013-9685-9
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发表时间：
2013-07
期刊：
影响因子：
3.7
通讯作者：
Tiziana Gentilesca;M. Vieno;M. Perks;M. Borghetti;Maurizio Mencuccini
中科院分区：
文献类型：
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作者：
Tiziana Gentilesca;M. Vieno;M. Perks;M. Borghetti;Maurizio Mencuccini
本研究旨在评价长期氮素供应和氮素沉积(NDEP)对锡特卡云杉[Picea Sitchensis(Bong.)Carr.]苏格兰的种植园。从1970年到1982年建立的六个研究地点定期进行氮肥，随着时间的推移进行监测，并在2010年进行了普遍调查。分析了土壤、地上生物量和地面植被C储量的变化；地上C储量与每个站点经历的总额外N相关，即1900-2010年间实验N供应(NADD)和特定地点累积N的总和。结果表明，无论是在施肥过程中，还是在最后一次施氮后，林木生长均未观察到氮素对地上部分树种C的正效应。施氮量试验区凋落物中碳含量显著高于对照区，而对照区林下植被中碳含量显著高于对照区。将所有分区(即林下植被、凋落物、土壤和树木生物量)合并在一起，估计了每个地点的总生态系统碳含量，在大多数地点，施N处理的样地估计了更高的C储量。在Ndep积累水平较高的地点，处理地和对照地之间的地上C积累速率差异较小。我们的结果表明，要了解树木对氮肥的生长反应，应考虑特定地点的累积NDEPE。
This study aimed to assess the combined effects of long-term nitrogen (N) supply and nitrogen deposition (Ndep) on carbon (C) accumulation within Sitka spruce [Picea sitchensis(Bong.) Carr.] plantations in Scotland. Six study sites established from 1970 to 1982 were periodically N-fertilized, monitored over time and commonly surveyed in 2010. Soil, aboveground biomass, and ground vegetation C stock changes were analyzed; aboveground C stocks were correlated with total additional N experienced at each site, that is, the sum of experimental N supply (Nadd) and site-specific accumulatedNdepfrom 1900 to 2010. Results showed a positive N effect on aboveground tree C stock and no decline in tree growth was observed either during fertilization or after the latest N addition. The amount of C in litter was significantly higher in experimentally N-treated plots, whereas the amount of C in understory vegetation was higher in control plots. Pooling all the compartments (that is, understory vegetation, litter, soil, and tree biomass) the total ecosystem C content was estimated for each site, and at most sites a higher C stock was estimated for N-treated plots. Differences in aboveground C accumulation rates between treated and control plots were lower at sites with high levels of accumulatedNdep. Our results indicate that site-specific accumulatedNdepshould be considered to understand tree growth responses to N fertilization.