Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China.
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China.
Sci Total Environ. 2018 Jun 1;625:640-646. doi: 10.1016/j.scitotenv.2017.12.311. Epub 2018 Jan 2.
Nitrogen (N) availability affects litter decomposition and nutrient dynamics, especially in N-limited ecosystems. We investigated the response of litter decomposition to N additions in Eriophorum vaginatum and Vaccinium uliginosum peatlands. These two species dominate peatlands in Northeast China. In 2012, mesh bags containing senesced leaf litter of Eriophorum vaginatum and Vaccinium uliginosum were placed in N addition plots and sprayed monthly for two years with NHNO solution at dose rates of 0, 6, 12, and 24gNmyear (CK, N1, N2 and N3, respectively). Mass loss, N and phosphorus (P) content, and enzymatic activity were measured over time as litter decomposed. In the control plots, V. uliginosum litter decomposed faster than E. vaginatum litter. N1, N2, and N3 treatments increased the mass losses of V. uliginosum litter by 6%, 9%, and 4% respectively, when compared with control. No significant influence of N additions was found on the decomposition of E. vaginatum litter. However, N and P content in E. vaginatum litter and V. uliginosum litter significantly increased with N additions. Moreover, N additions significantly promoted invertase and β-glucosidase activity in E. vaginatum and V. uliginosum litter. However, only in V. uliginosum litter was polyphenol oxidase activity significantly enhanced. Our results showed that initial litter quality and polyphenol oxidase activity influence the response of plant litter to N additions in peatland ecosystems. Increased N availability may change peatland soil N and P cycling by enhancing N and P immobilization during litter decomposition.
氮（N）供应会影响凋落物分解和养分动态，尤其是在 N 限制的生态系统中。我们研究了 N 添加对中国东北芦苇和越橘泥炭地凋落物分解的影响。这两个物种是中国东北泥炭地的主要优势种。2012 年，在 N 添加试验区和对照区分别将含有芦苇和越橘凋落叶的网袋放置在土壤中，并在两年内每月用 NHNO 溶液喷洒，剂量率分别为 0、6、12 和 24gNmyear（对照、N1、N2 和 N3）。随着凋落物的分解，测量了一段时间内的质量损失、N 和磷（P）含量以及酶活性。在对照区，越橘凋落物比芦苇凋落物分解得更快。与对照相比，N1、N2 和 N3 处理分别增加了越橘凋落物质量损失的 6%、9%和 4%。N 添加对芦苇凋落物分解没有显著影响。然而，N 添加显著增加了芦苇和越橘凋落物的 N 和 P 含量。此外，N 添加显著促进了芦苇和越橘凋落物中转化酶和β-葡萄糖苷酶的活性。然而，只有在越橘凋落物中，多酚氧化酶活性显著增强。我们的研究结果表明，初始凋落物质量和多酚氧化酶活性影响泥炭地生态系统中植物凋落物对 N 添加的响应。增加的 N 供应可能通过在凋落物分解过程中增强 N 和 P 的固定化来改变泥炭地土壤的 N 和 P 循环。
