Academic Journal
Effects of airborne ammonium and nitrate pollution strongly differ in peat bogs, but symbiotic nitrogen fixation remains unaffected
| العنوان: | Effects of airborne ammonium and nitrate pollution strongly differ in peat bogs, but symbiotic nitrogen fixation remains unaffected |
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| المؤلفون: | van den Elzen, Eva, van den Berg, Leon J. L., van der Weijden, Bas, Fritz, Christian, Sheppard, Lucy J., Lamers, Leon P. M. |
| المصدر: | van den Elzen , E , van den Berg , L J L , van der Weijden , B , Fritz , C , Sheppard , L J & Lamers , L P M 2018 , ' Effects of airborne ammonium and nitrate pollution strongly differ in peat bogs, but symbiotic nitrogen fixation remains unaffected ' , Science of the Total Environment , vol. 610 , pp. 732-740 . https://doi.org/10.1016/j.scitotenv.2017.08.102 |
| سنة النشر: | 2018 |
| المجموعة: | University of Groningen research database |
| مصطلحات موضوعية: | Sphagnum capillifolium, Nitrogen deposition, Biogeochemical processes, Diazotrophs, Amino acids, N DEPOSITION, OMBROTROPHIC BOG, SPHAGNUM MOSSES, N-2 FIXATION, BACTERIAL COMMUNITIES, ATMOSPHERIC AMMONIA, WET DEPOSITION, SOIL-PH, VEGETATION, GROWTH |
| الوصف: | Pristine bogs, peatlands in which vegetation is exclusively fed by rainwater (ombrotrophic), typically have a low atmospheric deposition of reactive nitrogen (N) (<0.5 kg ha(-1) y(-1)). An important additional N source is N-2 fixation by symbiotic microorganisms (diazotrophs) in peat and mosses. Although the effects of increased total airborne N by anthropogenic emissions on bog vegetation are well documented, the important question remains how different N forms (ammonium, NH4+, versus nitrate, NO3-) affect N cycling, as their relative contribution to the total load strongly varies among regions globally. Here, we studied the effects of 11 years of experimentally increased deposition (32 versus 8 kg N ha(-1) y(-1)) of either NH4+ or NO3- on N accumulation in three moss and one lichen species (Sphagnum capillifolium, S. papillosum, Pleurozium schreberi and Cladonia portentosa), N-2 fixation rates of their symbionts, and potential N losses to peat soil and atmosphere, in a bog in Scotland. Increased input of both N forms led to 15-90% increase in N content for all moss species, without affecting their cover. The keystone species S. capillifolium showed 4 times higher N allocation into free amino acids, indicating N stress, but only in response to increased NH4+. In contrast, NO3- addition resulted in enhanced peat N mineralization linked to microbial NO(3)(-)reduction, increasing soil pH, N concentrations and N losses via denitrification. Unexpectedly, increased deposition from 8 to 32 kg ha(-1) y(-1) in both N forms did not affect N-2 fixation rates for any of the moss species and corresponded to an additional input of 5 kg N ha(-1) y(-1) with a 100% S. capillifolium cover. Since both N forms clearly show differential effects on living Sphagnum and biogeochemical processes in the underlying peat, N form should be included in the assessment of the effects of N pollution on peatlands. (C) 2017 Elsevier B.V. All rights reserved. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| DOI: | 10.1016/j.scitotenv.2017.08.102 |
| الاتاحة: | https://hdl.handle.net/11370/4ea2f29b-6b32-40c7-998b-f81d2ca3bfcf https://research.rug.nl/en/publications/4ea2f29b-6b32-40c7-998b-f81d2ca3bfcf https://doi.org/10.1016/j.scitotenv.2017.08.102 https://pure.rug.nl/ws/files/76269324/1_s2.0_S0048969717321009_main.pdf |
| Rights: | info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.97377692 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1016/j.scitotenv.2017.08.102 |
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