Challenging the paradigm of nitrogen cycling: no evidence of in situ resource partitioning by coexisting plant species in grasslands of contrasting fertility
| العنوان: | Challenging the paradigm of nitrogen cycling: no evidence of in situ resource partitioning by coexisting plant species in grasslands of contrasting fertility |
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| المؤلفون: | Richard D. Bardgett, Anna V. Wilkinson, Paul W. Hill, Davey L. Jones, John Farrar, Marie Victoria Vaieretti |
| المصدر: | Ecology and Evolution CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| سنة النشر: | 2013 |
| مصطلحات موضوعية: | chemistry.chemical_element, Biology, dissolved organic nitrogen, Grassland, DISSOLVED INORGANIC NITROGEN, soil, purl.org/becyt/ford/1 [https], Ciencias Biológicas, nitrogen cycling, GRASSLAND PRODUCTIVITY, NITROGEN PARTITIONING, Botany, Ecosystem, PEPTIDE, purl.org/becyt/ford/1.6 [https], grassland productivity, Nitrogen cycle, Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation, Original Research, 2. Zero hunger, Ecological niche, geography, geography.geographical_feature_category, Ecology, Stable isotope ratio, Niche differentiation, food and beverages, 15. Life on land, Ecología, Nitrogen, peptide, NITROGEN CYCLING, SOIL, chemistry, Dissolved inorganic nitrogen, nitrogen partitioning, DISSOLVED ORGANIC NITROGEN, Monoculture, CIENCIAS NATURALES Y EXACTAS |
| الوصف: | In monoculture, certain plant species are able to preferentially utilize different nitrogen (N) forms, both inorganic and organic, including amino acids and peptides, thus forming fundamental niches based on the chemical form of N. Results from field studies, however, are inconsistent: Some showing that coexisting plant species predominantly utilize inorganic N, while others reveal distinct interspecies preferences for different N forms. As a result, the extent to which hypothetical niches are realized in nature remains unclear. Here, we used in situ stable isotope tracer techniques to test the idea, in temperate grassland, that niche partitioning of N based on chemical form is related to plant productivity and the relative availability of organic and inorganic N. We also tested in situ whether grassland plants vary in their ability to compete for, and utilize peptides,which have recently been shown to act as an N source for plants in strongly N-limited ecosystems. We hypothesized that plants would preferentially use NO3--N and NH4+-N over dissolved organic N in high-productivity grassland where inorganic N availability is high. On the other hand, in low-productivity grasslands, where the availability of dissolved inorganic N is low, and soil availability of dissolved organic N is greater, we predicted that plants would preferentially use N from amino acids and peptides, prior to microbial mineralization. Turves from two well-characterized grasslands of contrasting productivity and soil N availability were injected, in situ, with mixtures of 15N-labeled inorganic N (NO3- and NH4+) and 13C15N labeled amino acid (L-alanine) and peptide (L-tri-alanine). In order to measure rapid assimilation of these N forms by soil microbes and plants, the uptake of these substrates was traced within 2.5 hours into the shoots of the most abundant plant species, as well as roots and the soil microbial biomass. We found that, contrary to our hypothesis, the majority of plant species across both grasslands took up most N in the form of NH4+, suggesting that inorganic N is their predominant N source. However, we did find that organic N was a source of N which could be utilized by plant species at both sites, and in the low-productivity grassland, plants were able to capture some tri-alanine-N directly. Although our findings did not support the hypothesis that differences in the availability of inorganic and organic N facilitate resource partitioning in grassland, they do support the emerging view that peptides represent a significant, but until now neglected, component of the terrestrial N cycle. Fil: Wilkinson, Anna. Lancaster University. Lancaster Environment Centre; Reino Unido. University Of Manchester; Reino Unido Fil: Hill, Paul. Bangor University. College of Natural Sciences; Reino Unido Fil: Vaieretti, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Farrar, John. Bangor University. College of Natural Sciences; Reino Unido Fil: Jones, Davey. Bangor University. College of Natural Sciences; Reino Unido Fil: Bardgett, Richard. Lancaster University. Lancaster Environment Centre; Reino Unido. University Of Manchester; Reino Unido |
| وصف الملف: | application/pdf |
| تدمد: | 2045-7758 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::303618c376aaad4356016a4af2d464feTest https://pubmed.ncbi.nlm.nih.gov/25691957Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....303618c376aaad4356016a4af2d464fe |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 20457758 |
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