Academic Journal
Microbial substrate stoichiometry governs nutrient effects on nitrogen cycling in grassland soils
| العنوان: | Microbial substrate stoichiometry governs nutrient effects on nitrogen cycling in grassland soils |
|---|---|
| المؤلفون: | Schleuss, P. M., Widdig, M., Biederman, Lori A., Borer, E. T., Crawley, M. J., Kirkman, K. P., Seabloom, E. W., Wragg, P. D., Spohn, M. |
| المصدر: | Ecology, Evolution and Organismal Biology Publications |
| بيانات النشر: | Iowa State University Digital Repository |
| سنة النشر: | 2021 |
| المجموعة: | Digital Repository @ Iowa State University |
| مصطلحات موضوعية: | Nitrogen release and acquisition, net N mineralization, non-symbiotic N2 fixation, leucineaminopeptidase activity, nutrient fertilization, ecological stoichiometry, Nutrient Network (NutNet), Ecology and Evolutionary Biology, Environmental Microbiology and Microbial Ecology, Soil Science |
| الوصف: | Human activities have increased nitrogen (N) and phosphorus (P) inputs in terrestrial ecosystems and altered carbon (C) availability, shifting the stoichiometry of microbial substrates in soils, such as the C:N:P ratios of the dissolved organic matter pool. These stoichiometric deviations between microbial biomass and its substrate may control microbial processes of N cycling. We studied the effects of this stoichiometric mismatch using a full factorial N and P addition experiment replicated in six grassland ecosystems in South Africa, the USA, and the UK. We found that N and P addition changed the dissolved organic matter C:N ratio, but not the C:N ratio of the soil microbial biomass. Compared to P addition, N addition decreased microbial N acquisition via non-symbiotic N2 fixation by -55% and increased microbial N release via net N mineralization by +134%. A possible explanation is that the dissolved elements, e.g., dissolved organic C (DOC) and dissolved total N (DN), serve as the main microbial substrate and its C:N ratio defines whether N is scarce or abundant with respect to microbial demands. If N is available in excess relative to microbial demands, net N mineralization increases. In contrast, when N is scarce, immobilization outweighs release decreasing net N mineralization. However, the activity of leucine aminopeptidases, which decompose peptides, was not affected by nutrient additions. Further, C rather than P availability may control the rates of non-symbiotic N2 fixation in the six studied grassland sites. In conclusion, globally increasing nutrient inputs change processes of microbial N acquisition and release in grassland ecosystems and these changes are largely driven by shifts in substrate stoichiometry. |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | https://lib.dr.iastate.edu/eeob_ag_pubs/448; https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1454&context=eeob_ag_pubs |
| الاتاحة: | https://lib.dr.iastate.edu/eeob_ag_pubs/448 https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1454&context=eeob_ag_pubs |
| Rights: | http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| رقم الانضمام: | edsbas.3770C356 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |