Fungal and bacterial contributions to nitrogen cycling in cheatgrass-invaded and uninvaded native sagebrush soils of the western USA
| Autor: | Andrew T. Giguere, Elizabeth DeLorenze, Peter J. Bottomley, Nicole M. DeCrappeo, David A. Pyke |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
Fungal protein biology Chemistry Soil Science Soil classification 04 agricultural and veterinary sciences Plant Science Mineralization (soil science) Bromus tectorum biology.organism_classification complex mixtures 010603 evolutionary biology 01 natural sciences Agronomy Soil water 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Artemisia Nitrification Nitrogen cycle |
| Zdroj: | Plant and Soil. 416:271-281 |
| ISSN: | 1573-5036 0032-079X |
| DOI: | 10.1007/s11104-017-3209-x |
| Popis: | There is interest in determining how cheatgrass (Bromus tectorum L.) modifies N cycling in sagebrush (Artemisia tridentata Nutt.) soils of the western USA. To gain insight into the roles of fungi and bacteria in N cycling of cheatgrass-invaded and uninvaded sagebrush soils, the fungal protein synthesis inhibitor, cycloheximide (CHX), and the bacteriocidal compound, bronopol (BRO) were combined with a 15NH4 + isotope pool dilution approach. CHX reduced gross N mineralization to the same rate in both sagebrush and cheatgrass soils indicating a role for fungi in N mineralization in both soil types. In cheatgrass soils BRO completely inhibited gross N mineralization, whereas, in sagebrush soils a BRO-resistant gross N mineralization rate was detected that was slower than CHX sensitive gross N mineralization, suggesting that the microbial drivers of gross N mineralization were different in sagebrush and cheatgrass soils. Net N mineralization was stimulated to a higher rate in sagebrush than in cheatgrass soils by CHX, implying that a CHX inhibited N sink was larger in the former than the latter soils. Initial gross NH4 + consumption rates were reduced significantly by both CHX and BRO in both soil types, yet, consumption rates recovered significantly between 24 and 48 h in CHX-treated sagebrush soils. The recovery of NH4 + consumption in sagebrush soils corresponded with an increase in the rate of net nitrification. These results suggest that cheatgrass invasion of sagebrush soils of the northern Great Basin reduces the capacity of the fungal N consumption sink, enhances the capacity of a CHX resistant N sink and alters the contributions of bacteria and fungi to gross N mineralization. |
| Databáze: | OpenAIRE |
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