Wild, Birgit; Schnecker, Joerg; Knoltsch, Anna; Takriti, Mounir; Mooshammer, Maria et al.: Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia. In: Global Biogeochemical Cycles 29 (2015), Nr. 5, S. 567-582. DOI: http://dx.doi.org/10.1002/2015GB005084
Zusammenfassung: | |
Soil N availability is constrained by the breakdown of N-containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using N-15 pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67 degrees N) to steppe (54 degrees N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high-latitude systems such as tundra and boreal forest. | |
Lizenzbestimmungen: | CC BY 4.0 Unported |
Publikationstyp: | Article |
Publikationsstatus: | publishedVersion |
Erstveröffentlichung: | 2015-05 |
Die Publikation erscheint in Sammlung(en): | Naturwissenschaftliche Fakultät |
Pos. | Land | Downloads | ||
---|---|---|---|---|
Anzahl | Proz. | |||
1 | Germany | 474 | 90,98% | |
2 | United States | 17 | 3,26% | |
3 | China | 8 | 1,54% | |
4 | No geo information available | 4 | 0,77% | |
5 | Europe | 4 | 0,77% | |
6 | Switzerland | 2 | 0,38% | |
7 | Canada | 2 | 0,38% | |
8 | Taiwan | 1 | 0,19% | |
9 | Pakistan | 1 | 0,19% | |
10 | Netherlands | 1 | 0,19% | |
andere | 7 | 1,34% |
Hinweis
Zur Erhebung der Downloadstatistiken kommen entsprechend dem „COUNTER Code of Practice for e-Resources“ international anerkannte Regeln und Normen zur Anwendung. COUNTER ist eine internationale Non-Profit-Organisation, in der Bibliotheksverbände, Datenbankanbieter und Verlage gemeinsam an Standards zur Erhebung, Speicherung und Verarbeitung von Nutzungsdaten elektronischer Ressourcen arbeiten, welche so Objektivität und Vergleichbarkeit gewährleisten sollen. Es werden hierbei ausschließlich Zugriffe auf die entsprechenden Volltexte ausgewertet, keine Aufrufe der Website an sich.