Soil carbon stocks in temperate grasslands differ strongly across sites but are insensitive to decade-long fertilization

Bibliographische Detailangaben
Veröffentlicht in:	Global change biology. - 1999. - 28(2022), 4 vom: 13. Feb., Seite 1659-1677
1. Verfasser:	Keller, Adrienne B (VerfasserIn)
Weitere Verfasser:	Borer, Elizabeth T, Collins, Scott L, DeLancey, Lang C, Fay, Philip A, Hofmockel, Kirsten S, Leakey, Andrew D B, Mayes, Melanie A, Seabloom, Eric W, Walter, Christopher A, Wang, Yong, Zhao, Qian, Hobbie, Sarah E
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2022
Zugriff auf das übergeordnete Werk:	Global change biology
Schlagworte:	Journal Article carbon cycling carbon sequestration fertilization nutrient network piecewise structural equation model soil carbon fractions Soil Carbon 7440-44-0 mehr... Nitrogen N762921K75

Beschreibung
Zusammenfassung:	© 2021 John Wiley & Sons Ltd. Enhancing soil carbon (C) storage has the potential to offset human-caused increases in atmospheric CO2 . Rising CO2 has occurred concurrently with increasing supply rates of biologically limiting nutrients such as nitrogen (N) and phosphorus (P). However, it is unclear how increased supplies of N and P will alter soil C sequestration, particularly in grasslands, which make up nearly a third of non-agricultural land worldwide. Here, we leverage a globally distributed nutrient addition experiment (the Nutrient Network) to examine how a decade of N and P fertilization (alone and in combination) influenced soil C and N stocks at nine grassland sites spanning the continental United States. We measured changes in bulk soil C and N stocks and in three soil C fractions (light and heavy particulate organic matter, and mineral-associated organic matter fractions). Nutrient amendment had variable effects on soil C and N pools that ranged from strongly positive to strongly negative, while soil C and N pool sizes varied by more than an order of magnitude across sites. Piecewise SEM clarified that small increases in plant C inputs with fertilization did not translate to greater soil C storage. Nevertheless, peak season aboveground plant biomass (but not root biomass or production) was strongly positively related to soil C storage at seven of the nine sites, and across all nine sites, soil C covaried with moisture index and soil mineralogy, regardless of fertilization. Overall, we show that site factors such as moisture index, plant productivity, soil texture, and mineralogy were key predictors of cross-site soil C, while nutrient amendment had weaker and site-specific effects on C sequestration. This suggests that prioritizing the protection of highly productive temperate grasslands is critical for reducing future greenhouse gas losses arising from land use change
Beschreibung:	Date Completed 24.02.2022 Date Revised 24.02.2022 published: Print-Electronic Citation Status MEDLINE
ISSN:	1365-2486
DOI:	10.1111/gcb.15988