Litter type control on soil C and N stabilization dynamics in a temperate forest. (5th December 2014)

• Record Type: Journal Article
• Authors: Hatton, Pierre‐Joseph; Castanha, Cristina; Torn, Margaret S.; Bird, Jeffrey A.
• Is Part Of: Global change biology. Volume 21:Number 3(2015:Mar.)
• Page Start: 1358
• Page End: 1367
• Publication Date: 2014-12-05
• Subjects: 13C -- 15N -- fine root -- forest -- litter -- litter decomposition -- needle -- soil organic matter -- stabilization; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.12786
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: While plant litters are the main source of soil organic matter (SOM) in forests, the controllers and pathways to stable SOM formation remain unclear. Here, we address how litter type ( 13 C/ 15 N‐labeled needles vs. fine roots) and placement‐depth (O vs. A horizon) affect in situ C and N dynamics in a temperate forest soil after 5 years. Litter type rather than placement‐depth controlled soil C and N retention after 5 years in situ, with belowground fine root inputs greatly enhancing soil C (x1.4) and N (x1.2) retention compared with aboveground needles. While the proportions of added needle and fine root‐derived C and N recovered into stable SOM fractions were similar, they followed different transformation pathways into stable SOM fractions: fine root transfer was slower than for needles, but proportionally more of the remaining needle‐derived C and N was transferred into stable SOM fractions. The stoichiometry of litter‐derived C vs. N within individual SOM fractions revealed the presence at least two pools of different turnover times (per SOM fraction) and emphasized the role of N‐rich compounds for long‐term persistence. Finally, a regression approach suggested that models may underestimate soil C retention from litter with fast decomposition rates.