High‐level nitrogen additions accelerate soil respiration reduction over time in a boreal forest. (28th June 2022)

• Record Type: Journal Article
• Authors: Xing, Aijun; Du, Enzai; Shen, Haihua; Xu, Longchao; Zhao, Mengying; Liu, Xiuyuan; Fang, Jingyun
• Is Part Of: Ecology letters. Volume 25:Number 8(2022)
• Page Start: 1869
• Page End: 1878
• Publication Date: 2022-06-28
• Subjects: boreal forest -- nitrogen deposition -- soil respiration -- temporal dynamics; Ecology -- Periodicals; 577
• DOI: 10.1111/ele.14065
• Languages: English
• ISSNs: 1461-023X

Abstract

Abstract: Increased nitrogen (N) inputs are widely recognised to reduce soil respiration (Rs), but how N deposition affects the temporal dynamics of Rs remains unclear. Using a decade‐long fertilisation experiment in a boreal larch forest ( Larix gmelini ) in northeast China, we found that the effects of N additions on Rs showed a temporal shift from a positive effect in the short‐term (increased by 8% on average in the first year) to a negative effect over the longer term (decreased by 21% on average in the 11th year). The rates of decrease in Rs for the higher N levels were almost twice as high as those of the low N level. Our results suggest that the reduction in Rs in response to increased N input is accelerated by high‐level N additions, and experimental high N applications are likely to overestimate the contribution of N deposition to soil carbon sequestration in a boreal forest. Abstract : Using a decade‐long fertilization experiment in a boreal larch forest in northeast China, we found that the effects of N additions on soil respiration shifted from a positive effect in the short‐term to a negative effect over the longer term. The rates of decrease in soil respiration for the higher N‐levels were almost twice as high as those of the low N‐level. Our results suggest that the reduction in soil respiration in response to increased N input over time is accelerated by higher N addition rate, and experimental high N applications are likely to overestimate the contribution of N deposition to soil carbon sequestration in boreal forest.