Responses of Soil CO 2 Emission and Tree Productivity to Nitrogen and Phosphorus Additions in a Nitrogen-Rich Subtropical Chinese Fir Plantation

Xiaochen Lu, Binjie Li and Guangsheng Chen ()
Additional contact information
Xiaochen Lu: State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
Binjie Li: State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
Guangsheng Chen: State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China

Sustainability, 2023, vol. 15, issue 12, 1-15

Abstract: Nitrogen (N) and phosphorus (P) nutrients have been regularly applied to improve productivity in intensively managed and short-rotation forest plantations in subtropical China. Under the constraint of the national policy of “carbon neutrality”, it is necessary to determine the rational fertilization options by considering both forest productivity and soil CO 2 emissions. Past worldwide studies have shown varied responses of forest soil heterotrophic respiration and CO 2 emissions to N and P additions. This study designed six treatments with N additions (high level: 15 g N/m 2 , HN), P (low: 5 g P/m 2 , LP; high: 15 g P/m 2 , HP), and their interactions (HNLP and HNHP) to explore the effects of N and P additions on soil CO 2 emissions in a P-limited and N-rich Chinese fir plantation ( Cunninghamia lanceolata ), and we identified the underlying controls using the structural equation model (SEM). The results indicated that LP, HNLP, and HNHP treatments significantly increased soil CO 2 emissions in the first four months after treatment and the effects leveled since then. The balance between N and P inputs affected the responses of soil CO 2 emissions to P additions. A low P addition significantly increased tree productivity, but the promoting effect gradually declined and was no longer significant after 3 years. Other treatments did not significantly affect tree productivity. The SEM analysis revealed that the promoting effects of P additions on CO 2 emission were mainly due to their effects on increasing soil water-soluble organic carbon content and reducing microbial biomass nitrogen content. Considering both soil respiration and tree productivity, this study suggested that LP treatment can effectively balance the N and P nutrients and, in the meantime, maintain relatively low greenhouse gas emissions; thus a low P application level is suggested for N-rich Chinese fir plantations.

Keywords: nitrogen addition; phosphorus addition; soil CO 2 emission; tree productivity; Chinese fir forest (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/12/9466/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/12/9466/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2023:i:12:p:9466-:d:1169641

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().