The amounts and ratio of nitrogen and phosphorus addition drive the rate of litter decomposition in a subtropical forest

Liehua Tie; Junxi Hu; Josep Peñuelas; Jordi Sardans; Shengzhao Wei; Xing Liu; Shixing Zhou; Congde Huang

doi:10.1016/j.scitotenv.2022.155163

The amounts and ratio of nitrogen and phosphorus addition drive the rate of litter decomposition in a subtropical forest

Sci Total Environ. 2022 Aug 10:833:155163. doi: 10.1016/j.scitotenv.2022.155163. Epub 2022 Apr 10.

Authors

Liehua Tie¹, Junxi Hu², Josep Peñuelas³, Jordi Sardans⁴, Shengzhao Wei², Xing Liu², Shixing Zhou⁵, Congde Huang⁶

Affiliations

¹ Institute for Forest Resources and Environment Research Center of Guizhou Province, Guizhou University, 550025 Guiyang, China; National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China; Sichuan Province Key Laboratory of Ecological Forestry Engineering on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China; CSIC, Unitat d'Ecologia Global CREAFCSIC-UAB, Edifici C, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Catalonia, Spain; CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain. Electronic address: tiefromchina@163.com.
² National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China; Sichuan Province Key Laboratory of Ecological Forestry Engineering on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China.
³ CSIC, Unitat d'Ecologia Global CREAFCSIC-UAB, Edifici C, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Catalonia, Spain; CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain. Electronic address: josep.penuelas@uab.cat.
⁴ CSIC, Unitat d'Ecologia Global CREAFCSIC-UAB, Edifici C, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Catalonia, Spain; CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain. Electronic address: j.sardans@creaf.uab.cat.
⁵ National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China; Sichuan Province Key Laboratory of Ecological Forestry Engineering on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China. Electronic address: szhou@sicau.edu.cn.
⁶ National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China; Sichuan Province Key Laboratory of Ecological Forestry Engineering on the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, 611130 Chengdu, China. Electronic address: lyyxq100@aliyun.com.

PMID: 35413342
DOI: 10.1016/j.scitotenv.2022.155163

Abstract

Nitrogen (N) and phosphorus (P) control biogeochemical cycling in terrestrial ecosystems. However, N and P addition effects on litter decomposition, especially biological pathways in subtropical forests, remain unclear. Here, a two-year field litterbag experiment was employed in a subtropical forest in southwestern China to examine N and P addition effects on litter biological decomposition with nine treatments: low and high N- and P-only addition (LN, HN, LP, and HP), NP coaddition (LNLP, LNHP, HNLP, and HNHP), and a control (CK). The results showed that the decomposition coefficient (k) was higher in NP coaddition treatments (P < 0.05), and lower in N- and P-only addition treatments than in CK (P < 0.05). The highest k was observed with LNLP (P < 0.05). The N- and P-only addition treatments decreased the losses of litter mass, lignin, cellulose, and condensed tannins, litter microbial biomass carbon (MBC), litter cellulase, and soil pH (P < 0.05). The NP coaddition treatments increased the losses of litter mass, lignin, and cellulose, MBC concentration, litter invertase, urease, cellulase, and catalase activities, soil arthropod diversity (S) in litterbags, and soil pH (P < 0.05). Litter acid phosphatase activity and N:P ratio were lower in N-only addition treatments but higher in P-only addition and NP coaddition treatments than in CK (P < 0.05). Structural equation model showed that litter MBC, S, cellulase, acid phosphatase, and polyphenol oxidase contributed to the loss of litter mass (P < 0.05). The litter N:P ratio was negatively logarithmically correlated with mass loss (P < 0.01). In conclusion, the negative effect of N addition on litter decomposition was reversed when P was added by increasing decomposed litter soil arthropod diversity, MBC concentration, and invertase and cellulase activities. Finally, the results highlighted the important role of the N:P ratio in litter decomposition.

Keywords: Extracellular enzymatic activities; Litter decomposition; Microbial biomass; Nitrogen deposition; Soil fauna; Stoichiometry.

MeSH terms

Acid Phosphatase / metabolism
Carbon / analysis
Cellulases* / analysis
Cellulases* / metabolism
China
Ecosystem
Forests
Lignin / metabolism
Nitrogen* / analysis
Phosphorus / analysis
Plant Leaves / chemistry
Soil / chemistry
beta-Fructofuranosidase / analysis
beta-Fructofuranosidase / metabolism

Substances

Soil
Phosphorus
Carbon
Lignin
Acid Phosphatase
Cellulases
beta-Fructofuranosidase
Nitrogen