Mowing enhances the positive effects of nitrogen addition on ecosystem carbon fluxes and water use efficiency in a semi-arid meadow steppe

Wenzheng Song; Raúl Ochoa-Hueso; Fei Li; Haiying Cui; Shangzhi Zhong; Xuechen Yang; Tianhang Zhao; Wei Sun

doi:10.1016/j.jenvman.2022.115889

Mowing enhances the positive effects of nitrogen addition on ecosystem carbon fluxes and water use efficiency in a semi-arid meadow steppe

J Environ Manage. 2022 Oct 15:320:115889. doi: 10.1016/j.jenvman.2022.115889. Epub 2022 Aug 3.

Authors

Wenzheng Song¹, Raúl Ochoa-Hueso², Fei Li³, Haiying Cui³, Shangzhi Zhong⁴, Xuechen Yang⁵, Tianhang Zhao³, Wei Sun⁶

Affiliations

¹ Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus Del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain.
² Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus Del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain; Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700, AB, Wageningen, the Netherlands. Electronic address: rochoahueso@gmail.com.
³ Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China.
⁴ Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Grassland Agri-Husbandry Research Center, College of Grassland Science, Qingdao Agricultural University, Qingdao, 266109, China.
⁵ Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
⁶ Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China. Electronic address: sunwei@nenu.edu.cn.

PMID: 35932732
DOI: 10.1016/j.jenvman.2022.115889

Abstract

Grasslands are now facing a continuously increasing supply of nitrogen (N) fertilizers, resulting in alterations in ecosystem functioning, including changes in carbon (C) and water cycling. Mowing, one of the most widely used grassland management techniques, has been shown to mitigate the negative impacts of increased N availability on species richness. However, knowledge of how N addition and mowing, alone and/or in combination, affect ecosystem-level C fluxes and water use efficiency (W_N) is still limited. We experimentally manipulated N fertilization (0 and 10 g N m^-2 yr^-1) and mowing (once per year at the end of the growing season) following a randomized block design in a meadow steppe characterized by salinization and alkalinization in northeastern China. We found that, compared to the control plots, N addition, mowing, and their interaction increased net ecosystem CO₂ exchange by 65.1%, 14.7%, and 133%, and W_N by 40.7%, 18.5%, and 96.1%, respectively. Nitrogen enrichment also decreased soil pH, which resulted in greater aboveground biomass (AGB). Moreover, N addition indirectly increased AGB by inducing changes in species richness. Our results indicate that mowing enhances the positive effects of N addition on ecosystem C fluxes and W_N. Therefore, appropriate grassland management practices are essential to improve ecosystem C sequestration, W_N, and mitigate future species diversity declines due to ecosystem eutrophication.

Keywords: Ecosystem carbon flux; Meadow steppe; Mowing; Nitrogen; Water use efficiency.

MeSH terms

Carbon / analysis
China
Ecosystem*
Grassland
Nitrogen* / analysis
Soil / chemistry
Water / analysis

Substances

Soil
Water
Carbon
Nitrogen