Vegetation restoration of abandoned cropland improves soil ecosystem multifunctionality through alleviating nitrogen-limitation in the China Danxia

Chao Wang; Qiannan Yang; Chi Zhang; Xiaolong Zhang; Jing Chen; Kexue Liu

doi:10.3389/fpls.2023.1116179

Vegetation restoration of abandoned cropland improves soil ecosystem multifunctionality through alleviating nitrogen-limitation in the China Danxia

Front Plant Sci. 2023 Feb 28:14:1116179. doi: 10.3389/fpls.2023.1116179. eCollection 2023.

Authors

Chao Wang^{1

2

3}, Qiannan Yang^{1

2}, Chi Zhang³, Xiaolong Zhang^{1

2}, Jing Chen^{1

2}, Kexue Liu^{1

2}

Affiliations

¹ School of Resources and Planning, Guangzhou Xinhua University, Guangzhou, China.
² Ecological Restoration Research Center, China Institute of south China Urban-Rural Economic and Social Development, Guangzhou, China.
³ College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.

Abstract

The microbial requirement for nutrient resources can be estimated by soil extracellular enzyme stoichiometry (EES) and their stoichiometries. Implementing the Grain for Green Program has significantly impacted land use and soil nutrient management in the China Danxia. However, drivers of soil microbial nutrient limitation changes in abandoned cropland (AC) remained unclear after vegetation restoration. Here, according to vector analysis, we evaluated microbial nutrient limitation by studying soil EES across vegetation restoration types (naturally restored secondary forests (NF) and artificially planted forests (AF)) with AC as a control. Results showed both NF and AF soils averaged higher C- and P- acquiring enzyme, indicating rapid C and P turnover rates after vegetation restoration. However, vegetation restoration resulted in higher C requirement for microorganisms with higher enzyme C:N and vector length. In addition, microorganisms shifted from N- (< 45°) to P-limited (> 45°) conditions with enzyme N:P less than 1 after vegetation restoration, and NF exacerbated microbial P limitation compared to AF. Decreased N limitation following vegetation restoration could be contributed to improving soil ecosystem multifunctionality. The greater variation of EES was explained by the interaction of pH, soil nutrient, and microbial biomass than by any one of these factors alone, suggesting that both abiotic and biotic factors regulate microbial nutrient limitation and microbial process. Overall, our results revealed vegetation restoration could alleviate N limitation in the China Danxia, and thus enhance soil ecosystem by regulating lower microbial N limitation, which provide insight into nutrient management strategies under ecological restoration of degraded areas.

Keywords: China Danxia; enzyme stoichiometry; microbial nutrient limitation; soil ecosystem multifunctionality; soil enzyme activity; vegetation restoration.

Grants and funding

This study is supported by Natural Science Foundation of Guangdong Province (2021A1515011543), 13^th Five-Year Plan Project of Guangdong Education Science (2020GXJK116), and Key Project of Natural Science of Guangzhou Xinhua University (2020KYZD02).