The below-ground carbon and nitrogen cycling patterns of different mycorrhizal forests on the eastern Qinghai-Tibetan Plateau

Miaomiao Zhang; Shun Liu; Miao Chen; Jian Chen; Xiangwen Cao; Gexi Xu; Hongshuang Xing; Feifan Li; Zuomin Shi

doi:10.7717/peerj.14028

The below-ground carbon and nitrogen cycling patterns of different mycorrhizal forests on the eastern Qinghai-Tibetan Plateau

PeerJ. 2022 Sep 14:10:e14028. doi: 10.7717/peerj.14028. eCollection 2022.

Authors

Miaomiao Zhang^{1

2}, Shun Liu^{1

2}, Miao Chen^{1

2}, Jian Chen^{1

2}, Xiangwen Cao^{1

2}, Gexi Xu^{1

2}, Hongshuang Xing^{1

2}, Feifan Li^{1

2}, Zuomin Shi^{1

2

3

4}

Affiliations

¹ Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China.
² Miyaluo Research Station of Alpine Forest Ecosystem, Lixian County, Sichuan, China.
³ Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
⁴ Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, Italy.

Abstract

Mycorrhizal fungi can form symbiotic associations with tree species, which not only play an important role in plant survival and growth, but also in soil carbon (C) and nitrogen (N) cycling. However, the understanding of differences in soil C and N cycling patterns among forests with different mycorrhizal types is still incomplete. In order to determine the similarities and differences of soil C and N cycling patterns in different mycorrhizal forest types, three primary forests dominated by ectomycorrhizal (EcM), arbuscular mycorrhizal (AM) and ericoid mycorrhizal (ErM) trees respectively were studied on the eastern Qinghai-Tibetan Plateau. Indicators associated with soil C and N cycling, including leaf litter quality, soil C and N contents, soil C and N fluxes, and soil microbial biomass C and N contents were measured in each mycorrhizal type forest. The results showed that leaf litter quality was significantly lower with high C:N ratio and lignin: N ratio in ErM forest than that in AM and EcM forests. Soil CO₂ flux (508.25 ± 65.51 mg m^-2 h^-1) in AM forest was significantly higher than that in EcM forest (387.18 ± 56.19 mg m^-2 h^-1) and ErM forest (177.87 ± 58.40 mg m^-2 h^-1). Furthermore, soil inorganic N content was higher in the AM forest than that in EcM and ErM forests. Soil net N mineralization rate (-0.02 ± 0.03 mg kg^-1 d^-1) was lower in ErM forest than that in EcM and AM forests. We speculated that AM and EcM forests were relatively characterized by rapid soil C cycling comparing to ErM forest. The soil N cycling in EcM and ErM forests were lower, implying they were 'organic' N nutrition patterns, and the pattern in ErM forest was more obvious.

Keywords: AM forest; EcM forest; ErM forest; Mycorrhizal association; Soil C and N cycling.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carbon
Forests
Mycorrhizae*
Nitrogen
Soil
Tibet
Trees / microbiology

Substances

Carbon
Nitrogen
Soil

Grants and funding

This work was supported by the Scientific Research and Development Project of the Ecology and Nature Conservation Institute, the Chinese Academy of Forestry (CAF) (99805-2020) and the Fundamental Research Funds of CAF (CAFYBB2018ZA003). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.