Drought induces opposite changes in organ carbon and soil organic carbon to increase resistance on moso bamboo

Xiaogai Ge; Yilian Mao; Benzhi Zhou; Xiaoming Wang; Mai-He Li

doi:10.3389/fpls.2024.1474671

Drought induces opposite changes in organ carbon and soil organic carbon to increase resistance on moso bamboo

Front Plant Sci. 2024 Nov 26:15:1474671. doi: 10.3389/fpls.2024.1474671. eCollection 2024.

Authors

Xiaogai Ge^{1

2}, Yilian Mao^{1

2}, Benzhi Zhou^{1

2}, Xiaoming Wang^{1

2}, Mai-He Li^{3

4

5}

Affiliations

¹ Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China.
² Qianjiangyuan Forest Ecosystem Research Station, National Forestry and Grassland Administration, Hangzhou, Zhejiang, China.
³ Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland.
⁴ Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education/School of Geographical Sciences, Northeast Normal University, Changchun, Jilin, China.
⁵ College of Life Science, Hebei University, Baoding, Hebei, China.

Abstract

Introduction: The variety of organs carbon concentration may be important for tree survival rate, drought resistance and tree subsequent recovery. However, it remains unclear how drought affect structural carbohydrate (SC) and non-structural carbohydrate (NSC) export and transport on clonal plant, which can be correlated with sustain physiological metabolism and group drought resistance by resource sharing. To better understand the adaption ability of clone plants to drought and the linkage of organ carbon with soil organic carbon (SOC) fractions, we assessed how long-term drought affects organ carbon and its impact on SOC fractions among moso bamboo (Phyllostachys edulis) ramets.

Methods: Throughfall exclusion included two treatments with simulated drought (TE) and control sample (CK, natural rainfall) by waterproofing panels, which excluded 70-80% of the precipitation. We measured the SC and NSC of leaves, branches and roots as well as soil organic carbon components on three ramets, which emerged in 2017 (grandma, GB), ramets that appeared in 2018 (mother bamboo, MB) and ramets emerging in 2019 (current-year bamboo, CB).

Results: The results showed that there was significant difference on lignin, cellulose: lignin ratio and soluble sugar in leaves and roots (p<0.05) instead of branches (p>0.05). Effect of drought on SC and NSC varied with different organs and ramet age. Drought significantly increased soluble sugar concentration of leaves and roots by 15.5-31.0% and 10.6-24.8% for current-year bamboo. Compared with CK, drought decreased SOC by 6.7-19.1%, microbial biomass carbon (MBC) by 55.3-68.7%, readily oxidizable carbon (ROC) by 11.2-29.8%, particulate organic carbon (POC) by 25.1-47.4% but no effect on mineral-associated organic carbon (MOC). Drought changed the relationships of carbon components between plant organs and soil. In the control treatments, SC of leaves were significantly positively correlated with ROC, NSC of branches were positively correlated with ROC and MBC, NSC of roots were significantly positively correlated with SOC.

Discussion: Overall, our results suggest that drought strengthened the linkage of plant organ carbon and soil carbon cycling among moso bamboo ramets in ecosystem studies, which are critical for predicting tree resistance and management in subtropical forest under drought.

Keywords: clone plant; drought; non-structural carbohydrate; soil organic carbon fractions; structural carbohydrate.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the Fundamental Research Funds for the National Natural Science Foundation of China (32071756), the Central Non-profit Research Institution (CAFYBB2020ZE001), Basic Public Welfare Research Project of Zhejiang Province (LGN21C030002), Qianjiangyuan National Forest Ecological Research Station, and the Swiss National Science Foundation (No. 213367).