Relationship between phosphorus stoichiometric homeostasis and deepwater adaptability of submerged macrophytes in Erhai Lake, China: Insights from allometric plasticity

Qihang Wu; Ling Jin; Changqun Duan; Jiaqing Xu; Song Peng; Shili Shen; Ying Pan; Torben L Lauridsen; Erik Jeppesen

doi:10.1016/j.watres.2024.122468

Relationship between phosphorus stoichiometric homeostasis and deepwater adaptability of submerged macrophytes in Erhai Lake, China: Insights from allometric plasticity

Water Res. 2024 Sep 17:267:122468. doi: 10.1016/j.watres.2024.122468. Online ahead of print.

Authors

Qihang Wu¹, Ling Jin¹, Changqun Duan¹, Jiaqing Xu², Song Peng², Shili Shen¹, Ying Pan³, Torben L Lauridsen⁴, Erik Jeppesen⁴

Affiliations

¹ School of Ecology and Environmental Sciences, Yunnan University & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Kunming 650091, Yunnan, China; International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management of Yunnan, Kunming 650091, Yunnan, China.
² Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Trans-Boundary Eco-security, Yunnan University, Kunming, 650091, China.
³ School of Ecology and Environmental Sciences, Yunnan University & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Kunming 650091, Yunnan, China; International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management of Yunnan, Kunming 650091, Yunnan, China. Electronic address: panying@ynu.edu.cn.
⁴ Department of Ecoscience, Aarhus University, Aarhus 8000, Denmark.

PMID: 39303579
DOI: 10.1016/j.watres.2024.122468

Abstract

The state transition theory suggests that the decline of submerged macrophytes in shallow lakes is closely associated with reduced stoichiometric homeostasis, particularly phosphorus homeostasis (H_P). The degradation typically progresses from deeper to shallower regions, indicating a potential positive correlation between the deepwater adaptability (DA) and H_P values of submerged macrophytes. Here, we investigated the distribution pattern of submerged macrophytes across different water depths of Erhai Lake to test this hypothesis. The results revealed a significant positive correlation between the DA and H_P values of submerged macrophytes. Allometric analysis indicated that the morphological plasticity of submerged macrophytes was linked to their H_P. Species with higher H_P values, like Potamogeton maackianus, had robust plasticity strategies, particularly "real plasticity", that enabled them to cope with deeper water stress. In contrast, species with lower H_P values (Ceratophyllum demersum and Hydrilla verticillata) experienced nutrient declines, which hindered their adaptation. Additionally, species with higher H_P values exhibited closer connections within the plant traits-environment network, indicating that their morphological plasticity adjustments allow better adaptation to the environmental changes caused by increasing water depth. These results confirm the relationship between DA and H_P in submerged macrophytes and explain the mechanisms underlying the correlation, thus expanding regime shift theory.

Keywords: Allometric analysis; Deepwater adaptability; Phenotypic plasticity; Plant traits-environment network; Real plasticity; Stoichiometric homeostasis.