Species-specific functional trait responses of canopy-forming and rosette-forming macrophytes to nitrogen loading : Implications for water-sediment interactions

Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved..

Globally intensified lake eutrophication, attributed to excessive anthropogenic nitrogen loading, emerges as a significant driver of submerged vegetation degradation. Consequently, the impact of nitrogen on the decline of submerged macrophytes has received increasing attention. However, a functional trait-based approach to exploring the response of submerged macrophytes to nitrogen loading and its environmental feedback mechanism was unclear. Our study utilized two different growth forms of submerged macrophytes (canopy-forming Myriophyllum spicatum, and rosette-forming Vallisneria natans) to established "submerged macrophytes-water-sediment" microcosms. We assessed the influence of nitrogen loading, across four targeted total nitrogen concentrations (original control, 2, 5, 10 mg/L), on plant traits, water parameters, sediment properties, enzyme activities, and microbial characteristics. Our findings revealed that high nitrogen (10 mg/L) adversely impacted the relative growth rate of fresh biomass and total chlorophyll content in canopy-forming M. spicatum, while the chlorophyll a/b and free amino acid content increased. On the contrary, the growth and photosynthetic traits of resource-conservative V. natans were not affected by nitrogen loading. Functional traits (growth, photosynthetic, and stoichiometric) of M. spicatum but not V. natans exhibited significant correlations with environmental variables. Nitrogen loading significantly increased the concentration of nitrogen components in overlying water and pore water. The presence of submerged macrophytes significantly reduced the ammonia nitrogen and total nitrogen both in overlying water and pore water, and decreased total organic carbon in pore water. Nitrogen loading significantly inhibited sediment extracellular enzyme activities, but the planting of submerged macrophytes mitigated their negative effects. Furthermore, rhizosphere bacterial interactions were less compact compared to bare control, while eukaryotic communities exhibited increased complexity and connectivity. Path modeling indicated that submerged macrophytes mitigated the direct effects of nitrogen loading on overlying water and amplified the indirect effects on pore water, while also attenuating the direct negative effects of pore water on extracellular enzymes. The findings indicated that the restoration of submerged vegetation can mitigate eutrophication resulting from increased nitrogen loading through species-specific changes in functional traits and direct or indirect feedback mechanisms in the water-sediment system.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:185

Enthalten in:

Environment international - 185(2024) vom: 21. März, Seite 108557

Sprache:

Englisch

Beteiligte Personen:

Tao, Min [VerfasserIn]
Zhang, Chang [VerfasserIn]
Zhang, Zhiqiang [VerfasserIn]
Zuo, Zhenjun [VerfasserIn]
Zhao, Haocun [VerfasserIn]
Lv, Tian [VerfasserIn]
Li, Yang [VerfasserIn]
Yu, Haihao [VerfasserIn]
Liu, Chunhua [VerfasserIn]
Yu, Dan [VerfasserIn]

Links:

Volltext

Themen:

059QF0KO0R
Chlorophyll A
Eutrophication
Functional traits
Journal Article
N762921K75
Nitrogen
Rhizosphere microbial community
Submerged macrophyte
Water
Water-sediment system
YF5Q9EJC8Y

Anmerkungen:

Date Completed 26.03.2024

Date Revised 26.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.envint.2024.108557

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369478495