Seasonality and Species Specificity of Submerged Macrophyte Biomass in Shallow Lakes Under the Influence of Climate Warming and Eutrophication.

Haoping Wu,Yanpeng Cai,Hyunbin Jo,Beibei Hao

doi:10.3389/fpls.2021.678259

Abstract

Climate warming and eutrophication caused by anthropogenic activities strongly affect aquatic ecosystems. Submerged macrophytes usually play a key role in shallow lakes and can maintain a stable clear state. It is extremely important to study the effects of climate warming and eutrophication on the growth of submerged macrophytes in shallow lakes. However, the responses of submerged macrophytes to climate warming and eutrophication are still controversial. Additionally, the understanding of the main pathways impacting submerged macrophytes remains to be clarified. In addition, the influence of seasonality on the growth responses of submerged macrophytes to climate warming and eutrophication requires further elucidation. In this study, we conducted a series of mesocosm experiments with four replicates across four seasons to study the effects of rising temperature and nutrient enrichment on the biomass of two submerged macrophytes, Potamogeton crispus and Elodea canadensis. Our results demonstrated the seasonality and species specificity of plant biomass under the influence of climate warming and eutrophication, as well as the main explanatory factors in each season. Consistent with the seasonal results, the overall results showed that E. canadensis biomass was directly increased by rising temperature rather than by nutrient enrichment. Conversely, the overall results showed that P. crispus biomass was indirectly reduced by phosphorus enrichment via the strengthening of competition among primary producers. Distinct physiological and morphological traits may induce species-specific responses of submerged macrophytes to climate warming and eutrophication, indicating that further research should take interspecies differences into account.

Highlights

IntroductionRapid changes, such as climate change and pollution have exerted strong stress on aquatic ecosystems globally (IPCC, 2014; Steffen et al, 2015)
Because of anthropogenic activities, rapid changes, such as climate change and pollution have exerted strong stress on aquatic ecosystems globally (IPCC, 2014; Steffen et al, 2015)
According to the results of two-way ANOVA, significant effects of temperature could be observed on E. canadensis biomass in spring (p = 0.012), summer (p = 0.001), and autumn (p = 0.043), and on P. crispus biomass only in spring (p = 0.034)

Summary

Introduction

Rapid changes, such as climate change and pollution have exerted strong stress on aquatic ecosystems globally (IPCC, 2014; Steffen et al, 2015). It has been suggested that the alteration of temperature and nutrient availability will change the ecosystem structure and thereafter threaten the ecological functioning of shallow lakes (Liboriussen et al, 2005; Özkan et al, 2010; Kosten et al, 2012; Hao et al, 2020). Submerged macrophytes are an important component in aquatic ecosystems and usually play a vital role in the ecological functioning of shallow lakes (Jeppesen et al, 2012; Hao et al, 2017). It is wellknown that submerged macrophytes can maintain clear water by regulating nutrient retention and cycling in aquatic ecosystems (Jeppesen et al, 2012; Wu et al, 2021)

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Discussion

Conclusion