Nitrogen addition mediates the response of foliar stoichiometry to phosphorus addition: a meta-analysis

Chengming You,Paul Kardol,Yang Liu,Zhenfeng Xu,Li Zhang,Changhui Peng,Rui Yin,Han Li,Sining Liu,Lixia Wang,Bo Tan,Lin Liu

doi:10.1186/s13717-021-00329-x

Abstract

BackgroundChanges in foliar nitrogen (N) and phosphorus (P) stoichiometry play important roles in predicting the effects of global change on ecosystem structure and function. However, there is substantial debate on the effects of P addition on foliar N and P stoichiometry, particularly under different levels of N addition. Thus, we conducted a global meta-analysis to investigate how N addition alters the effects of P addition on foliar N and P stoichiometry across different rates and durations of P addition and plant growth types based on more than 1150 observations.ResultsWe found that P addition without N addition increased foliar N concentrations, whereas P addition with N addition had no effect. The positive effects of P addition on foliar P concentrations were greater without N addition than with N addition. Additionally, the effects of P addition on foliar N, P and N:P ratios varied with the rate and duration of P addition. In particular, short-term or low-dose P addition with and without N addition increased foliar N concentration, and the positive effects of short-term or low-dose P addition on foliar P concentrations were greater without N addition than with N addition. The responses of foliar N and P stoichiometry of evergreen plants to P addition were greater without N addition than with N addition. Moreover, regardless of N addition, soil P availability was more effective than P resorption efficiency in predicting the changes in foliar N and P stoichiometry in response to P addition.ConclusionsOur results highlight that increasing N deposition might alter the response of foliar N and P stoichiometry to P addition and demonstrate the important effect of the experimental environment on the results. These results advance our understanding of the response of plant nutrient use efficiency to P addition with increasing N deposition.

Highlights

Human activities, including the increased use of artificial fertilizers and fossil fuel combustion, have led to increased concentrations of atmospheric reactive nitrogen (N) (Liu et al 2013; Peñuelas et al 2013)
The positive effects of P addition on foliar P concentrations were greater without N addition than with N addition, whereas the opposite pattern was found for the soil P availability (Fig. 1b, c, Additional file 1: Table S1)
These findings reveal that N enrichment can alter the foliar N and P stoichiometry in response to P addition, which suggests that we should consider the effects of experimental background conditions on the experiment to better understand how global change affects plants

Summary

Introduction

Human activities, including the increased use of artificial fertilizers and fossil fuel combustion, have led to increased concentrations of atmospheric reactive nitrogen (N) (Liu et al 2013; Peñuelas et al 2013). To improve our understanding of the P deficiency caused by human-induced imbalances in N and P inputs, many studies have investigated how P addition affects ecosystem processes and functions, such as foliar N and P stoichiometry (Mayor et al 2014; Mo et al 2019; Ostertag 2010; Yan et al 2015). Comprehensive analysis of foliar N and P stoichiometry in response to P addition is important for understanding how plants will adapt to future environmental changes. Changes in foliar nitrogen (N) and phosphorus (P) stoichiometry play important roles in predicting the effects of global change on ecosystem structure and function. We conducted a global meta-analysis to investigate how N addition alters the effects of P addition on foliar N and P stoichiometry across different rates and durations of P addition and plant growth types based on more than 1150 observations

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Discussion

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