Changes in species abundances with short-term and long-term nitrogen addition are mediated by stoichiometric homeostasis

Tian Yang,Anke Jentsch,Melinda D Smith,Qian Gu,Chong Xu,Yadong Yang,Jinling Zhao,Leena Vilonen,Honghui Wu,Min Long,Qiang Yu,Nianpeng He

doi:10.1007/s11104-021-05141-2

Abstract

Background Increasing nitrogen (N) deposition has altered plant communities globally, however the changes in species abundances with short-term vs. long-term N enrichment remains unclear. Stoichiometric homeostasis, quantified by the homoeostatic regulation coefficient (H) is a key trait predictive of plant species dominance and species responses to short-term global changes. It is unknown whether H changes with N enrichment over time, thereby affecting species responses to long-term N addition. Methods Here we investigated three representative plant species how species dominance changed to short-term and long-term N addition with a field N addition experiment (2006–2013) in an Inner Mongolia grassland. Changes in species H with long-term N addition were analyzed using a sand culture experiment, and the correlation between species H and species abundances were explored to address the above research gaps. Results The abundance of Leymus chinensis decreased with short-term N addition, and increased with long-term N addition, while Chenopodium glaucum exhibited the opposite pattern. Cleistogenes squarrosa was only favored by 1-year N addition, and depressed by two or more years of N addition. The H values of L. chinensis and C. glaucum decreased significantly with long-term N addition, but did not change for C. squarrosa. The H values were significantly related with the abundance both in Control and long-term N addition treatments. Conclusion Species abundance had opposite responses to short-term vs. long-term N addition. The decrease of H suggested the nutrients use strategy became more progressive, which mediated the responses of species abundances to short- and long-term N addition.

Highlights

Increasing fertilizer application and fossil fuel combustion has drastically accelerated atmospheric nitrogen (N) deposition (Zhu et al 2016; Yu et al 2019), and in turn has altered plant species composition of various ecosystems globally in the last several decades (Harpole et al 2016)
The H values of L. chinensis and C. glaucum decreased significantly with long-term N addition did not change for C. squarrosa
The decrease of H suggested the nutrients use strategy became more progressive, which mediated the responses of species abundances to short- and long-term N addition

Summary

Introduction

Increasing fertilizer application and fossil fuel combustion has drastically accelerated atmospheric nitrogen (N) deposition (Zhu et al 2016; Yu et al 2019), and in turn has altered plant species composition of various ecosystems globally in the last several decades (Harpole et al 2016). There are several potential mechanisms underlying community composition change with N addition, including light competition (Hautier et al 2009), nutrient competitive exclusion (Burson et al 2018), soil acidification (Chen et al 2017), manganese poisoning (Tian et al 2016), and litter accumulation (Fang et al 2012). What is often not taken into account is that species traits related to nutrient strategies may change with long-term N addition (Li et al 2017; Zheng et al 2019), which might induce shifts in the relative importance of different mechanisms

Methods

Results

Conclusion