Plant community re-organization and increased productivity due to multi-year nutrient enrichment of a coastal grassland

PLoS One. 2022 Jul 28;17(7):e0270798. doi: 10.1371/journal.pone.0270798. eCollection 2022.

Abstract

Nutrient enrichment alters plant community structure and function at a global scale. Coastal plant systems are expected to experience increased rates of nitrogen and phosphorus deposition by 2100, caused mostly by anthropogenic activity. Despite high density of studies investigating connections between plant community structure and ecosystem function in response to nutrient addition, inconsistencies in system response based on the ecosystem in question calls for more detailed analyses of nutrient impacts on community organization and resulting productivity response. Here, we focus on nutrient addition impacts on community structure and organization as well as productivity of different lifeforms in a coastal grassland. We established long-term nutrient enrichment plots in 2015 consisting of control (C), nitrogen (N), phosphorus (P), and nitrogen + phosphorus (NP) treatments. In 2017 we collected graminoid and forb productivity, root productivity, and community composition for each plot. We found no N x P interaction, but N enrichment was a significant main effect on productivity, highlighting N limitation in coastal systems. Importantly, nutrient enrichment treatments did not alter root productivity. However, all treatments caused significant differences in community composition. Using rank abundance curves, we determined that community composition differences were driven by increased dominance of nitrophilous graminoids, re-organization of subordinate species, and species absences in N and NP plots. Results of this study highlight how coastal grassland communities are impacted by nutrient enrichment. We show that community re-organization, increased dominance, and absence of critical species are all important mechanisms that reflect community-level impacts of nutrient enrichment in our coastal grassland site.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ecosystem*
  • Grassland*
  • Nitrogen / analysis
  • Nutrients / analysis
  • Phosphorus / analysis
  • Plants
  • Soil / chemistry

Substances

  • Soil
  • Phosphorus
  • Nitrogen

Grants and funding

National Science Foundation, grant numbers DEB-1237733 and DEB-1832221 to JCZ https://www.nsf.gov/div/index.jsp?div=DEB Virginia Commonwealth University Dean’s Funds to JCZ https://www.vcu.edu The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.