Can nutrient enrichment influence the invasion of Phragmites australis?

Md Nazim Uddin; Randall William Robinson

doi:10.1016/j.scitotenv.2017.06.131

Can nutrient enrichment influence the invasion of Phragmites australis?

Sci Total Environ. 2018 Feb 1:613-614:1449-1459. doi: 10.1016/j.scitotenv.2017.06.131. Epub 2017 Jun 23.

Authors

Md Nazim Uddin¹, Randall William Robinson²

Affiliations

¹ Department of Ecology and Environmental Management, College of Engineering and Science, Victoria University, St Albans Campus, Melbourne, Vic. 8001, Australia; Institute of Sustainability and Innovation, College of Engineering and Science, Victoria University, St Albans Campus, Melbourne, Vic. 8001, Australia. Electronic address: Nazim.Uddin@vu.edu.au.
² Department of Ecology and Environmental Management, College of Engineering and Science, Victoria University, St Albans Campus, Melbourne, Vic. 8001, Australia; Institute of Sustainability and Innovation, College of Engineering and Science, Victoria University, St Albans Campus, Melbourne, Vic. 8001, Australia.

PMID: 28648370
DOI: 10.1016/j.scitotenv.2017.06.131

Abstract

Plant invasion and nutrient enrichment because of anthropogenic landscape modifications seriously threaten native plant community diversity in aquatic and wetland ecosystems. It is poorly understood, however, whether these two disturbances interact with the functional identity of recipient native plants to drive community change. We performed combined studies in the fields and greenhouse to examine whether nutrient enrichment may trigger the invasion of Phragmites australis in wetlands through competitive advantage over native Melaleuca ericifolia. Chemical characterizations of rhizosphere water were distinguished in two different nutrient enriched wetlands associated with and without Phragmites over the seasons. Significant changes in rhizosphere water were observed in invaded area compared to uninvaded area at both sites. High nitrogen (NO₃^-), phosphorous (PO₄^3-), dissolved organic carbon, phenolics contents, with low pH were found in invaded areas compared to uninvaded areas. Total biomass of Phragmites was positively regressed with rhizosphere water nitrogen (NO₃^-) and phosphorous (PO₄^3-) content. Nutrient addition significantly enhanced the growth and competitive ability of Phragmites over Melaleuca. In contrast, Melaleuca was significantly less competitive than Phragmites. There was a significantly positive correlation between the growth of Phragmites grown alone and its competitive ability. The findings in greenhouse studies coupled with characteristics of Phragmites and its' rhizosphere chemistry in the nutrient enriched fields suggest that nutrient enrichment may enhance Phragmites invasion through correspondingly increasing growth and maintaining inherent competitive advantages of Phragmites. Nutrient management could limit the vigorous growth of Phragmites in wetlands and thereby reduce invasion through competitive advantages over natives, which might have important management implications for wetland managers.

Keywords: Biodiversity; Ecosystems; Nutrient enrichment; Phragmites australis; Plant invasion; Wetland.

MeSH terms

Australia
Introduced Species
Nitrogen / analysis
Phosphorous Acids / analysis
Poaceae / growth & development*
Rhizosphere*
Saline Waters / chemistry*
Soil
Wetlands*

Substances

Phosphorous Acids
Soil
phosphonic acid
Nitrogen