Competitive effects of Phragmites australis on the endangered artesian spring endemic Eriocaulon carsonii

• Published in: Aquatic botany Vol. 92; no. 4; pp. 245 - 249
• Main Authors: Davies, Richard J.-P., Mackay, Duncan A., Whalen, Molly A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2010; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Biological and medical sciences; Competition; Eriocaulon; Fen; Freshwater; Fundamental and applied biological sciences. Psychology; Mound springs; Phenology; Phragmites; Phragmites australis; Plants and fungi; Threatened species; Wetland management; Australia; Competition; Phragmites; Threatened species; Phenology; Eriocaulon; Mound springs; Wetland management; Fen; Monocotyledones; Endemic species; Endangered species; Phragmites australis; Aquatic environment; Mounds; Gramineae; Angiospermae; Spermatophyta; Aquatic plant; Wetland
• ISSN: 0304-3770; 1879-1522
• DOI: 10.1016/j.aquabot.2009.12.003

We investigated the relative importance of above- and below-ground competition by reeds ( Phragmites australis (Cav.) Trin. ex Steud) on the growth rate of Eriocaulon carsonii F.Muell. subsp. carsonii, an endangered plant threatened by reeds on artesian springs in Australia. Soil-filled buckets containing E. carsonii were frequently watered to simulate artesian spring conditions and subject to three treatments: (1) no Phragmites (control), (2) Phragmites (ABG), and (3) Phragmites with shoots tied back (BG). After thirteen months, Phragmites mean below-ground biomasses had increased to c. 3 kg m −2 and mean above-ground biomasses to c. 1 kg m −2. After the same period, mean root biomass of E. carsonii plants was significantly lower in buckets subject to both Phragmites treatments compared with control plants, as was E. carsonii foliage area. Comparison of the two Phragmites treatments indicated that below-ground competition was the primary cause of this reduced growth in E. carsonii. The vulnerability of E. carsonii to competitive exclusion by P. australis is in part due to the highly synchronized phenologies of the two species.