Effects of salinity on growth, competitive interaction and total nitrogen content of two estuarine macrophyte species cultivated on artificial substrate

Author(s)

Nunes, Lais Samira Correia ^[1] ; Camargo, Antonio Fernando Monteiro ^{[1, 2]}

Affiliation

^[1] Univ Estadual Paulista, Programa Posgrad Ciencias Biol Biol Vegetal, UNESP, Ave 24-A, 1515, BR-13506900 Rio Claro, SP - Brazil

^[2] Univ Estadual Paulista, Dept Biodiversidade, Inst Biociencias, UNESP, Ave 24-A, 1515, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: AQUATIC ECOLOGY; v. 54, n. 4 JUL 2020.
• Web of Science Citations: 0

Abstract

Salinity can compromise the growth of aquatic macrophytes, influencing their nutrient content and interspecific interactions. In estuaries, the sediment characteristics vary in salinity as well as nutrient availability, granulometry and microbiota. The use of artificial substrates in manipulative experiments allows the evaluation of the isolated effect of salinity on plants. We evaluated the effects of salinity on growth, interspecific interaction and total nitrogen (TN) content of the estuarine macrophytesSpartina alternifloraandCrinum americanumcultivated on expanded vermiculite. We conducted a two-factor experiment (3 cultures x 3 salinities x 5 replicates = 45 experimental units) lasting 185 days in a greenhouse. We cultivated monocultures (8:0 and 0:8) and mixed cultures (4:4) at 0, 20 and 30 ppt salinity levels with the same concentration of nutrient solution. We found that salinity did not influence the growth ofS. alternifloraandC. americanumin monoculture. In mixed culture, there was an asymmetric competition, asS. alternifloralimited the growth of the aboveground fraction ofC. americanumat higher salinity; however,C. americanumdid not limit the growth ofS. alternifloraat any treatment. Salinity did not influence the TN content inS. alterniflora. However,C. americanumhad greater TN content in the aboveground fraction at higher salinity, possibly as a strategy of salt tolerance. The TN content in the aboveground fraction ofC. americanumwas lower in the mixed cultures than in the monocultures, indicating an effect of the interspecific interaction. (AU)

• FAPESP's process: 16/01416-4 - Spatial distribution and competitive interaction among aquatic macrophytes in tropical estuaries
• Grantee: Lais Samira Correia Nunes
• Support type: Scholarships in Brazil - Doctorate