Primary production of Utricularia foliosa L., Egeria densa PlanchonandCabomba furcata Schult & Schult.f from rivers of the coastal plainof the State of Sao Paulo, Brazil

摘要

Seasonal variation in gross primary production (GPP) of Utricularia foliosa Linnaeus, Egeria densa Planchon and Cabomba furcata Schult & Schult.f. in rivers of the coastal plain of the state of Sao Paulo, Brazil was examined in relation to water physico-chemistry. These three species do not affect the multiple uses of the streams and are present throughout the year. The most productive was U. foliosa (maximum production 24.7 mgO sub(2) g super(-1) DW h super(-1)), while C. furcata had an intermediate GPP (maximum production 17.5 mgO sub(2) g super(-1) DW h super(-1)) and E. densa was lowest at 5.6 mgO sub(2) g super(-1) DW h super(-1). Despite the low amplitude of seasonal variation in this south tropical area, the three species showed seasonal variation in the primary production: GPP was positively correlated with photosynthetic active radiation for U. foliosa and E. densa, and there was a negative correlation for C. furcata. For U. foliosa, GPP was positively correlated with temperature and dissolved inorganic carbon and the GPP of C. furcata was positively correlated with dissolved inorganic carbon.