Premium
SEASONAL AND ZONAL VARIATION IN NITROGEN SOURCE FOR FOUR INTERTIDAL SEAWEEDS FROM NEW ZEALAND
Author(s) -
Phillips J.C.,
Hurd C. L.
Publication year - 2000
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1046/j.1529-8817.1999.00001-161.x
Subject(s) - intertidal zone , biology , nitrogen , rocky shore , standing crop , nutrient , nitrate , seasonality , ammonium , urea , botany , ecology , chemistry , biomass (ecology) , biochemistry , organic chemistry
Seasonal patterns in nitrogen uptake by four species of intertidal macroalgae ( Stictosiphonia arbuscula , Apophlaea lyallii , Scytothamnus australis , Xiphophora gladiata ) from Otago in New Zealand's south island were investigated. Field‐collected material from species occurring at different shore heights was exposed to inorganic (NO −3 , NH +4 ) and organic (urea) nitrogen at different concentrations (5μM, 30μM), and the rate of uptake over 30min intervals for 3hr was determined. Active uptake of nitrate was shown by all species in both seasons but uptake rates were 2–5 times greater in summer compared to winter. Ammonium uptake was highest in all species regardless of season, indicating a preference for this form of nitrogen. For all species, urea uptake was negligible during winter but represented a substantial proportion of the total nitrogen taken up during summer. Comparison of species in relation to their shore position revealed differences in uptake rates for each nitrogen source. These results suggest that intertidal seaweeds growing at different shore positions employ different strategies for procuring nitrogen in an environment where nutrient supply may be limited.