Seasonal patterns of growth and nutrient status of the macroalga Adamsiella chauvinii (Rhodophyta) in soft sediment environments |
| |
Authors: | Louise T. Kregting Christopher D. Hepburn Catriona L. Hurd Conrad A. Pilditch |
| |
Affiliation: | aDepartment of Botany, University of Otago, PO Box 56, Dunedin 9015, New Zealand;bDepartment of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton, New Zealand |
| |
Abstract: | The seasonal growth and nutrient status of the temperate subtidal macroalga Adamsiella chauvinii was determined at three soft sediment sites with different ranges of tidally-driven current speeds. A. chauvinii thalli exhibited maximum growth rates during the late summer (February) and no evidence of nitrogen limited growth in summer as often exhibited by macroalgae growing on hard substrata in temperate environments. We suggest that growth was maintained during the summer period, when seawater nitrogen concentrations were low, by localized sources of ammonium probably produced by sediments and fauna within the canopy. Growth rates were up to 50% lower at the site with the slowest water velocity throughout most of the experimental period. However a greater tissue nitrogen content of A. chauvinii thalli at the slow flow site did not support evidence for mass-transfer limitation. It is suggested that as a consequence of slow flow, sedimentation on blade surfaces reduced the amount of light available for photosynthesis and growth. Lower growth rates at the slow flow site reduced metabolic demand for nutrients resulting in accumulation of tissue nitrogen and phosphate. |
| |
Keywords: | Adamsiella chauvinii Nitrogen Seasonal growth Subtidal macroalgae Water motion |
本文献已被 ScienceDirect 等数据库收录! |
|