The temperature response of gross and net community production and respiration in time-varying assemblages of temperate marine micro-plankton

Abstract

Micro-organism community respiration and net community production rates and their response to temperature were determined as oxygen flux rates in the Menai Strait during a 6-month period including the spring and summer of 1993. The rates for gross community production were calculated from polynomial fits of community respiration and net community production data. The cardinal temperatures of gross community production were estimated from these equations. The optimal temperature was positively correlated to the in situ temperature. The natural population gave no evidence of being shocked due to experimental temperature manipulation. Frequency histograms of the temperature coefficients of community respiration and gross community production were distinct in this environment. Q 10 values for respiration were greater than Q 10 values for photosynthesis, in contrast to published observations from the Southern Ocean where they overlapped. It was argued that this was a consequence of the short-term temperature variability of the environment.