Production-Respiration Relationships at Different Timescales within the Biosphere 2 Coral Reef Biome

Temporal relationships between organic carbon production and respiration are not well understood in coral reef ecosystems. We monitored dissolved oxygen (O2) concentrations within the Biosphere 2 coral reef biome over a 3-yr period (1 January 1997-1 January 2000), to calculate daily rates of gross production (P), community respiration (R), and net community production (NCP). P averaged 170 mmol $O_2\>m^{-2}\>d^{-1}$, and R averaged 173 mmol $O_2\>m^{-2}\>d^{-1}$, which yielded a mean NCP of only -3 mmol $O_2\>m^{-2}\>d^{-1}$, or a difference of only 2%. This long-term balance between P and R reflects the closed-system design of the biome. The SD of P, however, was ±56 mmol $O_2\>m^{-2}\>d^{-1}$; that of R was ±47 mmol $O_2\>m^{-2}\>d^{-1}$; and that of NCP was ±26 mmol $O_2\>m^{-2}\>d^{-1}$ or ±15% of mean P. To better resolve the behavior of P, R, and NCP at different timescales, each of these time series were spectrally decomposed into four frequency bands that corresponded to four timescales: 3 months (seasonal to annual). At timescales >1 month, the variance of P was not different from the variance of R. At timescales of