Whole stream metabolism measurements as an indicator of ecosystem functions in urban streams

Whole stream measurements provide valuable information regarding the functional characteristic of stream ecosystems. We measured the whole stream metabolism in 6 streams with different land use patterns (forest, cropland, pasture, and urban developments). Three metabolism parameters (gross primary production, community respiration, net daily metabolism and diel dissolved oxygen amplitude) measured in three seasons and major land use coverage were selected and their relationships were analyzed using the correlation analysis. During spring, GPP, CR, DO_amp showed positive correlations with pasture area. The positive correlation between CR and pasture became stronger during summer, while GPP and DO_amp showed positive relationship with crop area. NDM showed a positive correlation against urban developed areas during summer. During fall, GPP showed a strong negative correlation against forested area, while showing positive correlations against crop land and developed areas. The developed areas also showed a negative correlation against CR during fall. Land use parameters did not show any significant correlations against diel DO changes during fall. Mean water temperature was not correlated to any metabolism parameters throughout the study. We believe that stream metabolism measurements can serve as a useful tool in understanding the functional changes in urbanizing stream ecosystems.