Urban parks play an important role for mitigating urban heat island and greenhouse gas emissions. For understanding the role of urban parks, we have conducted the eddy covariance measurements of energy, water vapor, and CO2 fluxes at an urban park. The urban park, Oizumi Ryokuchi Park, is 101.5 ha in size, located in Sakai City. The aerial fraction of the park is 52% trees, 22% grasses and waterweeds, 7% bare soil, 6% water, 12% pavement, and 1% buildings. The leaf area index of ten tree sectors ranged from 2.0 in the winter to 4.3 in the summer months. The mean tree height was estimated as 12.3.
