Seasonal variations in soil respiration and environmental factors were measured at a monthly time step for two years in three ecosystems (a deciduous broad-leaved forest, a deciduous needle-leaved forest and a grassland) under the same physical-geographical environmental conditions in central Japan. We then investigated the temperature sensitivity of soil respiration (Q₁₀) at each site for two phenological stages, the foliation and defoliation periods.

The seasonal patterns of soil respiration and soil temperature were nearly parallel among the three sites. Although Q₁₀ based on the entire measurement period were roughly the same for two years at the three sites, there was a large difference in Q₁₀ between the foliation and defoliation periods in both years, especially at the two forest sites. These differences may be caused by differences in soil temperature dynamics and precipitation activity. To better understand the relationship between soil respiration and environmental factors, continuous observations are needed of soil respiration, environmental factors, and biological activities both below ground and aboveground under the same physical-geographical environmental conditions.