Spatial and Temporal Variability of Soil Respiration Rate at a Small Watershed Revegetated with Japanese Cypress.

Abstract

Soil respiration rate was measured for 2.5 years along the slope at Kiryu Experimental Watershed in Shiga Prefecture, Japan. The soil respiration rate was lower at the bottom of slope with saturated conditions, than that at the upper part of slope with unsaturated condition. Seasonal fluctuations of the soil respiration rate were related to soil temperature and soil water content. Drought induced the decline of the soil respiration rate. The soil respiration rate exponentially increased with soil temperature and Q_<10> ranged between 2.00 and 2.20. The second order polynomial model fitted best for the relationship with soil water content. Using these relationships, annual soil respiration was estimated to be 692±21, and 716±46gCm^ yr^ for 2003 and 2004, respectively.