Figure 1.
Seasonal patterns of precipitation (gray rectangle), soil moisture (black dashed line), soil temperature (black line) and soil respiration (gray line) during the growing seasons of 2006 (a) and 2009 (b).
Figure 2.
The response of soil respiration to rain pulses under different rain sizes.
Open circles are the measured data and shown as mean ± standard deviation. Exponential equations in the form of y = y0+ate−bt are used to fit the data (represented by solid lines). Rain size is shown in each panel. The 0 in the x-axis represents the day before the rainfall event.
Figure 3.
The relationship between dependent variables including the peak time (Tpeak) and the duration (Tduration) of the pulses, and the pulse effects on soil respiration, and independent variables including rain size (a, b, c) and WSI (rain size × the ratio of antecedent soil temperature to soil moisture; d, e, f) in 2006 (solid circle) and 2009 (open circle), respectively.
Figure 4.
The frequency distribution of different class-categories of rainfall events (a) and dry-spell events (c) during the growing seasons of 2006 and 2009.
The long-term mean annual precipitations from 1953 to 2009 are also represented here by black columns. The insert panels show the precipitation during the growing season (b) and the mean dry-spell duration during the growing season (d) in 2006 and 2009.
Figure 5.
The relationships between the rain size and the change in water availability after a rainfall event (ΔSM; the changes in the largest volumetric soil moisture after a rainfall event from the antecedent volumetric soil moisture) in 2006 (open circle) and 2009 (solid circle) with the coefficient (r2) and the significance level (P-value).