Performance
- Soil Moisture
- Warming
- Radiation
- Humidity
Soil moisture
Decreased rainfall event size (-40%) during the summer (May-September) strongly reduced volumetric soil moisture content in the redistributed plots compared to the control plots (Figure 1). Increased rainfall event sizes during the spring (March-April) and autumn (October-November) months resulted in an increase in volumetric soil moisture content, however, this increase was smaller than the decrease during the summer (Figure 1).
 |
Fig.1. Volumetric soil moisture in the plots measured using Time Domain Reflectometry (TDR) probes, inserted vertically in the top 20 cm of the soil. Measurements until Dec 9, 2004 are based upon 10 probes per precipitation treatment, after Dec 9, 2004 are based upon 40 probes per precipitation treatment. |
Warming also consistently reduced soil moisture content, as seen in figure 2. The reduction averaged around 1% volumetric soil moisture content.
| Fig.2. Absolute volumetric soil moisture reduction in the warmed plots compared to the unwarmed plots. |
 |
Canopy had a strong influence on soil water content. Plots with a grass or a juniper canopy had reduced soil water contents compared with those with an oak canopy. This effect was particularly strong during the summer months (Figure 3). Within the plots with a grass canopy (i.e. grass monocultures and grass-tree mixtures), there were only minor differences in soil water content.
| Fig.3. Volumetric soil moisture content in the grass (green), juniper (purple) and oak (brown) monocultures. |
 |
Top of page
Warming
Top of page
Radiation
Top of page
Humidity
Top of page
|
