Post-fire Soil Hydrophobicity Degradation

This resource includes code and data used within manuscript titled \"Freeze-Thaw Processes Degrade Post-fire Water Repellency in Wet Soils\" submitted to the Hydrological Processes Journal.

Wildfires can cause heightened soil water repellency (hydrophobicity), which reduces infiltration while increasing erosion and flooding from post-fire rainfall. Post-fire soil water repellency degrades over time, often in response to repeated wetting and drying of the soil.

This study characterized the changes in hydrophobicity of Sierra Nevada mountain soils exposed to different combinations of wet-dry and freeze-thaw cycling. There are five treatments total consisted of 11 cycles and replicated 6 times. These treatments are:
1) WD -> wet/dry.
2) WDFT -> wet/dry/freeze/thaw
3) WFTD -> wet/freeze/thaw/dry
4) WFT -> wet/freeze/thaw (soil is wetted once but never dried)
5) DFT -> dry/freeze/thaw (soil is never wetted)

After each, cycle molarity of ethanol test (MED) was used to assess soil hydrophobicity. MED results are recorded in \"MED.xlsx\" under \"MED and SOM Data\" collection.

Soil Organic Matter (SOM) is often associated with soil hydrophobicity, thus we also measured SOM content of each cycle and treatment with 3 replicas for each using Walkley-Black test. SOM results are recorded in \"SOM.xlsx\" under \"MED and SOM Data\" collection.

Furthermore, soils of different hydrophobicities and one opportunistic sample of the 7th cycle of wet/dry/freeze/thaw treatment were imaged using scanning electron microscopy (SEM) in a BSE mode at 100 times resolution. Sizes of each individual aggregate were measured using ImageJ software and their area was recorded. SEM images along with recorded grain sizes can be found in the \"SEM\" collection.