Managing degraded rangelands to bring them to a more productive state requires a good understanding of the impacts that conservation efforts may have on local biotic and abiotic conditions.
Properly conducted soil and water conservation practices can be beneficial to capture precipitation and store moisture for longer periods. In turn, this increase in moisture residence time can be beneficial for plant production, it can help recharge the soil profile, and in some cases, it can contribute to subsurface flow and groundwater recharge.
Since 2012, a series of conservation practices including land imprinting, grade control structures, small basins, and planting of native shrubland species (Atriplex canescens) and (Prosopis glandulosa) have been conducted in a 500 ha watershed in a rangeland location in the Chihuahuan Desert, in northern Mexico. In March of 2014, we began our collaborative research work to investigate plant-soil-water relationships following these restoration efforts.
We have instrumented the site to monitor rainfall, soil moisture, soil temperature, and shallow groundwater fluctuations. Also, vegetation variables such as canopy cover, species frequency, and planted shrub-growth response are being evaluated.
Preliminary results show that average annual precipitation at the study site was 293 mm. Results provided valuable information regarding precipitation effects on soil moisture response at shallow (20 cm) and deeper (50 and 80 cm) depths. A greater soil moisture response, and variability, was observed in sensors located at 20 cm depth when compared to deeper probes. Shallow probes responded relatively rapid to specific precipitation events, particularly during the monsoon season. An increase in soil moisture level observed during the winter season in all probes was attributed to decreased plant water uptake during dormancy.
Study results provide valuable information towards understanding ecohydrologic response following land conservation practices in arid environments.