Soil Moisture Dynamics in Response to Precipitation and Thinning in a Semi-Dry Forest in Northern Mexico

Abstract

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.

Rainfall interception by mountain big sagebrush (Artemisia tridentata spp. vaseyana): Dryland shrub canopy cover affects net precipitation

“…A growing body of research indicates that interception losses are highest for small storms (Rascón‐Ramos et al, 2021; Zhu et al, 2017) and canopy interception plays a significant role in preventing soil moisture recharge (Rascón‐Ramos et al, 2021; Zhu et al, 2017). In this study, we focused on storm amounts between 5 and 20 mm h −1 , while most discrete rain events at the study site are much smaller.…”

“…Interception is an important factor in understanding hydrological effects of plant cover both in water budget modelling (e.g., Breuer et al, 2003) and for ecological considerations. Interception loss is quantified to estimate the varying effects of tree species and thinning on the water budget in plantations (Rascón‐Ramos et al, 2021; Zhu et al, 2017), the effects trees have on runoff in urban areas (Beidokhti & Moore, 2021; Holder & Gibbes, 2017; Nytch et al, 2019), and to understand how plant communities may respond to climate change and changing rainfall regimes (Crockford & Richardson, 2000; Niemeyer et al, 2016). Interception is affected by total precipitation (Muzylo et al, 2009), storm intensity (Levia et al, 2019), droplet size (Calder et al, 1996; Levia et al, 2019), wind speed (Klaassen et al, 1996), plant architecture and branching (Domingo et al, 1998), leaf size and shape (Beidokhti & Moore, 2021; Yan et al, 2021), bark characteristics (Beidokhti & Moore, 2021; Tonello et al, 2021), and canopy cover (Jian et al, 2014; Soulsby et al, 2017; Stringham et al, 2018; Zhang et al, 2020).…”