Spatial Gradients of Intensity and Persistence of Soil Water Repellency Under Different Forest Types in Central Mexico

Abstract

Organic residues release hydrophobic compounds to the soil that may induce soil water repellency (WR), which may inhibit infiltration and increase runoff and soil loss rates. Although there are many studies on soil WR through the world, very few investigations have been conducted in Mexican areas. This paper studies the natural background of soil WR in soils from central Mexico under representative forest types, analyzing the spatial distribution of soil WR in relation with tree canopy, vegetation cover and main soil chemical (pH, CaCO3, organic C content and exchangeable cations) and physical properties (texture). The water drop penetration time and the ethanol tests were used to assess persistence and intensity of soil WR, respectively. Although soil WR was not related with soil properties, it decreased strongly from soil below the canopy of conifers to soil below oaks. When different types of vegetation cover were considered, the proportion of water‐repellent soil increased following the sequence: bare soil < shrubs and herbaceous plants < shrubs < trees from fir, fir‐pine‐oak and pine‐oak forest. We found an inverse relation with distance to the tree trunks, contributing to create a patchy pattern of soil WR, with soils under the canopy of conifers showing the most severe WR levels. The spatial distribution of soil WR is also conditioned by microclimatic gradients, as persistence and intensity of soil WR were usually lower in shaded areas (upslope transects from the tree trunks), where soil moisture content is expected to be higher on average through the year. Copyright © 2016 John Wiley & Sons, Ltd.

Intensity and Persistence of Soil Water Repellency in Pine Forest Soil in a Temperate Continental Climate under Drought Conditions

“…More than likely, the fire in the central part contributed to substances which were mostly associated with certain plant species, with tissues rich in resins and waxes, such as pines [78], being burned out, and wettability was noted in all analysed layers 13 months after the fire.…”

Soil moisture influences sorptivity and water repellency of topsoil aggregates in native grasslands

“…High temporal and spatial variability is a vital aspect of hydrophobicity (Benito Rueda et al, 2016;Alanís et al, 2016;Keesstra et al, 2017) but this phenomenon is not permanent; maximum persistence and severity occurs in driest seasons, and diminish or even vanish in wet seasons (Keizer et al, 2007). Long periods of soil desiccation might promote the increase in persistence and severity in water repellency restricting the soil re-wetting, thus requiring a long time for the soil recover its wettability (Bodí et al, 2013).…”

Pinus halepensis M. versus Quercus ilex subsp. Rotundifolia L. runoff and soil erosion at pedon scale under natural rainfall in Eastern Spain three decades after a forest fire

“…The patches covered by Holm oak will only act as a source of surface runoff in two rainfall events per year, meanwhile Aleppo pine is actively contributing with runoff around 7 times per year, and the discharges in each event are higher. Most likely this is due to water repellency issue as was found by other researchers recently in Tropical and Wet Mediterranean climates (Benito Rueda et al, 2016;Alanís et al, 2017).…”