The effects of Woylie (Bettongia penicillata) foraging on soil water repellency and water infiltration in heavy textured soils in southwestern Australia

Abstract

In the wheatbelt region of Western Australia, brush-tailed bettongs or woylies, Bettongia penicillata, occur in remnant woodlands that have highly water repellent soils. As these marsupials dig for the fruiting bodies of hjfpogeous fungi they disturb the soil surface. The effect of these diggings was evaluated by laboratory and in situ assessments of soil water repellency. The undisturbed woodland soil surface showed severe water repellence whereas diggings had low water repellence, and appear to act as preferential water infiltration paths after autumn rainfall events. This indicates that Bettongia penicillata has an impact on the non-wetting property of soils in this region.

Seasonal changes in the soil hydrological and erosive response depending on aspect, vegetation type and soil water repellency in different Mediterranean microenvironments

“…This generates a feedback process (Pugnaire et al, 1996;Cerdá, 1997;Holmgren et al, 1997) that continuously improves the soil properties of so-called fertility islands (Schlesinger et al, 1990). Due to the good soil conditions and the biological activity, Hortonian overland flow generated by repellent conditions was rapidly reinfiltrated through animal burrows (Garkaklis et al, 1998), root channels and macropores (Sevink et al, 1989;Doerr et al, 2003), and there was no connectivity between the small patches source of runoff, even at a plot scale.…”

When losing your nuts increases your reproductive success: sandalwood (Santalum spicatum) nut caching by the woylie (Bettongia penicillata)

“…Thus, woylies have the potential to alter the fate of the seeds and subsequent sandalwood regeneration and to modify the distribution of sandalwood (Murphy et al 2005). The bettongs' foraging activity has been shown to be important in ecosystem function (Garkaklis et al 2004): as well as being a vector for mycorrhizal fungal spores, they can help create heterogeneity in nutrients (Noble 1993) and the water repellency of surface (Garkaklis et al 1998) and subsurface soils (Garkaklis et al 2000).…”

Digging by vertebrates as an activity promoting the development of water-repellent patches in sub-surface soil

“…Fires in this vegetation can lead to thin, intensely water-repellent layers that have formed lower in the soil horizon due to the combustion of organic material at the surface (De Bano et al, 1970;De Bano & Rice, 1973). In Australia, soil water repellency can be altered by vertebrates whose digging has been shown to cause discontinuities in surface soil water repellency, leading to preferential water infiltration (Garkaklis et al, 1998). However, although disturbed areas around these diggings are water absorbent, some diggings show a slight increase in soil water repellency at the bottom of the holes (Garkaklis et al, 1998).…”

“…Hydrophobic organic compounds that make soils waterrepellent are derived from fungal hyphae, soil micro-organisms and decomposing plant material (Bond, 1964;Roberts & Carbon, 1972;De Bano & Rice, 1973). Water repellency causes a reduced infiltration rate of water (De Bano, 1969), and may lead to uneven water infiltration (Burcar et al, 1994;Harper & Gilkes, 1994;Garkaklis et al, 1998), extensive surface runoff and erosion in environments affected by fire (Osborne et al, 1964;Scott, 1997), as well as a decrease in the germination of seeds (Osborne et al, 1967).…”

“…In Australia, soil water repellency can be altered by vertebrates whose digging has been shown to cause discontinuities in surface soil water repellency, leading to preferential water infiltration (Garkaklis et al, 1998). However, although disturbed areas around these diggings are water absorbent, some diggings show a slight increase in soil water repellency at the bottom of the holes (Garkaklis et al, 1998). Leaf litter quickly accumulates in these holes once they are dug and the slight elevation in water repellency at the base of diggings could be due to this build-up of organic material.…”