- Title
- Quantifying the influence of rainfall, vegetation and animals on soil erosion and hillslope connectivity in the monsoonal tropics of northern Australia
- Creator
- Hancock, Greg; Lowry, John
- Relation
- ARC.DP0556941 http://purl.org/au-research/grants/arc/DP0556941
- Relation
- Earth Surface Processes and Landforms Vol. 46, Issue 10, p. 2110-2123
- Publisher Link
- http://dx.doi.org/10.1002/esp.5147
- Publisher
- Wiley-Blackwell
- Resource Type
- journal article
- Date
- 2021
- Description
- Erosion of soil by water is facilitated by both diffusive and fluvial processes. Here we examine three different soil redistribution processes operating at very different spatial and temporal scales in the monsoonal tropics of northern Australia. The first process, rainsplash, operates across the entire catchment. This process, while subject to annual and seasonal variations in rainfall amount and intensity, can be considered a constant forcing and redistributes on average 9 t ha−1 year−1 (range −0.9 to 19 t ha−1 year−1). The second process, bioturbation, where in this study soil is disturbed by feral pigs (wild boar), occurs in selected areas throughout each year. Pigs exhume 3 to 36.0 t ha−1 year−1 (average ~11 t ha−1 year−1). The effect of this disturbance may last for many years afterwards. The third process is the disturbance of the soil surface by tree throw and creation of pit–mound topography (also a form of bioturbation), together with the resultant placement of the tree superstructure (above ground biomass) on the ground, which may form debris dams. Tree throw at the scale examined here is likely to occur only once every 50–100 years, with the influence of this single event lasting for at least 10 years post event. Tree throw in a single event exhumed ~5 t ha−1 (1.1–9.5 t ha−1) of soil. In contrast to rainsplash, pig disturbance and tree throw events are largely point-based phenomena. Field observation suggests that it takes many years for the disturbance from both pigs and tree throw to be removed. We find here that in terms of relative soil redistribution, rainsplash has the largest influence, with any erosional disturbance by pigs and tree throw being within the variability of rainsplash. However, the disruption of surface flow by the pig digs and tree throw disrupts sedimentological and hydrological connectivity.
- Subject
- bioturbation; connectivity; diffusion; erosion pins; feral pigs; rainsplash
- Identifier
- http://hdl.handle.net/1959.13/1450145
- Identifier
- uon:43836
- Identifier
- ISSN:0197-9337
- Rights
- This is the peer reviewed version of the following article: Hancock, Greg; Lowry, John. “Quantifying the influence of rainfall, vegetation and animals on soil erosion and hillslope connectivity in the monsoonal tropics of northern Australia”. Earth Surface Processes and Landforms Vol. 46, Issue 10, p. 2110-2123 (2021), which has been published in final form at http://dx.doi.org/10.1002/esp.5147. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
- Language
- eng
- Full Text
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