Anthropogenic dust emissions due to livestock trampling in a Mongolian temperate grassland

Abstract

Abstract. Mongolian grasslands are a natural dust source region and they contribute to anthropogenic dust due to the long tradition of raising livestock there. Past decades of abrupt changes in a nomadic society necessitate a study on the effects of livestock trampling on dust emissions, so that research studies may help maintain a sustainable ecosystem and well-conditioned atmospheric environment. In this study, we conducted a mini wind tunnel experiment (using a PI-SWERL ® device) to measure dust emissions fluxes from trampling (at three disturbance levels of livestock density, N) and zero trampling (natural as the background level) at test areas in a Mongolian temperate grassland. Moreover, we scaled anthropogenic dust emissions to natural dust emissions as a relative consequence of livestock trampling. We found a substantial increase in dust emissions due to livestock trampling. This effect of trampling on dust emissions was persistent throughout all wind friction velocities, u * (varying from 0.44 to 0.82 m s −1 ). Significantly higher dust loading occurs after a certain disturbance level has been reached by the livestock trampling. Our results suggest that both friction velocity (u * ) and disturbance level of livestock density (N) have an enormous combinational effect on dust emissions from the trampling test surface. This means that the effect of livestock trampling on dust emissions can be seen or revealed when wind is strong. Our results also emphasize that better management for livestock allocation coupled with strategies to prevent anthropogenic dust loads are needed. However, there are many uncertainties and assumptions to be improved on in this study.

Evaluation of Climatic and Anthropogenic Impacts on Dust Erodibility: A Case Study in Xilingol Grassland, China

“…A key process in the weakening and destruction of soil crust is livestock trampling [45], in addition to strong wind, sand-dust storm [39], and the soil freezethaw process [39,46], usually in spring at our study site. Munkhtsetseg et al [47] measured dust emission fluxes by conducting a mini-wind tunnel experiment using a PI-SWERI device under three different intensity levels of livestock trampling in Mongolian grassland: they demonstrated an increase in dust occurrence in response to more intense livestock trampling. Forbidding grazing in Erodibility depends not only on the amount of roughness elements such as vegetation cover but also on soil surface conditions such as soil hardness.…”

Quantifying Anthropogenic Dust Emissions

“…Anthropogenic impacts on the wind erodibility and dust emission potential of landscapes may be extensive or intensive in terms of the area affected and the degree of land surface modification and, therefore, potentially have different levels of detectability at different spatial scales. For example, livestock grazing and trampling of rangelands can modify the foliar cover and height of vegetation (Aubault et al, ; Belnap et al, ) and break down protective soil crusts in the short term (Baddock et al, ; Leys & Eldridge, ; Munkhtsetseg et al, ), or act as a driver of long‐term ecological (land cover) change (Bestelmeyer et al, ). These impacts typically occur at the landscape scale (extensive), but can also be concentrated—for example, around livestock watering points that may become locally degraded and susceptible to accelerated wind erosion (i.e., net soil loss) and dust emission (e.g., Dougill et al, ).…”

Quantifying the effect of geomorphology on aeolian dust emission potential in northern China

“…Sankey et al, 2011;von Holdt et al, 2017) and grasslands (e.g. Munkhtsetseg et al, 2016Munkhtsetseg et al, , 2017. These studies have provided insights into the physical processes of dust emission and its dependency on soil characteristics (Bryant, 2013).…”

“…King et al, 2011;Sweeney et al, 2011), fluvial surfaces (e.g. Munkhtsetseg et al, 2016Munkhtsetseg et al, , 2017. Munkhtsetseg et al, 2016Munkhtsetseg et al, , 2017.…”