Trees are more efficient than shrubs in controlling aeolian erosion

August 26, 2014

By renewing the methods used to model aeolian erosion in the presence of vegetation, INRA and CNRS researchers have shown that trees are more efficient that shrubs in reducing this type of soil erosion.

The replanting of land is a common technique used to limit aeolian erosion in arid regions. By renewing the methods used to model aeolian erosion in the presence of vegetation, INRA and CNRS researchers have shown that trees are more efficient that shrubs in reducing this type of . The model thus developed constitutes a promising tool to quantify aeolian erosion in semi-arid regions which causes numerous environmental problems. This work was published in the Journal of Geophysical Research Earth Surface in February 2014.

Aeolian erosion corresponds to the transportation of by the wind (saltation) and the emission of dusts into the atmosphere following the impact of these grains on the ground. Saltation can damage crops by abrading, burying or uprooting them, and forming sand dunes in desert regions. Dust emissions can locally reduce the fertility of , and have a global impact on cloud formation and the terrestrial radiation balance. This can also have health consequences linked to its inhalation by humans, the spread of potentially pathogenic agents and the dispersal of pollutants. The replanting of land is a common technique used to reduce aeolian erosion in regions vulnerable to desertification, but its efficiency as a function of the type of vegetation, and its organisation, are not yet well understood. Furthermore, the models currently available to quantify aeolian erosion are poorly adapted to sparsely planted surfaces because of their crude representation of the wind.

A digital model to renew the modelling of erosion in the presence of vegetation

INRA and CNRS scientists have developed an original modelling technique for soil saltation by instantaneously reproducing the overall interaction between the movement of several million sand grains and the wind at that time, and their interactions with soil and vegetation. An initial version of this model without vegetation had previously been designed by the same authors to reproduce sand ridges oscillating on the surface of a beach in a stiff wind. By including vegetation in this second version of the model, the team was able to show that for the same land area, trees were more efficient than shrubs in reducing aeolian erosion. Although shrubs trap saltation particles, trees induce a reduction in wind speed at a larger scale the the simply local protective effect of shrubs. Furthermore, a reduction in aeolian erosion seems to be strongly dependent on the arrangement of vegetation relative to wind direction.

A first step to quantify the aeolian erosion of soils in semi-arid regions

Semi-arid regions are a major source of atmospheric dust. Unlike deserts, these regions are characterised by sparse, seasonal vegetation. These research findings will help to better quantify in these regions. This is particularly important because the loss of fertility of agricultural soils in these regions is expected to increase in future years under the combined effects of climate change and modifications to land use linked to human activities. Indeed, these regions are climatic transition zones, notably in terms of the amplitude and frequency of rainfall that affect plant cover on the land and hence aeolian erosion of the soil. These regions are also subject to marked growth in the population, leading to radical changes in land use such as the extension and intensification of cultivated areas.

Explore further: Loess landscapes could be major source of dust

More information: S. Dupont, G. Bergametti, and S. Simoëns, "Modeling Aeolian erosion in presence of vegetation." Journal of Geophysical Research Earth Surface, Vol. 119, pp168-187, DOI: 10.1002/2013JF002875, February 2014.

Related Stories

Loess landscapes could be major source of dust

September 3, 2013

Dust, which affects weather and climate and can be hazardous to health, can be generated when sand or silt grains are either dislodged from the surface by other windblown grains (saltation) or lifted by wind directly (direct ...

Soil carbon 'blowing in the wind'

August 2, 2013

Top soil is rich in nutrients and carbon but is increasingly being blown away by events such as the 'Red Dawn' in Sydney in 2009.

Sand drift explained

April 7, 2011

Researchers in countries such as Denmark, the Netherlands and Poland study sand drift, but most of them are focusing on sand dunes along the coastline, not on the plains further inland.

Recommended for you

Scientists capture Earth's 'hum' on ocean floor

December 7, 2017

Scientists have long known earthquakes can cause the Earth to vibrate for extended periods of time. However, in 1998 a research team found the Earth also constantly generates a low-frequency vibrational signal in the absence ...

Birth of a storm in the Arabian Sea validates climate model

December 6, 2017

Researchers from Princeton University and the National Oceanic and Atmospheric Administration (NOAA) report in the journal Nature Climate Change that extreme cyclones that formed in the Arabian Sea for the first time in 2014 ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.