Quantifying the Impact of Off-Road Driving on Root-Area Distribution in Soils

Abstract

Studies on the effects of off-road driving on soils were conducted in the Makuleke Contractual Park of the Kruger National Park. The studies were conducted on three different soils with different textures and soil compactibilities. Traffic pressure was applied with a game drive vehicle loaded with 10 sand bags, each weighing 70 kg, plus the driver. This gave a total vehicle mass of 3795 kg, simulating a vehicle fully laden with tourists. The results of the study reported here included comparing of the effects of four different tyre pressures on the root area distribution below each tyre pressure. At all sites, root density fractions under the tracks were reduced significantly at all tyre pressures, compared with the control values. Results indicated that root penetration percentage and root area distribution were reduced drastically as tyre pressure increased. Our work reaffirms previous research showing that higher tyre pressures cause higher sub-soil compaction than lower tyre pressures. Thus, driving with lower tyre pressures when driving off-road should be considered when developing management strategies for off-road driving in wildlife protected areas.

Status of Road Ecology Research in Africa: Do We Understand the Impacts of Roads, and How to Successfully Mitigate Them?

“…We found a shift in study focus across the continent in the last decade, from species distributions to that of landscape change (e.g., Maeda et al, 2010;Nortjé et al, 2016), specifically in Central Africa (e.g., Laporte et al, 2007;Kleinschroth et al, 2016). This is unsurprising given that this region of Africa has been recognised in recent years as a "conflict zone" (Laurance et al, 2014a), with high environmental costs accorded to infrastructure development or future impacts of climate change (Laurance et al, 2014a).…”

Finders' eaters: Increasing bush encroachment may shift carcass detection from diurnal avian to nocturnal mammalian scavengers

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“…The image threshold, that is, partitioning the image into a foreground and background, was adjusted until the sky as background (= white) and foliage as foreground (= black) were visually separated. The number of black and total (black + white) pixels was then counted, and the % canopy cover was calculated as the fraction of black pixels over total pixels (Chianucci, 2016; Nortjé et al., 2016). The % canopy cover was calculated as the fraction of black pixels to fall upon scrub vegetation over total pixels.…”

Review of existing knowledge on subsurface soil compaction in South Africa

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