If you’ve ever wondered why off-roading may be restricted, governed or even completely prohibited in wild areas around Africa, then this section is for you.
Off-road driving (ORD) is when vehicles are driven off of marked/established tracks or roads, either into the bush or down riverbeds. ORD protocols in our area are usually regulated and are dependent on multiple factors.
If regulated, off-roading policies or protocols are usually decided based on each property’s rules and regulations, management strategies, geology/soil types, geographical location and sometimes even method of income (e.g. ecotourism). Here at Ingwelala, off-roading is not permitted for various reasons, the most important of which is for the protection and preservation of the environment, riverbeds, soils and animals. But, in many areas around us, ORD is allowed.
Professor Gerhardus Nortjé, a specialist in the field of Soil Science, and an Associate Professor at the School of Ecological and Human Sustainability (Department of Environmental Sciences: UNISA) has studied the impacts of off-road driving extensively and provides training in the management of the impacts of ORD across southern Africa, particularly for ecotourism. We were privileged to attend one of his training sessions, and wanted to share the most important impacts and take-home messages we learned about ORD, especially in our greater general area:
- Soils have both a degree of sensitivity (how easily it is damaged) and resilience (how easily it may recover from damage), which are dependent on the soil type. Sandy soils, for example, have high sensitivity but also high resilience, so are more likely to recover than sodic soils, which have high sensitivity but low resilience. Sodic soils would more likely have more permanent damage, while sandy soils may recover over time.
- Off-roading in the bush causes both sub-soil compaction (when soil grains below the surface become more densely packed together, and the void space - open space - between the grains is decreased - Figure 1), and surface crusting (when a tight, uniform seal is formed on top of the soil surface). Both phenomena negatively affect vegetation growth, which affects animals in turn, and will cause degradation and erosion over time. This is achieved through reduced water infiltration, reduced seed emergence and root growth, and increased waterflow leading to soil erosion.
Figure 1 - When you remove the void space between soil grains, there is little to no space left for water or gases (Oxygen and Carbon Dioxide) to move through, or for plants and roots to grow and spread. This means there will be a serious impact on soil stability and vegetation/cover, causing bare patches of soil, erosion, hardening of the soil below the surface and a decrease in soil fertility.
- South African soil forms and types are particularly susceptible to the above-mentioned phenomena, and as a result, random ORD is not ecologically sustainable in South Africa and should be carefully monitored and assessed, if allowed at all in any area.
- Most of the impact is caused on the first instance of ORD and doesn’t only fall directly under the tyre treads. It spreads out sideways/laterally as well (Figure 2), including the whole area in-between the tyre tracks, and is worse in wet conditions or under heavier loads. Thinner tyres also increase the damage, as the load is more concentrated below the vehicle, as opposed to wider tyres that help to spread the load more evenly (Figure 3).
Figure 2
Figure 3 - Because of the damage caused, and the increased risk of erosion, this can also be harmful to rivers and water courses, potentially changing the natural flow pattern of the water courses, and the siltation, and cause an increase in erosion along the water course. This will have knock-on effects, especially downstream of any major water course/riverbed in the wild.
- Natural soil rehabilitation from ORD will not happen in our lifetime: it can take 42-200+ years to rehabilitate and/or recover by itself, depending on the extent and the soil type, and possibly even never fully recover to its original state. Therefore, if there is to be any rehabilitation it should be by us, as humans. As it stands, rehabilitation methods are varied, and often combined methods are needed to begin the process of rehabilitation. This can include chemical, physical and biological methods, or a combination of multiple.
- With the impacts of ORD on the soil, visually the landscape will change and become more barren. This would severely affect animal densities and populations, and plainly would not be nice to look at either, decreasing the overall ecological and even monetary value of an area.
- When driving off-road, it is impossible to avoid all small plants, young tree saplings, small animals, reptiles, birds, eggs, etc. as you drive. As a result, the impact becomes more severe as we toll up the various species affected by both the ORD impacts on soil and the direct damage inflicted on those species.
- With ORD, there will also inevitably be an impact on underground organisms, burrows, networks and biodiversity. This includes everything from bacteria and micro-organisms in the soil to termite colonies, ants, various other insects and arthropods, spiders and even things like porcupines, aardvarks, springhares, mongooses and other mammals which all use burrows/underground networks for their survival. Bear in mind, this is not only if they are actively in burrows, but potentially also affects their ability to find food, dig new burrows, etc. if soils have been compacted and affected in other areas where they occur.
- In areas of heavy ORD instances, we see a decrease in the health of the ecosystem, the diversity of animals, the productivity of soils and the vegetation. We also see increased instances of erosion, resulting in habitat loss and extended damage to the environment. This has the potential to change ecotourism and the larger ecosystem in general, possibly impacting larger-scale populations, dynamics and successions, as well as the future of wildlife conservation in southern Africa.
- Given the time frames necessary for soil rehabilitation, it is important that the preservation and protection of soils is focused on now, so that by the time future generations come through, the process of recovery is underway and has a chance of being completed before biodiversity and ecotourism are potentially forever changed in a negative way.
- Protecting the soil ultimately protects the vegetation. This, therefore, protects animals and living organisms in that area as well. In that sense, eco-tourism is balancing on the success of soil preservation and soil rehabilitation in the long-term.
As mentioned before, these are the key take-home aspects of understanding the damage that off-roading can inflict, all of which will have knock-on effects for a lot longer than is generally realised. Sharing this knowledge is aimed at opening conversations in the wider realm of conservation, but also for learning something new. We also found that the knowledge gained assists us with the management of soil erosion and rehabilitation here at Ingwelala.
It is incredibly important to understand and absorb this information, and to share it. When thinking about off-road driving, as a group, people don’t often think of the larger-scale effects, the small things that add up, or the long-term impacts of what we are doing. This is something that needs to be spoken about and understood in the bigger picture.
At Ingwelala, we pride ourselves on not off-roading and doing our part for protecting the soils and corresponding vegetation, wildlife, living organisms and environment. We can only hope that a deeper understanding of the impacts will continue to encourage everyone to be mindful of their footprint, and hopefully with time and awareness the protection of soils will spread across the ecotourism industry as a whole, and that the impacts become something we have in our minds every time we think about deviating from the roads anywhere we go in the bush.
We’d like to thank Prof Nortjé for sharing his knowledge and extensive studies with us and allowing us to share this with you from our perspective in this short article. If you’d like to read some of his published works on the impacts of ORD, have a look at: https://www.researchgate.net/profile/Gerhardus-Nortje
by Tess Woollgar. Illustrations courtesy of Tess Woollgar. (Illustrations not to scale)