Abstract:
Eco-tourism activities specifically, sometimes have very negative environmental impacts.
One such activity which has been observed to have severe negative impacts is driving in
dirt tracks (ungravelled natural soil) by game drive vehicles in private game reserves and
some National Parks (Nortjé 2005; Laker 2009). It has also been observed that the
severity of the impacts and the resilience (recovery potential) of the affected areas differ
widely between different areas. It is strongly linked to the properties and qualities of
different soils.
This study has shown that off-road driving (ORD) has the same effects, and to a greater
extent, if it is not well managed and judiciously controlled. Wild animals tend to
concentrate in areas with the most nutritious en most palatable vegetation. Consequently
these are also the areas where predators, e.g. lion, leopard and cheetah are most likely to
be found. It can be expected that these will be the areas with the highest frequencies of
ORD in order to get close to these animals. In many landscapes these are the areas which
are the most vulnerable to negative impacts by actions like ORD and have the lowest
resilience. It has also been observed during game drives and personal communications at
several occasions that there is tremendous ignorance amongst tourists regarding the
negative environmental impacts of certain activities.
This study proved that ORD have strong negative impacts on vegetation recovery, soil
resilience and root density distribution through soil crusting and sub-soil compaction. An
important finding is that these negative impacts are during both dry and wet soil
conditions. Game drive vehicles driving off-road damages the surface soil structure, which
lead to soil crust formation and sub-surface compaction. A highly significant result is that
most crusting and sub-soil compaction occurred during the first pass of the game drive
vehicle, irrespective of the soil type and tyre pressure, thus rewriting the current
guidelines for ORD of the South African National Parks, SANParks.
Furthermore, results of this study indicated that a significant area in the flood plains of
the Makuleke Contractual Park is impacted by ORD. The impacts are serious if one looks
at the amount of land that an ORD vehicle can disturb. One of the recommendations
would thus be to drive in the same tracks when driving off-road, and lower the tyre
pressures. Driving in the same tracks is known as "controlled-traffic" in the agricultural
industry. Controlled traffic is very important to minimize compaction. Driving in the same
University of Pretoria etd Nortjé, G.P. (2013)
tracks during off-road incidents does not significantly affect the degree of compaction under the tracks, but greatly reduces the compacted area. Further results indicated a strong lateral effect of the vehicle tracks, in most cases the
whole area between the two tyre tracks as well as up to a distance outside of the vehicle
tracks, thus increasing the total area disturbed by ORD. Comparing these vehicle impacts
with animal path resulted in some important findings. Animals only caused a soil crust
with soil strength values much lower than that of vehicles. The effects of animals are also
much more vertical than lateral as with vehicles.
Another important finding is the role that historical human activities play in such study
areas and how it may influence results. The results in this study are aggravated by the
historical human activities in this study area, as indicated. These historical activities were
the main cause of the surface crusting, and the resultant low vegetation growth in the
area. This, therefore, explains partially the relatively high control values and also the soil’s
higher susceptibility to compaction due to vehicle ORD.
The root density trials had very interesting and important results. Significant differences
occurred between mean root density fractions across all tyre pressures at all three trial
sites. The trend is that an increase in tyre pressure causes a decrease in root density
distribution. These results show clearly that even lower tyre pressures are harmful, but
are more environmental friendly than higher tyre pressures.
Results of the second part of the study with regards to tourists' perceptions on ORD, and
the impact of their activities on the environment, showed that the majority of tourists areignorant when it comes to the impacts of their activities on soil and vegetation. Tourists'
had significantly variable demographic characteristics. Tourists' environmental perceptions
varied, but a significant majority of tourists agreed that ORD has a negative impact on the
environment. Contradictions exist between what they know or perceive as being damaging and what
they prefer to act on. Results indicate a need for improved visitor education on the
possible negative impacts of demands for ORD, and a need for government intervention
with regards to the enforcement of legal measures to control ORD. The results also
indicate that game guides and tourism operators can play a major role in educating the
tourists. The results demonstrate that both an understanding of the chemical and physical factors
influencing soil compaction, as well as tourists' environmental views are important in
formulating a management strategy to control and manage these impacts.
