Gobabeb Training and Research Internship Programme – Learning to be Custodians of the Namib
The 2014 Gobabeb Training and Research Internship Programme exposed two young Namibian scientists to the importance of protecting the Namib through a focus on the impacts of vehicle scars on the landscape. Over the last century, different activities have left scars across this unique and fragile ecosystem known as the gravel plains. Activities such as mining exploration, road building, military exercises, and off-road driving by tourists have literally left their mark upon the landscape with visible scars and unknown ecological impacts. With the extent and impacts of these scars still unknown, the GTRIP 2014 participants aimed to understand where these tracks occur, how they impact the soil surface ecosystem, and how they are recovering, if at all. The two GTRIP participants, Martin Handjaba and Nerson Tjelos, studied the distribution and attributes of off-road vehicle tracks and the impact of driving on and recovery of hypolithic cyanobacteria after disturbance.
We thank Gobabeb’s NERMU Project (the Namib Ecological Restoration and Monitoring Unit) who supported the project financially and logistically. Additionally, we would like to thank a number of visiting scientists from the Centre for Microbial Ecology and Genomics who graciously presented lectures, especially Aline Frossard, for their support.
Highlights from the projects
Impacts of surface scars in the central Namib: With emphasis on the magnitude and factors contributing to scarring – Nerson Tjelos
Off road driving, a popular activity in many arid parts of the world, has been singled out as a problem in the central Namib. The central Namib is especially susceptible to such activities due to low resilience of the ecosystem to disturbance, as evidenced by the military tracks created over 100 years ago in the central Namib that remain visible even today. Recent increase in exploration of minerals and outdoor tourism activities in the central Namib have created more vehicle tracks and scars in this fragile ecosystem, yet the extent and magnitude of this disturbance has not been documented. Using Google Earth (GE), off-road driving tracks were found to be concentrated at the coast and near population centres, but not necessarily around mining areas or near major roads. A comparison of GE images from the early 2000s to current images showed a general increase in visible tracks. Ground truthing of GE images established that Google Earth is an acceptable tool to assess the extent of surface scars, but not a perfect one. Ground surveys also showed that the severity of disturbance does not depend significantly on substrate type. The information gathered in this study will support further research on the magnitude and distribution of tracks across the central Namib and provides baseline information for restoration of these disturbed sites. In order to protect the unique and fragile gravel plains, it is essential that all stakeholders and the general public be educated about the long lasting impacts of off-road driving.
The effects of various stone parameters and age on the colonization and recovery of hypolithic cyanobacteria in the central Namib Desert, Namibia – Martin Handjaba
The hyper-arid Namib Desert is a highly variable and extreme environment that makes life difficult for its inhabitants. Despite the harshness, the Namib remains a biological hotspot for micro flora such as hypolithic cyanobacteria (HLC). HLC are pioneers of early colonization in arid environments and live on the underside of quartz stones. With the increase in off-road driving and especially exploration and prospecting activities in recent years, this microbe has seen an increase in disturbance across the central Namib. However, the basic colonization and recovery mechanisms remain unknown for the Namib. To fill this knowledge gap, Martin’s project aimed to establish a baseline understanding of some factors affecting colonisation and recovery of HLC, such as stone burial depth, mass, and thickness. By studying stones of various post-disturbance age, he also assessed the rate at which recovery occurs (and in so doing building upon previous similar studies at Gobabeb). Colonised quartz stones were on average deeper, heavier and thicker than uncolonised stones. Depth had the biggest impact on colonisation and there was some evidence of a colonisation threshold since all stones buried deeper than 5mm were colonised. Interestingly, none of the stone size or burial variables, nor the distance from the sea (a proxy for fog precipitation) were linked to the actual percent cover of HLC. Finally, the number of years since disturbance, or the age of a disturbed site, did not seem to strongly impact the amount of recovery at disturbed sites, so there must be other factors involved in the recovery of HLC after disturbance. However, this project focused on only some of the potential drivers of colonization. More research needs to be conducted on factors such as opacity, vegetation, and moisture regime. Such knowledge will help us to understand the likelihood of recovery better, and may lead to better rehabilitation methods in the future.