The value of biodiversity: ‘What will this area look like in 30 years?’

By Tsumbedzo Leonard Ramalevha and Joe Sibiya, SAEON Ndlovu Node Tweet

A group of 13 grade 11 learners from Phalaborwa participated in the SAEON annual science camp at the Timbavati Foundation Environmental School from 25 to 28 June.

The group has been part of the Ndlovu Node’s Science Engagement Programme since 2017 and this was their final science camp.

Learners and their lecturers on a visit to Nourish Eco Village, a non-profit organisation that is focused on community upliftment, social responsibility and environmental education of rural villages and communities in Mpumalanga (Photo: Joe Sibiya)

The programme was aimed at exposing the learners to ‘The Value of Biodiversity’. Activities throughout the week comprised ecological lectures, analysis of environmental documentaries and tours to the Timbavati Nature Reserve museums, Elephant Museum in the Kruger National Park, Nourish Eco Village and the real-time water monitoring station at the Olifants River.

The main activity for the learners was a small-scale science research project led by Dr Tony Swemmer, manager of the Ndlovu Node. During a brainstorming session on the activities of the camp, he emphasised that one of the greatest challenges of the 21st century lay in balancing the sustainable use of resources with the changes taking place in the environment. He added that rapid population growth, climate change and various land-use and land-cover changes all have a negative impact on the environment.

A brief observation of the Timbavati Nature Reserve and Timbavati Communal Area led to the formulation of the question What will the area look like in 30 years?, which informed the scope of the small-scale research project. In order to predict how the current use of resources is likely to shape the area in years to come, learners were divided into three groups to sample the two areas for the presence of vegetation, soil erosion and animals.

Learners measure tree height at the Timbavati Nature Reserve (Photo: Joe Sibiya) Members of the Vegetation Group measure the amount of grass at the communal land using a disc pasture meter (Photo: Joe Sibiya)

Hypothesis

Following a brief observation of the two areas, the three groups hypothesised that there would be a higher density of trees, a higher diversity of tree species and more grass in the nature reserve (vegetation), more soil erosion at the communal area (soil erosion) and more animals in the nature reserve (animal).

Sampling

After brainstorming their project under the guidance of Dr Swemmer and Una Furumele (soil erosion), Tsumbedzo Ramalevha and Elijan Masango (animals), Caitlin Ransom and Joe Sibiya (vegetation), the data were collected at both areas over two days.

The Vegetation Group used a disc pasture meter to measure the amount of grass at a marked point. They also measured the distance of the five closest trees taller than 0,5 metres from a marked point, measured the height of the five trees, identified the tree species and moved approximately 30 steps up the slope to the next point. This exercise was repeated three times.

The Soil Group collected data and sampled two areas to determine which of the two had more soil erosion. They used step-point transects, measured the biggest gully, captured the data and compared the variables.

The Animal Group search for droppings and tracks indicating the presence of animals in the Timbavati Nature Reserve (Photo: Joe Sibiya) The learners explore the museum at the Timbavati Nature Reserve (Photo: Joe Sibiya)

The Animal Group constructed four 10-metre by 4-metre transects using measuring pipe, ribbon and measuring tape, moving away from the river in the two study areas. In each transect, they identified animals found in the area based on tracks, droppings and dung. Insects, birds and reptiles were also identified.

Data analysis and results

After two days of sampling the areas, the groups analysed their data. More grasses and fewer trees were found in the communal area than in the nature reserve, with sickle bush (Dichrostachys cinerea) being the only plant found in both areas. In terms of soil erosion, more gullies and rills were found in the communal area than in the nature reserve. A greater diversity of animal species was found in the nature reserve than in the communal area.

The young scientists analyse their data, assisted by Dr Tony Swemmer, manager of SAEON’s Ndlovu Node (Photo: Joe Sibiya)

Conclusion

After presenting their results, the groups concluded that the likelihood of soil erosion would increase in the communal area due to soil and sand harvesting combined with high vegetation clearing for firewood, infrastructure development and the movement of animals, particularly cattle. This would result in a reduction of vegetation cover and ultimately a lower number of animals found in the area.

On the other hand, as tree numbers decrease, the grass cover would increase. This would probably result in optimal grazing for cattle. “We expect that within the thirty-year period the ecosystem of the nature reserve will continue to flourish and that there will be a greater loss of vegetation species in the village as more land is used for infrastructure,” the learners concluded.