There is a global movement to plant trees to mitigate climate change (including the Bonn Challenge, AFR 100 and UN Trillion Tree campaign). This is driven by international agendas that negate evidence-based science from open ecosystems in Africa. Planting trees in well-managed open systems like African grasslands will not solve the climate crisis; it might create even more problems. These intact, well-managed and diverse ecosystems are vital for assisting climate mitigation efforts. They need to be managed in conjunction with reducing fossil fuel emissions (not instead of).

The United Nations recently launched the Decade on Ecosystem Restoration to prevent, halt and reverse the degradation of ecosystems worldwide. While the initiative is catalysing restoration efforts across the globe, care should be taken that these efforts are ecosystem appropriate.

South Africa’s grass-dominated ecosystems include fire-climax grassland in many of the key strategic water source areas, such as the Drakensberg Mountains. Until now there has been a paucity of in situ data exploring the carbon dynamics of these systems. We need such data to be able to assess the role of different ecosystems in the carbon cycle and the potential impacts of land-use change, for example from grasslands to exotic afforestation or indigenous woody dominated systems, to provide evidence-based information on the consequences of such changes.

For my PhD, I set out to provide much needed data points in southern hemisphere grassy systems on temporal and spatial soil CO₂ flux. This work will provide detailed data on soil carbon composition and dynamics under several experimental treatments, elucidate on mechanisms driving soil carbon storage in grassy systems, as well as guide restoration work and contribute to climate change adaptation strategy.

During this time, I became involved with the SAEON Graduate Student Network and came to realise the importance of sharing my research experiences with fellow students. With the fieldwork component of my work now complete, I reflect on the journey thus far and offer some teaser results.

To do science is to search for patterns and understanding, not simply to accumulate facts. For me this meant month-to-month visits to remote locations in the most beautiful mountains in KwaZulu-Natal for almost three years. Conducting research in such locations, however beautiful, can be challenging if you are going at it alone and the PhD process itself can be lonely, hard and emotionally draining. Add to this the misery, uncertainty and rules that came with the pandemic and the challenges can seem insurmountable.

Benefits of the SAEON platform 

I have learned that a strong support system, personal passion and commitment are crucial in undertaking a PhD and doing long-term field-based research. SAEON is an enabler, and it is indeed a privilege to have had so much support and equipment to undertake such exciting research in some of the most remote, yet breathtaking, montane grasslands. By being part of a team and harnessing the benefits of the SAEON platform, I was able to enjoy my field research and pause from time to time to take in the stunning scenery.

My PhD work (see here) focuses on soil carbon dynamics of fire-prone grasslands in Cathedral Peak. I am interested in two aspects: 1) Carbon release (soil respiration or soil carbon dioxide [CO₂] flux using a monthly manual method and a continuous long-term LI-8100A Automated Soil Gas Flux System owned by SAEON); and 2) Carbon storage through quantifying current carbon stocks in an entire catchment at different soil depths and within different aggregate sizes, as well as carbon isotopic signatures to understand the contribution from C3 trees and C4 grasses. My work thus required monthly week-long visits to sites to take measurements, check equipment and get a long-term time series of repeated measurements through the seasons.       

The calm before the storm: sampling in beautiful mountains with unpredictable weather conditions  

I am passionate about the kind of research that I do, and I often start with the end goal in mind. Sampling in the Drakensberg Mountains is an amazing experience and for the first few months, fieldwork felt like a holiday. Indeed, being exposed to new equipment and a new kind of science was among the most interesting experiences.

Coming from a grassland and restoration ecology background, with limited knowledge of soil CO₂ flux measurement and equipment, SAEON and the mountains allowed me to explore and learn more about in-situ data measurement equipment and multidisciplinary research. The mountains made clear the interconnectivity and dynamic nature of environmental research – from the atmosphere to the vegetation to the soils to the water. Working in these majestic mountains is like working in a multidisciplinary living laboratory.

But I did encounter some challenges. The beauty of the Drakensberg landscapes can go unnoticed if your goal is to finish a time-dependent four-hour (sometimes six-hour) soil gas sampling per site. This can be especially difficult in summer knowing that weather conditions can change within a matter of minutes.

While it was possible to work in the rain and during gale-force winds, thunderstorms would end field sampling because of the possibility of lightning strikes. We experienced all these conditions but were able to escape thunderstorms and run to safety just in time, sometimes halting field sampling an hour after commencing it.

Fluctuating temperatures would also kill the batteries of a soil MicroStation, sometimes on a monthly basis during the winter months. Aside from weather conditions, porcupines would dig out sampling collars affecting the experiment, while other small animals (possibly rodents) would chew soil MicroStation cables.

All these difficulties taught me a lot about planning ahead and I quickly learned how to fix the equipment. These are lessons I would not have learned if weather conditions were smooth and there were no pesky porcupines on site!