Redeemed by Charcoal

by Abraham Nqabutho Dabengwa 

“Not much pollen at ten sites!” was the dreadful proclamation. “This isn’t any good. There’s lots of charcoal but not much of a story without a vegetation proxy.”

The diagnosis was clear. It’s the type that shakes a palynologist’s stiff spine, normally adapted for slavishly counting pollen and other microscopic fossils. Disaster had struck me at the larval stage of my Ph.D. No pollen. What was I to do? How was I going to justify my inclusion in a pollen lab? Better yet, how was I going to rise from the valley of academic Hades where the Unfortunate fight to reach “heaven” or sink into oblivion? 

Now, I know some of you have heard or personally experienced research horrors. Yes, stuff happens. Bad stuff. Even to people who think they are innocent. Horrors or “game changers” are rarely due to lack of intelligence, poor foresight, and vile spirits. It seems life works on timetables different from the conventional academic assembly line. Even those lucky in academia experience misfortune elsewhere. It’s life.

Redeemed by charcoal

The passage of time has lifted me out of the Ph.D. fog, allowing me to reflect on my academic journey and lovely encounter with charcoal. Oh charcoal, you deep and kaleidoscopic teller of the past – how I could write a poem about you! Like the mythical phoenix who rose from the ashes, you lifted me up from the bowels of academic Hades into the realm of creative experience.

The stars of my Ph.D. The main attraction of course were very large grazers which visited wetlands to eat and mill charcoal. Charcoal fragments indicative of grass burnt are shown in top right while Sporormiella dung spores at bottom-right are associated with grazing pressure and herbivore densities

Insights from charcoal collected from sediments have altered the way we think about the long-term ecosystems processes driven by fires: nutrient cycling, variation among habitats, and biodiversity patterns. Mysteriously, charcoal fragments are said to come from near and far. However, sizes of charcoal fragments can change locally without invoking a transporter genie which discriminates by size.

The mystery hooked me. I decided this was going to be my salvation. I was going to manually count microscopic charcoal fragments and relate them to dung spores linked with herbivore densities. Grazers are attracted to tasty grass shoots following the burning of tall and may even grind enough charcoal particles with their hooves, especially in dry periods. Grazers also love wetlands. I had plenty of wetland sediment samples to work with. Charcoal would turn out to be a signal of vegetation and indirectly, climate and herbivory. The path towards redemption was clear following my unceremonious rejection by pollen. I could now restore my self-confidence and ability to do science. However, I was naturally upset since these developments happened in what is traditionally considered the half-way stage of the Ph.D. journey!

But courage! Perseverance in the face of adversity! Yes. I wasn’t going to let my dream get deferred, or as Hughes says, “dry up like a raisin in the sun.”

Racing time

They say genius should never be rushed. At the back of my mind I was aware that folly won no prize. After all, slow minds may never reach their destination. With time, I soon found myself spiraling backwards. Financial insecurity. No clear end in sight. Confidence waned following graduation days. Once upon a time I had rekindled hope but now I was on the edge of a cliff. Of course, I summoned my willpower and survival skills, I had past victories. However, each situation is different. And sometimes one doesn’t know how beat-up they are. With my powers sapped, I pressed the help button. O charcoal, did you lead me downwards?

The Cape Town mountains I used to hike and run up to find solace in my darkest days 

When I looked back at charcoal with a fresh pair of eyes, the findings were astounding. I did find the expected patterns of positive feedbacks between drought, herbivory, and short grass development for my Ph.D. However, I also found that my hunch was right. Herbivores did affect charcoal particle sizes and concentrations. This was suggested by some positive charcoal-spore feedbacks indicative of re-grazing of palatable post-fire grass regrowth, which probably fragmented particles through trampling. The most interesting observation was that charcoal concentrations were significantly lower where herbivores were few, adding support for the local origin of charcoal at my sites.

Nature decoded

So, here I was analyzing charcoal fragments, which had broken up predictably, regardless of local processes such as combustion, compaction in sediment or reworking by herbivore trampling. Wow! I had stumbled on self-similar particles which are ‘fractal like’ or with a ‘power law-like’ behavior. I was hypnotized. To the uninitiated, the results seem trivial, but I must assure you, there are many ecological consequences.

If local processes could explain charcoal sizes and concentrations in sediments, this meant blindly using smaller charcoal fragments as indicators of distance fires in grassland environments might be a stretch of imagination. This follows since charcoal represents a fraction of burnt biomass produced by my local grasses. (Of course, these ecosystems became mine since scientists tend to appropriate nature and sites as you all know).

Also, when grazing herbivores suppress flammable grasses for extended periods, direct relationships between climate and fire blurred. What may have happened is that fragmentation of charcoal in burned grasses around the sedimentary basins was high in grazing systems compared to sites with fewer animals. This implies that some comparisons of fire activity among sites using charcoal concentrations are indirect measurements of herbivore pressure. Importantly, wetland grasslands couple fire and herbivory in savannas with possible implications on other sediment-based environmental interpretations. My skepticism regarding charcoal dispersal paid off!

Life lessons

I was going to shout it from a mountain top! Hooray! I was worried I might be called mad like folks gyrating or twerking to a silent disco at a funeral. But like all aspiring academics, a humble article without hyperbole is in process of completion. There is still a lot to uncover about charcoal, one of the few stable sedimentary proxies that are preserved in sediments for long periods. Like the phoenix, I arose. I’m happy to say the Ph.D. has been conquered. I am still passionate about how large grazing mammals use wetlands to survive at ecological to evolutionary timescales and the stuff they do to local grasses, soil structure, and nutrient pools.

On a hill somewhere in China
when I realised that everything was well
              

Many people assisted me along the way. Family was a blessing. Friends were priceless. My partner was gold and light. Supervisors were encouraging. My therapist the oracle helped me see these winning factors while I limped forward. I gradually recovered what was lost, I had lost who I was when I considered myself as a stalled product in an assembly line. I found out that taking care of myself was one non-negotiable. The bigger picture returned. I was more than enough and capable of meeting any challenge. The setbacks were life experiences in the way forward and not failure. It was liberating. No judgment. Gratitude. Gradually, curiosity, passion, and motivation returned. Breaks are good. The captain of the ship was back to navigate toward a desirable future.

A seemingly desperate decision to look at different sizes of charcoal lured me into the mysteries of life and science. Charcoal continues to hold many secrets, but I leave that to others. Humble like a cup of tea and as deep as one dares to peer, like so many other things in life. Charcoal spurred my resolve to move headlong not into darkness, but the less traveled road of discovery. I also learned the importance of taking care of myself and trusting in my abilities. I can say that has made huge difference in how I experience life, how I value people, because you never know what mysteries lurk beneath simple facades. My transformation into a doctoral butterfly has been a long and interesting journey full of stories.



Abraham Nqabutho Dabengwa 
Doctoral student, University of Cape Town, South Africa



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