We have now come to the second Surf and turf paper in Oikos february issue. I let Deron Burkepile introduce you to his study “Comparing aquatic and terrestrial grazing ecosystems: is the grass really greener?”
At a big ecology meeting, you can often tell what people study by how they dress – the marine ecologists (Hawaiian shirts, flip flops), the terrestrial ecologists (Chacos or Tevas, Carharts). As an ecologist, the communities and ecosystems you study often define you – forest ecologist, intertidal ecologist, benthic ecologist. Like our current series of reviews and commentaries in Oikos trying to bridge the gaps among terrestrial, marine, and freshwater ecology, we often compare and contrast the different patterns and process in our different ecosystems via reviews and our meta-analyses. We search for common patterns and themes and build testable hypotheses, even theories. Yet, many of us don’t have research experience outside of a couple of closely related ecosystems. For many of us, branching out to a new ecosystem means including tropical forests into our research program on temperate forests. But, I would argue that we could all be better ecologists, if we truly had diverse research experiences on our ecological resumes, and the field would be better for it.
Having had a diversity of research experience, I feel like I am one of the lucky ones. I’ve spent more than a decade studying coral reefs, even lived underwater for a total of twenty days in the Aquarius, an undersea research station off of Key Largo, Florida to study herbivorous fishes (parrotfishes and surgeonfishes) and their importance to reef ecosystems. But, I also got to spend two years living in a tent in Kruger National Park in South Africa (periodically having to put my computer in the refrigerator to keep it from overheating in the 40°C+ heat). Instead of parrotfish and surgeonfish, I was studying elephants, wildebeest, and impala and how these different herbivores structured savanna ecosystems. While the beasts were different, the ecological processes were not. I like to think I’m the only ecologist who has gotten to live and work both in the bush in Africa and also underwater (if you know otherwise, please don’t burst my bubble).
How did I get from coral reefs to African savannas and back? It all started with reading broadly. While studying for my qualifying exams as a graduate student in coral reef ecology, I came across the classic papers on the Serengeti by Sam McNaughton and the book Serengeti: Dynamics of an Ecosystem by Sinclair and Norton-Griffiths. I was enthralled reading about wildebeest migrations, the dynamics of multiple large predators, and the overwhelming impact of herbivores on the landscape. As I was devouring the coral reef ecology literature, I couldn’t help thinking how similar coral reefs and African savannas actually were. Instead of herds of wildebeest there were schools of parrotfish. Instead of roving impala, there were marauding urchins. Regardless of whether the system was wet or dry, big, diverse groups of herbivores ran the show. I was fixated on how cool it would be to test similar hypotheses about how diverse groups of herbivores impact community structure and ecosystem function in two structurally different, but functionally similar ecosystems.
After convincing my future post-doc advisor, terrestrial ecologist Melinda Smith, that it would be a good idea to let a marine ecologist who had never even been to the African continent to go live in a tent in South Africa and study ungulates, it was mostly downhill from there. Of course I had to learn a brand new ecosystem (dry vs. wet), a new set of taxonomy (grasses vs. seaweeds), a new set of dangers (lions vs. sharks), get used to new field methods (see picture as exhibit A), and learn a new set of literature (fun, and probably the most challenging part). There are clearly concepts that don’t cross these ecosystem boundaries. The effects of drought and water stress are extremely important at our sites in the savanna – on a coral reef, not so much of a problem. But after six years of working in both African and North American savannas while also continuing my work in reef systems (yes I have a lot of frequent flyer miles), I’ve been able to build a much more nuanced and thorough understanding of how herbivores shape ecosystems and of the drivers that determine herbivory.
So I encourage ecologists at all levels (especially ones early in their careers) not just to read broadly but to research broadly. Start a collaboration with someone in a very different ecosystem than your primary research. If you work in forests, go talk to someone about kelps. It will push your intellectual boundaries and stimulate more ideas to tackle in your primary research area. Every aspect of your career will likely benefit, from your lectures to your journal reviews to your grants.
I remember in my first few months in South Africa walking through an area of savanna where an African buffalo herd had been the day before. The soils were churned, the small shrubs mangled, the grasses gnawed. But what I remember most was the amount of dung. Buffalo flops everywhere. I distinctly remember thinking how important these big herds must be for moving nutrients around the landscape and impacting primary production. That same scene came to mind a couple of years ago while diving on a coral reef watching big schools of fish congregate around corals. That same thought then popped into my head – how important these fish must be for moving nutrients around within this landscape. So, now one of my lab’s main areas of research is the impact of fish-derived nutrients on coral reef community structure and ecosystem function. My blended heritage of marine and terrestrial ecology will, hopefully, continue to help me unravel the connections and common themes between wet and dry ecosystems. Even now, when I am following a parrotfish around the reef documenting its feeding behavior, I can’t help but think “What would a rhino be doing?”