I enjoy taking walks, and currently, my favorite route is a cemetery path in the town where I live. I like the cemetery for a number of reasons; one of them is the trees. I always say that it has the best trees in town—mostly tall, straight-trunked pin oaks and gnarly-branched bur oaks, but also scattered basswoods and hackberries, a row of pines, and at least one old cedar. Despite their appeal, the trees aren’t the only graveyard vegetation catching my eye this summer.
Along the path, on a Sunday afternoon in early August, I noticed something I hadn’t before. Huddled up against a headstone island in the sea of Kentucky bluegrass was big bluestem, one of the so-called “big four” grasses of the ecosystem formerly known as tallgrass prairie. Immediately, a question came to my mind: “How did you get here?” I thought about the location of the cemetery within the town, and the town within the surrounding landscape, as well as big bluestem seed dispersal. Although certainly not impossible, its establishment from a nearby seed source didn’t seem likely. Instead, might this be a tallgrass prairie remnant? In this context, more appropriate questions might be, “Are you still here?” or, “How are you still here?”
I parted the grass to read the worn dates on the stone, which were both from the 19th century. From there, I began scanning for more bluestem—and I found it, not everywhere, but sporadically. From stone to stone, three general patterns in the spatial distribution of bluestem became apparent to me: 1) It was only present in the southern half of the cemetery; 2) It only grew in close proximity (less than 1 meter, estimating conservatively) to headstones; 3) It only grew next to stones laid at least 50 years ago (several well over 100). I’ll note that patterns 1 and 3 are related, as older graves tend to be located on the south side of the cemetery.
With my curiosity sufficiently sparked, I decided to supplement my on-the-ground assessment with one from a bird’s-eye-view, using a geographic information system (GIS), an important tool of my ecological modeling trade. The view from above shows the cemetery embedded within the town, surrounded primarily by residential zones, but also several more open spaces, which happen to be schools and churches.
Zooming in a bit, a marked difference can be seen between the spatial distribution of trees in the northern and southern halves of the cemetery. Trees on the north side grow in straight rows, whereas growth on the south side appears more haphazard (this isn’t as apparent from the ground as it is from above). There are also several relatively large open areas on the south side not shaded by trees.
In addition to this informal spatial analysis, I recorded the years of birth and death on the stones with bluestem close by and did some basic number crunching. Among the 25 stones with bluestem growing around them (and legible dates), the earliest year of death was 1879, the latest was 1983, and the average was 1921, with a decadal peak of six deaths over the course of the 1920s.
Taking all of these observations together, it seems to me at least plausible, if not probable, that this bluestem is indeed a tallgrass prairie remnant. In the vast majority of the cemetery—and large swaths of the surrounding landscape—tallgrass prairie species have been largely plowed under, mowed over, and crowded out by other plants, to the point of practically, but not completely, vanishing. But here, against stones laid in the prairie sod (or something closer to it than today’s Kentucky bluegrass monoculture), select prairie slivers persist. Although likely cut off by a weed-eater several times each summer, avoidance of the more frequent lawn mower passes provides sufficient time for growth and energy acquisition. This is my interpretation.
While discussing this last week with a friend, I was reminded that I’m not the first ecologist to consider the persistence of prairie vegetation in a graveyard. In A Sand County Almanac ( 1987:45-46), the great ecologist and conservationist Aldo Leopold commented on the annual flowering of compass plant in a cemetery fenceline: “Heretofore unreachable by scythe or mower, this yard-square relic of original Wisconsin gives birth, each July, to a man-high stalk of compass plant or cutleaf Silphium, spangled with saucer-sized yellow blooms resembling sunflowers." Several weeks later, Leopold described the event that he surmised would be the end of this compass plant: “…the fence had been removed by a road crew, and the Silphium cut. It is easy now to predict the future; for a few years my Silphium will try in vain to rise above the mowing machine, and then it will die. With it will die the prairie epoch.” Like Leopold’s compass plant, the big bluestem of the cemetery has escaped the frequent lawn mower encounters that eliminated its neighbors, and like Leopold’s compass plant, the bluestem reveals its persistence—at least to passing human eyes—in the height of summer, at its “prairie birthday” celebration.
So, what does all of this have do with critical theory? Besides interpreting big bluestem presence through historical and spatial lenses, I can’t help but think about it in the context of social-ecological systems (SES) and social-ecological memory (SEM). At a fundamental level, SES thinking recognizes that human societies and nature are inextricably linked, and that divisions between them are ultimately artificial. SEM—as implied by its name—involves the linking of social memory and ecological memory. More specifically, it is the collective memory of management practices that sustain ecosystem services in SES (Barthel et al. 2010).
What exactly are social memory and ecological memory? Here, social memory refers simply to the accumulated collective experiences and knowledge of social groups or cultures, whereas ecological memory pertains to the remnants of biodiversity that persist in an area in the wake of a disturbance (Andersson et al. 2016), such as a fire, flood, or the plowing of a prairie. As the ecosystem recovers from disturbance, ecological memory influences its reorganization. With a high degree of memory retention, the reorganized state of the system is more likely to resemble its former (i.e., pre-disturbance) state, but with low memory retention, the result of reorganization may be a fundamentally different, alternative stable state.
Okay, back to SEM. How is it retained and eroded, and what might be the consequences of each? Integral to the production and persistence of SEM are memory carriers—repositories and structures by which SEM is transported in space and time (Andersson & Bathel 2016). Memory carriers may be ecological (e.g., gene pools, seed banks, and tree groves) or social (e.g., oral traditions, social norms, and media), and improved understanding of how ecological and social memory carriers interact is hypothesized to be useful for fostering SEM and imagining new (or perhaps, remembering old) avenues for place-based, sustainable living in the midst of rapidly unfolding global change. Insights from traditional ecological knowledge (TEK) may be especially relevant in this regard (Barthel et al. 2013). Alternatively, the loss of SEM—described as social-ecological amnesia—is likely to reinforce our all-too-common reliance on “detached social memory,” which yields solutions that are neither sustainable nor well-matched to the intricacies and diversities of local places (Anderson & Bathel 2016).
Now, back to bluestem. How can SEM help us grapple with phenomena like the persistence of bluestem in a cemetery, and vice versa, and what might the broader implications of those considerations be? To me, the realization that a headstone set in the ground to commemorate the life and preserve memory about a person might simultaneously shelter the memory of the tallgrass prairie is, if nothing else, interesting. Surely I could gain a fuller understanding of the reasons for bluestem’s persistence by drawing from records of previous landcover, the cemetery’s history, and the recollections of people who have observed changes in the landscape for many years. That too would be interesting.
Yet, in a broader context, a headstone—even a cemetery—is a small refuge, at least spatially, and its role in conserving regional or global biodiversity seems negligible. But what if instead of just headstones, entire landscapes acted as “biocultural refugia” (Barthel et al. 2013)? What would it mean for SEM, and perhaps sustainability, to be apparent from a bird’s-eye-view? How might we recover SEM that has been lost while fostering its continued development in novel environments? It seems intuitive that such big-picture questions and answers are critical for engaging the large-scale social-ecological challenges of our present and future. In this, it is important to emphasize that SES and SEM are dynamic, not static, and that knowledge of novel social–ecological interactions can be continually and adaptively incorporated into the SEM of local cultures as they encounter and respond to the challenges of global change. Perhaps easier said than done, but then again, so is a century of dodging lawn mowers.
On last night’s walk, I noticed that the weed-eater had passed through the south side of the cemetery, tracing each stone in preparation for the holiday weekend. I couldn’t see any tallgrass prairie, but I know it is there, huddled up against a few old headstones, still remembering and committing to memory.
- Dan Uden
Andersson, E. and S. Barthel. 2016. Memory carriers and stewardship of metropolitan landscapes. Ecological Indicators 70:606-614.
Barthel, S., C. Folke, and J. Colding. 2010. Social-ecological memory in urban gardens—Retaining the capacity for management of ecosystem services. Global Environmental Change 20:255–265.
Barthel, S., C. L. Crumley, and U. Svedin. 2013. Biocultural refugia: Combating the erosion of diversity in landscapes of food production. Ecology and Society 18(4):71.
Leopold, A. 1987. A Sand County Almanac: And sketches here and there. Oxford University Press, New York, NY, U.S.A.