refugia

The heterogeneity and hybridity of peatlands contrasts binary conceptions of environments, especially insofar as water and land are concerned. Islands of peat (called batteries) are dislodged from the swamp, rise, and float in the Okefenokee, from the Creek nation’s O-ke-fin-o-cau or E-cun-fin-o-cau from Ooka meaning “water” or E-cun-nau meaning “earth” and Fin-o-cau meaning “quivering.” (58) When tree roots anchor it again, it is called a house. A house situated in a continuum of wetness.

I am taking up Dilip da Cunha’s call “to seek out and engage the cracks and interstices of an imposed surface as transgressors with the purpose of drawing out a vocabulary of wetness,” (59) to counter the established surface between land and water, queer it, substitute it for a spectrum. This shift deemphasizes water bodies and watersheds in favor of a different spatial imaginary of connectivity in which water is always embodied, (60) and asks: What might we find if we attend to fluctuations in wetness rather than the location of water?

Wetness is the linkage between the Great Dismal and the Okefenokee, "a corridor through which unique plants and animals migrate and diversify." (61) Wetness is in the production of methylmercury that becomes bound to the tissue of a fish.

Listen to Leigh and Lodovica Guarnieri in conversation with Ifor Duncan on the subject of subbmergences

2022 • About | Notes

Wetness is also around the seed of a cedar tree that has been dropped into peat. Chamaecyparis, which is a catastrophe-dependent and stress-tolerant genus of conifers in the cypress family Cupressaceae, makes Southeastern swamps its home, surviving “where, and only where, others cannot.'“ (62) Despite this, Chamaecyparis thyoides, or the Atlantic white cedar, once common to the Atlantic Coastal Plain, has disappeared largely because their stands grow atop peat, which has been lost to oxidation and fire.

Peat provides refugia for their seeds and facilitates regeneration after fire. (63) Short term, the wetness at the time of a fire impacts how deep it will burn into the peat, and whether the seeds will be charred, while longer term, wetness impacts the rates of plant productivity and decomposition, and thus peat accumulation and seed burial. (64) The cedar’s family member, the bald cypress, which lives in the Okefenokee, similarly likes a mossy or wet seedbed and it must be saturated for up to three months after seedfall for germination. (65)

The interrelation of wetness and fire, peat production, and plant communities in the Southeast is complex. Periodic severe fires are required for many plants to regenerate, but a sequence of severe fires with short return intervals shifts community composition significantly; herbaceous vegetation goes from being intermixed in aquatic prairies to being widespread. This transition can be extremely destructive—for the beings that cannot survive the more frequent, severe fire; for the human communities living nearby suffering effects from wildfire smoke; for the amount of carbon dioxide released into a warming atmosphere.

Peat fires produce a unique composition of emissions containing volatile organic compounds, PM2.5 (particulate matter with a diameter of <2.5 mm), and PM10 (particulate matter with a diameter of <10 mm). (66) They also release mercury at a rate 15 times greater than upland forest fires, posing harm to the nervous, digestive and immune systems, lungs, and kidneys; and increasing risk of cardiovascular disease and neurological damage. (67) Counties in eastern North Carolina that bore the brunt of a peat fire in the Pocosin Lakes National Wildlife Refuge area were more rural and had a higher percentage of African Americans, and of lower socioeconomic status than most other counties. (68)

We may not be able to correct for settler colonial land management in peatlands by simply reverting them to an “original” state because present conditions are not what they were when peatlands began forming some thousands of years ago. In fact, peat cores show both the Okefenokee (69) and Great Dismal (70) were more marsh-like before conditions allowed peat surfaces to be colonized, forming swamp-forests.

The creation of marshy conditions by frequent, severe fire also makes way for conditions that benefit different species:

Greater water storage or longer hydroperiod may mean that small wetlands may be able to serve for longer periods of time as watering holes for wildlife, or as habitat for their prey, during dry periods. In southern Florida, for example, two federally listed endangered species (the wood stork, Mycteria americana, and the Florida panther, Felis concolor coryi) may depend on the existence of standing water late in the region’s dry season. The additional stresses on already-imperiled wildlife species due to predicted increases in climatic variability may make drought-condition refugia ever more valuable. Therefore, to the extent that soil-consuming ground fires maintain open water by lowering soil elevations and reducing encroachment of vegetation, there may be an indirect ecological benefit of ground fires in certain areas. (71)

Geographer Joseph Holden claims that we may not be able to avoid allowing peatland ecosystems and their hydrochemistries to develop in new directions, and, “Judging the success of peatland restoration and management must then depend on our perception of peatland functions and our understanding of the links between small-scale and large-scale spatial and temporal processes.” (72) See below for a transcript of a conversation from July 28, 2020 with a peatland researcher in Scotland on this topic.

This is what it means to cultivate refugia—recognising environments are constantly becoming and we are mutually becoming with them, instead of simply aiming to restore them to a past state. This is especially relevant to sink ecologies, which are perhaps most often made objects of calculation and function. Caring for sink ecologies is a matter of reorienting away from fixed states and towards the anti-essentialism of queerness.

“We know that, at the very, very small scale like sphagnum, in individual loss, there are feedback loops: if it's under stress, it will bleach, and when it bleaches, it reduces its color and increases its albedo; it becomes white and reflects the light. When the condition resumes, it's not completely dead. It can come back but only if it's above a certain threshold. It may be that different sphagnum are differently adapted. If you're a sphagnum living in a very dry climate edge environment, maybe you're better adapted, maybe you can cope with more stress before you bleach. If you're in a really wet environment, as soon as it's a little bit dry, you bleach. How these different adaptations are or if they exist we don't really know. If you take a few sphagnums clumped together, then they also have mechanisms of resilience by turning into clumps that are tightly packed or loosely packed. If they're tightly packed, they can cope with drier conditions. If they're loosely packed, they are very good in really wet habitat. At the slightly bigger scale, you have units of peatland landscape like the pools system surrounded by drier margins. The pools system may expand and contract over time depending on how the climate is. Even during a drought year, you might see surface collapse. When it gets wet again, it's more dense so the water gets on the surface and the sphagnum can grow again. So, there are all these feedback mechanisms.”

“One of the things I've been working on in the last years is looking at what's called bog breathing—that's the capacity of the whole surface of the peat to go up and down in response to changes of volume and gas into the peat matrix itself. What we're finding is extremely cool. You can basically pick out the breathing pattern of a bog and you can tell from that breathing pattern, whether it's a healthy peatland, or what bit of the healthy peatland it is, or if it's degraded. This is one of the key feedback mechanisms at the landscape scale, this capacity to change the volume is really related to the mechanical properties of the peat. If you lose that capacity of moving in response to increasing volume of gas and bubbles and water coming in, you lose one of the resilience mechanisms. We're interested in understanding how that mechanism of moving up and down relates to disturbance and resilience and to things like greenhouse gas emissions or movement of water out and into the peatlands and things like that. That's one of the things that regulates this breathing pattern or that is closely associated with it is the types of vegetation that are in the peatland. If you have sphagnum, it'll have a different typical signature than if you have other plants, and that relates to how the plants function, whether they have roots to actively get water out of the system or whether they're more evaporating of it's hot or getting lots of moisture if it's cool. It really reflects this dynamism. When you talk about the carbon sink not just being this thing that's there... I think that's true. It's all these processes. It's very dynamic at a whole range of scales and the shifts in those dynamics can trigger catastrophic changes in how the stock, what's underneath, behaves and that can be triggered by a one-time event like fires or can be triggered by a series of shorter time events like a series of droughts that can progressively erode this capacity to respond.” (73)