The Letter’s central claim is distilled in its title: signage will not make carbon visible. Carbon dioxide, as Sampurno emphasizes by drawing on Timothy Morton’s influential concept of hyperobjects, is precisely the kind of phenomenon that resists direct perception. Hyperobjects are entities so massively distributed in time and space that they cannot be seen, touched, or heard as discrete things, even though their effects are everywhere. Climate-warming carbon is the paradigm case. A city dweller strolling through a planted grove cannot see the tonnes of carbon being drawn down by leaves and locked into trunk wood, and no placard listing sequestration figures will change that. Information, the argument goes, does not automatically become perception, and perception does not automatically become care.

This is where aesthetic mediation enters the analysis. Sampurno’s background is in the performing arts rather than forestry or atmospheric science, and that disciplinary position shapes the Letter’s distinctive approach. Rather than treating urban forests as engineering assets with a public-relations problem, the Letter treats them as social-ecological landscapes in which meaning is produced through embodied, sensory, and emotional engagement. In this framing, the value of an urban forest is not exhausted by its biophysical performance metrics. It also lies in how the forest is experienced — how light falls through a canopy, how a path invites repetition, how a place accrues personal and collective significance over years of visits.

To build this case, the Letter engages a body of anthropological and philosophical theory that has rarely been brought to bear on municipal climate infrastructure. Alfred Gell’s anthropology of art, which understands artworks as agents that act upon the world rather than as passive objects of contemplation, provides one pillar. Tim Ingold’s work on the temporality of landscape provides another: for Ingold, a landscape is not a static scene to be read but a record of ongoing dwelling, a palimpsest of tasks, memories, and histories written and rewritten by the people who move through it. From this perspective, an urban forest remembers. It carries environmental memory — the sedimented experiences of the communities who planted it, tended it, mourned trees lost to storms or development, and returned to it across seasons and generations.

Environmental memory, as the Letter frames it, is not a metaphorical flourish but a functional component of how green spaces sustain public commitment to them. When residents can trace the growth of a sapling they once helped plant, or navigate a park by remembered landmarks rather than posted signs, the forest becomes part of their autobiographical and communal narrative. This embeddedness is what allows a green space to matter morally, not merely instrumentally. Signage, by contrast, is an intrinsically thin form of mediation. It delivers declarative content — numbers, names, dates — but it does not participate in the slow accumulation of lived relationship. A sign can state that a stand of trees stores a certain quantity of carbon; it cannot make that fact felt.

The psychological literature on climate-related art, which the Letter surveys through work by researchers such as Lisette van Someren-adjacent scholars Roosen, Klöckner, and Swim, and subsequent studies of activist art at events like ArtCOP21 in Paris, offers empirical support for this distinction. That research suggests visual and performative art can communicate climate change in ways that exceed informational channels, engaging emotion, imagination, and identity in a single encounter. Related work by Julia Bentz and Karen O’Brien on art-for-change programs with young people points toward transformative learning: encounters with art can shift not just what people know about environmental change but how they position themselves within it. Sampurno’s wager is that urban forests themselves, when approached aesthetically rather than informationally, can operate in this same register — as living artworks whose agency works on their audiences.

The Letter also confronts the darker emotional side of this relationship. It invokes Glenn Albrecht’s concept of solastalgia, the distinctive distress experienced when a loved environment degrades while one remains in place. Urban forests are acutely exposed to this dynamic: they are cherished, proximate, and vulnerable, threatened by heat, drought, pests, and the relentless pressure of urban development. If environmental memory binds communities to these spaces, then their loss is not merely an ecological subtraction but a wound to collective identity. Any strategy for communicating the climate significance of urban forests must therefore reckon with grief and attachment, not just with data literacy.

Significantly, Sampurno’s argument is situated in dialogue with a companion study published in the same journal by Lukman and colleagues, which examines urban forests as social-ecological landscapes and traces pathways linking memory and well-being in Indonesia. That research context matters, because Southeast Asian cities are undergoing rapid transformation in which green space is simultaneously a climate asset, a heritage repository, and a contested development frontier. The Letter does not present new empirical data of its own — the author explicitly reports that no new data were generated or analysed, and the piece carries no funding declaration. Instead, it functions as a conceptual intervention, using the tools of environmental humanities to reframe what counts as evidence in debates about urban greening.

The practical implications are likely to discomfort municipal planners who lean on signage as a default engagement strategy. If the Letter is right, then a park saturated with interpretive boards but stripped of genuine participatory life will fail precisely where it matters most: in cultivating residents who notice, remember, and defend their urban canopy. Aesthetic mediation, by contrast, suggests investment in programming, performance, co-created public art, and design that deepens dwelling rather than annotating it. The goal would be to make the forest itself the medium — a place whose rhythms, growth, and vulnerability make planetary processes tangible through direct, repeated, embodied contact.

None of this diminishes the biophysical case for urban forests, which remains robust across the ecosystem-services literature. What it challenges is a communication model in which information is assumed to flow unidirectionally from label to mind to motivation. Sampurno’s Letter insists that between the chemistry of carbon and the consciousness of the city lies a vast aesthetic and memorial gap that no signboard can bridge. Closing that gap requires treating urban forests not as green infrastructure with an instruction manual, but as living, memory-bearing landscapes whose visibility to the human heart precedes any visibility on a placard. For a field increasingly convinced that the climate crisis is, at its core, a crisis of perception, the argument lands with uncomfortable force: we have been labeling our forests when we should have been learning to see them.

Subject of Research: Aesthetic mediation and environmental memory in the public perception of carbon in urban forests

Article Title: Signage will not make carbon visible: aesthetic mediation and environmental memory in urban forests

Article References: Sampurno, M. B. T. (2026). Signage will not make carbon visible: aesthetic mediation and environmental memory in urban forests. Journal of Environmental Studies and Sciences. https://doi.org/10.1007/s13412-026-01147-3

Image Credits: AI Generated

DOI: 10.1007/s13412-026-01147-3

Keywords: urban forests, carbon visibility, aesthetic mediation, environmental memory, climate communication, signage, hyperobjects, solastalgia, environmental humanities, social-ecological landscapes, urban greening, environmental psychology

The research, led by Gaoji Zhang and Hongyi Liu of Nanjing Forestry University together with colleagues at Nanjing Xiaozhuang University, set out to answer a deceptively simple question: what does a soil-dwelling millipede actually eat, and does it choose? Understanding diet is fundamental to understanding how animals adapt to their environments, yet for cryptic soil invertebrates, direct observation is nearly impossible. The team therefore turned to molecular methods, combining DNA barcoding of gut contents with detailed surveys of the surrounding plant communities, soil properties, and the elemental composition of available leaf litter. This multi-pronged approach allowed the researchers to compare what the millipedes ate against what was actually available to them, a crucial step in distinguishing true dietary selection from mere opportunistic consumption.

The results were striking in their breadth. Across the sampled populations, S. bungii was found to have consumed litter from 76 plant genera spanning 48 families and 30 orders. This extraordinary dietary range suggests that the species functions as a generalist at the population level, capable of exploiting a wide variety of plant material. Population-level niche width, a statistical measure of how broad a population’s resource use is, was correspondingly large, registering 15.32 at the family level and 16.46 at the genus level. Such values indicate that collectively, these millipede populations draw on a deep pool of plant diversity, a flexibility that may underpin the species’ success in habitats heavily altered by human activity.

Yet the broad population-level diet masked considerable variation between individual mountain populations. Analysis of similarity, a non-parametric multivariate technique known as ANOSIM, revealed significant differences in dietary composition among millipedes collected from different mountains. In other words, each population has its own distinct dietary signature, shaped largely by the local plant community on offer. Niche overlap analysis reinforced this picture: most mountain populations showed little dietary overlap, with Ojk values below 0.6, the threshold typically interpreted as meaningful separation. The one notable exception involved populations from Jiangjun Mountain and Fang Mountain, which overlapped at Ojk = 0.65, hinting at either similar local vegetation or genuine sharing of preferred resources between these two sites.

Perhaps the most consequential finding concerns habitat fragmentation itself. The researchers measured fragmentation using two standard landscape metrics: patch density (PD), which counts habitat patches per unit area, and edge density (ED), which quantifies the amount of forest edge relative to area. Both were strongly correlated with the class-level trophic niche width of the millipedes, with patch density showing a Spearman correlation of ρ = 0.93 (p = 0.007) and edge density ρ = 0.79 (p = 0.048). In practical terms, as forests become more chopped up and edge-dominated, the dietary repertoire of S. bungii appears to shift. This is one of the clearest demonstrations to date that the spatial configuration of urban habitat, not just its total area, can leave a measurable imprint on the feeding ecology of a soil animal.

The study also uncovered pronounced selectivity. When the researchers compared consumption against availability using null-model approaches, S. bungii exhibited a positive selection tendency toward three plant genera: Cinnamomum, the genus that includes camphor and cinnamon trees; Carya, the hickories; and Ailanthus, the tree of heaven. Conversely, the millipedes showed a negative selection tendency toward Trachelospermum, a genus of woody vines and lianas common in Chinese forest understories. The avoidance of Trachelospermum is intriguing from a biochemical standpoint, as the genus is known to contain a rich arsenal of phytochemical compounds, some of which may render its litter unpalatable or even deterrent to detritivores. Preference for the favored genera, by contrast, may reflect more favorable litter chemistry, softer tissues, or higher nutritional returns per bite.

Elemental analysis added another layer to the story. The team found that S. bungii tended to consume plants with high calcium content, with a Spearman correlation of ρ = 0.83 and a p-value of 0.058, just shy of conventional significance thresholds but strongly suggestive of a pattern. Calcium matters enormously to millipedes. Their calcified exoskeletons, which must be built and repeatedly rebuilt through successive molts, demand substantial calcium reserves drawn directly from their food. A millipede that preferentially grazes calcium-rich litter is, in effect, mining the leaf fall for skeletal raw material. This finding connects the feeding behavior of a humble arthropod to the broader biogeochemistry of the forest floor, where leaf elemental composition varies widely among tree species and shapes the entire decomposer food web.

The implications extend beyond millipede biology. Detritivores such as S. bungii are engine rooms of soil nutrient cycling: by fragmenting litter and converting it into faeces, they accelerate organic matter turnover, release nutrients locked in dead leaves, and create conditions that favor microbial decomposition. Their bioturbation, the mixing of organic and mineral soil layers as they burrow, further alters soil structure and water movement. If urban fragmentation changes what these animals eat, it may also change how efficiently they perform these ecosystem services. A population forced onto a narrower or lower-quality diet could process litter more slowly, with knock-on effects for soil fertility in the very green spaces that cities depend on for cooling, flood regulation, and recreation.

The study also fits into a growing body of work on urban soil biodiversity. Previous research by some of the same authors showed that urbanization affects millipede gut microbiota by impeding host gene flow, and other studies have found that even small urban forest fragments can maintain complex food webs of litter-dwelling arthropods. Taken together, these findings challenge the assumption that fragmented urban habitats are ecological deserts. Instead, they suggest that the dietary flexibility of generalist detritivores, combined with thoughtful conservation of plant diversity within fragments, could sustain functioning decomposer communities even in heavily built-up landscapes. For urban planners, the message is concrete: preserving a diverse mix of native trees, including calcium-rich species that detritivores favor, may be as important for soil health as simply preserving green space.

Methodologically, the study showcases the power of DNA barcoding for diet analysis in organisms that cannot be observed feeding directly. By sequencing plant DNA recovered from millipede gut contents and matching it against reference libraries, the researchers achieved a taxonomic resolution that traditional gut-content microscopy could never match. All raw sequences from the study were deposited in the NCBI Sequence Read Archive under accession number PRJNA1182097, ensuring that other researchers can verify and build upon the work. As cities continue to expand and fragment the forests around them, studies like this one make clear that the fate of above-ground biodiversity and the hidden economy of the soil are tightly intertwined, and that even a millipede’s dinner menu can tell us whether an urban forest is truly thriving.

Subject of Research: Dietary selection and trophic niche of the millipede Spirobolus bungii in fragmented urban forests

Article Title: Dietary selection of millipedes (Spirobolus bungii) in fragmented urban forests

Article References: Dietary selection of millipedes (Spirobolus bungii) in fragmented urban forests. (n.d.). https://doi.org/10.1007/s11104-026-09152-9

Image Credits: AI Generated

DOI: 10.1007/s11104-026-09152-9

Keywords: millipedes, Spirobolus bungii, DNA barcoding, diet selection, habitat fragmentation, urban forests, soil biodiversity, detritivores, leaf litter, calcium, trophic niche, nutrient cycling