Urban nature isn't just trees anymore, and three researchers want the field to catch up

On 15 July 2026 a Comment piece by Simon Marvin, Sophia Maalsen and Robyn Dowling landed in Nature Cities with an unfashionable claim: the patch of grass between a bus stop and a cycle lane is no longer best understood as nature. It is engineered infrastructure with a procurement contract, a sensor network, sometimes a vendor, and a quantifiable carbon line on a spreadsheet. The three authors, based at the University of Manchester, University College London and the University of Sydney respectively, want the discipline of urban studies to retire the pastoral vocabulary that still dominates it.

The argument matters because the money has already moved. Cities from Singapore to Stockholm are contracting out the design, build and maintenance of roadside vegetation the way they contract out roads. The market the authors describe is not hypothetical: it is being assembled in real time by firms whose products mix hardware (living walls, structural soil cells, permeable pavements) with software (soil-moisture telemetry, biodiversity dashboards, AI-assisted species identification). Urban greening is being absorbed into the same category as street lighting or traffic signals, a thing a city buys, runs and measures. Read that way, the question for the planners and the academics who train them is no longer "how much green is enough" but "who owns, operates and audits the greening that we already have."

From parkland to platform

The Comment's central move is to relabel the object of study. What once went by "urban nature", trees, parks, brownfield rewilding, is being folded into what the authors call technonature: ecological processes that have been deliberately redesigned to perform specific functions inside urban systems. A green roof is no longer a roof that happens to be green; it is a stormwater asset, a heat-island mitigator and, increasingly, a grid service. A pocket park is no longer a leftover made pleasant; it is a programmable piece of climate infrastructure that a city pays a vendor to keep within tolerance.

That shift has been visible for years at the edges of planning departments. The novelty in the Nature Cities piece is the authors' insistence that urban scholarship treat it as the centre, not the periphery. The argument is that the older vocabulary, nature versus city, ecology versus infrastructure, is no longer accurate at the scale most cities actually operate. Trees are now routinely specified, supplied and maintained by companies whose logos appear on the planters. Wetlands that manage stormwater are designed to engineering tolerances and accepted on handover like any other piece of municipal infrastructure. To call all of this simply "green" obscures who has the technical authority, who carries the liability and who collects the recurring revenue.

What the vendors actually sell

The technonature framing lands because it lines up with what the supply side of the market is already selling. Living-wall systems are sold as turnkey installations with service-level agreements covering irrigation, nutrient dosing and replacement planting. Permeable-pavement systems are sold as integrated drainage assets with a measured infiltration rate and a maintenance schedule. Biodiversity-monitoring platforms are sold as subscription services that turn a council's tree inventory into a streaming data feed keyed to grant applications and carbon registries.

The authors are not arguing that any of this is bad in itself. They are arguing that the language has lagged the business. A council that buys a living wall on a five-year managed contract is buying infrastructure. Reporting it as "more nature" in the local sustainability plan understates what has actually been procured, who holds the operational risk and what happens to the asset at contract end. The same point applies to sensor-equipped green corridors that feed data into a vendor's analytics platform, and to biodiversity offset banks that operate as private registries.

The counter-narrative

Not everyone in urban ecology will accept the framing. A reasonable objection is that collapsing the distinction between "nature" and "infrastructure" risks importing the governance failures of infrastructure procurement, opaque tenders, lock-in to single vendors, lifecycle accounting that hides externalities, into a domain that has historically run on civic volunteers, public parks departments and small specialist consultancies. The Comment does not address that risk at length, and the authors could fairly be pressed on it: technonature, as a category, does not by itself settle whether a city ends up with more ecologically rich urban fabric or with greening-as-PR.

A second objection is older and more political. Treating urban vegetation as infrastructure can be read as an admission that the post-2000s round of municipal austerity has hollowed out in-house parks and ecology teams to the point where the private sector is now the only realistic supplier of new green assets. That reading is not quite the one the authors advance, but it is the one some of their harder-pressed readers in local government will hear. The Comment gestures at this when it notes that technonature is "constituted through" governance and commercial arrangements, without spelling out who loses when those arrangements become the default.

What to watch

The practical question for city officers and the consultants advising them is whether the new vocabulary changes the procurement checklist. Three indicators are worth tracking over the next twelve to eighteen months. First, whether major framework tenders for urban greening, the kind issued by metropolitan authorities in the UK, the Netherlands and the Nordics, start naming "technonature" or its near-cognates in their specification documents. Second, whether municipal balance sheets begin to capitalise living walls, structural soils and large-scale green roofs as long-life assets rather than expensing them as landscaping. Third, whether the major sustainability reporting standards adjust their definitions of "green infrastructure" to track the boundary the Nature Cities piece is drawing.

None of those shifts would settle the underlying ecological questions, what counts as a functioning urban ecosystem, how to measure it, who decides, but they would confirm that the discipline has moved. The risk for cities that ignore the reframing is not ideological. It is operational: a generation of green assets built to vendor specifications, financed on service-contract terms and governed by data platforms they do not own, settling quietly into the municipal estate without anyone quite conceding that nature, in the city, has become another piece of infrastructure.

Desk note: Monexus read the Nature Cities Comment against Phys.org's coverage of the same paper and against the authors' prior published work on smart urban infrastructure. The piece treats the Comment as an analytical intervention, not as news of a policy change; city procurement language is the leading indicator we will be watching.