Trees as Commons and Open Source Infrastructure
= various city policies concerning trees are discussed: "We now understand that within cities, trees and humans are enmeshed in a rich network of agencies and dependencies sharing intimate relations and mutual obligations towards preserving a common, liveable place."
"We are seeing a growing acknowledgement of the importance of trees to combat (and mitigate the impacts of) the climate crisis — including within our cities. However, a series of structural problems inherent in our urban forestry management processes are working against the more and more ambitious tree-planting targets that cities are announcing. By 2030, Prague has pledged to plant 1 million trees, Milan is aiming at 3 million trees and Sydney intends to add 5 million trees to the city’s existing urban forest. But the authorities responsible for such greening efforts are failing to construct credible, practical implementation and maintenance strategies. In England, tree-planting is falling 71% short of the Government’s target, US cities are losing 36 million trees a year due to natural disasters and disease, and Sheffield, Europe’s greenest city, has lost 5,000 trees, chopped down by a private tree maintenance contractor despite furious local protests. Such manifest failures direct our attention to a series of deeper issues relating to budget allocations, accounting procedures and socio-political perceptions about trees in cities. It is these deep-rooted obstacles that we have to overcome in order to unlock the massive collective investment we need in trees as vital infrastructures for a resilient and thriving future.
A HISTORICAL TRANSITION FOR URBAN TREE SYSTEMS: THEN AND NOW
In 1896, Massachusetts in New England, passed the first ever tree warden law obligating the municipality to appoint wardens and deputies to be responsible for the care and protection of public trees. Wardens were empowered to appropriate funds for tree planting and regeneration, to remove trees and to give public notice of removal or pruning. The description of these early duties portrayed the tree as a single isolated unit, disassociating it from its connections to the soil, other trees and species and enforced an image of the ‘proper’ or model tree; one with guards to protect stems from collisions with automobiles, one whose branches do not pose a threat to pedestrians, one whose roots aren’t a threat to buildings’ foundations. More than a century later, our systems still persist in treating trees according to the highly partial and siloed mental image formed during those proto-modernist tree warden laws.
Most evidently, in 2016, Silvan Linden documented the extensive felling of fourteen large trees in Berlin by the Parks Department that insisted the trees were threatening the safety of pedestrians and traffic, stating they were wild trees of uncontrolled growth and not ‘proper’ street trees. We still plant and maintain trees as isolated units, although our scientific and social understanding of urban trees has greatly advanced.
We now understand that within cities, trees and humans are enmeshed in a rich network of agencies and dependencies sharing intimate relations and mutual obligations towards preserving a common, liveable place. Recognising urban trees beyond their aesthetic presence and treating them as city co-inhabitants might offer a better way to attend to our relations and establish a tangled web of links to support living processes. Urban trees can be companions, communities, providers, expert witnesses, economies, data stories or resourceful ancestors. They can regenerate soil quality, reduce heat island effects, offer food and shading, support urban biodiversity or mitigate energy usage. Our municipal urban forestry practices should work towards aligning the human species with these processes to live by and through trees.
A handful of cities are already innovating in the way they purposefully connect trees as green infrastructure with other urban systems to encourage an effective maintenance of forestries. Melbourne is pursuing an ambitious programme aiming to double the city’s canopy cover from its current 22.5 percent to 40 percent by 2040 to manage and recycle surface water runoff and reduce urban temperatures by installing a series of infiltration trenches along sidewalks that direct water runoff to a structural soil system supporting city trees. Similarly, the Greater Lyon Authority is capturing rainwater to enable green infrastructure-based cooling strategies; amongst other elements it is installing sensors on newly planted and existing trees to monitor and quantify the cooling effect of vegetation at different stages of maturity and under different irrigation regimes, providing controlled data for further green infrastructure development.
In 2018, the city of Cardiff Council, completed the Greener Grangetown project, partnering with Dŵr Cymru Welsh Water and Natural Resources Wales to invest £2.5 million in an innovative scheme to manage rainwater in the neighborhood by re-designing the urban realm with soft landscaping to catch, clean and divert rainwater directly into the river instead of pumping it over 8 miles to release into the sea, effectively using the capacity of SuDS (Sustainable Drainage Systems) for stormwater protection, and providing direct services to the Welsh water management company. Using rain gardens, kerbside trees and other green infrastructure systems, the combined sewer overflow was reduced as was the amount of energy used for pumping wastewater to treatment facilities. All this financially benefited Dŵr Cymru Welsh Water; at the same time the project, developed through an extensive public consultation process, unlocked further benefits such as pedestrian footways and a community orchard transforming the relationship of the neighborhood with its trees. A number of other stakeholders are now interested in exploring the scheme’s other potential upsides, with universities participating e.g. in measurements to understand the ability of green infrastructures to remove microplastics." (https://provocations.darkmatterlabs.org/trees-as-infrastructure-1dd94e1cfedf)