6.4.8 Pyropangenesis: The Variation of Fire at the Wildland Urban Interface

“Wilderness fire, in its purest form, should be “wild” fire: unfettered by the constraints of humans.” Agee, 2000.

Since the dawn of the Industrial Age, human systems, including but not limited to the architectural and urban design narratives of the Global North, have been largely treated as a thing apart from Earth systems. This tri-part paradigm advocates that not merely must the former be synchronous to the latter, but form a synecological unit therewith, in which, be they seasonal, decadal, millennial, or epochal, material and information exchanges flow with, not against fire cycles. Thus, the principle parameters within which decisions are to be made when applying this trichotomous paradigm fall within the domain of the Earth, not political nor economic sciences.

As in life, the moment a building is ‘born’ it progresses towards death, the event thereof not an ‘if’, but a ‘when’. This paradigm, in which materially and informatically architecture evolves in space and time, is consumed not with creating architectural ‘specimens’, but ‘lineages’: an Origin of Architectural Genera endowed with functional traits that enable coexistence with one or more fire regimes, and with their affiliated intensities, severities, and behaviours.

A pan-archaic paradigm, in that its scope is as expansive as its origins are ancient, Panarchistic Architecture rejects the notion that any one architectural schema has universal application. As flora and fauna exhibit not homogeneity in their resilience to wildfire and to other environmental disturbances, so too must architectures that straddle wild and urban lands. Thus, Panarchistic Architecture will become manifest in not one, but various forms of which the workings, thus appearance, will vary from one fire regime-type to another. Therein, unlike most other architectural paradigms, sensu Woods, though highly principled in its approach, Panarchistic Architecture is not prescriptive.

Practice of Panarchistic Architecture will necessitate familiarity with the low-severity, mixed-severity, and high-severity fire regimes, and with the fundamental biochemistry, physics, and ecology of wildfire more generally. Furthermore, as one of the fastest-developing scientific fields worldwide, practitioners’ research thereof will need to be ongoing, and particularly given that climate trajectories suggest that transitions from one fire-regime type to another are highly probable in wide-ranging regions.

As do species native to fire-prone regions, Panarchitectural genera will select traits which, sensu Rowe, be they morphological, biochemical, physiological, phenological [exhibiting cyclic behaviours], and/or behavioural, align to one of three the ‘modes of persistence’:

Pyro-Endurance

Evolved to persist in WUI adjoining low and mixed-severity fire regimes, such as Californian chaparral and oak forests, pyro-enduring architectures will comprise functional traits selected to endure frequent, but relatively low intensity fires.

Morphologically, like their ecological equivalents, pyro-enduring architectures will feature perennating parts, including below-ground data and storage networks, which like Canyon live oak roots, are protected from surface and crown fires by a layer of soil and/or other insulting material. The depth thereof will be proportionate to the soil /material type [i.e. Percentage mineral vs. organic matter, thus level of flammability]. In addition to subsurface modes of data and other storage, pyro-endurers harness the potential of remote storage networks, thus, their perennating parts may extend to satellite-enabled communications and other IOT infrastructure [i.e. cloud networks]. Coexisting with frequent wildfires, unlike Panarchitectural genera adapted to infrequent, but intense wildfires, pyro-endurers may simply ‘clone’ their data and the outputs thereof from one wildfire to another.

Physiologically, should a wildfire’s intensity exceed the historical regime precedent and compromise the integrity of subsurface networks, thus the data stored therein [i.e. copies of documents such as land-ownership, marriage, birth, and insurance certificates, and architectural plans and other design blueprints, together with personal paraphernalia such as photographs, love letters, etc] as do superspecies variants of ecological endurers, architectural pyro-endurers will exhibit a trait based on postfire seedling recruitment by means of an ‘insurance policy’. Data-storage and network technologies now fast evolving, as biocomputing advances, pyro-endurers will advance away from digital and towards biotechnologies. Hence, morphologically and physiologically, materially and informatically, pyro-enduring architectures will become increasingly ‘life-like’.

Endowed with environmental sensing, actuating, and analysis technologies, pyro- enduring architectures will perform both pyriscence and pyrogermination wherein upon detection of heat and/or chemical signals that evidence the passing of wildfire, ‘seeding’, thereon ‘germination’ of data will occur. As do fire-adapted floral species, such as several members of the genus Pinus, architectural pyro-endurers may use serotiny to distribute their data-encoded ‘seeds’, wherein resins are formulated to melt at specific temperatures, thus releasing mechanisms that propel said items into their surroundings. In concert with pyrogerminating processes, such for example as heat cracking of ‘seedcasings’ and/or responses which are triggered by the breakdown of organic compounds in the soil, pyro-enduring architectures could exhibit phoenix-like recovery from wildfire. Research and development thereof would involve transdisciplinary programmes populated by fire ecologists, biochemists, engineers, architects, and data scientists of whom the training spans both established and emerging practice.

Foremost suited to open canopy terrains, in which their structures stand sufficiently distant from both biomass and human constructions as to limit the probability of wildfire spreading above surface-level, pyro-enduring architectures will be free of features that enable fire to climb their exterior parts. The trait thereof may involve a form of architectural abscission, which a phenological behaviour would be cyclic [i.e. shedding occurring prior to the commencement of the annual fire season].

Functional Traits Translated from Ecological to Architectural Applications:

• Resprouting

• Pyriscence

• Pyrogermination

• Abscission

Pyro-Evasion

Evolved to persist in WUI adjoining mixed and high-severity fire regimes, such as Yellowstone’s Lodgepole pine forests, pyro-evading architectures will comprise functional traits selected to evade relatively infrequent, but high intensity fires.

Like their pyro-enduring Panarchistic cousins, pyro-evaders back-up their architectural and other valuable and/or treasured data. But, whereas the former take a two-pronged approach, succumbing to wildfire, the latter rely not partially on perennating parts, but solely on ‘seed banking’. Shielded either by serotinous structures or buried below ground, thus protected by the insulating properties of mineral soil and/or a synthetic equivalent, seeds of pyro-evaders remain dormant for decades, to then be activated by pyriscence and pyrogermination, via the same or similar processes to those discussed above.

Persisting in landscapes where, historically, fire regimes are so intense as to incinerate flora and architecture alike, pyro-evaders are ‘built to burn’. Designed such that upon wildfire’s passing their materiality is redistributed into its surroundings, pyro-evading structures will help propagate both ecological and architectural seeds. Thus, like the Pomo’s people’s ‘wickiup’, pyro-evaders are temporary structures. However, persisting in landscapes where fires are less frequent, though cyclical, their temporality is not seasonal.

Suited to regions where biomass and/or architectural density is high, like their ecological equivalent, pyro-evaders will nonetheless necessitate the creation of urban landscape mosaics. The feature thereof increasing the probability of heterogeneity in wildfire’s spread, it is posited that ‘mosaical WUI planning’ could provide of pockets of refuge for both residents and/or emergency workers that had not the time to evacuate. The concept thereof is born of the behaviours of faunal species in the presence of both forest and grass fires. Few materials able to withstand the fire intensities that are present in mixed and high-severity fire regimes, it is proposed that pockets of refuge are born not principally of architectural, but of landscape architectural interventions, which harness understanding of how vegetative state, structure, type, and distribution, together with topography, therein wind speeds and direction, together with humidity levels impact upon wildfire behaviour. Research and development thereof will principally involve transdisciplinary programmes populated by fire ecologists, biochemists, atmospheric and other planetary scientists, landscape architects, and data scientists.

Pockets of refuge would also provide of safe haven for data seed banks of which the contents inform post-fire recovery. However, whereas the inter-fire periods to which pyro-endurers are adapted are sufficiently brief as afford for architectural cloning, their inter-fire periods spanning not years, but decades, or even centuries, ever- responsive to changes in their environment, and particularly within the fire regime, pyro-evaders will ‘evolve’ upon their regeneration. Reconfigurations in pyro-evaders’ architectural DNA will be triggered by environmental cues. Whereas ecological evaders are often endowed with biochemical properties that propagate fire intensities, given the possible risks to human and other faunal life, as may be in near proximity during a wildfire, their architectural cousin will exclude this particular trait.

Functional Traits Translated from Ecological to Architectural Applications:

• Pyriscence

• Pyrogermination

Pyro-Resistance

Evolved to persist in WUI adjoining low and mixed-severity fire regimes, such as California’s Ponderosa pine forests, pyro-resisting architectures will comprise functional traits selected to resist frequent, but relatively low intensity fires.

Physiologically, die-hardy pyro-resistors will be endowed with exterior parts designed to withstand fast-spreading wildfires. The form and materiality of buildings and infrastructure of this Panarchistic genus will be bespoke to the site. Choice of composition and chemistry of materials, together with decisions of structure and form will be informed by the surrounding vegetation type, structure, and distribution, and landscape topography, therein wind and atmospheric conditions as may become manifest. Wherein the sum thereof, in concert with the historical fire regime make evident that wildfire will, most likely, spread at the surface, like their ecological counterparts, pyro-resisting architectures will focus their fire defences towards their base. For example, from their foundations upward several meters, pyro-resistors in regions prone to surface fires will feature fire-resistant walls, windows, and doors, and ‘self-pruning’ of all such parts as might enable fire to scale their exteriors [i.e. features made from flammable materials, such as wooden verandas, and trellises]. Whereas, in regions prone to canopy fires, upper building parts, such as roofs and balconies, will feature robust pyro-armoury, as did the Chinese vernacular architectures of Zhou City [i.e. fire-resistant roof tiles and topologies].

As with their ecological equivalents, such as the Coulter pine, pyro-resistors will feature exterior walls of which both the molecular composition and the surface texture dissipate heat, thus helping to protect interior parts [i.e. bark-like plating]. Several routes may facilitate the research and development thereof. For example, mineral- based materials could be recycled into plate-like furrowed amour that could be affixed to building exteriors. Alternatively, biotechnology and/or biodesign may present the potential to build bark-like bricks biologically. Integration of chemical sensors and actuators thereto could enable self-repairing processes similar to they as enable post- fire rhytidome renewal.

Like endurers and evaders, pyro-resistors will store data in serotinous, and other pyriscent ‘seeds’, of which ‘germination’ is activated by wildfire’s presence. Phenologically adapted to relatively short fire-cycles, whereupon the spatiotemporal dimensions thereof align to the historical fire regime, like pyro-endurers, resistors of the architectural variant will commonly replicate pre-fire conditions.

Functional Traits Translated from Ecological to Architectural Applications:

• Retardant Rhytidome

• Abscission

• Pyriscence

• Pyrogermination

Perpetual Pyropangenesis

Highly attuned to their environment, whereupon climatic and/or ecological regime shifts occur, all three members of the Panarchistic architectural trio will evolve in response. Thus, their DNA [codes] will edit functional traits as befit the conditions as emerge. One might perceive of pyro-endurers, pyro-evaders, and pyro-resistors as three architectural R’s, not ‘re-use, reduce, and recycle’, but resprout [replicate], redistribute [reproduce], and resist [remain].

Pyropangenesis as expressed in the tri-part Panarchistic Architecture paradigm aligns to the principles of the Adaptive Cycle (Gunderson et al, 1995, 2002), but the spatiotemporal dimensions thereof vary across the three quantitatively and qualitatively distinct modes of wildfire persistence. Four stages [functions] are expressed within the cycle: exploitation [r-phase], conservation [K-phase], release [Ω- phase], and reorganisation [α-phase], which in toto express the integration of creative destruction to the successional model as preceded it, thus the addition of the Ω and α phases [Fig. 77].

As applied to the panarchic wildfire persisting trio, the Adaptive Cycle is expressed at:

• The level of the architectural ‘specimen’ in pyro-evaders, which, like their ecological counterparts succumb to wildfire, but reproduce [seed] upon the passing of a mixed to high-severity fire, thus, transition from the K to Ω phase occurs with each fire cycle.

• The scale of the architectural ‘species’ in pyro-endurers, which, like their ecological counterparts, resprout upon the passing of a low to mixed-severity fire, but which absent of traits that enable them to endure high-severity fires, at the species-level, transition from the K to Ω phase whereupon the historical fire regime shifts from low-to-mixed, to mixed-to-high severity.

• The scale of the architectural ‘ecosystem’ in pyro-resistors, which, like their ecological counterparts, resist upon the passing of low to mixed-severity fire for several fire seasons, but of limited life-term, can only successfully reproduce whereupon fire intervals are long enough for their offspring to grow sufficiently robust defences to resist wildfire’s passing. Thus, the transition from the K to Ω phase occurs whereupon the historical fire regime shifts not merely shifts from low-to-mixed to mixed-to-high severity, but to fire return intervals too short for even die-hardy resistors to accommodate.

Put succinctly, pyro evaders, endurers, and resistors may be perceived as expressions of the Adaptive Cycle at multiple spatiotemporal scales.