Vivek Kumar Dhiman, Vinay Kumar Dhiman
Urbanization represents one of the most consequential environmental transformations of the 21st century, necessitating a fundamental re-evaluation of biological capital within rapidly expanding anthropogenic systems. Within this burgeoning anthropogenic environment, the traditional concept of the natural tree is no longer a viable solitary unit for environmental management. As urbanization concentrates people, materials, and energy, it replaces resilient natural landscapes with surfaces that generate heat, combustion byproducts, and persistent chemical emissions (Fineschi and Loreto, 2020). As a result, urban forestry must be reimagined as an integrated systems approach rather than solely as a biological intervention. Future urban forests should function as engineered biological infrastructure that combines advances in biotechnology, computational design, sensor-based monitoring, and environmental engineering to optimize ecosystem service delivery under highly modified urban conditions. Within this systems framework, biotechnology serves as one component of a broader strategy for designing resilient, adaptive, and measurable urban green infrastructure (Wolf et al., 2020).A critical limitation of conventional urban forestry lies in its reliance on canopy cover as a proxy for ecosystem performance. While canopy metrics quantify spatial extent, they fail to capture functional outputs such as pollutant removal efficiency, thermal regulation, and survivability under stress. This discrepancy is particularly significant given that the average lifespan of urban street trees is approximately 13 years (Moll, 1987;Roman and Scatena, 2011), compared to over a century in natural environments, reflecting systemic failure under urban stress conditions (Smith et al., 2019). Compounded stressors, including urban heat island effects, soil compaction, hydrological disruption, and atmospheric pollutants, drive this mortality burden. These constraints create a physiological threshold beyond which traditional planting strategies become economically and ecologically inefficient. Therefore, incremental increases in planting density cannot resolve performance deficits. Instead, biotechnology must be positioned as a core infrastructural strategy, enabling the engineering of trees as highperformance biological systems optimized for survival and measurable ecosystem service delivery.The survival of the urban canopy in future cities will require genetic and cellular-level interventions that enhance the natural resilience of vegetation. To achieve this, urban forestry should deploy a biological toolkit across three distinct scales: cellular selection for contaminated substrates, genome engineering for resilience to multiple urban stressors, and strategic management of urban genetic resources. Cell selection enables the identification and propagation of plants capable of tolerating extreme urban stressors such as heavy-metal contamination, providing a practical strategy for improving urban tree resilience (Gladkov et al., 2022). Beyond heavy metal tolerance, genomic engineering offers opportunities to introduce traits that improve resilience to multiple urban stressors. In addition to genetic engineering, strategic management of genetic resources is essential for developing resilient urban forestry systems. Clonal propagation enables deployment of elite genotypes with predictable performance but should be balanced with genetic diversity to reduce landscapescale vulnerability (Politov et al., 2015). Maintaining diversity across species, genotypes, and provenances is essential for long-term resilience in engineered urban forests (Plant and Kendal, 2019;Love et al., 2025). We argue that cell selection, genome editing, propagation technologies, and genetic resource management should be integrated into a unified strategy for designing resilient, performance-engineered urban forests.Reconceptualizing urban forests as biological infrastructure requires a transition from passive management to active, data-driven management and modeling. Models such as UFORE and its hydrological version UFORE-Hydro are crucial to this process. These models quantify ecosystem services and support evidence-based planning by linking urban forest structure with environmental performance, thereby enabling urban forests to be managed as measurable infrastructure (Nowak et al., 2008). Computational design also enables trees to be managed as active biological systems. Trees function as active biological systems that regulate microclimate, capture pollutants, and support phyllosphere microorganisms involved in pollutant degradation, reinforcing their role as long-term components of urban environmental infrastructure (Bringel and Couée, 2015;Stevens et al., 2021). Several technologies are already operational or approaching widespread deployment. Artificial intelligence-based platforms combining satellite imagery, computer vision, and deep learning now enable large-scale urban tree inventory, health assessment, and risk monitoring (Velasquez-Camacho et al., 2023).Additional sensing technologies, including ground-penetrating radar, can further improve nondestructive assessment of root systems and tree stability.Established tree-improvement and propagation approaches, including genomic selection, tissue culture, and clonal propagation, contribute to the selection and multiplication of elite tree material. These biological advances can be integrated with IoT-enabled monitoring systems to support adaptive management and real-time assessment of urban forest performance. Although genetic engineering shows considerable promise for improving tree performance, most applications still require long-term field validation before deployment in urban environments.Emerging technologies such as plant nanobionics and advanced genome editing further expand the potential of engineered urban forests. However, their practical application remains dependent on long-term biosafety evaluation and field validation. Building on these modeling approaches, contemporary urban forest systems have evolved beyond static assessments toward dynamic, data-integrated frameworks that combine ecosystem service calculations with real-time environmental inputs. The integration of Internet of Things sensor networks enables continuous monitoring of air quality, soil moisture, and physiological plant responses, transforming trees into active nodes within smart city infrastructure (Uçar et al., 2020).Additionally, plant nanobionics extends this capability by embedding functional nanoparticles within plant tissues, enabling detection of pollutants such as NOx, heavy metals, and volatile organic compounds (Bringel and Couée, 2015;Stevens et al., 2021). Importantly, the phyllomicrobiome functions as a decentralized bioreactor, facilitating degradation of airborne pollutants. This integration enables urban forests to function as measurable, reportable, and regulated infrastructure components, supporting their inclusion in air quality management plans and climate mitigation accounting systems. Lifecycle pollutant management must account for defined stages of capture, transformation, sequestration, and final biomass handling to prevent re-release into the environment, thereby ensuring that urban trees function as longterm pollutant sinks rather than temporary reservoirs. From our perspective, the future of urban forestry depends not on individual technologies but on their integration into a unified, performance-based system that continuously links biological function, environmental monitoring, and adaptive management (Figure 1). A performance-based design framework for urban forestry moves beyond generalized planting principles toward the design of site-specific biological systems intended to deliver defined infrastructure and environmental outcomes (Verma et al., 2024). This framework prioritizes matching engineered biological traits with local environmental conditions, enabling species and genotypes to be selected according to site-specific stressors and desired ecosystem functions. Under a performance-based approach, urban forests can be incorporated into broader environmental planning and infrastructure management strategies. Lifecycle planning is a defining characteristic of this approach, recognizing that pollutants must be managed beyond initial capture through to final disposal. This requires systems that ensure contaminants retained within biomass are effectively contained and do not re-enter the environment. The performance metrics illustrated in Figure 1 are conceptual examples intended to demonstrate how engineered urban forests can be evaluated using measurable environmental indicators rather than fixed design thresholds. By integrating design, performance metrics, and lifecycle management, urban forestry is repositioned from a passive municipal amenity to a structured, technology-driven environmental infrastructure (Popek et al., 2013).Implementing a technologically enhanced canopy presents significant challenges related to public acceptance and equity. The transition from conventional urban forests to engineered biological systems must be managed carefully to avoid unintended consequences, including reduced genetic diversity and increased susceptibility to pests, diseases, and other environmental stressors. Therefore, adaptive governance is needed to prevent trade-offs in ecological performance when optimizing for high-performance traits. Policy strategies also need to account for potential negative impacts, such as biogenic volatile organic compound emissions, which can form other pollutants under certain conditions (Calfapietra et al., 2013).Ensuring that species selection aligns with environmental performance goals is therefore essential for maintaining the net benefits of engineered urban forests. Effective governance should combine public engagement, transparent decision-making, and biodiversity conservation to ensure socially acceptable implementation of engineered urban forests.The implementation of biotechnology-modified trees in urban landscapes is influenced by complex and jurisdiction-specific regulatory frameworks that can substantially affect research, field testing, approval, and deployment. Regulatory approaches differ in how they classify technologies, traits, and methods of genetic modification, creating considerable variation in approval requirements among jurisdictions. Recent analyses further indicate that regulatory systems are increasingly adopting adaptive and risk-proportionate approaches to accommodate the rapid evolution of genome-editing technologies while maintaining biosafety, transparency, and public trust (Bao et al., 2026). Although regulatory frameworks continue to evolve internationally, harmonized, science-based, and risk-proportionate governance will be essential for the responsible deployment of biotechnology in urban forestry.For long-lived and potentially reproductive tree species, considerations such as gene flow and environmental spread may form part of regulatory assessment. Still, their relevance and potential consequences depend on the engineered trait, reproductive biology, presence of compatible relatives, receiving environment, intended application, and applicable social and regulatory standards (Ellstrand, 2003). Biological containment approaches, including male sterility or complete reproductive sterility, represent potential management strategies where reproductive containment is considered desirable for a particular application or required by regulation; in urban settings, such traits may also reduce allergenic pollen production or nuisance fruiting (Brunner et al., 2007;Klocko et al., 2018). Ultimately, public acceptance remains fundamental to successful implementation, emphasizing the need for transparent communication regarding ecological benefits, potential risks, and regulatory safeguards to foster public trust and socially responsible deployment. We propose that future governance frameworks should move beyond technology-specific regulation toward adaptive systems that integrate biosafety, environmental performance, and public participation, thereby enabling responsible implementation of performance-engineered urban forests.Urban forestry must evolve beyond conventional tree planting toward integrated biological and engineering systems capable of delivering measurable ecosystem services under increasingly complex urban conditions. We argue that future urban forests should be designed as performance-engineered biological infrastructure in which biotechnology, computational modeling, sensor-based monitoring, and adaptive governance operate as interconnected components rather than independent technologies. Achieving this vision will require coordinated advances in biological innovation, robust biosafety frameworks, and transparent public engagement. Together, these elements provide a foundation for resilient, evidence-based urban green infrastructure capable of addressing future environmental challenges.