How can urban ecology be better prepared to contribute to a comprehensive understanding of cities? And what do world cities need from urban ecology to move toward desired, more sustainable futures? Speaking to these questions, all contributions in the Special Section ‘‘Shifts in Urban Ecology’’frame contemporary urban ecology as an ongoing bridging effort; the scientific field of urban ecology has broadened and diversified by adopting new perspectives and concerns within its scope. From a focus on examining nature in urban landscapes and how it is valued, understood, and stewarded by different social groups, it has expanded to ecologically grounded, systemic explorations, including complex dynamics of social, institutional, cultural, and technological dimensions. This pluralization of the field, sometimes captured by the use of ‘‘ecologies’’(Nishime and Hester Williams 2018; Rademacher et al. 2019; Pickett et al. 2022), has been facilitated by the engagement with many different disciplines, such as urban studies, sociology, geography, urban policy, and urban planning, as well as infrastructure engineering. This development comes with many conceptual and empirical gains, especially in opening scientific inquiry to multiple knowledges and perspectives with participatory and collaborative research methods. This opening has allowed new questions to emerge, especially about the situatedness, equality, accessibility, and justice of urban ecosystems. The present and the future of urban ecology, as a field, are shaped in dialogue and collaboration with other disciplines (Childers et al. 2015; McPhearson et al. 2016; Crouzat et al. 2018; Pickett et al. 2021). The expansion of urban ecology has allowed conceptual innovations to emerge, led to the formation of inter-paradigmatic approaches, and opened up for a critical examination of the fundamentals of urban ecology. In this Special Section, we conceptualize the pathways of coevolution and collaboration with other disciplines as ‘‘shifts.’’The contributions examine and synthesize our understanding of these shifts in urban ecology relative to the subject of study, the evidence base used, the ways of knowing, and methodological approaches. Through the shifts, we can elucidate the links of the field to important contemporary urban issues, such as justice, climate adaptation, and resilience.

It is becoming clear that to realize the vision of a more engaged urban ecology, vestiges of colonialism, racism, classism, and exclusionary power differentials must be countered (Simone 2017; Schell et al. 2020). We need to examine how the shifts contribute to the evolution of urban ecology into a field that has improved its potential to contribute to positive scenarios within the Anthropocene. The plural views, conceptual innovations, and ways of knowing must be critically interrogated, and unpacked. Theoretical deepening and conceptual innovations in urban ecology are equally important for guiding future research. Indeed, conceptual innovations are required to explore, beyond thin-in-theory justifications for urban research, such as the fact that urbanization is a large, diverse, and continuing collection of global trajectories. While this is true and has great practical significance in and of itself, it is a superficial motivation for transdisciplinary urban research. Such developments should be pursued in a way that can avoid developing new labels that become ‘‘ivy concepts’’meaning those that are incremental additions that develop around others, but which add no depth (Westman and Castan Broto 2022).