Shifting forward: Urban ecology in perspective.

The world has become urban; cities increasingly shape our worldviews, relation to other species, and the large-scale, long-term decisions we make. Cities are nature, but they need to align better with other ecosystems to avoid accelerating climate change and loss of biodiversity. We need a science to guide urban development across the diverse realities of global cities. This need can be met, in part, by shifts in urban ecology and its linkages to related sciences. This perspective is a "synthesis of syntheses", consolidating ideas from the other articles in the Special Section. It re-examines the role of urban ecology, and explores its integration with other disciplines that study cities. We conclude by summarizing the next steps in the ongoing shift in urban ecology, which is fast becoming an integral part of urban studies.

A transformative shift in urban ecology toward a more active and relevant future for the field and for cities.

This paper builds on the expansion of urban ecology from a biologically based discipline-ecology in the city-to an increasingly interdisciplinary field-ecology of the city-to a transdisciplinary, knowledge to action endeavor-an ecology for and with the city. We build on this "prepositional journey" by proposing a transformative shift in urban ecology, and we present a framework for how the field may continue this shift. We conceptualize that urban ecology is in a state of flux, and that this shift is needed to transform urban ecology into a more engaged and action based field, and one that includes a diversity of actors willing to participate in the future of their cities. In this transformative shift, these actors will engage, collaborate, and participate in a continuous spiral of knowledge → action → knowledge spiral and back to knowledge loop, with the goal of co producing sustainable and resilient solutions to myriad urban challenges. Our framework for this transformative shift includes three pathways: (1) a repeating knowledge → action → knowledge spiral of ideas, information, and solutions produced by a diverse community of agents of urban change working together in an "urban sandbox"; (2) incorporation of a social-ecological-technological systems framework in this spiral and expanding the spiral temporally to include the "deep future," where future scenarios are based on a visioning of seemingly unimaginable or plausible future states of cities that are sustainable and resilient; and (3) the expansion of the spiral in space, to include rural areas and places that are not yet cities. The three interrelated pathways that define the transformative shift demonstrate the power of an urban ecology that has moved beyond urban systems science and into a realm where collaborations among diverse knowledges and voices are working together to understand cities and what is urban while producing sustainable solutions to contemporary challenges and envisioning futures of socially, ecologically, and technologically resilient cities. We present case study examples of each of the three pathways that make up this transformative shift in urban ecology and discuss both limitations and opportunities for future research and action with this transdisciplinary broadening of the field.

The relational shift in urban ecology: From place and structures to multiple modes of coproduction for positive urban futures.

This perspective emerged from ongoing dialogue among ecologists initiated by a virtual workshop in 2021. A transdisciplinary group of researchers and practitioners conclude that urban ecology as a science can better contribute to positive futures by focusing on relationships, rather than prioritizing urban structures. Insights from other relational disciplines, such as political ecology, governance, urban design, and conservation also contribute. Relationality is especially powerful given the need to rapidly adapt to the changing social and biophysical drivers of global urban systems. These unprecedented dynamics are better understood through a relational lens than traditional structural questions. We use three kinds of coproduction-of the social-ecological world, of science, and of actionable knowledge-to identify key processes of coproduction within urban places. Connectivity is crucial to relational urban ecology. Eight themes emerge from the joint explorations of the paper and point toward social action for improving life and environment in urban futures.

A transformative mission for prioritising nature in Australian cities.

Australia is experiencing mounting pressures related to processes of urbanisation, biodiversity loss and climate change felt at large in cities. At the same time, it is cities that can take the leading role in pioneering approaches and solutions to respond to those coupling emergencies. In this perspective piece we respond to the following question: What are the required transformations for prioritising, valuing, maintaining and embracing nature in cities in Australia? We adopt the mission framework as an organising framework to present proposed pathways to transform Australian cities as nature-positive places of the future. We propose three interconnected pathways as starting actions to steer urban planning, policy and governance in Australian cities: First, cities need to establish evidence-based planning for nature in cities and mainstream new planning tools that safeguard and foreground urban nature. Second, collaborative planning needs to become a standard practice in cities and inclusive governance for nature in cities needs to prioritise Aboriginal knowledge systems and practices as well as look beyond what local governments can do. Third, for progressing to nature-positive cities, it is paramount to empower communities to innovate with nature across Australian cities. Whilst we focus on Australian cities, the lessons and pathways are broadly applicably globally and can inspire science-policy debates for the post COP15 biodiversity and COP26 climate change implementation processes.

Principles for urban nature-based solutions.

Nature-based solutions (NBS) were introduced as integrated, multifunctional and multi-beneficial solutions to a wide array of socio-ecological challenges. Although principles for a common understanding and implementation of NBS were already developed on a landscape scale, specific principles are needed with regard to an application in urban areas. Urban areas come with particular challenges including (i) spatial conflicts with urban system nestedness, (ii) specific urban biodiversity, fragmentation and altered environments, (iii) value plurality, multi-actor interdependencies and environmental injustices, (iv) path-dependencies with cultural and planning legacies and (v) a potential misconception of cities as being artificial landscapes disconnected from nature. Given these challenges, in this perspective paper, we build upon and integrate knowledge from the most recent academic work on NBS in urban areas and introduce five distinct, integrated principles for urban NBS design, planning and implementation. Our five principles should help to transcend governance gaps and advance the scientific discourse of urban NBS towards a more effective and sustainable urban development. To contribute to resilient urban futures, the design, planning, policy and governance of NBS should (1) consider the need for a systemic understanding, (2) contribute to benefiting people and biodiversity, (3) contribute to inclusive solutions for the long-term, (4) consider context conditions and (5) foster communication and learning.

Transformative low-carbon urban innovations: Operationalizing transformative capacity for urban planning.

Cities can set in motion sustainability transitions through experimentation and innovation. To invest in and mainstream solutions that contribute to urban transformation agendas, urban planners needs to understand which innovations have transformational potential as well as how these innovations can accelerate sustainability transitions. In order to explore this, existing frameworks of transformative capacity provide the guidance, but they are generic, abstract, and challenging to apply for urban planning. As part of our effort to develop a more operational version of the transformative capacity framework by Wolfram (2016), we conducted a systematic scoping review of the academic literature to determine the characteristics of people-based and nature-based low-carbon innovations that constitutes their transformative capacity. After reviewing 65 records, we identified dimensions indicating each of the transformative capacity components through analysis and synthesis. Besides contributing to the science-policy interface through a knowledge synthesis on low-carbon people-based and nature-based innovations, this paper examines bridging frameworks to inform urban planners in developing practical solutions and actionable elements for low-carbon urban futures.

The potential of nature-based solutions to deliver ecologically just cities: Lessons for research and urban planning from a systematic literature review.

Planning for and implementing multifunctional nature-based solutions can improve urban ecosystems' adaptation to climate change, foster urban resilience, and enable social and environmental innovation. There is, however, a knowledge gap in how to design and plan nature-based solutions in a nonanthropocentric manner that enhances co-benefits for humans and nonhuman living organisms. To address this gap, we conducted a systematic literature review to explore how an ecological justice perspective can advance the understanding of nature-based solutions. We argue that ecological justice, which builds on the equitable distribution of environmental goods and bads, social-ecological interconnectedness, nature's agency and capabilities, and participation and inclusion in decision-making, provides a transformative framework for rethinking nature-based solutions in and for cities. A qualitative analysis of 121 peer-reviewed records shows a highly human-centred worldview for delivering nature-based solutions and a relationship to social justice with no direct reference to the dimensions of ecological justice. There is, however, an underlying recognition of the importance of nonhumans, ecosystem integrity and well-being, and a need to consider their needs and capacities through multispecies nature-based solutions design and planning. We conclude with a discussion of the critical aspects for designing and planning ecologically just cities through nature-based solutions and future research directions to further integrate these fields.

Integrating solutions to adapt cities for climate change.

Record climate extremes are reducing urban liveability, compounding inequality, and threatening infrastructure. Adaptation measures that integrate technological, nature-based, and social solutions can provide multiple co-benefits to address complex socioecological issues in cities while increasing resilience to potential impacts. However, there remain many challenges to developing and implementing integrated solutions. In this Viewpoint, we consider the value of integrating across the three solution sets, the challenges and potential enablers for integrating solution sets, and present examples of challenges and adopted solutions in three cities with different urban contexts and climates (Freiburg, Germany; Durban, South Africa; and Singapore). We conclude with a discussion of research directions and provide a road map to identify the actions that enable successful implementation of integrated climate solutions. We highlight the need for more systematic research that targets enabling environments for integration; achieving integrated solutions in different contexts to avoid maladaptation; simultaneously improving liveability, sustainability, and equality; and replicating via transfer and scale-up of local solutions. Cities in systematically disadvantaged countries (sometimes referred to as the Global South) are central to future urban development and must be prioritised. Helping decision makers and communities understand the potential opportunities associated with integrated solutions for climate change will encourage urgent and deliberate strides towards adapting cities to the dynamic climate reality.

Urban sustainability science: prospects for innovations through a system's perspective, relational and transformations' approaches : This article belongs to Ambio's 50th Anniversary Collection. Theme: Urbanization.

In this perspective, we present how three initial landmark papers on urban sustainability research contributed to the larger sustainability science scholarship and paved the way for the continued development of urban sustainability research. Based on this, we propose three conceptual innovation pathways to trace the progression of urban sustainability science: First, urban sustainability from a system's perspective, meaning that urban sustainability requires integrative solutions to work in the tripled social-ecological-technological system setting. Second, urban sustainability from a (people and place) relational perspective, meaning urban sustainability is a contested and dynamic social-ecological contract of cities. As a governance mission, urban sustainability requires evidence from research that can inform coordinated action to bridge people, places, meanings, visions and ecosystems. Third, urban sustainability from a transformative science perspective, meaning that for urban sustainability to be achieved and progressed, deep transformations are required in systems, relations, policies and governance approaches. Our proposal for the future of urban sustainability science centres on emphasizing the relevance and policy applicability of systems' thinking, value and place thinking and transitions/transformations thinking as fundamental to how knowledge is co-produced by research science, policy and society and becomes actionable.

A Research Agenda for the Future of Urban Water Management: Exploring the Potential of Nongrid, Small-Grid, and Hybrid Solutions.

Recent developments in high- and middle-income countries have exhibited a shift from conventional urban water systems to alternative solutions that are more diverse in source separation, decentralization, and modularization. These solutions include nongrid, small-grid, and hybrid systems to address such pressing global challenges as climate change, eutrophication, and rapid urbanization. They close loops, recover valuable resources, and adapt quickly to changing boundary conditions such as population size. Moving to such alternative solutions requires both technical and social innovations to coevolve over time into integrated socio-technical urban water systems. Current implementations of alternative systems in high- and middle-income countries are promising, but they also underline the need for research questions to be addressed from technical, social, and transformative perspectives. Future research should pursue a transdisciplinary research approach to generating evidence through socio-technical "lighthouse" projects that apply alternative urban water systems at scale. Such research should leverage experiences from these projects in diverse socio-economic contexts, identify their potentials and limitations from an integrated perspective, and share their successes and failures across the urban water sector.

Tales of transforming cities: Transformative climate governance capacities in New York City, U.S. and Rotterdam, Netherlands.

Climate change actions in cities worldwide are driving deep changes in urban governance. We ask whether new capacities for transformative climate governance are emerging in two cities that have experimented with urban climate governance: Rotterdam, the Netherlands, and New York City (NYC), United States. Transformative climate governance creates the conditions for developing integrated and innovative climate mitigation and adaptation policies and interventions that respond to and shape urban transformation dynamics and contribute to sustainability and resilience. The comparison of capacities for transformative climate governance in Rotterdam and NYC offers insights into the emerging features of urban climate governance vis-à-vis existing urban governance regimes: how urban climate governance is driven and delivered, what new governance conditions emerge, and whether these conditions enable transformative climate governance. In both cities, an integrated, experimental and inclusive approach to climate governance is emerging, which crosses multiple policy sectors and domains (e.g. transport, energy, health, justice), involves a variety of actors and facilitates innovative solutions. Envisioning, long-term goal and knowledge integration, experimentation and tapping into coalitions for change help to provide the basis (including guiding principles, urgency, actor networks, innovative solutions) for transformative climate governance. However, these transformative approaches tend to be still subordinate to business-as-usual interests and policy and planning approaches, which favour isolated, incremental and short-term responses. The challenge for strengthening transformative climate governance will be to develop rigorous institutional and organisational conditions that decisively stipulate a prioritisation of climate change across scales and sectors, provide action mandates and enable wider coordination, collaboration and learning.

Sense of place and experimentation in urban sustainability transitions: the Resilience Lab in Carnisse, Rotterdam, The Netherlands.

Experimentation as a means of governance for sustainability transitions has been advocated for years by transition scholars and geography scholars. We propose that examining the impact of experimentation requires an understanding of its embeddedness in place as a socio-spatial context. This notion of embeddedness, which conceptually aligns well with the understanding of sense of place, is under-examined in sustainability transitions literature. By conjoining the sense of place and sustainability transition literatures, we conceptualize that sense of place can be one outcome of experimentation fostering sustainability transitions. We examine urban living labs as an open format of urban experimentation, where multiple actors interact with the aim to co-design, test, and implement governance innovations. From the literature, we have distilled three phenomena that relate to a sense of place as mechanisms for transformation: a symbolic understanding or meaning of place; a narrative of place that connects to a transformative vision; and new types of relations between people and place. With this conceptual lens, we analyze our case study, an urban living lab called The Resilience Lab in a neighborhood of the city of Rotterdam, The Netherlands. Drawing from a longitudinal case study research, we contend that urban living labs can connect a sense of change (transformation) with a sense of place by co-creating new narratives of place, by co-producing knowledge on new practices and new relations between people and place, and by allowing the co-design or (re)establishment of places with symbolic meaning. As such, urban living labs facilitate urban sustainability transitions.

Organising a safe space for navigating social-ecological transformations to sustainability.

The need for developing socially just living conditions for the world's growing population whilst keeping human societies within a 'safe operating space' has become a modern imperative. This requires transformative changes in the dominant social norms, behaviours, governance and management regimes that guide human responses in areas such as urban ecology, public health, resource security (e.g., food, water, energy access), economic development and biodiversity conservation. However, such systemic transformations necessitate experimentation in public arenas of exchange and a deepening of processes that can widen multi-stakeholder learning. We argue that there is an emergent potential in bridging the sustainability transitions and resilience approaches to create new scientific capacity that can support large-scale social-ecological transformations (SETs) to sustainability globally, not just in the West. In this article, we elucidate a set of guiding principles for the design of a 'safe space' to encourage stronger interactions between these research areas and others that are relevant to the challenges faced. We envisage new opportunities for transdisciplinary collaboration that will develop an adaptive and evolving community of practice. In particular, we emphasise the great opportunity for engaging with the role of emerging economies in facilitating safe space experimentation.

Ecosystem services in urban landscapes: practical applications and governance implications.

Urban landscapes are the everyday environment for the majority of the global population, and almost 80 % of the Europeans live in urban areas. The continuous growth in the number and size of urban areas along with an increasing demand on resources and energy poses great challenges for ensuring human welfare in cities while preventing an increasing loss of biodiversity. The understanding of how urban ecosystems function, provide goods and services for urban dwellers; and how they change and what allows and limits their performance can add to the understanding of ecosystem change and governance in general in an ever more human-dominated world. This Special Issue aims at bridging the knowledge gap among urbanization, demand creation, and provisioning of ecosystem services in urban regions on the one hand and schemes of urban governance and planning on the other.

The dynamics of urban ecosystem governance in Rotterdam, the Netherlands.

We explore whether Rotterdam city has the governance capacity in terms of processes at place, and the attention in terms of vision and strategy to take up an integrated approach toward urban resilience. We adopt an interpretative policy analysis approach to assess the dynamics of urban ecosystem governance considering interviews, gray literature, and facilitated dialogues with policy practitioners. We show the inner workings of local government across strategic, operational, tactical, and reflective governance processes about the way urban ecosystems are regulated. Despite the existing capacity to steer such processes, a number of underlying challenges exist: need for coordination between planning departments; need to ease the integration of new policy objectives into established adaptive policy cycles; and need to assess the lessons learnt from pilots and emerging green initiatives. Regulating and provisioning ecosystem services receive heightened policy attention. Focus on regulating services is maintained by a policy renewal cycle that limits and delays consideration of other ecosystem services in policy and planning.

The enabling institutional context for integrated water management: lessons from Melbourne.

There is widespread international acceptance that climate change, demographic shifts and resource limitations impact on the performance of water servicing in cities. In response to these challenges, many scholars propose that a fundamental move away from traditional centralised infrastructure towards more integrated water management is required. However, there is limited practical or scholarly understanding of how to enable this change in practice and few modern cities have done so successfully. This paper addresses this gap by analysing empirical evidence of Melbourne's recent experience in shifting towards a hybrid of centralised and decentralised infrastructure to draw lessons about the institutional context that enabled this shift. The research was based on a qualitative single-case study, involving interviews and envisioning workshops with urban water practitioners who have been directly involved in Melbourne's water system changes. It was found that significant changes occurred in the cultural-cognitive, normative and regulative dimensions of Melbourne's water system. These included a shift in cultural beliefs for the water profession, new knowledge through evidence and learning, additional water servicing goals and priorities, political leadership, community pressure, better coordinated governance arrangements and strong market mechanisms. The paper synthesises lessons from the case study that, with further development, could form the basis of prescriptive guidance for enabling the shift to new modes of water servicing to support more liveable, sustainable and resilient outcomes for future cities.