Coupled human and natural systems: The evolution and applications of an integrated framework : This article belongs to Ambio's 50th Anniversary Collection. Theme: Anthropocene

Changes in planned and unplanned canopy openings are linked in Europe's forests

Canopy openings are increasing in Europe's forests, yet the contributions of anthropogenic and ecological agents of disturbance to this increase remain debated. Here we attribute the root cause of all stand-replacing canopy disturbances identified for Europe in the period 1986-2020 from Landsat data (417,000 km²), distinguishing between planned and unplanned canopy openings (i.e., disturbance by human land use versus by wind, bark beetles, and wildfire). We show that canopy openings by humans dominate the European forest disturbance regime, accounting for 82% of the area disturbed. Both planned and unplanned canopy openings increased in the early 21st century (+24% and +30% relative to the late 20th century). Their changes are linked, with simultaneous increases in planned and unplanned canopy openings on 68% of Europe's forest area. We conclude that an important direction for tackling disturbance change in policy and management is to break the link between planned and unplanned canopy openings in Europe's forests.

Four recommendations to tackle the complex reality of transdisciplinary, natural experiment research

Natural experiments are often used to study interventions in which randomization to control versus intervention conditions are impossible. Nature-based interventions (i.e., programs designed to increase human interaction with nature and improve human health) are commonly studied as natural experiments. We used a natural experiment design to explore the benefits of ecological rehabilitation of parks on biodiversity and resident health in low-income, minoritized neighborhoods in Detroit, MI. Given the complexities and interconnectedness of lived experiences, community needs, and ecological health, this research design has presented challenges. Based on our experiences, we pose four key recommendations for researchers and practitioners conducting natural experiments, nature-based interventions, and those working in low-income, minoritized neighborhoods. We use the explicit examples of challenges faced as rationale for these recommendations. The key recommendations are (1) Engage with community leaders; (2) Build a transdisciplinary team and work closely; (3) Examine privilege; and (4) Create a unified vision.

Leveraging the metacoupling framework for sustainability science and global sustainable development

Sustainability science seeks to understand human-nature interactions behind sustainability challenges, but has largely been place-based. Traditional sustainability efforts often solved problems in one place at the cost of other places, compromising global sustainability. The metacoupling framework offers a conceptual foundation and a holistic approach to integrating human-nature interactions within a place, as well as between adjacent places and between distant places worldwide. Its applications show broad utilities for advancing sustainability science with profound implications for global sustainable development. They have revealed effects of metacoupling on the performance, synergies, and trade-offs of United Nations Sustainable Development Goals (SDGs) across borders and across local to global scales; untangled complex interactions; identified new network attributes; unveiled spatio-temporal dynamics and effects of metacoupling; uncovered invisible feedbacks across metacoupled systems; expanded the nexus approach; detected and integrated hidden phenomena and overlooked issues; re-examined theories such as Tobler's First Law of Geography; and unfolded transformations among noncoupling, coupling, decoupling, and recoupling. Results from the applications are also helpful to achieve SDGs across space, amplify benefits of ecosystem restoration across boundaries and across scales, augment transboundary management, broaden spatial planning, boost supply chains, empower small agents in the large world, and shift from place-based to flow-based governance. Key topics for future research include cascading effects of an event in one place on other places both nearby and far away. Operationalizing the framework can benefit from further tracing flows across scales and space, uplifting the rigor of causal attribution, enlarging toolboxes, and elevating financial and human resources. Unleashing the full potential of the framework will generate more important scientific discoveries and more effective solutions for global justice and sustainable development.

Narratives to revert overconsumption: human-nature interdependence and Circular Economy

Policy and practitioners' initiatives to stimulate sustainable consumption have so far failed to have notable impact on individuals' behaviors. The current commentary is a plea to social and sustainability scientists, particularly to economists dealing with sustainable agri-food systems, to dig deeper into the notion of narratives to trigger societal dynamics that stir consumers toward more sufficient lifestyles. As dominant cultural narratives have a critical role in shaping shared meanings and acceptable behaviors, in the future they could guide dramatic changes in individuals' conduct, triggering drastic modifications of current consumption patterns. Based on the power that concepts as the Circular Economy and the Anthropocene have had in the recent past, a future step to develop an ecological worldview across society, and nourish individual identities deeply committed with the preservation of natural ecosystems, is working on narratives based on the notion of human-nature interdependence.

Global gateways as telecoupled human and natural systems: The emerging case of the Bering Strait

Numerous narrow marine passages around the world serve as essential gateways for the transportation of goods, the movement of people, and the migration of fish and wildlife. These global gateways facilitate human-nature interactions across distant regions. The socioeconomic and environmental interactions among distant coupled human and natural systems affect the sustainability of global gateways in complex ways. However, the assessment and analysis of global gateways are scattered and fragmented. To fill this knowledge gap, we frame global gateways as telecoupled human and natural systems using an emerging global gateway, the Bering Strait, as a demonstration. We examine how three telecoupling processes (tourism, vessel traffic, and natural resource development) impact and are impacted by the coupled human and natural system of the Bering Strait Region. Given that global gateways share many similarities, our analysis of the Bering Strait Region provides a foundation for the assessment of other telecoupled global gateways.

Physical and virtual nutrient flows in global telecoupled agricultural trade networks

Global agricultural trade creates multiple telecoupled flows of nitrogen (N) and phosphorus (P). The flows of physical and virtual nutrients along with trade have discrepant effects on natural resources in different countries. However, existing literature has not quantified or analyzed such effects yet. Here we quantified the physical and virtual N and P flows embedded in the global agricultural trade networks from 1997 to 2016 and elaborated components of the telecoupling framework. The N and P flows both increased continuously and more than 25% of global consumption of nutrients in agricultural products were related to physical nutrient flows, while virtual nutrient flows were equivalent to one-third of the nutrients inputs into global agricultural system. These flows have positive telecoupling effects on saving N and P resources at the global scale. Reducing inefficient trade flows will enhance resource conservation, environmental sustainability in the hyper-globalized world.

Effects of global shocks on the evolution of an interconnected world

As the world grows more interconnected through the flows of people, goods, and information, many challenges are becoming more difficult to address since human needs are increasingly being met through global supply chains. Global shocks (e.g., war, economic recession, pandemic) can severely disrupt these interconnections and generate cascading consequences across local to global scales. To comprehensively evaluate these consequences, it is crucial to use integrated frameworks that consider multiple interconnections and flows among coupled human and natural systems. Here we use the framework of metacoupling (human-nature interactions within as well as across adjacent and distant systems) to illustrate the effects of major global shocks on the evolution of global interconnectedness between the early 1900s and the 2010s. Based on these results we make a few actionable recommendations to reduce the negative impacts of an ongoing global shock, the COVID-19 pandemic, to promote global sustainability.

Complexity and diversity of nexuses: A review of the nexus approach in the sustainability context

Achieving global sustainability is a coupled human-environment system issue that requires resource planning and management that goes beyond siloed thinking. As such, there has been a growing interest in nexus thinking as a way to address global sustainability challenges in an integrated manner. In general, the nexus approach serves as a tool for systems integration, a platform for stakeholder engagement, and a method for exploring development pathways. This review traces the historical origin and progress of the nexus approach and examines the changes in the complexity and diversity of nexuses over time. Since its emergence in the early 1980s, the nexus approach has undergone several phases of development, resulting in more complex and diverse nexuses, whose components can be resource sectors/systems and/or specific social-ecological issues. This progress is favorable for the sustainable development agenda because the more components involved in a nexus, the greater the reality that can be potentially captured. Currently, however, there is still no consensus with regards to the key nexus components that could potentially cover all of the sustainable development goals. The development of frameworks for implementing the nexus approach and the identification of relevant indicators and target values to be used for assessing trade-offs and synergies are among the current issues with regards to the use of the nexus approach in the sustainability context.

The metacoupled Arctic: Human-nature interactions across local to global scales as drivers of sustainability

The Arctic is an epicenter of complex environmental and socioeconomic change. Strengthened connections between Arctic and non-Arctic systems could threaten or enhance Arctic sustainability, but studies of external influences on the Arctic are scattered and fragmented in academic literature. Here, we review and synthesize how external influences have been analyzed in Arctic-coupled human and natural systems (CHANS) literature. Results show that the Arctic is affected by numerous external influences nearby and faraway, including global markets, climate change, governance, military security, and tourism. However, apart from climate change, these connections are infrequently the focus of Arctic CHANS analyses. We demonstrate how Arctic CHANS research could be enhanced and research gaps could be filled using the holistic framework of metacoupling (human-nature interactions within as well as between adjacent and distant systems). Our perspectives provide new approaches to enhance the sustainability of Arctic systems in an interconnected world.

Coupled and Synchronization Models of Rhythmic Arm Movement in Planar Plane

Nonlinear dynamics have become a new perspective on model human movement variability; however, it is still a debate whether chaotic behavior is indeed possible to present during a rhythmic movement. This paper reports on the nonlinear dynamical behavior of coupled and synchronization models of a planar rhythmic arm movement. Two coupling schemes between a planar arm and an extended Duffing-Van der Pol (DVP) oscillator are investigated. Chaos tools, namely phase space, Poincare section, Lyapunov Exponent (LE), and heuristic approach are applied to observe the dynamical behavior of orbit solutions. For the synchronization, an orientation angle is modeled as a single well DVP oscillator implementing a Proportional Derivative (PD)-scheme. The extended DVP oscillator is used as a drive system, while the orientation angle of the planar arm is a response system. The results show that the coupled system exhibits very rich dynamical behavior where a variety of solutions from periodic, quasi-periodic, to chaotic orbits exist. An advanced coupling scheme is necessary to yield the route to chaos. By modeling the orientation angle as the single well DVP oscillator, which can synchronize with other dynamical systems, the synchronization can be achieved through the PD-scheme approach.

A Socio-Hydrological Unit Division and Confluence Relationship Generation Method for Human–Water Systems

Studies on human activities and the natural water cycle as a coupled system are essential for effective water resource management in river basins. However, existing calculation methods based solely on the natural water cycle do not meet the accuracy requirements of natural society dualistic water cycle simulations. Therefore, it is necessary to establish a more scientific and reasonable calculation unit division method and river confluence relationship determination method. This paper presents a socio-hydrological unit with natural society dual characteristics based on both the hydrological characteristics and the social administrative characteristics of the river basin. According to the elevation of the river buffer zone, river confluence relationships among socio-hydrological units are determined, and upstream and downstream confluence of the human–water system is obtained. Finally, a case study of the Jing-Jin-Ji region in China, an area of intensive human activities, was performed. A reliability of 94.3% was reached using the proposed socio-hydrological unit division and river confluence calculation method, suggesting that the approach is highly applicable. Thus, the proposed method for generating socio-hydrological units and determining river confluence relationships can be applied to study the mutual influence and spatial distribution characteristics of natural society dualistic water cycles. The data requirement is minimal, and the approach can provide benefits in research on human water systems.

Beliefs about Human-Nature Relationships and Implications for Investment and Stewardship Surrounding Land-Water System Conservation

When engaging stakeholders in environmental conservation, it is critical to understand not only their group-level needs, but also the individually held beliefs that contribute to each person’s decisions to endorse or reject policies. To this end, we examined the extent to which people conceptualize the interconnected relationship between humans and nature in the context of a hypothetical urban waterway, and the implications thereof for environmental investment and stewardship. We also explored how these beliefs varied based on describing the waterway as having either local or global impacts, and as originating either naturally or through artificial processes. Three hundred and seventy-nine adults from the United States read vignettes about a polluted urban waterway and thereafter reported their investment in river clean-up, their stewardship of the river, and their beliefs surrounding human-nature relationships. Results revealed a common belief pattern whereby humans were believed to impact the urban river disproportionately more than the river impacts humans, suggesting that lay adults often weigh the impacts of humans on the natural world disproportionally. Critically, this disproportionate pattern of thinking inversely predicted investment of time and money in river clean-up. Results also revealed a potential solution to this psychological bias: highlighting local benefits of the waterway decreased the asymmetry of the human-nature relationship. We discuss the psychological factors contributing to this cognitive bias, and the implications of these findings on stakeholder engagement.

Climate Change and Water Dynamics in Rural Uganda

The purpose of this case study is to examine the effects of climate change on agricultural life in rural Uganda. Based on primary data, the authors examine major themes related to climate change and disasters as conveyed by individuals in a small agricultural region in Eastern Uganda. Specifically, we focus on the effects of living in constant threat of flooding and landslides. Results show that water is a major source of loss for most people, ranging from crop loss to contaminated water. Findings also point to the chronic nature of dealing with water issues, as opposed to acute. Further, our results indicate that disasters are a great equalizer among affected populations, with only neighbors to depend on in the aftermath.