Achieving effective, sustainable environmental governance requires a better understanding of the causes and consequences of the complex patterns of interdependencies connecting people and ecosystems within and across scales. Network approaches for conceptualizing and analyzing these interdependencies offer one promising solution. Here, we present two advances we argue are needed to further this area of research: (i) a typology of causal assumptions explicating the causal aims of any given network-centric study of social-ecological interdependencies; (ii) unifying research design considerations that facilitate conceptualizing exactly what is interdependent, through what types of relationships, and in relation to what kinds of environmental problems. The latter builds on the appreciation that many environmental problems draw from a set of core challenges that re-occur across contexts. We demonstrate how these advances combine into a comparative heuristic that facilitates leveraging case-specific findings of social-ecological

Social-ecological network (SEN) concepts and tools are increasingly used in human-environment and sustainability sciences. We take stock of this budding research area to further show the strength of SEN analysis for complex human-environment settings, identify future synergies between SEN and wider human-environment research, and provide guidance about when to use different kinds of SEN approaches and models. We characterize SEN research along a spectrum specifying the degree of explicit network representation of system components and dynamics. We then systematically review one end of this spectrum, what we term 'fully articulated SEN' studies, which specifically model unique social and ecological units and relationships. Results show a larger number of papers focus on methodological advancement and applied ends. While there has been some development and testing of theories, this remains an area for future work and would help develop SENs as a unique field of research, not just a method. Authors have studied diverse systems, while mainly focusing on the problem of social-ecological fit alongside a scattering of other topics. There is strong potential, however, to engage other issues central to human-environment studies. Analyzing the simultaneous effects of multiple social, environmental, and coupled processes, change over time, and linking network structures to outcomes are also areas for future advancement. This review provides a comprehensive assessment of (fully articulated) SEN research, a necessary step that can help scholars develop comparable cases and fill research gaps.

.Lianas are a common plant growth form in tropical forests, where they compete intensely with trees, decreasing tree recruitment, growth, and survival. If the detrimental effects of lianas vary signifi cantly with tree species identity, as is often assumed, then lianas may infl uence tree species diversity and community composition. Furthermore, recent studies have shown that liana abundance and biomass are increasing relative to trees in neotropical forests, which will likely magnify the detrimental effects of lianas and may ultimately alter tree species diversity, relative abundances, and community composition. Few studies, however, have tested the responses of multiple tree species to the presence of lianas in robust, well-replicated experiments. We tested the hypotheses that lianas reduce tree seedling growth and survival, and that the effect of lianas varies with tree species identity. We used a large-scale liana removal experiment in Central Panama in which we planted 14 replicate seedlings of 14 different tree species that varied in shade tolerance in each of 16 80 × 80 m plots (eight liana-removal and eight unmanipulated controls; 3136 total seedlings). Over a nearly two-yr period, we found that tree seedlings survived 75% more, grew 300% taller, and had twice the aboveground biomass in liana-removal plots than seedlings in control plots, consistent with strong competition between lianas and tree seedlings. There were no signifi cant differences in the response of tree species to liana competition (i.e., there was no species by treatment interaction), indicating that lianas had a similar negative effect on all 14 tree species. Furthermore, the effect of lianas did not vary with tree species shade tolerance classifi cation, suggesting that the liana effect was not solely based on light. Based on these fi ndings, recently observed increases in liana abundance in neotropical forests will substantially reduce tree regeneration, but will not signifi cantly alter tropical tree species diversity, relative abundance, or community composition.

1. Research on social-ecological systems (SES) has highlighted their complex and adaptive character and pointed to the importance of recognizing their intertwined nature.2. Yet, we often base our analysis and governance of SES on static and independent objects, such as actors and resources which are not well suited to address complexity and intertwinedness. This bias, which is largely implicit, has its roots in substance ontologies that have influenced most of contemporary science.3. This paper argues that it is useful to critically reflect on this ontological grounding and develop SES research from a process ontological perspective.4. Key insights are that process ontological concepts such as process, event and possibility space are able to overcome the dichotomy between the social and the ecological and allow for a conceptualization of continuous change (dynamism) that enhances our understanding of SES as truly intertwined and complex systems.5. This will enable SES researchers to conceptualize problems as well as corresponding solutions in novel ways which will ultimately support the development of novel governance approaches, from rethinking the aims of policies from managing people towards managing relations between and among people and the natural system. 6. To fully tap the potential which comes with a change in worldview towards a process ontology, changing research approaches and ways of abstracting are required. K E Y W O R D Scomplexity, dichotomies (or dichotomy nature/society), events, relational ontologies, social-ecological systems, substance ontologies, the practice of abstraction

Most if not all environmental problems entail conflicts of interest. Yet, different actors and opposing coalitions often but certainly not always cooperate in solving these problems. Hence, processes of conflict and cooperation often work in tandem, albeit much of the scholarly literature tends to focus on either of these phenomena in isolation. Social network analysis (SNA) provides opportunities to study cooperation and conflict together. In this review, we demonstrate how SNA has increased our understanding of the promises and pitfalls of collaborative approaches in addressing environmental problems. The potential of SNA to investigate conflicts in environmental governance, however, remains largely underutilized. Furthermore, a network perspective is not restricted to the social domain. A multilevel social-ecological network perspective facilitates integration of social and environmental sciences in understanding how different patterns of resource access can trigger both cooperation and conflict. Expected final online publication date for the Annual Review of Environment and Resources, Volume 45 is October 19, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Ecology of Games Framework (EGF) draws attention to the intertwined nature of different forums in a given policy setting and how this affects governance outcomes. In this article, we associate the EGF with the literature on power asymmetries, in order to investigate hypotheses of actors’ perceived level of influence in a forum. Focusing on the Paraíba do Sul river basin committee in Brazil, we specifically explore actors’ participation in multiple forums, time spent participating in the basin committee, and actors’ degree of involvement in the committee as factors that might explain actors’ level of perceived influence in the forum. The findings suggest participation in multiple forums is a key driver of perceived influence and thus highlight a way to challenge traditional power asymmetries. More research, however, is needed to determine to what extent perceived influence is affecting decision‐making processes and governance outcomes in the Paraíba do Sul river basin committee.

Local governments, or municipalities, play a key role in water governance around the world owing to the many administrative competencies they hold, ranging from water service delivery to urban planning. However, the ability of municipalities to carry out their competencies effectively depends in large part on the characteristics of the institutional arrangements in which they are embedded. In particular, the relationship between municipalities and watershed governance institutions has received little attention in the literature on polycentric and multilevel governance. Drawing on insights from diverse cases around the world, we argue that empirical research must pay closer attention to the links, or lack thereof, between municipalities and watershed governance institutions to improve the sustainability of water governance outcomes in practice. We identify a set of critical issues affecting municipalities' engagement in governance at the watershed scale that broadly apply across different contexts, and which we argue deserve more attention in future research: (1) disconnect and ambiguities of authority across hierarchical levels; (2) internal and external challenges to municipalities engaging in effective collaborations; (3) barriers to expanding the scope of traditional municipal affairs; and (4) misalignment of biophysical, institutional, and political timescales.

No abstract