Presenting a framework to evaluate the sustainability of different social-ecological systems: Associate Editor, Cristina Garcia discusses the recently published paper, Quantifying ecological and social drivers of ecological surprise by Filbee‐Dexter et al.

Yunnan
An example of complex social-ecological systems (SES) in Yunnan province, China

Conservation Biology has operated under different paradigms since the 1960s, when the preservation of pristine natural ecosystems and species was the frontmost goal under the ‘nature itself‘ paradigm. More recently, conservation biologists have recognized the ‘people and nature’ framework as the most functional paradigm to preserve biodiversity and ecosystem services in an increasingly managed world. This framework explicitly recognizes that ecosystems are driven by complex feedbacks between ecological processes and anthropic interventions that jointly impact the dynamics of populations, communities, and ecosystems. The main challenge, therefore, is to identify a set of scenarios where ecological, social, and economic drivers act to guarantee both ecosystem services and functioning. This approach integrates ecologists, sociologists, economists and policy makers, and it has become highly influential in defining the United Nations’ Sustainable Development Goals (SDG). Moreover, the ‘people and nature’ framework guides the strategy of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) to assess the current status of biodiversity and to evaluate the impact of ecosystem services on human well-being. Yet, researchers still recognize the need to apply robust quantitative tools to test whether current policies guarantee the sustainability of exploited resources or, rather, if they are pushing managed ecosystems to a critical transition and collapse.

A study by Filbee-Dexter et al., recently published in Journal of Applied Ecology, applies an integrative framework to evaluate the sustainability of three different social-ecological systems (SESs): (i) a managed pine forest with cyclic pest outbreaks; (ii) a lake with recurrent events of eutrophication; and (iii) a cod fishery in the Northern Atlantic. This study develops on Ostrom’s framework that dissects complex SESs into seven main elements (resource systems, governance systems, resource units, users, interactions, outcomes and related ecosystems) to elucidate why some SESs are sustainable whereas others tend to collapse. Each element is defined by a set of measurable variables to evaluate their impact on the whole system by applying structural equation models, including non-linear interactions between variables. For each case study, authors used different long-term data sets on the response variable as follows: the annual forest area affected by a pine beetle outbreak; the concentration of Chl-a in a study lake as a proxy of algae abundance; and the average biomass of cod caught. They also included data on management actions, such as the annual volume of timber allowed by the Canadian Department of Forest, Lands, and Natural resources; the fish quota set by the Canadian Department of Fisheries and Oceans; and the maximum daily load of phosphorous in a lake allowed by the United States Environmental Protection Agency. The authors first identified tipping points in the response variable of each study system, and then, by applying the Ostrom’s framework they evaluated whether management decisions had contributed to push the system to a tipping point. Interestingly, the study found that quotas set to control the consumption or extraction of natural resources had little impact on the ecosystem dynamic, at least at the spatial and temporal scales included in the study.

If we aim to guarantee that governmental decisions work in the right direction to avoid total or partial ecosystem collapse, this approach may assist in drafting an effective environmental policy. Overall, this study illustrates the application of an integrative and quantitative framework that will provide scientific-based evidences to evaluate the suitability of management plans and policy decisions. In doing so, we can identify the environmental, cultural, and socio-economic factors that sometimes preclude a sustainable use of resources. As pointed out by Ostrom, lack of long-term data on SESs (or difficult access) hampers the wide application of this framework needed to move environmental policy forward. However, on a positive note, ecologists have already proposed a set of environmental variables easy to track worldwide that represent the core of ongoing and future ecological forecasting programs . Furthermore, an increasing number of new devices available for ecologists and managers (such as drones, image satellites, or environmental DNA) provide a timely opportunity to fill the data gap. In turn, the application of Ostrom’s framework to preserve SESs, such as fisheries, combined with a long-term ecological forecasting will strengthen science-policy interface to manage and preserve biodiversity and ecosystem function and services.

Read the full paper, Quantifying ecological and social drivers of ecological surprise in Journal of Applied Ecology.