Reporting the First International Workshop on Social Ecological Resilience in Freshwater Systems in the Anthropocene
(8-10 July, 2017), Nanjing, China
A three-day international (8-10th July, 2017) workshop on “Social Ecological Resilience in Freshwater Systems in the Anthropocene” was organised by the newly established research centre in Nanjing, ‘Resilience and Transformation Centre in China (RTCC) of the Nanjing Institute of Geography and Limnology Chinese Academy Sciences (NIGLAS)’. More than 100 delegates including 20 international scientists contributed to the workshop, representing a range of research institutions/universities and international academic organizations, such as IHOPE, PAGES, Global land project etc. The workshop was financially supported by State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences (CAS) and the National Natural Science Foundation of China (NSFC).
Organising such workshop is timely when the humanity faces global challenges of freshwater resources in the Anthropocene. The key objectives of the three-day international symposium are to help improve knowledge and understanding of nonlinear transition of freshwater system and their relevance to adaptive management. The workshop have two overarching themes: (1) Resilience and regime shift of freshwater social and ecological systems; (2) Resilience-based management in freshwater ecosystems. The workshop of this kind by bringing global leaders in social and ecological resilience of freshwaters in a platform is significant for exchanging knowledge and ideas and to find better solutions for managing degrading freshwaters.
The workshop commenced with three welcome speeches by Shen Ji, the head of NIGLAS, John Dearing, professor of University of Southampton and Yang Xiangdong, the director of research room at NIGLAS made the welcome speech, respectively. Then followed by 20 significant talks covering a range of topics, including new approaches/models to quantify ecosystem resilience, critical review of regime shift in lakes, as well as new theories about soicalcultural evolution, modelling resilience/transformation and adaptive management approached to safeguarded degraded lake ecosystem etc. On day two after all oral presentation finished, brainstorming sessions were organised with three break-out groups to discuss around topics related with regime shift, resilience indicator as well as resilience based management (see details in the bellow session). The final activity undertaken during the workshop was to have an open scientific committee meeting in regard to the new established centre (RTCC), in regard to the centre development strategy, future research plan, international funding application, research collaboration and staff/student exchange program etc. Overall, the workshop was considered a very success by those who attend, despite some controversial opinions in regard to regime shift issues in lakes. At the close of the workshop, it is proposed that second workshop of the RTCC will be held in Guanghzou next year.
Breakout session discussion summary
Resilience and resilience and regime shifts in freshwater ecosystems
Some critical questions today, every freshwater scientist asks that do tipping points or alternative stable states exist in real world ecosystem? Would EWS be identified and measured?
Participants discussed a range of issues on tipping points and regime shifts. Tipping points can exist in real world ecosystem. However, this is not a default in the system. Some participants argue that the system going through the tipping points are not yet well understood, this is due to a lack of our ability to quantify the feedback mechanisms. Freshwater system approaches tipping points when system becomes more sensitive to stochastic phenomena. Climate change increases stochasticity then lead to tipping points. Some participants argue that alternative state shifts should be viewed differently from the tipping points. When assessing the tipping points timescales are important to identify non-linearity. In non-linearity, the use of response curve is crucial as this would provide the information of the recovery of the system. Mathematical models are still problematic as these models do not show actual changes of the ecosystem dynamics. As a result, identification of the EWS is also becoming difficult as EWS itself is not generic. For temporal records, equal internal sampling is important for observing the EWS. Sometimes, structural indicators such as Daphina, piscivore: planktivore ratios of fish and macrophytes can help identify ecological shifts. Small change in external driver can substantially alter the biological structure and dynamics in the system. This then can lead to irreversible regime shift. For example, in Lake Victoria (Africa), eutrophication occurred in the 1950s. Since then the lake is unable to shift back possibly due to the introduction of Nile Perch. The silica diatom collapsed, meantime population grew rapidly and land use change intensified and water quality declined significantly. The safe operating space should be set around the threshold in order to protect the stochasticity brought upon by multiple drivers.
Measurement of social ecological resilience is a complex process. Primarily resilience has not been defined properly. Often resilience and resistance have been used as interchangeably. Understanding the structural change of system can help define resilience and resistance. Skewness in biological data can help inform resilience. But this needs larger number of species and sampling points to measure. The most important is to ask a question, resilience for what? Look at the impacts of different perturbations: all antagonistic, synergistic and additive on ecosystem productivity needs to be assessed
Resilience management through social ecological perspective
The other frequently asked question today is: how useful the resilience-based freshwater ecosystem management in the context of regime shift? This debate has taken some momentums to address freshwater ecosystems management globally. However, social ecological resilience is a very broad concept which is influenced by multiple interactions of social and environmental drivers. Both qualitative and quantitative assessments of social ecological resilience can provide better outcomes in freshwater ecosystems management. For example, the freshwater ecosystems of the lower Yangtze River basin have shown complex responses to social and environmental drivers particularly after the 1980s. The conventional fisheries practices in the floodplain system have changed. There has been cumulative impacts of land reclamation and construction of upstream hydropower dams on downstream flow regimes and sedimentation processes in floodplain systems. In some cases, important ecological and archaeological sites have been lost. The restoration of social ecological resilience is not achievable in the region. The system is almost verge of collapse, or has already crossed the threshold. For managing resilience of such system, a new co-designed, integrated approach is needed. The use of this management approach is more effective at catchment scale and should be backed by advanced research planning, vigorous knowledge exchange programs among scientists and stakeholders. Liaison with government agencies is important during planning of social ecological resilience of freshwaters.
In the lower Yangtze River basin, for example, the Blue Line is the function of social ecological system (SES). Hence, the use of transformation model is significant for resilience-based management in freshwater ecosystem in the Anthropocene. For this, a prior understanding of the system, a set of key management frameworks, the aspiration of the society and the future demand of the region are significant to enhance social ecological resilience of freshwaters. The Blue Line and Red Line concepts need to be incorporated in management of social ecological resilience of freshwaters. However, the benchmarks for Blue Line and Red Line are not well defined. Recently, the government of China has introduced Blue Line concept. For example, Urban Blue Line-2015, which restricts occupying the urban wetlands. However, this only restricts the construction of housing not for the protection of land and water. Putting science behind the Anthropocene baseline concepts is the best approach in resilience-based ecosystem management of freshwaters. However, after its introduction, both Blue Line and Red Line concepts in resilience-based freshwater ecosystem management of freshwaters should be strongly guided by science, and stakeholders’ participation.