Poverty and ecology: developing a new evolutionary approach

John A Dearing University of Southampton

Introduction Results

References

Key Findings

Methods

John Dearing1,2, Ke Zhang1,2, Richard Treves1, Terry Dawson3, Paul Sillitoe4; Xiangdong Yang5; Xuhui Dong5; Weiguo Zhang6

1Geography and Environment, University of Southampton; 2Sustainability Science at Southampton; 3Geography, University of Dundee; 4Anthroplogy, Durham University; 5NIGLAS, Academy of Sciences, Nanjing; 6Geography, East China Normal University, Shanghai The ESPA Yangtze project is located in the lower Yangtze basin, eastern China, including the four counties and adjacent lakes/estuaries of Chongming-Changjiang estuary, Wujiang-lake Taihu, Shucheng-lake Chaohu and Huangmei –lake Taibai. Project timescale February 2011-January 2013

Reconciling wealth creation with the need to avoid environmental damage is a major challenge: not just for China, but for many rapidly developing regions worldwide. There is a growing view that rapid rates of change in social, economic and climate drivers coupled with increasingly nonlinear ecological responses, such as critical transitions, demand an understanding of the complex dynamics of social-ecological systems to a much higher level than currently prevails (e.g. Dearing et al 2012a).

Here, we show how an evolutionary approach to observing changes in ecosystem services in the lower Yangtze river basin (LYB), in eastern China, provides new insight into the complex dynamics of social-ecological systems. We reconstruct multi-decadal time-series of ecosystem services from lake and estuarine sediment records and compare them against official records for social-economic data (Dearing et al 2012b).

This approach allows us to observe 1) tradeoffs between provisioning and regulating services; 2) analysis of trajectories and critical transitions in regulating services; and 3) the opportunity to gauge the degree of success in uncoupling growth from environmental degradation over multi-decadal timescales.

Additionally we have used new visualisation techniques to show the evolving pattern of ecosystem services and drivers, system dynamics models to explore future trajectories, and questionnaire analyses and face-to-face interviews/presentations in poverty-stricken and less poor counties to obtain feedback on our findings.

• Lake sediment records provide an unrivalled opportunity to observe multi-decadal dynamics, like trajectories, trade-offs and critical transitions, across a wide range of ecosystem services

• In the LYB, declining levels of regulating services is the tradeoff for increasing levels of provisioning services. A tipping point in key regulating services occurred in the 1980s, particularly in water purification.

• Since the 1980s, rural poverty alleviation and ecosystem services have been coupled through agricultural intensification, resulting in fewer transformations of landscapes but much larger effects on local and, ultimately, regional biogeochemical cycles.

• Increasing variability in regulating services supports local views that extreme events like the 1998 Yangtze ‘mega flood’ and 2007 ‘monster bloom’ in Taihu lake are increasing. Recent theory (eg. Wang et al 2012) supports the view that increasing variability is a generic sign of decreasing system stability and loss of resilience.

• Other ESPA projects and future policies for sustainable management should take into account the vital information about nonlinear dynamics that comes only from a multi-scale analysis of the social-ecological system.

Project website https://sites.google.com/site/loweryangtzeriver/ Dearing, J.A., Bullock, S., Costanza, R., Dawson, T.P., Edwards, M.E., Poppy, G.M., Smith, G. Navigating the Perfect Storm: research strategies for social-ecological systems in a rapidly evolving world. 2012a Environmental Management 49 (4), 767-775 doii:10.1007/s00267-012-9833-6 Dearing, J.A., Yang, X., Dong, X., Zhang, E., Chen, X., Langdon, P.G., Zhang, K., Zhang, W. and Dawson, T.P. 2012b. Extending the timescale and range of ecosystem services through paleoenvironmental analyses: the example of the lower Yangtze basin. Proceedings of the National Academy of Sciences 109, E1111-1120 doi:10.1073/pnas.1118263109 Wang, R., Dearing, J.A., Langdon, P.G., Zhang, E., Yang, X., Dakos, V., Scheffer, M. 2012. Flickering gives early warning signals of a critical transition to a eutrophic lake state. Nature doi:10.1038/nature11655

Fig. 1. Tradeoff between provisioning services and regulating services in the LYB during the period 1900-2006. A) Map showing study site and locations with names. B-F) Indices of provisioning (red) and regulating (green) services based on aggregated and scaled data from official statistics, monitoring records and lake sediments for tidal (B) Yangtze, (C) Wujiang, (D) Huangmei, (E) Shucheng and (F) the whole LYB respectively.

Fig. 2. Environmental Kuznets curve relationships between environmental degradation (regulating service indices) and economic growth (GDP/capita RMB-renminbi) for Wujiang, Huangmei, Shucheng and the whole LYB over the period 1950-2006.