This interdisciplinary research programme draws together scientists from mainly the UK and China with the aim of assessing the sustainability of modern agriculture across China through understanding its regional social-ecological dynamics.
The rapid economic growth in China over the past 20 years has taken huge numbers of people out of poverty but not without an environmental cost. Soil erosion, water pollution, loss of biodiversity and urban haze have all created challenges for environmental management. In the case of agriculture there is some evidence that ecological degradation is even beginning to have a negative impact on food security. Thus, in this long-running project, the aim has been to improve the scientific basis for sustainable agriculture using long social and ecological records to define the key dynamics of agricultural and related systems.
The impact of these findings so far has been mainly in terms of highly rated scientific journals. But in the last couple of years we have organised and run successful workshop sessions in China with environmental managers, surveyed the attitudes of rural farmers to ecological degradation and created a website, with a Chinese version, that now receives over 1000 visits per month. Change in China comes from the top. Our tactic has therefore been to aggregate the findings from scientific study, social survey and official discussions and set them in the context of recent government statements about sustainable management of resources. Our most recent work (currently in review) draws together these findings and lays out explicitly the needs for new policy with regards farmers and farming practises.
Three key elements inform the research: ecosystem services, complex system science and lake sediment records of ecological change. The methodology employed (Dearing et al., 2012) uses lake sediment records across China (Figure 1) to provide proxy records of biophysical processes and conditions in the lake and surrounding catchment, which can also be interpreted as records of regulating ecosystem services. These are compared with official statistical records, land use data and other social documents that provide records of provisioning ecosystem services. The patterns of interaction through time are assessed with respect to external pressures on the system, such as global food prices, national policy, and climate change. Together, this evolutionary perspective of emergent system properties provides evidence for a) system properties such as tipping points, network connectivity, and early warning signals of instability, and b) the roles of political, social and environmental pressures in shaping or driving the system trajectories. The methodology maps on to the science priorities of the IHOPE and PAGES Regional Integration initiatives. To date, the results have led to 13 international research articles, including papers in the high impact journals Global Environmental Change, Nature and Proceedings of the National Academy of Sciences.
Tipping Points and Early Warning Signals: Two major problems confront landscape mangers in the mountainous areas of south-western China: soil erosion often leading to gullying, and nutrient enrichment of rivers and lakes (Figure 2). In both cases, environmental managers have struggled to reverse the degradation through reforestation and water quality management, respectively. Why are these ecological systems so difficult to restore? Analyses of the slope erosion problems in Yunnan Province show (Dearing, 2008; Dearing et al., 2008; Elvin et al., 2002; Shen et al., 2006) that the problem is a very old one. Lake sediment records show that a tipping point was passed around 1430 BP as population pressure forced minority groups into more marginal farmland. The transition from the first stable state to the current stable, but degraded, state involving the development of widespread and deep gully systems took about 600 years to complete. The lack of success in reducing erosion rates through reforestation programmes is explained, in large part, by the current system existing in, effectively, an irreversible state.
Modern observations since the 1950s indicate that some Chinese lakes have shifted from fairly clear water systems to turbid, eutrophic systems. The tipping points between alternate steady states have been reached as a result of nutrient enrichment from increasing fertilizer usage and sewage that have reduced overall system resilience. Studies of water quality monitoring and lake sediment records suggest (Wang et al., 2012) that such shifts are fold bifurcations with highly nonlinear properties that make current attempts to manage and restore the water quality highly challenging. At lake Erhai, in Yunnan, preserved records of diatom algae show increasing volatility several decades before the tipping point supporting the theory that some classes of tipping points may be anticipated through early warning signals.
Safe and Just Operating Spaces for Regional Development: In this project, the Planetary Boundaries concept has been extended to include social conditions, downscaled and applied to two poor, rural social-ecological systems in China. A new, pragmatic classification for biophysical limits uses our current understanding of complex system science to define the ‘health’ of the system (Dearing et al., 2014). Consequently, recent time-series of regulating services can be analysed and defined with respect to bounded operating spaces. Traffic light colours are used to show ‘safe’, ‘cautious’ or ‘dangerous’ system states with respect to a ‘business-as-usual’ future. This provides scientifically based guidelines for managers and agencies about the current state or health of different ecosystem services. In addition, the guidelines summarise the degree to which social norms are met within the region, using data taken from local official statistical records. A range of development goals are reviewed, such as education, food security, jobs, water access and sanitation. Bringing together ideas of limits on the use of ecosystem processes with the priorities for social development helps to highlight the potential links and, importantly, the potential conflicts between the two. For example, in the two Chinese counties studied the greatest social needs are for improved sanitation and access to clean water yet the state of the natural water systems is already in the ‘dangerous’ zone as a result of, mainly, unregulated agricultural effluent. As increasing rural wealth allows more farmers to switch from cesspit systems to modern facilities there is the need for investment and very careful establishment of centralised sewage and water systems that are effectively decoupled from the natural water bodies that already pose great challenges for management. Application of the methodology to other rural areas in China is in progress.
Poverty Alleviation and Ecosystem Services: This project shows how the analyses of 55 time-series of social, economic and ecological conditions provides an evolutionary perspective for the modern Lower Yangtze region with powerful insights about the sustainability of modern ecosystem services (Zhang et al., 2015). Increasing trends in provisioning ecosystem services within the region over the past 60 years reflect economic growth and successful poverty alleviation but are paralleled by steep losses in a range of regulating ecosystem services mainly since the 1980s (Figure 3). Increasing connectedness across the social and ecological domains after 1985 points to a greater uniformity in the drivers of the rural economy as individual farmers make decisions more aligned with national policy and global economic conditions, rather than demands from local markets. Regime shifts and heightened levels of variability since the 1970s in local ecosystem services indicate progressive loss of resilience across the region. Of special concern are water quality services that have already passed critical transitions in several areas. Viewed collectively, the results suggest that the regional social–ecological system passed a tipping point in the late 1970s and is now in a transient phase heading towards a new steady state. However, the long-term relationship between economic growth and ecological degradation (as Environmental Kuznets curve-type analysis) shows no sign of decoupling as demanded by the need to reverse an unsustainable trajectory (Figure 4). This research has recently been extended (Dearing et al., in manuscript) to try and understand farming behaviours and what changes at local, provincial and national scales would be needed to speed up the decoupling process. Social surveys have been conducted in selected townships of farmer’s perceptions of change, the influences on their decision-making processes, and their plans for the future. The results of that analysis point firmly to the need for more efficient use of water, soils, fertilizer and pesticides: but this can only come through a faster rationalisation of farm (and field sizes) and much greater levels of information/technology transfer to farmers.
Dynamic Syndromes of Social-Ecological Systems: This project, recently funded (2014) by the Chinese Academy of Sciences introduces the new idea of ‘dynamical syndromes’ to describe the general system properties of modern social-ecological/agricultural systems across China so that generalised strategies can be designed for sustainable management. The idea extends the previous definition of global syndromes by extending the timescale of observation to cover all slow and fast processes that influence the contemporary system. By using all available time-series for social, economic and ecological variables, systems are classified and modelled according to long term trajectories, resilience, instabilities and the likelihood of near future collapse over tipping points. There are several key steps:
• Compile and synthesize published and unpublished lake sediment records from China covering the past 60 years (potentially from Tibet, Xinjiang, Gansu, Qinghai, Sichuan, Yunnan, Guizhou, Shanxi, Hubei, Hunan, Jiangxi, Guangdong, Hainan, Shandong, Anhui, Jiangsu, Zhejiang, Heilongjiang, and Jilin Provinces).
• Compile social, economic and climate records for all China’s Provinces since 1949, including GDP, population, poverty level, agricultural production (grains, vegetables, fish, livestock), arable land area.
• Classify Provincial data (statistically and mathematically) according to different types and sets of social-ecological system trajectory for: wealth creation, agricultural outputs and ecological degradation; evidence of past tipping points; metrics for instability and connectedness. Define a number of agricultural social-ecological syndromes with reference locations.
Chavez, V.A., Doncaster, C.P., Dearing, J.A., Wang, R., Huang, J.L., Dyke, J.G. 2013. Detecting regime shifts in artificial ecosystems. Advances in Artificial Life, ECAL 12, 625-632
Dai X., Yu L., Dearing, J.A., Zhang W., Shi Y., Zhang F., Gu C., Boyle, J.F, Coulthard, T.J. and Foster, G.C. 2009. The recent history of hydro-geomorphic processes in the upper Hangbu river system, Anhui Province, China. Geomorphology 106, 363-375. Doi: 10.1016/j.geomorph.2008.11.016
Dearing, J.A. 2008. Landscape change and resilience theory: a palaeoenvironmental assessment from Yunnan, SW China. The Holocene 18, 117-127. doi: 10.1177/0959683607085601
Dearing, J.A., Jones, R.T., Shen, J., Yang, X., Boyle, J.F., Foster, G.C., Crook, D.S. and Elvin, M.J.D. 2008. Using multiple archives to understand past and present climate–human–environment interactions: the lake Erhai catchment, Yunnan Province, China (invited Deevey and Frey Review Article), J. Paleolimnology 40:3-31. 10.1007/s10933-007-9182-2
Dearing, J.A., Wang, R., Zhang, K., Dyke, J.G., Haberl, H., Hossain, M.S., Langdon, P.G., Lenton, T.M., Raworth, K., Brown, S., Carstensen, J., Cole, M.J., Cornell, S.E., Dawson, T.P., Doncaster, C.P., Eigenbrod, F., Flörken, M., Jeffers, E., Mackay, A.S., Nykvist, B., Poppy, G.M. 2014. Safe and just operating spaces for regional social-ecological system. Global Environmental Change 28, 227-238. DOI: 10.1016/j.gloenvcha.2014.06.012 Open Access
Dearing, J.A., Yang, X., Dong, X., Zhang, E., Chen, X., Langdon, P.G., Zhang, K., Zhang, W. and Dawson, T.P. 2012. 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 Open Access
Dearing, J.A., Zhang, K., Cao, W.D., Dawson, T.P., Sillitoe, P., and Treves, R. (in review) Chinese agricultural policy, farm responses and ecosystem services since 1950: implications for the future.
Elvin, M., Crook, D.S., Jones, R.T. and Dearing, J.A. 2002. The Impact of Clearance and Irrigation on the Environment in the Lake Erhai Catchment from the Ninth to the Nineteenth Century, East Asian Studies, 23, 1-60.
Shen, J., Jones, R.T., Yang, X., Dearing, J.A., Wang, S. 2006. The Holocene vegetation history of Erhai Lake, Yunnan Province southwestern China: The role of climate and human forcings. The Holocene. 16, 265-276 DOI: 10.1191/0959683606h1923rp
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 492, 419–422. DOI 10.1038/nature11655
Wang, R., Dearing, J.A., Langdon, P.G., Zhang, E., Yang, X., Dakos, V., Scheffer, M. 2012. Reply to Carstensen, J., Telford, R.J. and Birks, H.J.B. Diatom flickering prior to regime shift. 27 June 2013, Nature 498, E12-E13 doi:10.1038/nature12273
Yan Z., Gu H., Dai Y., Wu X., Dearing, J.A., Zhang, W. and Yu L. 2009. Population, land use and environmental impacts in Shucheng County, Anhui Province, China during the Ming and Qing dynasties. Environment and History 15, 61-78 doi:10.3197/096734009X404662
Zhang, K., Dearing, J.A., Dawson, T.P., Dong, X., Yang, X., Zhang, W. 2015. Poverty alleviation strategies in eastern China lead to critical ecological dynamics, Science of the Total Environment 506–507, 164–181. doi:10.1016/j.scitotenv.2014.10.096 Open Access
Major collaborators and affiliated institutions
Universities of Southampton (lead researcher John Dearing with Patrick Doncaster, James Dyke, Felix Eigenbrod, Sarwar Hossain, Peter Langdon, Richard Treves, Rong Wang, Simon Willcock, Ke Zhang), Dundee (Terry Dawson), Exeter (Richard Jones), Hertfordshire (Darren Crook) and Durham (Paul Sillitoe)
Anhui Normal University (Weidong Cao), East China Normal University (Yu Lizhong, Dai Xuerong, Weiguo Zhang), Nanjing Institute of Geography and Limnology (Xuhui Dong, Ji Shen, Yang Xiangdong, Rong Wang, Sumin Wang, Enlou Zhang), and Lanzhou University (Fahu Chen – proposed)
Other major collaborators:
Australia: Australian National University (Mark Elvin –retired).
Austria: Alpen-Adria University Klagenfurt (Helmut Haberl)
Spain: Consejo Superior de Investigaciones Científicas (Vasilis Dakos)
Netherlands: Wageningen University (Marten Scheffer)
UK: Exeter University (Tim Lenton); OXFAM/Oxford University (Kate Raworth).
Professor of Physical Geography
Geography and Environment
University of Southampton
Southampton SO17 1BJ, UK