Given their substantial societal benefits, such as supporting economic activities and providing better livelihoods in rural areas, ecosystem services should gain higher importance in water-food-energy nexus debates. Yet, not all values from ecosystems are quantifiable, data is often not adequate and methods of measuring these values are not sound. This situation challenges researchers and water managers to improve research tools and give adequate attention to ecosystem services by implementing interdisciplinary approaches and integrated management of ecosystems and their services.

The food and beverage industry is one of the most water intensive industries. Therefore, an effective and efficient water management, based on eco-system related indicators, is crucial. This study analyzes the connection between indicators that address sustainable water management as a subgroup of ecosystem management and the general corporate social performance of firms. The study explores which water eco-system indicators are used in the food and beverage industry to assess corporate water risk management. Secondly, we analyzed the relationship between corporate water risk management and overall corporate social performance. Based on an analysis of 61 firms in the food and beverage sector, our results suggest that the most used indicators were Operations' Dependency on Freshwater, Change in Water Supply, Use of Water in the Facilities, Collaboration with Communities, and Water Risks for Agricultural Inputs. Indicators addressing an insideout perspective, such as Impacts on Communities were less often used. Furthermore, we found that the firms' general corporate social performance, measured by MSCI KLD-ESG indicators, is a good predictor for their use of water indicators. We conclude that the firms in the sample follow an outside-in approach for their water management activities and that water management is a significant part of corporate social responsibility activities in the sector because the business performance of food and beverage firms is interwoven with their water management activities.

The authors of the recently completed Comprehensive Assessment of Water Management in Agriculture (CA) concluded that there are sufficient water resources to produce food for a growing population but that trends in consumption, production and environmental patterns, if continued, will lead to water crises in many parts of the world. Only if we act to improve water use will we meet the acute fresh water challenge. Recent spikes in food prices, partially caused by the increasing demand for agricultural products in non-food uses, underline the urgent need to invest in agricultural production, of which water management is a crucial part. The world experienced similar pressure on per capita food supplies and food prices in the 1960s and 1970s, but the challenges now are different than those we experienced 50 years ago. The world's population is substantially larger, there are many more people living in poverty, and the costs of many agricultural inputs are much higher. The current situation and the long-term outlook require a fresh look at approaches that combine different elements such as the importance of access to water for the poor, providing multiple ecosystem services, rainwater management, adapting irrigation to new needs, enhancing water productivity, and promoting the use of low-quality water in agriculture. This special issue highlights the analysis behind a number of policy options identified by the CA, a five-year multi-disciplinary research program involving 700 scientists. This introductory article sets the background and context of this special issue, introduces the key recommendations from the CA and summarizes the papers in this issue.

Ecosystem restoration projects (ERPs) are effective for achieving sustainable development goals. However, a nexus perspective has not yet been effectively used to examine the regimes and interconnections between the sectors of agricultural production, ecosystem restoration, and the livelihoods of farmers, which may have constrained the efficacy of ERPs. In this study, the evolution of these different sectors in ecosystem restoration hotspot cases was investigated using a novel nexus perspective, and their interconnections and implications for ecosystem management were determined. Rapid urbanisation, reclamation, and ERPs have profoundly altered landscape patterns and caused significant ecological changes. Prior to 1999, extensive reclamation proved unsustainable because deforestation activities and cultivation on sloping cropland resulted in severe soil loss and ecosystem deterioration, despite providing significant increases in grain productivity and economic profits. Although revegetation practices after 1999 accelerated vegetation regeneration and enhanced soil retention and carbon sequestration, they also resulted in a decline in grain productivity and economic profits during the initial period of implementing ERPs (1999–2008). However, subsequent policy adjustments and the construction of terraced fields have mitigated cropland loss and maintained the grain supply. The nexus perspective was effective in identifying and coordinating relationships among the sectors, and timely policy interventions have transformed the relationships from trade-offs to synergies and provided win–win outcomes. However, the ongoing urbanisation continues to be a challenge for conserving ecosystems and ensuring food security; therefore, further optimised, and targeted strategies are required to balance contrasting goals and maximise co-benefits according to the environmental and socio-economic conditions.

The attainment of food and water security rank high on the agendas of governments in the Middle East and North Africa (MENA) region and sub-Saharan Africa (SSA). Although the objectives are similar, the underlying drivers, resource endowments and opportunities for achieving them are different. Differences between two regions in natural resource endowment and investment capital stock can, in theory, lead to mutually beneficial trade to achieve desired objectives. Concerns about the recent food crises coupled with the disparity in land and water endowment and investable capital between MENA and SSA have led in recent years to investment in agricultural land in the latter by a number of MENA countries with the aim of producing food. At the same time, many SSA countries seek these investments to infuse capital, technology and know-how into their agricultural sector to improve productivity, food security and rural livelihoods. However, these recent foreign direct agricultural investments have to date performed poorly or have been abandoned without achieving the initial objectives of setting them up. Based on research conducted in selected sub-Saharan countries, this paper analyses the reasons for the failure of these investments. It then reviews a few successful agricultural investments by private sector companies with a long history of operation in SSA. Juxtaposing lessons distilled from failed and successful case studies, the paper argues that large-scale agricultural investments that take advantage of this accumulated knowledge are needed and do have a critical role to play. Such investments, when they also incorporate ecosystems management practices and smallholder inclusive business models in their operations, can serve as appropriate instruments to reconcile the food and water security objectives of both the MENA region and SSA, while promoting sustainable intensification of agriculture and improved rural livelihoods in SSA.

Hongze Lake (HZL) is the largest impounded lake along the eastern route of China's South-to-North Water Diversion Project. However, there is surprisingly little ecological understanding on this important ecosystem, especially under the potential water diversion threats. Here, a mass-balance model was constructed to characterize trophic structure and ecosystem properties of HZL. The model outputs indicated that small sized fishes have dominated the food web, and fishery resources were suffered from high pressures of overfishing. Mandarin fish, Northern snakehead, Other piscivores and Large culters occupied the top trophic niche, while macrophytes, phytoplankton and detritus consisted of the main energy sources. HZL food web was fairly based on two main food chains: primary production (49.9%) and detritus pool (50.1%), but transfer efficiencies in both chains were relatively low as 6.37% and 6.49%, respectively. Predator-prey interactions, trophic cascading effects and competition of different components were also exhibited in the mixed trophic impacts map. Results from the network analysis suggested that the HZL ecosystem was a relatively mature ecosystem since the total primary production to respiration (TPP/TR) and to biomass (TPP/TB) were 1.138 and 6.922, and the Finn Cycling Index was 6.77%. Nevertheless, the relatively low values of Connectance Index (0.195) and System Omnivory Index (0.089), together with Finn's Mean path Length (2.849) also indicated that the food web structure was vulnerable, characterized by linear, rather than web-like features. Our results suggested that the HZL ecosystem would be potentially affected by the future inter-basin water diversion, and thus ecosystem-based strategies were also presented accordingly.