Collectively engaging complex socio-ecological systems: re-envisioning science, governance, and the California Delta

We address the future of science and governance for the California Delta, focusing on the CALFED Bay-Delta Program, an interagency, multi-stakeholder effort to understand and manage the Delta for multiple purposes. We portray a Delta history as a coevolutionary process between science, governance and ecosystems. Global integrated environmental assessments (IEA) provide insights into understanding complex, dynamic socio-ecological systems. Many of the discursive stakeholder and scientific activities that have arisen under CALFED are similar to IEA and remain essential to the shared learning needed to effectively interact with a dynamic Delta. More deliberately enmeshing environmental monitoring, analysis, and collective learning into Delta governance will improve outcomes.     

Heat waves and floods in urban areas: a policy-oriented review of ecosystem services

Urbanisation is increasing and today more than a half of the world’s population lives in urban areas. Cities, especially those where urbanisation is un-planned or poorly planned, are increasingly vulnerable to hydro-meteorological hazards such as heat waves and floods. Urban areas tend to degrade the environment, fragmenting and isolating ecosystems, compromising their capacity to provide services. The regulating role of ecosystems in buffering hydro-meteorological hazards and reducing urban vulnerability has not received adequate policy attention until now. Whereas there is a wide body of studies in the specialised biological and ecological literature about particular urban ecosystem features and the impacts of hazards upon people and infrastructures, there is no policy-driven overview looking holistically at the ways in which ecosystem features can be managed by cities to reduce their vulnerability to hazards. Using heat waves and floods as examples, this review article identifies the aggravating factors related to urbanisation, the various regulating ecosystem services that buffer cities from hydro-meteorological impacts as well as the impacts of the hazards on the ecosystem. The review also assesses how different cities have attempted to manage related ecosystem services and draws policy-relevant conclusions.     

A comprehensive air quality investigation at an aquatic centre: Indoor/outdoor comparisons

Environmental Science and Pollution Research - Air quality and comfort parameters in a naturally ventilated aquatic centre were studied in relation to the outdoor pollution levels. Simultaneous...     

Caps yes,but how? A response to Alcott

This articles argues that extraction and emission caps are a promising strategy for a sustainable degrowth transition, but that their design and implementation is far from simple. We draw attention to the institutional structures and processes through which caps are to be set, designed and enforced, and discuss the danger of eco-authoritarian politics in the name of enforcing caps or other environmental limitations.     

Socio-environmental co-evolution: some ideas for an analytical approach

A number of scholars, mainly in ecological economics, have been attracted to the concept of co-evolution for the analysis of socio-environmental change. Yet none has adopted and developed an applied analytical approach using an explicitly evolutionary framework. This paper discusses how other scholars in economics, technological studies, organization and political science have been using evolutionary explanations and draws some lessons for ecological economics. Evolutionary is a mode of explanation based on the selective retention of renewable variation. It accounts for phenomena of structural fit and change in a variety of domains. A co-evolutionary explanation, by extension, entails two or more evolving systems whose interaction affects their evolution. Socio-environmental co-evolution involves human systems (material practices and non-material ideas and values) and non-human systems (living and physical). The challenge then is how to develop case-specific, empirical applications that define and elaborate the variants that co-evolve and specify the processes of mutual selection. Applications could benefit from existing classifications and causal propositions in the natural and social sciences. Co-evolution is part of a larger analytical toolkit for looking at complex socio-environmental problems. Although distinct, there are strong synergies, complementarities and potential for combined uses between co-evolutionary, co-dynamic and complexity-based explanations.     

Use of halophytes in pilot-scale horizontal flow constructed wetland treating domestic wastewater

Recent findings encourage the use of halophytes in constructed wetlands for domestic wastewater treatment due to their special physiological characteristics as the ability to accumulate heavy metals and salts in their tissues makes them ideal candidates for constructed wetland vegetation. In this particular study, we investigated the application of halophytic plants in a horizontal flow constructed wetland for domestic wastewater treatment purposes. The pilot plant which was situated in Crete (Greece) was planted with a polyculture of halophytes (Tamarix parviflora, Juncus acutus, Sarcocornia perrenis, and Limoniastrum monopetalum). The system’s performance was monitored for a period of 11 months during which it received primary treated wastewater from the local wastewater treatment plant. Results show that halophytes developed successfully in the constructed wetland and achieved organic matter and pathogen removal efficiencies comparable to those reported for reeds in previous works (63% and 1.6 log units, respectively). In addition, boron concentration in the effluent was reduced by 40% in comparison with the influent. Salinity as expressed by electrical conductivity did not change during the treatment, indicating that the accumulation of salts in the leaves is not able to overcome electrical conductivity increasing due to evapotranspiration. The results indicate an improvement in the treatment of domestic wastewater via the use of halophyte-planted CWs.     

Greenhouse gas emissions from two hydroelectric reservoirs in Mediterranean region

Water reservoirs are used for many purposes, such as water supply, irrigation, flood mitigation, and hydroelectric energy generation. Although hydroelectric energy is considered “green,” many studies show that the construction of a reservoir enhances greenhouse gas (GHG) emissions at the transformed area. These emissions, mainly of CO₂, CH₄, and N₂O gases, depend on the age of the reservoir, landscape and soil composition, fauna and flora remnants of the impounded area, climatic conditions, and basin runoffs. Consequently, GHG emissions significantly vary between reservoirs and depending on local specificities. Several studies have investigated GHG emissions from reservoirs around the world, focusing mainly on reservoirs located in cold regions, temperate regions, and tropical regions. Research is lacking for reservoirs in Mediterranean countries, like Greece, and similar regions. This work initially assesses the net GHG emissions of a newly created reservoir (Ilarion est. 2012) in Western Macedonia, Greece. The methodology for net GHG emission calculation was based on the use of literature data concerning pre-impoundment emission factors and local specificities of the reservoir (terrain type, canopy cover), as well as on the 2-year measurement data that were collected using a “static floating chamber.” Furthermore, in this work, the gross GHG emissions of an older, in-line reservoir (Polyfytos est. 1974) were also calculated, based on 2-year measurement data. The results show that the global warming potential (GWP) of the reservoirs is dictated by methane emissions; it minimizes during winter and spring and maximizes during summer and autumn. Hydroelectric energy production at Ilarion Reservoir results in 32 to 97 times less total CO₂ equivalent emissions in comparison to fossil fuels, while at Polyfytos Reservoir only 8 to 24 times less (based on gross emissions). It appears that the impact of a reservoir’s morphology on GHG emissions is more significant than that of a reservoir’s age.