Adapting empirical equations to Lake Kinneret data by using three calibration methods

This paper examines whether the relationships between a number of characteristic limnological variables (suspended particulate matter, turbidity, Secchi depth, light attenuation, and chlorophyll a) determined for temperate lakes are consistent with the relationships found in Mediterranean lakes such as Lake Kinneret. We found that the use of published relationships between lake variables may lead to erroneous results when applied indiscriminately to other lake types.     

In situ push-pull method to determine ground water denitrification in riparian zones

To quantify ground water denitrification in discrete locations of riparian aquifers, we modified and evaluated an in situ method based on conservative tracers and 15N-enriched nitrate. Ground water was "pushed" (i.e., injected) into a mini-piezometer and then "pulled" (i.e., extracted) from the same mini-piezometer after an incubation period. This push-pull method was applied in replicate mini-piezometers at two Rhode Island riparian sites, one fresh water and one brackish water. Conservative tracer pretests were conducted to determine incubation periods, ranging from 5 to 120 h, to optimize recovery of introduced plumes. For nitrate push-pull tests, we used two conservative tracers, sulfur hexafluoride and bromide, to provide insight into plume recovery. The two conservative tracers behaved similarly. The dosing solutions were amended with 15N-enriched nitrate that enabled us to quantify the mass of denitrification gases generated during the incubation period. The in situ push-pull method detected substantial denitrification rates at a site where we had previously observed high denitrification rates. At our brackish site, we found high rates of ground water denitrification in marsh locations and minimal denitrification in soils fringing the marsh. The push-pull method can provide useful insights into spatial and temporal patterns of denitrification in riparian zones. The method is robust and results are not seriously affected by dilution or degassing from ground water to soil air. In conjunction with measurements of ground water flow-paths, this method holds promise for evaluating the influence of site and management factors on the ground water nitrate removal capacity of riparian zones.     

Bio-energy supply chains and stakeholders

What are the management challenges and opportunities of bio-energy chains for both running their business efficiently and effectively and fostering the relationships with most relevant external stakeholders? This question is approached by systematically reviewing papers at the interface of bio-energy and supply chain or logistics issues. The review conducted as content analysis is based on an analytic framework that conceives bio-energy chains between challenges and benefits of bio-energy production with simultaneous internal supply chain management and external stakeholder management needs. Smartly designed and operated bio-energy projects hold promising potentials of contributing to sustainable development by both mitigating climate change and strengthening adaptation capabilities. Our analysis distils specific strategies and success factors for tapping this potential on two levels: On a supply chain level, individually adapted and designed supply chain systems relying on trustful information exchange, cooperation and relational governance safeguard profitability while holding adverse ecological and social impacts of operation down; they allow, for instance, minimising costs and emissions, implementing new technologies, and coping with environmental uncertainties such as crop failures and volatile prices. On a stakeholder level, governments as key actors for designing the future legal framework of bio-energy are primary targets for lobbying activities of bio-energy representatives. Respective arguments may focus on economic development and job generation. By minimising its adverse impacts on society and eco-systems and by communicating these efforts credibly, bio-energy warrants its superiority over fossil energy systems. Involving NGOs and residents in early stages of bio-energy projects via transparent two-way communication considerably increase societal acceptance.