Correlations between in situ denitrification activity and nir-gene abundances in pristine and impacted prairie streams

Denitrification is a process that reduces nitrogen levels in headwaters and other streams. We compared nirS and nirK abundances with the absolute rate of denitrification, the longitudinal coefficient of denitrification (i.e., K_den, which represents optimal denitrification rates at given environmental conditions), and water quality in seven prairie streams to determine if nir-gene abundances explain denitrification activity. Previous work showed that absolute rates of denitrification correlate with nitrate levels; however, no correlation has been found for denitrification efficiency, which we hypothesise might be related to gene abundances. Water-column nitrate and soluble-reactive phosphorus levels significantly correlated with absolute rates of denitrification, but nir-gene abundances did not. However, nirS and nirK abundances significantly correlated with K_den, as well as phosphorus, although no correlation was found between K_den and nitrate. These data confirm that absolute denitrification rates are controlled by nitrate load, but intrinsic denitrification efficiency is linked to nirS and nirK gene abundances.     

Biomass Carbon Ratio of Polymer Composites Measured by Accelerator Mass Spectrometry

The evaluation method of biomass carbon ratio of polymer composite samples including organic and inorganic carbons individually was investigated. Biodegradable plastics and biobased plastics can have their mechanical properties improved by combining with inorganic fillers. Polymer composites consisting of biodegradable plastics and carbonate were prepared by two different methods. Poly(lactic acid) (PLA) composite was prepared by synthesis from l-lactide with catalyst and calcium carbonate (CaCO₃) powders from lime. Poly(butylene succinate) (PBS) composite was prepared by hot-pressing the mixture of PBS powder and CaCO₃ powders from oyster shells. The mechanical properties of composite samples were investigated by a tensile test and a compression test using an Instron type mechanical tester. Tensile test with a dumbbell shape specimen was performed for PBS composite samples and compression test with a column shape specimen for PLA composite samples. Strength, elastic modulus and fracture strain were obtained from the above tests. Biomass carbon ratio is regulated in the American Standards for Testing and Materials (ASTM). In ASTM standards on biomass carbon ratio, it is required that carbon atoms from carbonates, such as CaCO₃, are omitted. Biomass carbon ratio was evaluated by ratio of ¹⁴C to ¹²C in the samples using Accelerator Mass Spectrometry (AMS). The effect of pretreatment, such as oxidation temperature and reaction by acid, on results of biomass carbon ratio was investigated. Mechanical properties decrease with increasing CaCO₃ content. The possibility of an evaluation method of biomass carbon ratio of materials including organic and inorganic carbons was shown.     

From Rio to Johannesburg and Beyond: A long and winding road

This paper analyses the evolution of urban form in two North American metropolitan regions (Portland and Toronto) and asks how more sustainable regional form might come about in the future in these and other urban areas. In the past, dominant patterns of urban form have emerged in such regions at different historical periods. These morphological phases include mid 19th-century grids, streetcar suburb grids, garden suburbs, automobile suburbs and New Urbanist neighbourhoods (which have only recently made an appearance and may or may not become widespread). Judging by the performance of past types of urban morphology, five design values appear particularly important for more sustainable urban form in the future: compactness, contiguity, connectivity, diversity and ecological integration. Although these principles were not well supported by 20th-century development, contemporary movements such as the New Urbanism and Smart Growth re-emphasise them. The example of these two regions indicates that, in the absence of new technological, economic or geographical forces, public sector institutions and urban social movements represent the most likely means to bring about new, more sustainable types of urban form.     

Institutions for a sustainable development—experiences from EU-countries

This article is based on an international comparative study analysing innovations in national administrative institutions. Results of that research are presented and discussed here. Against the background of the institutionalising process of political institutions the study focused on innovations initiated or introduced by governments or parliaments by example of policies and politics supporting sustainable development. The countries involved in the original study were Belgium, Denmark, Finland, France, Germany, the Netherlands, Sweden and the United Kingdom. Three general lessons can be drawn: (1) Countries with a long tradition of integrated environmental policy-making are more open to the concept of sustainability. (2) A (institutional) “cure-all” solution does not seem to exist. It seems necessary to diffuse the concept of sustainability into all spheres of politics and society. Reaching this strategic goal requires a specific policy and polity mix. (3) Strong and well-equipped institutions result from specific policies and politics: they play a central role in promoting and intensifying sustainable development. Successful innovations integrating SD into everyday politics and policies are only a very first step though. Further improvements with regard to effective participation and public debate, global orientation of policies and the measurability of achieved progress are necessary.     

NON-ZERO LOWER LIMIT IN LOW FLOW FREQUENCY ANALYSIS?1

ABSTRACT: The implications of fitting distributions with non-zero lower limits to low flow data are examined. The 3-parameter Weibull distribution is fitted to annual minimum flow series from 60 long term stations in Canada. The relations between the estimated lower limit and three sampling variables (skewness, smallest, and largest observations) were investigated. The lower limit strongly depends on the sample skewness; it varies directly with the sample skewness, which in turn is highly influenced by the largest observation. For a given skewness, the value of the estimated lower limit is determined by the value of the smallest observation. Therefore, the lower limit cannot be accurately determined, and the resulting low flow estimates will be either too small or too high.     

Environmental drivers of decadal change of a mangrove forest in the North coast of the Yucatan peninsula,Mexico

Mangrove forests provide important ecosystem services, but are under constant pressure from natural, anthropogenic, and climate change related disturbances. Environmental drivers on mangrove change at large spatial scales, other than sea level rise, are not well understood. In here, we use spatially explicit methods to identify the main environmental drivers of mangrove coverage change over a decade in the landscape of the North coast of the Yucatan peninsula, Mexico. A post-supervised classification approach on seven SPOT 5 multispectral satellite images was used to construct thematic maps of mangrove coverage between 2004 and 2014. A linear regression model between the thematic maps was performed to estimate the mangrove coverage change rate per pixel. Climate surfaces for annual maximum, minimum and mean temperature, and annual mean and cumulative precipitation for the region were calculated for the period 1980–2009 using data obtained from the National Meteorological Service. The effect of environmental variables on mangrove coverage change rates was assessed with a boosted generalized additive model (boosted GAM). The lowest and highest overall accuracy obtained for the time series thematic maps were 87.14% (Kappa?=?0.78), and 97.5% (Kappa?=?0.95), respectively. The most influential environmental variables on mangrove coverage change were annual cumulative precipitation (21%), and annual maximum temperature (9%). Current climate change scenarios for the region predict an increase in temperature and a decrease in precipitation, intensifying environmental stress on this ecosystem. Therefore, adequate management strategies are fundamental to help maintain the mangrove forest under changing environmental conditions.     

Satellite observations of Mexico City pollution outflow from the Tropospheric Emissions Spectrometer (TES)

Concurrent tropospheric O₃ and CO vertical profiles from the Tropospheric Emission Spectrometer (TES) during the MILAGRO/INTEX-B aircraft campaigns over the Mexico City Metropolitan Area (MCMA) and its surrounding regions were used to examine Mexico City pollution outflow on a regional scale. The pollution outflow from the MCMA occurred predominantly at 600–800 hPa as evident in O₃, CO, and NO_x enhancements in the in situ aircraft observations. TES O₃ and CO are sensitive to the MCMA pollution outflow due to their relatively high sensitivities at 600–800 hPa. We examined O₃, CO, and their correlation at 600–800 hPa from TES retrievals, aircraft measurements, and GEOS-Chem model results. TES captures much of the spatial and day-to-day variability of O₃ seen in the in situ data. TES CO, however, shows much less spatial and day-to-day variability compared with the in situ observations. The ΔO₃/ΔCO slope is significantly higher in the TES data (0.43) than the in situ data (0.28) due partly to the lack of variability in TES CO. Extraordinarily high ΔO₃/ΔCO slope (0.81) from TES observations at 618 hPa over the Eastern U.S. was previously reported by Zhang et al. [Zhang, L., Jacob, D.J., Bowman, K.W., et al., 2006. Ozone–CO correlations determined by the TES satellite instrument in continental outflow regions. Geophys. Res. Lett. 33, L18804. 10.1029/2006GL026399.]. Thus the application of TES CO–O₃ correlation to map continental pollution outflow needs further examination.     

Analyzing the carbon footprint from public services provided by counties

In this paper we investigate the Carbon Footprint (CF) resulting from the activities of the county of Sogn og Fjordane (SFK). An Environmentally Expanded Input-Output model is applied to develop a consumption-based Greenhouse Gas (GHG) inventory for this purpose. The model has previously been used for the assessment of municipal CFs, and is in this paper further developed for the purpose of assessing county CFs. Results show that a large fraction of the CF is caused by the purchase of services from private actors, especially the purchase of transportation services, of which a steady increase from the year 2002–2008, is found. In the same period of time, the CF resulting from the operation of county vehicles has been reduced to only 1/6. This outsourcing regarding the provision of services is found in several departments of the county municipality. It indicates a necessary shift in local mitigation strategies, as more focus needs to be on the environmental performance of suppliers. One important finding in the SFK case is the potential of introducing environmental requirements in tenders on providing transportation services. Another is to make environmental requirements to the companies receiving financial support from the county administration.     

Adapting the bioblitz to meet conservation needs

When conservation strategies require new, field‐based information, practitioners must find the best ways to rapidly deliver high‐quality survey data. To address this challenge, several rapid‐assessment approaches have been developed since the early 1990s. These typically involve large areas, take many months to complete, and are not appropriate when conservation‐relevant survey data are urgently needed for a specific locale. In contrast, bioblitzes are designed for quick collection of site‐specific survey data. Although bioblitzes are commonly used to achieve educational or public‐engagement goals, conservation practitioners are increasingly using a modified bioblitz approach to generate conservation‐relevant data while simultaneously enhancing research capacity and building working partnerships focused on conservation concerns. We term these modified events expert bioblitzes. Several expert bioblitzes have taken place on lands of conservation concern in Southern California and have involved collaborative efforts of government agencies, nonprofit organizations, botanic gardens, museums, and universities. The results of expert bioblitzes directly informed on‐the‐ground conservation and decision‐making; increased capacity for rapid deployment of expert bioblitzes in the future; and fostered collaboration and communication among taxonomically and institutionally diverse experts. As research and conservation funding becomes increasingly scarce, expert bioblitzes can play an increasingly important role in biodiversity conservation.