Small habitat matrix: How does it work?

We present herein our perspective of a novel Small Habitats Matrix (SHM) concept showing how small habitats on private lands are untapped but can be valuable for mitigating ecological degradation. Grounded by the realities in Sabah, Malaysian Borneo, we model a discontinuous “stepping stones” linkage that includes both terrestrial and aquatic habitats to illustrate exactly how the SHM can be deployed. Taken together, the SHM is expected to optimize the meta-population vitality in monoculture landscapes for aerial, arboreal, terrestrial and aquatic wildlife communities. We also provide the tangible cost estimates and discuss how such a concept is both economically affordable and plausible to complement global conservation initiatives. By proposing a practical approach to conservation in the rapidly developing tropics, we present a perspective from “ground zero” that reaches out to fellow scientists, funders, activists and pro-environmental land owners who often ask, “What more can we do?”     

250-year records of mercury and trace element deposition in two lakes from Cajas National Park,SW Ecuadorian Andes

Environmental Science and Pollution Research - Historical records of trace elements in lake sediments provide source-to-sink information about potentially toxic pollutants across space and time. We...     

Bedded Sediment Conditions and Macroinvertebrate Responses in New Mexico Streams: A First Step in Establishing Sediment Criteria

Excess fine sediments in streambeds are among the most pervasive causes of degradation in streams of the United States. Simple criteria for acceptable streambed fines are elusive because streambed fines and biotic tolerances vary widely in the absence of human disturbances. In response to the need for sediment benchmarks that are protective of minimum aquatic life uses under the Clean Water Act, we undertook a case study using surveys of sediment, physical habitat, and macroinvertebrates from New Mexico streams. Our approach uses weight of evidence to develop suggested benchmarks for protective levels of surficial bedded sediments <0.06 mm (silt and finer) and <2.0 mm (sand and finer). We grouped streams into three ecoregions that were expected to produce similar naturally occurring streambed textures and patterns of response to human disturbances. Within ecoregions, we employed stressor response models to estimate fine sediment percentages and bed stability that are tolerated by resident macroinvertebrates. We then compared individual stream sediment data with distributions among least‐disturbed reference sites to determine deviation from natural conditions, accounting for natural variability across ecoregion, gradient, and drainage area. This approach for developing benchmark values could be applied more widely to provide a solid basis for developing bedded sediment criteria and other protective management strategies in other regions.     

The jurisdictional framework for municipal action to reduce greenhouse gas emissions: Case studies from Canada,the USA and Germany

Abstract

The development of ‘indicators’ and associated techniques for the appraisal of ‘sustainability’ requires efforts to systematically define, quantify and aggregate many disparate dimensions of social, environmental and economic performance. This necessarily raises a number of serious theoretical and methodological difficulties, including those relating to the selection and framing of ‘problems’ and ‘options’, the treatment of deep uncertainties and the ‘impossibility’ of aggregating in analysis the divergent social interests and value judgements which govern the prioritisation of the different dimensions of ‘sustainability’. After exploring the depth and scope of some of these difficulties, this paper argues that they render futile any attempt to develop an ‘analytical fix’ for the problems of appraisal. In this light, systematic public participation is recognised not just as an issue of political efficacy and legitimacy, but also as a fundamental matter of analytical rigour. However, it is also concluded that once aspirations to the ‘analytical fix’ are renounced, there is much that might be contributed by transparent, straightforward quantitative analytical tools and the paper ends with some recommendations and an example in this regard.     

Measurement and relationship between critical tube diameter and critical energy for direct blast initiation of gaseous detonations

For the explosion safety assessment in industrial setting, detonation dynamic parameters provide important information on the sensitivity and conditions whereby detonations can be favorably occurred. In this study, new measurement of the critical tube diameter and the critical energy for direct initiation of a detonation is reported for a number of hydrocarbon–oxygen mixtures. The simultaneous experimental measurement carried out in this work allows the investigation of the direct scaling between these two dynamic parameter quantities of gaseous detonations. Using the new set of data, this paper also assesses the validity of an existing semi-empirical initiation model, namely, the surface energy model by Lee, and a simplified work done model. Both phenomenological models provide a general relationship between the two dynamic detonation parameters and comparison shows a good agreement between the theoretical results and the experimental measurement. The scaling of critical tube diameter with detonation cell size in this study also confirms the results in the previous literature.     

An empirical approach to determine specific weights of driving factors for the price of commodities—A contribution to the measurement of the economic scarcity of minerals and metals

In recent years, commodity markets show a large amount of volatility and substantial price jumps, indicating an increasing economic scarcity in many cases. As this scarcity makes commodity procurement a critical issue for national economies, industry sectors and manufacturing companies, a number of criticality indices have been presented and utilized in science as well as in practice. These indices are mostly based on an aggregation of different key figures, both qualitative and quantitative. However, the weighting of the different factors is in most cases arbitrary or based on rough estimates.     

Non-hazardous waste generation characteristics and recycling practices in Saskatchewan and Manitoba,Canada

The paper presents the results on the analysis of non-hazardous waste generation characteristics and recycling practices in Saskatchewan (SK) and Manitoba (MB) using the biennial waste reports published by Statistic Canada. The objectives are to examine the waste generation rates from both residential and non-residential sources from 1998 to 2010, and to evaluate the effectiveness of their recycling programs and regulations. In spite of the many similarities between the provinces, MB on average generated 17.5 % more residential waste than SK, and about 15 % less non-residential waste than SK during the study period. It appears that MB waste generation characteristics were very different from SK and the rest of Canada. The amount of MSW generation in MB was, to a certain degree, independent from the economic factors. Assuming status quos conditions, the linear models predicted that the per capita MSW generations in MB would be about 33 % lower than SK in 2020. Data from this study suggest that (1) curbside recycling programs and (2) pay-as-you-throw collection systems may be important factors for increasing diversion rate in SK. It is also found that the non-residential waste generation in Canada was substantially larger than the residential waste generation during the 13-year period.     

Impact of undissociated volatile fatty acids on acidogenesis in a two-phase anaerobic system

This study investigated the degradation and production of volatile fatty acids(VFAs)in the acidogenic phase reactor of a two-phase anaerobic system.20 mmol/L bromoethanesulfonic acid(BESA)was used to inhibit acidogenic methanogens(which were present in the acidogenic phase reactor)from degrading VFAs.The impact of undissociated volatile fatty acids(un VFAs)on"net"VFAs production in the acidogenic phase reactor was then evaluated,with the exclusion of concurrent VFAs degradation."Net"VFAs production from glucose degradation was partially inhibited at high un VFAs concentrations,with 59%,37% and 60% reduction in production rates at 2190 mg chemical oxygen demand(COD)/L undissociated acetic acid(un HAc),2130 mg COD/L undissociated propionic acid(un HPr)and 2280 mg COD/L undissociated n-butyric acid(un HBu),respectively.The profile of VFAs produced further indicated that while an un VFA can primarily affect its own formation,there were also un VFAs that affected the formation of other VFAs.     

Soil and water conservation method adoption in a highly erosive watershed: the case of Southwest Oklahoma's Fort Cobb watershed

A major source of pollution in agricultural landscapes is surface runoff and non-point source pollution generated from agricultural production practices. In-stream, stream bank and riparian conservation/management practices can be implemented to reduce sediment loading solely or in conjunction with upland practices. Survey results from producers in the Fort Cobb Reservoir watershed, a highly erosive watershed in southwest Oklahoma with a history of state and federal conservation programs, provide information required for improving understanding of operators’ likelihood of adoption. Two models of soil and water conservation were estimated, a logit model of likelihood of enrollment and a Poisson model of the total number of practices adopted. Results reinforced previous findings that attitudes, gender and education influence conservation program enrollment. Farming experience, gender and attitudes towards conservation increased the total number of practices adopted.