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Ecological risk assessments are legally required to ensure that there are no unacceptable risks to living organisms from exposure to chemicals and other anthropogenic stressors. Significant data gaps, however, make it difficult to conduct such assessments for all species that we wish to protect. Consequently, there is growing interest in trait-based approaches because they provide a more functional and context-independent basis for characterizing biodiversity that is useful for biomonitoring, conservation, and management. In the present article, we discuss how trait-based approaches can support risk assessment, identify vulnerable and representative species to be used in ecological modeling, and inform decision-making more generally. We use examples to demonstrate the utility of trait-based approaches but also highlight some of the challenges and open questions that remain to be addressed. [ABSTRACT FROM AUTHOR]

The simulation of engine combustion processes, such as autoignition, an important process in the co-optimization of fuel-engine design, can be computationally expensive due to the large number of thermo-chemical scalars needed to describe the full chemical system. Yet, the inherent correlations between the different chemical species during oxidation can significantly reduce the complexity of representing this system. One strategy is to select a subset of representative species that accurately captures the combustion process at a fraction of the computational cost of the full system. In this study, we compare the performance of four different techniques to select these species. They include the two-step principal component analysis (PCA) approach, directed relation graphs (DRGs), the global pathway selection (GPS) approach, and the manifold-informed species selection method. A parametric study of the representative species selection is carried out on data from the simulation of homogeneous and perfectly stirred reactors by investigating seven cumulative variances and 47 different cut-off percentages for the two-step PCA, and 65 and 51 thresholds for the DRGs and GPS, respectively. Results show that these selection methods capture key important species that can accurately describe the chemical system and track each stage of oxidation. The two-step PCA is sensitive to the cumulative variance, and DRGs and GPS are sensitive to the choice of target variables. By selecting key representative species and reducing the number of thermo-chemical scalars, these three methods can be used to develop computationally efficient hybrid chemistry schemes. [ABSTRACT FROM AUTHOR]

An important ecosystem function of vegetation on riverbanks is the control of soil erosion. Riverbanks also offer potential semi-natural habitats for grassland species. Previous classification of riverbank vegetation in Japan ignored both seasonal changes of dominant species and species composition, offering no information on ecosystem functions. Here we aimed at clarifying the association between dominant species, vegetation composition and species attributes in spring and autumn. We surveyed vegetation in 125 plots on a riverbank in Japan. We identified seven vegetation types on the basis of dominant species in autumn. Imperata cylindrica var. koenigii (Type I) and Pleioblastus chino (Type P) dominated their vegetation year-round. Dominant species changed seasonally in the other five vegetation types, but Lolium multiflorum was dominant in spring. Since the dominance of annuals is linked to fast turnover of root systems and thus poor control of soil erosion, Types P and I are superior in controlling soil erosion. Both the total number of species and the number of grassland species were small, showing species-poor grasslands in all vegetation types. There were no clear differences in numbers of species between species attributes. Nevertheless, this classification was linked to differences in species composition, reflecting several representative species in each vegetation type. Type P has more indigenous representative species and typical grassland species. Since some representative species may be suitable for natural processes (e.g., for pollination), this classification reflects biodiversity functions. [ABSTRACT FROM AUTHOR]

Freshwater mussels are among the most critically endangered taxa globally. In the United States, 91 out of nearly 300 species are listed as Threatened or Endangered under the Endangered Species Act.Freshwater mussel species exhibit a range of life‐history traits. Owing to the large number of North American species, the rarity of many listed species and the often limited data available for those species, it can be difficult to gather all of the information necessary to develop ecological risk assessments and effective management plans for freshwater mussel species.The primary objective of this study was to categorize North American freshwater mussel species into life‐history categories to aid in the identification of representative species for risk assessment.To achieve these objectives, a literature review was conducted to identify available life‐history data for a large range of mussel species. Using this dataset, two ordinations were performed, non‐metric multidimensional scaling and discriminant analysis, to classify mussel species into previously described life‐history categories. Both analyses facilitated species classification into life‐history categories.Significant data gaps in basic life‐history information still exist for many species, but previously described life‐history categories were found to be robust and additional analysis allowed quantitative classification of additional species. [ABSTRACT FROM AUTHOR]

Context: Proxy species, which represent suites of organisms with similar habitat requirements, are common in conservation. Landscape Capability (LC) models aim to quantify the spatially-explicit capability of landscapes to support proxy species that represent suites of forest birds. Objectives: We evaluated the North Atlantic Landscape Conservation Cooperative (NALCC) proxy models of LC and represented species framework across 13 states in the northeastern United States from Virginia to Maine. We validated a suite of questions related to co-occurrence of proxy and represented species with a compilation of independent datasets. Methods: We tested proxy species LC models ability to explain represented species' occurrences, including using multiple proxies together, and benchmarked against empirical data and land cover type classifications. We tested effect of several factors on predictive ability including relative range overlap and ecological and taxonomic dissimilarity between proxy and represented species. Results: LC models performed variably, but represented species occurrences were rarely predicted as accurately as proxy species. Models improved predictions over macrohabitat classifications. Using multiple proxies together occasionally improved predictions of represented species. Considerable range overlap was needed for models to be predictive of represented species. Ecological and taxonomic similarity had no effect on predictive ability. LC models worked similarly to using empirical observations, suggesting shortcomings were because of imperfect surrogacy. Conclusions: Conservation proxies as representatives of species groups that are associated with macrohabitats are useful, but empirical data are necessary to evaluate proxy species' effectiveness. Habitat-based models can provide similar predictive ability as empirical observations of proxies and represent a useful tool in conservation planning. [ABSTRACT FROM AUTHOR]

To comprehend the codon usage pattern of genes in Eucommia ulmoides, taking the E. ulmoides genome codons as the research object, the 320 coding DNA sequences was analyzed to obtain the results of relative synonymous codon usage( RSCU), ENC-GC3s analysis of codon ENC values of coding genes and PR2-plot bias analysis of the codon base usage frequency of the coding genes. By using CUSP and Codon Usage Database software to compare the CC contents and codon occurrence frequency of E, ulmoides with those of Arabidopsis thaliana, Nicotiana tabacum, Escherichia coli and Saccharomyces cerevisiae. The results were as follows: The number of RSCU value greater than 1 had 30 codons, including 18 genes with ending G/C and 12 genes ending with A/U, and these suggested that the codons preferred ends with C/C, and had a strong bias: The number of effective codons (ENC) ranges from 30 to 60, and the codons within this range were far away from the standard curve and their ENC values were smaller and had a higher preference; PR2-plot analysis showed that G>C, U>A, in the base usage frequency: Analysis of C contents of Eucommia ulmoides and representative species showed that the E. ulmoides GC12, GC3 and average CC contents were higher than those of representative species: The analysis of the codon usage frequency of E. ulmoides and representative species showed that the codon preference of E. ulmoides and Nicotiana tabacum, Saccharomyces cerevisiae were close, and the codon preferences of Eucommia ulmoides, Arabidopsis thaliana and Escherichia coli were quite different Eucommia ulmoides is a precious Chinese medicinal material unique in China. Analysis of the codon usage pattern and studies of its codon preference will provide a theoretical basis for the improvement and expression of foreign genes in E. ulmoides plant genetic engineering. [ABSTRACT FROM AUTHOR]

While more developed countries have a well-established systems to develop water quality criteria (WQC), little research has been done on the adequacy of the current WQC to protect endemic species of China. In order to maintain the health of aquatic ecosystems in China, a series of projects to establish national WQC based on regional characteristics has recently been initiated. However, the establishment of a completely novel methodology would be costly and time consuming. Also, due to the similarities in physiologies and natural histories of classes of aquatic organisms, there is no reason to believe that WQC would not be sufficient to protect unique species in China. This review was undertaken to identify key outstanding issues regarding establishment of aquatic life criteria (ALC) to be applied in China, including prioritization of chemicals, test species, mode of action, field/semi-field data, and methods of aggregating the information and calculating the ALC. This was used to identify the principle issues that need to be addressed in order to better understand the methods for development of criteria for the protection of aquatic life and provide a reference to China and other developing countries committed to the establishment of their own WQC system. [ABSTRACT FROM AUTHOR]

Highlights: [•] We revisited an oribatid-mite dataset recorded in 72 plots covering 64km2. [•] We then moved a 25km2 grid into its 16 possible positions within the larger grid. [•] Each position inside the landscape produce a very different result. [•] Sub-sets of frequent species are reliable surrogates for the complete assemblage. [•] Efficient biomonitoring could target surrogate species while improving sampling area. [ABSTRACT FROM AUTHOR]

Flagship species are among key marketing tools used by conservation organizations to motivate public support, but are often selected in an ad hoc, rather than systematic, manner. Furthermore, it is unclear whether selected flagship species do motivate public support. This paper describes a multi-method exploratory study, carried out in Switzerland, which aimed to determine the selection criteria for flagship species and measure whether a species selected according to these criteria was able to motivate support. Fourteen representatives of international, regional and local conservation organizations were interviewed and the selection criteria for their flagship species were identified. A charismatic species (the great spotted woodpecker) that meets these criteria and an apparently less charismatic species (the clover stem weevil) were selected as treatments in a quantitative experiment with 900 respondents. Using conjoint analysis, it was found that both charismatic and uncharismatic species have the ability to positively influence public preferences for habitat variables that encourage biodiversity in urban landscapes. These results may be used by conservation organizations to assist in the selection of flagship species, and in particular for flagship species that are intended to perform a specific conservation function. [ABSTRACT FROM PUBLISHER]

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Abstract: Ecological communities consist of a large number of species. Most species are rare or have low abundance, and only a few are abundant and/or frequent. In quantitative community analysis, abundant species are commonly used to interpret patterns of habitat disturbance or ecosystem degradation. Rare species cause many difficulties in quantitative analysis by introducing noises and bulking datasets, which is worsened by the fact that large datasets suffer from difficulties of data handling. In this study we propose a method to reduce the size of large datasets by selecting the most ecologically representative species using a self organizing map (SOM) and structuring index (SI). As an example, we used diatom community data sampled at 836 sites with 941 species throughout the French hydrosystem. Out of the 941 species, 353 were selected. The selected dataset was effectively classified according to the similarities of community assemblages in the SOM map. Compared to the SOM map generated with the original dataset, the community pattern gave a very similar representation of ecological conditions of the sampling sites, displaying clear gradients of environmental factors between different clusters. Our results showed that this computational technique can be applied to preprocessing data in multivariate analysis. It could be useful for ecosystem assessment and management, helping to reduce both the list of species for identification and the size of datasets to be processed for diagnosing the ecological status of water courses. [Copyright &y& Elsevier]

In conservation biology, researchers often want to study the reasons why an endangered population is faring poorly but are unable to study it directly for logistical or political reasons. Instead they study a species that substitutes for the one of concern in the hope that it will cast light on the conservation problem. Here we outline the assumptions underlying this approach. Substitutes can be different populations or species and may be chosen because they are similar biologically to the target or representatives of a constellation of species of which the target is one. They also may be used to develop a predictive model to which the conservation target can be related. For substitutes to be appropriate, they should share the same key ecological or behavioral traits that make the target sensitive to environmental disturbance and the relationship between population vital rates and level of disturbance should match that of the target. These conditions are unlikely to pertain in most circumstances and the use of substitute species to predict endangered populations' responses to disturbance is questionable. [ABSTRACT FROM AUTHOR]

A representative number of 11 inland waterways of the north-eastern lowlands in Germany was surveyed between 1992 and 1994 using different fishing methods. Data were pooled for sites and waterways. From the234 sites investigated, a total of 53,432 fish were collected and 29species recorded. The typical fish assemblage of the waterways was subdivided into three defined classes according to presence and relative abundance of species: reference, accompanying and minor species. The fish fauna was characterized by the dominance of roach (Rutilus rutilus) and perch (Perca fluviatilis). Both fish species showed a meanabundance of 70.61% (SD=10.91%), whereas more than half of the species recorded had a relative abundance <1%. Two trends could be identified in the fish assemblage owing to human influences: an increase in the dominance of roach and perch and a decrease in species number. Inparticular, intolerant fish with a preference for sand or gravel substrata and current diversity have become rare and endangered. The typical fish assemblage of waterways in the lowlands differed from that in the uplands with respect to the higher abundance of rheophilic lithophils in the uplands. [ABSTRACT FROM AUTHOR]