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Moving Window Analysis (moving + window_analysis)
Selected AbstractsBiodiverse, a tool for the spatial analysis of biological and related diversityECOGRAPHY, Issue 4 2010Shawn W. Laffan Biodiverse is a tool for the spatial analysis of diversity using indices based on taxonomic, phylogenetic and matrix (e.g. genetic dissimilarity) relationships. The explosion in georeferenced biological specimen and survey data means there is an increasing need for such tools. Biodiverse supports four processes: 1) linked visualisation of data distributions in geographic, taxonomic, phylogenetic and matrix spaces; 2) spatial moving window analyses including richness, endemism, phylogenetic diversity and beta diversity; 3) spatially constrained agglomerative cluster analyses; and 4) randomisations for hypothesis testing. Biodiverse is open-source and supports user developed extensions. It can be used both through a graphical user interface and scripts. Biodiverse can be downloaded from Spatial metrics and methods for riverscapes: quantifying variability in riverine fish habitat patternsENVIRONMETRICS, Issue 5 2009Céline Le Pichon Abstract Defining the optimal configuration of all habitats required during a life cycle, called vital habitat, is a necessary step for effective management of riverine fishes and restoration of river habitats. Landscape ecology provides many metrics and methods to study the composition and configuration of habitats, but they need to be adapted for fishes in river environments or riverscapes. For example, hydrographic distance seems more appropriate than Euclidean distance for measuring distances between vital habitats in riverscapes. We adapted some metrics to assess habitats patterns of a threatened cyprinid species (Barbus barbus) for natural and artificial riverscapes of the Seine river, France. Composition metrics provided essential quantification of the relative abundance of the vital habitats, whereas configuration metrics were relevant to quantify their spatial arrangement and spatial relationships. Nearest-neighbor hydrographic distance was useful to evaluate the influence of flow variability in the natural riverscape, but was not relevant to discriminate the artificial riverscape from the natural one. Conversely, a proximity index revealed high fragmentation in the artificial riverscape. Spatial habitat relationships between feeding and resting habitats, evaluated with a moving window analysis, provided a map of daily activity patches and emphasized the gaps in the biological continuity of the riverscape. The spatial metrics and methods we adapted to the particularities of the Seine river allowed us to detect natural and artificial variability in fish habitat patterns. They should help in evaluating impacts of habitat alteration and isolation and prioritize preservation and restoration policies in human-impacted rivers. Copyright © 2008 John Wiley & Sons, Ltd. [source] Failure of the ammonia oxidation process in two pharmaceutical wastewater treatment plants is linked to shifts in the bacterial communitiesJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2005L. Wittebolle Abstract Aims:, To investigate whether two different wastewater treatment plants (WWTPs) , treating the same pharmaceutical influent , select for a different bacterial and/or ammonia oxidizing bacterial (AOB) community. Methods and Results:, Molecular fingerprinting demonstrated that each WWTP had its own total bacterial and AOB community structure, but Nitrosomonas eutropha and N. europea were dominant in both WWTP A and B. The DNA and RNA analysis of the AOB communities revealed different patterns; so the most abundant species may not necessarily be the most active ones. Nitritation failures, monitored by chemical parameter analysis, were reflected as AOB community shifts and visualized by denaturing gradient gel electrophoresis (DGGE)-based moving window analysis. Conclusions:, This research demonstrated the link between functional performance (nitritation parameters) and the presence and activity of a specific microbial ecology (AOB). Clustering and moving window analysis based on DGGE showed to be valuable to monitor community shifts in both WWTPs. Significance and Impact of the Study:, This study of specific community shifts together with functional parameter analysis has potential as a tool for relating functional instability (such as operational failures) to specific-bacterial community shifts. [source] Stream order controls geomorphic heterogeneity and plant distribution in a savanna landscapeAUSTRAL ECOLOGY, Issue 2 2009LESEGO KHOMO Abstract We posed the question: does viewing a savanna as a network of streams linked to a matrix of terrestrial hillslopes provide a useful framework to research and understand plant distribution in these landscapes? Our study area, the Phugwane River network, lies in the semi-arid savanna of Kruger National Park, South Africa. We examined changes in hillslope geomorphology from first-, third- and fifth-order hillslopes with regression equations. The distribution of geomorphic boundaries was enumerated by moving window analysis and the relationship between geomorphology and plant distribution was explored through ordination. First-order hillslopes had a simple geomorphology, fewer geomorphic boundaries and a relatively homogeneous plant assemblage. By contrast, fifth-order hillslopes were more complex in geomorphology, with more boundaries and a relatively heterogeneous vegetation pattern. Stream order classification of a savanna drainage network resulted in landscape units distinguishable by geomorphology, geomorphic boundaries and vegetation pattern. Therefore, the drainage network is a useful template to expose and organize the complexity in savanna landscapes into easily managed and researched units. This perspective should inform a shift from single-scale phytosociological views of homogeneous vegetation units towards multi-scale conceptualizations of savannas as water dependent ecosystems. [source]
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