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Wide Spread (wide + spread)
Selected AbstractsMicrogeographic genetic isolation in chub (Cyprinidae: Squalius cephalus) population of the Durance River: estimating fragmentation by damsECOLOGY OF FRESHWATER FISH, Issue 2 2010C. Dehais Dehais C, Eudeline R, Berrebi P, Argillier C. Microgeographic genetic isolation in chub (Cyprinidae: Squalius cephalus) population of the Durance River: estimating fragmentation by dams. Ecology of Freshwater Fish 2010: 19: 267,278. © 2010 John Wiley & Sons A/S Abstract ,, Weirs and dams are wide spread throughout the world's river systems. The most direct effect of these barriers is the limitation of organism movements, i.e., the alteration of connectivity by fragmentation of the aquatic habitat. Whereas the impact of fragmentation on migratory fish species has been well studied, insights on nonmigratory species are still needed. In particular, knowledge on the effects of dams on cyprinid populations at the watershed scale is lacking. Therefore, we studied the genetic structure of eleven chub (Squalius cephalus) samples lined up in the highly fragmented Durance River (France). Using five microsatellite loci, we show that even if the overall genetic differentiation is low, isolation by distance does occur and that genetic diversity increases from upstream to downstream. Dams seem to participate jointly with waterway distance in the explanation of this pattern. However more precise conclusions cannot be made. Guidance for future studies are given. [source] Leaf size and foraging for light in a sclerophyll woodlandFUNCTIONAL ECOLOGY, Issue 5 2002J. G. Bragg Summary 1It has been suggested that leaf size may represent a foraging scale, with smaller-leaved species exploiting and requiring higher resource concentrations that are available in smaller patches. 2Among 26 shrub species from a sclerophyll woodland community in New South Wales, Australia, species with smaller leaves tended to occur in better light environments, after controlling for height. The dark respiration rates of small-leaved species tended to exceed those of larger-leaved species. 3However, the higher-light environments where smaller-leaved species tended to occur had a patch scale larger than whole plants. There would not have been any foraging-scale impediment to large-leaved species occupying these higher-light patches. An alternative explanation for small-leaved species being more successful in higher-light patches, in this vegetation with moderate shading, might be that they were less prone to leaf overheating. 4Such relationships of leaf size to light across species at a given height may be important contributors to the wide spread of leaf sizes among species within a vegetation type, along with patterns down the light profile of the canopy, and effects associated with architecture and ramification strategy. [source] Determination of the soil organic carbon, nitrogen, available phosphorus and the combined aboveground plant materials in the semi-arid Mbulu District, TanzaniaAFRICAN JOURNAL OF ECOLOGY, Issue 3 2009Mligo Cosmas Abstract Soil of the semi-arid Mbulu District is part of the tropical soils, covered with sparse trees, shrubs or grasses in which domestic grazing animals have prevented the wide spread of vegetation cover. The study aimed at determining soil organic carbon (OC), total nitrogen (N), available phosphorus (P) and the combined aboveground plant materials. Six study sites were established in which soil samples were collected at the depths of 0,5, 6,10 and 11,20 cm. Soil samples were analysed for OC, N and P as well as the levels of N and P in the combined aboveground materials of Panicum coloratum and Hyparrhenia filipendula. The percentage concentrations of OC, N and P were high in the top soil than in the deeper soil horizons. However, analysis of variance showed significant differences of OC in some sites whereas no difference for N and P between soil depth classes. OC was highly related with N and P along soil depth classes. It was concluded that the availability of N and P was because of the decomposition of organic matter in the soil. Soil N and P were highly related with the same in the combined aboveground plant materials. It was concluded that the increased concentration of N and P in the soil resulted into availability of the same in P. coloratum and H. filipendula. There was a very high variation in N and P among sites with different levels of intensity of grazing. It was concluded that grazing animals contributes to the redistribution of soil elements in the rangelands because they graze upon plant parts but the excreta are dropped away from the grazed spot. Résumé Le sol du district semi-aride de Mbulu fait partie de ces sols tropicaux couverts d'arbres, de buissons et d'herbes rares où le pâturage des animaux domestiques a empêché une large dispersion du couvert végétal. L'étude visait à déterminer le carbone organique (CO) du sol, l'azote (N) total, le phosphore (P) disponible et l'ensemble combiné de la matière végétale aérienne. Six sites d'étude furent établis, où l'on a récolté des échantillons de sol à des profondeurs de 0 à 5 cm, 6 à 10 cm, et 11 à 20 cm. Les échantillons de sols ont été analysés pour le CO, le N et le P ainsi que les niveaux de N et de P dans la matière végétale aérienne composée de Panicum coloratum et Hyparrhenia filipendula. Le pourcentage des concentrations de CO, N et P était plus élevé dans la couche supérieure du sol que dans les couches plus profondes. Cependant, une analyse de variance a révélé des différences significatives du CO dans certains sites alors qu'il n'y avait pas de différences pour N ni P aux différentes profondeurs de sol. Le CO était fortement liéà N et à P selon les classes de profondeur. On en a conclu que la disponibilité de N et de P était due à la décomposition de la matière organique dans le sol. Le N et le P du sol étaient fortement liés aux mêmes éléments présents dans la matière végétale aérienne combinée. On a conclu que la concentration accrue de N et de P dans le sol résultait de la concentration de ces mêmes éléments dans P. coloratum et H. filipendula. Il y a avait une très grande variation de N et de P entre des sites où l'intensité de pâturage était différente. On a conclu que les animaux qui pâturent contribuent à la redistribution des éléments du sol dans tous les endroits fréquentés étant donné qu'ils mangent des plantes à certains endroits mais que leurs excréments peuvent être rejetés ailleurs que les zones pâturées. [source] Effects of parent material and land use on soil erodibilityJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2003Nutullah Özdemir Abstract The objective of the present investigation was to find out the effect of different parent materials and land use on soil erodibility. Four types of parent materials such as andesite, basalt, alluvial, and gypsum, and three land use types such as grass, clover, and maize, all wide spread in Erzurum Province in Turkey, were tested. Aggregate stability and soil erodibility factors were determined. The susceptibility of soils against erosion decreased in the order of parent materials basalt > andesite > alluvial > gypsum. Likewise, the susceptibility of land use can be sorted as follows: grass > clover > maize. [source] Customer-Driven Product Development Through Quality Function Deployment in the U.S. and JapanTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 4 2000John J. Cristiano Quality Function Deployment is a tool for bringing the voice of the customer into the product development process from conceptual design through to manufacturing. It begins with a matrix that links customer desires to product engineering requirements, along with competitive benchmarking information, and further matrices can be used to ultimately link this to design of the manufacturing system. Unlike other methods originally developed in the U.S. and transferred to Japan, the QFD methodology was born out of Total Quality Control (TQC) activities in Japan during the 1960s and has been transferred to companies in the U.S. This article reports on the results of a 1995 survey of more than 400 companies in the U.S. and Japan using QFD. The research questions investigated in this study were developed both inductively from QFD case studies in the U.S. and Japan and deductively from the literature. The reported results are in part counterintuitive. The U.S. companies reported a higher degree of usage, management support, cross-functional involvement, use of QFD driven data sources, and perceived benefits from using QFD. For the most part, the main uses of QFD in the U.S. were restricted to the first matrix ("House of Quality") that links customer requirements to product engineering requirements and rarely was this carried forward to later matrices. U.S. companies were more apt to use newly collected customer data sources (e.g., focus groups) and methods for analyzing customer requirements. Japanese companies reported using existing product data (e.g., warranty) and a broader set of matrices to a greater extent. The use of analytical techniques in conjunction with QFD (e.g., simulation, design of experiments, regression, mathematical target setting, and analytic hierarchy process) was not wide spread in either country. U.S. companies were more likely to report benefits of QFD in improving cross-functional integration and better decision-making processes compared to Japanese companies. Possible reasons for these cross-national differences as well as their implications are discussed. [source] | ||||||||||