958 resultados para British Columbia Dept. of Finance
Resumo:
Understanding the mechanisms that structure communities and influence biodiversity are fundamental goals of ecology. To test the hypothesis that the abundance and diversity of upper-trophic level predators (seabirds) is related to the underlying abundance and diversity of their prey (zooplankton) and ecosystem-wide energy availability (primary production), we initiated a monitoring program in 2002 that jointly and repeatedly surveys seabird and zooplankton populations across a 7,500 km British Columbia-Bering Sea-Japan transect. Seabird distributions were recorded by a single observer (MH) using a strip-width technique, mesozooplankton samples were collected with a Continuous Plankton Recorder, and primary production levels were derived using the appropriate satellite parameters and the Vertically Generalized Production Model (Behrenfeld and Falkowski 1997). Each trophic level showed clear spatio-temporal patterns over the course of the study. The strongest relationship between seabird abundance and diversity and the lower trophic levels was observed in March/April ('spring') and significant relationships were also found through June/July ('summer'). No discernable relationships were observed during the September/October ('fall') months. Overall, mesozooplankton abundance and biomass explained the dominant portion of seabird abundance and diversity indices (richness, Simpson's Index, and evenness), while primary production was only related to seabird richness. These findings underscore the notion that perturbations of ocean productivity and lower trophic level ecosystem constituents influenced by climate change, such as shifts in timing (phenology) and synchronicity (match-mismatch), could impart far-reaching consequences throughout the marine food web.
Resumo:
Cooperatives have a long historical experience in the Spanish economy and have demonstrated their ability to compete against traditional firms in the market. To maintain this capability, while taking advantage of the competitive advantages associated with their idiosyncrasies as social economy enterprises, they should take into consideration that the economy is increasingly globalized and increasingly knowledge-based, especially with regards to technological content. As a consequence, the innovative capacity appears to be a key aspect in order to be able to challenge competitors. This article characterizes the innovative behavior of cooperatives in the region of Castile and Leon and analyses the internal and external factors affecting their innovative performance, based on data from a survey of 581 cooperatives. The results of the empirical analysis, which is performed by multivariate binary logistic regression on various types of innovation, lead us to identify the size of the organizations, the existence of planning, the R & D activities and the human capital as the main determining factors.
Resumo:
There are now 91 records of individual Nathusius' pipistrelle Pipistrellus nathusii examined 'in the hand' in the U.K., and bat detector records from a further 36 localities in Britain and Ireland. These records are distributed throughout all months of the year with clear peaks in spring and autumn suggesting migratory movements into and out of the British Isles in autumn and spring, respectively. Three maternity colonies have been located and the species must now also be regarded as a resident breeding species in Britain and Ireland.
Resumo:
Recent climatic change has been recorded across the globe. Although environmental change is a characteristic feature of life on Earth and has played a major role in the evolution and global distribution of biodiversity, predicted future rates of climatic change, especially in temperature, are such that they will exceed any that has occurred over recent geological time. Climate change is considered as a key threat to biodiversity and to the structure and function of ecosystems that may already be subject to significant anthropogenic stress. The current understanding of climate change and its likely consequences for the fishes of Britain and Ireland and the surrounding seas are reviewed through a series of case studies detailing the likely response of several marine, diadromous and freshwater fishes to climate change. Changes in climate, and in particular, temperature have and will continue to affect fish at all levels of biological organization: cellular, individual, population, species, community and ecosystem, influencing physiological and ecological processes in a number of direct, indirect and complex ways. The response of fishes and of other aquatic taxa will vary according to their tolerances and life stage and are complex and difficult to predict. Fishes may respond directly to climate-change-related shifts in environmental processes or indirectly to other influences, such as community-level interactions with other taxa. However, the ability to adapt to the predicted changes in climate will vary between species and between habitats and there will be winners and losers. In marine habitats, recent changes in fish community structure will continue as fishes shift their distributions relative to their temperature preferences. This may lead to the loss of some economically important cold-adapted species such as Gadus morhua and Clupea harengus from some areas around Britain and Ireland, and the establishment of some new, warm-adapted species. Increased temperatures are likely to favour cool-adapted (e.g. Perca fluviatilis) and warm-adapted freshwater fishes (e.g. roach Rutilus rutilus and other cyprinids) whose distribution and reproductive success may currently be constrained by temperature rather than by cold-adapted species (e.g. salmonids). Species that occur in Britain and Ireland that are at the edge of their distribution will be most affected, both negatively and positively. Populations of conservation importance (e.g. Salvelinus alpinus and Coregonus spp.) may decline irreversibly. However, changes in food-web dynamics and physiological adaptation, for example because of climate change, may obscure or alter predicted responses. The residual inertia in climate systems is such that even a complete cessation in emissions would still leave fishes exposed to continued climate change for at least half a century. Hence, regardless of the success or failure of programmes aimed at curbing climate change, major changes in fish communities can be expected over the next 50 years with a concomitant need to adapt management strategies accordingly.
Resumo:
Previous phylogeographical and palaeontological studies on the biota of northern North America have revealed a complex scenario of glacial survival in multiple refugia and differing patterns of postglacial recolonization. Many putative refugial regions have been proposed both north and south of the ice sheets for species during the Last Glacial Maximum, but the locations of many of these refugia remain a topic of great debate. In this study, we used a phylogeographical approach to elucidate the refugial and recolonization history of the herbaceous plant species Orthilia secunda in North America, which is found in disjunct areas in the west and east of the continent, most of which were either glaciated or lay close to the limits of the ice sheets. Analysis of 596-bp of the chloroplast trnS-trnG intergenic spacer and five microsatellite loci in 84 populations spanning the species' range in North America suggests that O.secunda persisted through the Last Glacial Maximum (LGM) in western refugia, even though palaeodistribution modelling indicated a suitable climate envelope across the entire south of the continent. The present distribution of the species has resulted from recolonization from refugia north and south of the ice sheets, most likely in Beringia or coastal regions of Alaska and British Columbia, the Washington/Oregon region in the northwest USA, and possibly from the region associated with the putative 'ice-free corridor' between the Laurentide and Cordilleran ice sheets. Our findings also highlight the importance of the Pacific Northwest as an important centre of intraspecific genetic diversity, owing to a combination of refugial persistence in the area and recolonization from other refugia.