57 research outputs found
Five decades of terrestrial and freshwater research at Ny-Ã…lesund, Svalbard
ArtÃculo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMFor more than five decades, research has been conducted at Ny-Ã…lesund, in Svalbard, Norway, to understand the structure and functioning of High-Arctic ecosystems and the profound impacts on them of environmental change. Terrestrial, freshwater, glacial and marine ecosystems are accessible year-round from Ny-Ã…lesund, providing unique opportunities for interdisciplinary obser-vational and experimental studies along physical, chemical, hydrological and climatic gradients. Here, we synthesize terrestrial and freshwater research at Ny-Ã…lesund and review current knowledge of biodiversity patterns, species population dynamics and interactions, ecosystem processes, biogeochemical cycles and anthropogenic impacts. There is now strong evidence of past and ongoing biotic changes caused by climate change, including negative effects on populations of many taxa and impacts of rain-on-snow events across multiple trophic levels. While species-level characteristics and responses are well under-stood for macro-organisms, major knowledge gaps exist for microbes, inverte-brates and ecosystem-level processes. In order to fill current knowledge gaps, we recommend (1) maintaining monitoring efforts, while establishing a long-term ecosystem-based monitoring programme; (2) gaining a mechanistic under-standing of environmental change impacts on processes and linkages in food webs; (3) identifying trophic interactions and cascades across ecosystems; and (4) integrating long-term data on microbial, invertebrate and freshwater com-munities, along with measurements of carbon and nutrient fluxes among soils, atmosphere, freshwaters and the marine environment. The synthesis here shows that the Ny-Ã…lesund study system has the characteristics needed to fill these gaps in knowledge, thereby enhancing our understanding of High-Arctic ecosystems and their responses to environmental variability and chang
Bestandsovervåkning av Svalbardrype (Lagopus muta hyperborea): registrering av territoriell stegg våren 2008
Material from harvested Svalbard reindeer: evaluation of the material, the data and their areas of application for research and management
This report evaluates biological material from reindeer harvested in Svalbard and discusses
application areas for research and management. A collection of lower jaws located at the
University of Oslo (UiO) covers most of the period 1984–2009. Some material is, however,
currently missing from the collection. The available samples have been analysed for jaw length
and age (based on tooth set and counts of cementum annuli) by the Norwegian Institute for
Nature Research (NINA). A subset of the material has also been analysed previously (by different
personnel) for molar height and dressed weight. The hunting material has broad applicability for
research and management and represents an important resource for studying jaw lengths (i.e.
body growth) in relation to climate, population density, hunting area, and sex and age structure of
the harvested population. Based on preliminary analyses, there is clear variation between
subpopulations and also clear climate signals in body growth. Though limited by a smaller
sample size, similar information can be obtained from molar heights (e.g. tooth wear variation
with sex, age, and climate) and dressed weights. Furthermore, the hunting statistics reflect
spatiotemporal variation in sex-age distribution (of harvested animals) that could be of great
interest for the management of this species on Svalbard. A standardised procedure for collection
and handling of the material, including continuous sample analysis, is highly recommended
When ground-ice replaces fjord-ice: results from a study of GPS-collared Svalbard reindeer females
Arctic fox spatial ecology related to harvest management: final report to Svalbard Environmental Protection Fund
Hunting for ecological indicators: are large herbivore skeleton measures from harvest data useful proxies for monitoring?
Hunter-collected data and samples are used as indices of population performance, and monitoring programs often take advantage of such data as ecological indicators. Here, we establish the relationships between measures of skeleton size (lower jawbone length and hind-leg length) and autumn carcass mass of slaughtered individuals of known age and sex of the high Arctic and endemic Svalbard reindeer (Rangifer tarandus platyrhynchus). We assess these relationships using a long-term monitoring dataset derived from hunted or culled reindeer. The two skeleton measures were generally strongly correlated within age class. Both jaw length (R2 = 0.78) and hind-leg length (R2 = 0.74) represented good proxies of carcass mass. These relationships were primarily due to an age effect (i.e. due to growth) as the skeleton measures reached an asymptotic size at 4–6 years of age. Accordingly, strong positive correlations between skeleton measures and carcass mass were mainly evident at the young age classes (range r [0.45–0.84] for calves and yearlings). For the adults, these relationships weakened due to skeletal growth ceasing in mature animals causing increased variance in mass with age—potentially due to the expected substantial impacts of annual environmental fluctuations. As proxies for carcass mass, skeleton measurements should therefore be limited to young individuals. Although body mass is the ‘gold standard’ in monitoring large herbivores, our results indicate that skeleton measures collected by hunters only provide similar valuable information for young age classes, particularly calves and yearlings. In sum, jaw length and hind-leg length function as proxies identical to body mass when documenting the impacts of changing environmental conditions on important state variables for reindeer and other herbivores inhabiting highly variable environments. Arctic · Citizen science · Hunter-collected data · Life history · Terrestrial large herbivoreHunting for ecological indicators: are large herbivore skeleton measures from harvest data useful proxies for monitoring?publishedVersio
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