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1.
The critical situation with traditional reindeer husbandry in the Yamal district of the Yamalo- Nenets Autonomous Area, indicated by an anthrax epizootic, is analyzed from an ecological viewpoint. The phenomenon of epizootic is regarded as an ecosystemic homeostatic mechanism operating to prevent excess population growth and maintain ecosystem integrity. The shutdown of this mechanism by means of vaccination, with the proportion of reindeer removed from slaughter remaining low, has resulted in an increased grazing load of rangelands and their consequent severe degradation. These events have been aggravated due to change in the type of ownership in reindeer husbandry during the reforms of the 1990s. The ecological situation is classified as critical, posing a real hazard to this particular ethnic form of economy. It is concluded that the period of extensive/expansive development of Yamal reindeer husbandry has come to an end. Sociopsychological attitudes of the Nenets, acquired when biological resources were abundant, contradict with the principles of ecosystem existence and functioning in the period of resource depletion. The maintenance of reindeer husbandry in the traditional form requires increasing material, labor, and financial investments, but positive results are unlikely to be obtained because of ecological constraints.  相似文献   

2.
To explore the concentrations and dynamics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Finnish semi-domesticated reindeer (Rangifer tarandus tarandus L.) the reindeer milk and tissue samples were collected from the sub-arctic northern Finland. Reindeer milk's PCB sum (1.20 ng g(-1) wet weight) and PCDD/F sum (0.70 pg g(-1) ww) in autumn were higher than in summer (PCBs 0.50 ng g(-1) ww and PCDD/Fs 0.20 pg g(-1) ww). The mean fat content in autumn milk (26%) was significantly higher than in summer (10%). Concentrations in reindeer milk were generally far below 50% of that in adult reindeer body burden. However, the bioaccumulation factors were multiple in milk/reindeer calf ratio and that aroused the question of other important exposure routes than lactation. The muscle and liver of reindeer calves had higher PCDD/F and PCB concentrations than adult animals that possibly indicate the significance of transfer of these compounds from dam to calf through lactation and placenta. However, PBDE concentrations were higher in adult reindeer, especially in liver. In addition, reindeer liver seems to have a special feature to collect highly toxic PCDD/Fs, although the PCB sum concentrations (range from 0.33 to 1.69 ng g(-1) wet weight) were clearly higher than the sums of PCDD/Fs (range from 3.78 to 39.2 pg g(-1) ww). Stillborn reindeer calves represented individuals who had got their PCDD/F, PCB and PBDE load only via the placenta. Concentrations in muscle and brown adipose tissue samples did not indicate dependency on fat content. Obviously effective placental transfer of PCBs and PBDEs from reindeer dam to foetus was seen in this study.  相似文献   

3.
Local dandelion (Taraxacum officinales.l.) populations were studied in the areas of the Eastern Ural Radioactive Trace and the floodplain of the Techa River in its upper reaches. In impact plots, the density of soil and plant cover contamination with 90Sr and 137Cs exceeded the background level by factors of 13–440 and 2–500, respectively; the radiation load exceeded the background level by factors of 1.5 to 45. The seed progeny of plants from these plots was characterized by a high proportion of abnormal seedlings and an increased level of chromosome aberrations in meristem cells. In some years, variation in the seedling viability, growth rate, and developmental rate in these plots exceeded the reaction norm of plants from the background plot, demonstrating both stimulation and inhibition of growth processes. The response of seeds to acute irradiation at high challenging doses varied depending on the level of background radiation in the plots.  相似文献   

4.
Samples of summer pasture plants that reindeer feed on were collected in order to study 137Cs concentrations in different plant species and in species nested in certain site types, and to study the regional distribution of 137Cs in the Finnish reindeer management area. Plant species were categorized by the site types of mineral soil forest (xeric heath forest and mesic heath forest) and peatland. A third category called ’other plant species’ included plants with various site types, poorly determined species and species with poor statistics. The 137Cs concentrations in different site types differed significantly. The mean 137Cs concentrations of the whole reindeer management area in the xeric heath forest plant species was 44 ± 27 Bq/kg dw, in the mesic heath forest plant species 75 ± 59 Bq/kg dw and in the peatland plant species 219 ± 150 Bq/kg dw. The peatland species uptake 137Cs more efficiently than plant species of mineral soil forests. A particularly efficient collector of 137Cs was Trichophorum sp. It is suggested that Trichophorum sp. could be used as an indicator species for reindeer summer fodder plants. The highest concentrations of 137Cs were found in Southern Lapland and the lowest in Northern Lapland. Today, the concentrations of 137Cs in summer pasture plants that reindeer feed on in Finland are at such a level that there is no need to avoid any plant species. In the case of future nuclear fallout, reindeer grazing in peatlands would increase concentrations of 137Cs in reindeer meat.  相似文献   

5.
This paper presents an assessment scheme that should help local conservation management in their adaptation to potential effects of climate change. It can be used for the identification of robust adaptation options at site level. The assessment scheme was applied to the management of Europe’s largest population of wild mountain reindeer (Rangifer tarandus tarandus) living in the arctic-alpine plateau of Hardangervidda in south-western Norway. At first, the last four decades (1964–2004) were analysed to identify climate- and non-climate-related driving forces affecting the population. In addition, regional projections of climate change were used to build scenarios for the potential effects on these driving forces until 2050. In the second step, the potential effects of climate change were classified according to the risk they pose to the conservation of reindeer in Hardangervidda. Based on this assessment, no-regret strategies for biodiversity management under changing climate conditions could be identified.  相似文献   

6.
Concentrations of 90Sr, 210Po and 210Pb in lichen and reindeer were studied in central (Østre Namdal) and southern Norway (Vågå) during 2000–2003. The study focussed on potential differences in concentrations of these nuclides in reindeer of different ages. Concentrations of 90Sr in bones of ∼10 year old adult females were about 40% higher than those in calves' antlers (90Sr concentrations in antlers and bones of calves are similar), while the available data from Vågå suggest that 90Sr concentrations in reindeer calves decreased with an effective ecological half-time of 9.03 ± 0.06 years during 1988–2002. Furthermore, 90Sr concentrations were 50–80% higher in bone of reindeer of a similar age from Vågå compared to those from Østre Namdal. Concentrations of 210Po and 210Pb in muscle and liver tissues were comparable to those reported for reindeer in other Nordic areas, with no significant difference in 210Po and 210Pb concentrations between adults and calves or between reindeer from the two different study areas.  相似文献   

7.
Roles of intensive reindeer grazing and several additional land use factors in the reduction in ground lichens (Cladonia spp.) in pastures grazed by the semi-domesticated reindeer have been argued in Finland. Our analysis showed that several factors and processes explain the standing biomass of lichens (during 2005–2008) and the recent changes in this biomass (after 1995–1996) on lichen pastures located in the 20 northernmost herding districts in Finland. The higher the long-term reindeer densities on the lichen pastures the lower was the lichen biomass. The lichen biomass was also strongly affected by the grazing system; the lowest biomass values of lichens were measured in all grazing areas that were used in the snow-free seasons. The lichen biomass in pine forests less than 80 years old and in all mountain type lichen pastures was lower than that in mature and old pine forests. The lichen biomass also decreased as the proportion of arboreal lichen pastures within a district decreased and the proportion of human infrastructure increased. The aerial drift of heavy metals from the Kola Peninsula appeared to reduce lichens in a small north-eastern part of the study area. Increases in summer precipitation and winter temperatures increased the amount of lichens, but increases in summer temperatures and winter precipitation had the opposite effect. Reindeer densities, grazing system, pasture type and the previous abiotic factors were also associated with the reduction in lichen biomass between the inventories. We conclude that several local, regional and even global factors and processes affect the state of reindeer pastures in large and complex grazing ecosystems. Therefore, more comprehensive research and management strategies for the entire reindeer herding environment are needed.  相似文献   

8.
Activity concentrations of 137Cs and 90Sr in samples of vegetation and natural food products collected in the Kola Peninsula in 1998 and 1999 indicate a very slow decrease in contamination levels during the last decade, mainly due to the physical decay of the radionuclides. The activity concentrations of 137Cs in reindeer meat decreased with a half-life of about 9 years. 137Cs in lichen, moss and fungi is significantly higher than in natural vegetation (grasses) and agricultural plants (potatoes). The activity concentrations of 137Cs in reindeer meat were two orders of magnitude higher than those in locally produced beef and pork. Consumption of reindeer meat, fish, mushrooms and berries constituted the main contribution to the internal dose from 137Cs and 90Sr for reindeer-breeders in the Lovozero area. The estimated committed doses due to 137Cs intake in this group were about 10 microSv per month in summer 1998 and 15 microSv per month in winter, 1999. There was good agreement between internal dose estimates based on intake assessment and whole body measurements. The population of Umba settlement, which is not involved in reindeer breeding, received individual committed doses due to 137Cs intake of about 0.5 microSv per month, about a factor of 20 less than the reindeer-breeders in Lovozero. In this case, the main contribution to the internal dose of the general population came from consumption the of 137Cs in mushrooms and forest berries. The contribution of 90Sr to the internal dose varied from 1% to 5% in the different population groups studied.  相似文献   

9.
Concentrations of (90)Sr, (210)Po and (210)Pb in lichen and reindeer were studied in central (?stre Namdal) and southern Norway (V?g?) during 2000-2003. The study focussed on potential differences in concentrations of these nuclides in reindeer of different ages. Concentrations of (90)Sr in bones of approximately 10 year old adult females were about 40% higher than those in calves' antlers ((90)Sr concentrations in antlers and bones of calves are similar), while the available data from V?g? suggest that (90)Sr concentrations in reindeer calves decreased with an effective ecological half-time of 9.03+/-0.06 years during 1988-2002. Furthermore, (90)Sr concentrations were 50-80% higher in bone of reindeer of a similar age from V?g? compared to those from ?stre Namdal. Concentrations of (210)Po and (210)Pb in muscle and liver tissues were comparable to those reported for reindeer in other Nordic areas, with no significant difference in (210)Po and (210)Pb concentrations between adults and calves or between reindeer from the two different study areas.  相似文献   

10.
This study summarizes the spatial and temporal trends of fallout (137)Cs concentrations in caribou and reindeer (Rangifer tarandus ssp.), reported in various programs in Canada, Alaska and Greenland, over a 40-y period. During the 1960s, the highest (137)Cs concentrations (2000-3000Bqkg(-1) wet weight in muscle) were found in the large caribou herds of central northern Canada, with levels about 50% lower in Alaska and Greenland. Concentrations varied by up to a factor of 6 between spring and fall. Concentrations in reindeer were comparable to those in caribou from the same regions. The highest (137)Cs concentrations (750Bqkg(-1)) in the late 1980s were found in the Caniapiscau herd of central Québec. The contribution from the Chernobyl accident in 1986 was estimated from (134)Cs measurements to be 10-40% of the total (137)Cs. Present concentrations have declined to 200-300Bqkg(-1). The effective half-life (T(eff)) of (137)Cs in Canadian caribou herds was estimated to be about 6 y. The potential impact on the health of northern residents is discussed.  相似文献   

11.
The systemic approach based mainly on computer simulation has been used to assess the dynamics of ecosystems of the Yamal Peninsula, which have been exposed to the impact of numerous reindeer herds because of extensive development of reindeer breeding during the past decades. This type of development has been demonstrated to result in degradation of vegetation, whose profound changes preclude further development of reindeer breeding in the same way. The current situation requires major amendments to the ethnic-cultural and economic policy in the region.  相似文献   

12.
A dynamic model on (137)Cs in reindeer is presented, taking into consideration short- and long-term mechanisms, including the effect of ground deposition, transfer to vegetation, reindeer diet, feed intake, absorption and depletion of radiocaesium in the reindeer body. The model was optimised to fit measured activity concentrations in Swedish reindeer after the Chernobyl fallout. For comparison, regression analyses were made and aggregated transfer factors and effective ecological half-lives were estimated. The fit of the simulated model to observed activity concentrations was slightly better than the fit obtained by linear regressions. Improved knowledge about radiocaesium in vegetation would make the model more accurate for predictive purposes. Presently, the use of Tag and T(eff) is probably better for predictions, provided that their temporal and geographical limitations are taken into consideration. The dynamic model describes mechanisms better and may explain how changes in the system influence on activity concentrations of radiocaesium in the animal.  相似文献   

13.
The application of the critical loads methodology for radioactive contamination of Arctic and sub-arctic ecosystems, where natural and semi-natural food products are important components of the diet of many people, is proposed and discussed. The critical load is herein defined as the amount of radionuclide deposition necessary to produce radionuclide activity concentrations in food products exceeding intervention limits. The high transfer of radiocaesium to reindeer meat gives this product the lowest critical load, even though the intervention limit is relatively high compared with other products. Ecological half-lives of radiocaesium in natural and semi-natural products are often very long, and it is therefore important to take account of contamination already present in the event of an accident affecting areas where such products are important. In particular, the long ecological half-life for radiocaesium in moose meat means that the critical load is highly sensitive to prior deposition. An example of the potential application of the method for emergency preparedness is given for the Chernobyl accident.  相似文献   

14.
Among recent lemmings (D. torquatus from the Yamal Peninsula and D. groenlandicus from Somerset, Bathurst, Melville, and Devon islands), there are populations with archaic sets of morphotypes characteristic of the end of the Late Pleistocene. In some parts of the species range, lemming morphotypes follow the pattern characteristic of the Holocene stage of their evolution. Lemmings with the best developed tooth system live in the Bering Sea sector of the Arctic (Wrangel Island, Chukotka and Alaska). The correspondence of the boundaries of the groups distinguished by odontological traits to the phylogeographic data on mitochondrial DNA (mtDNA) and chromosomal groups is discussed.  相似文献   

15.
Transfer of 137Cs in the soil-plant/lichen-reindeer food chain was studied in central (?stre Namdal) and southern Norway (V?g?) during 2000-2003. Reindeer from these areas have been continuously subjected to countermeasure application since the 1986 Chernobyl accident. In both areas no decline in 137Cs concentrations was detectable in reindeer slaughtered in autumn since 1995, or in reindeer slaughtered in winter since 1998-1999. Seasonal differences in 137Cs concentrations in reindeer have been less pronounced in recent years, with 137Cs concentrations occasionally higher in autumn than in winter. Soil-to-plant 137Cs transfer was significantly higher in ?stre Namdal than in V?g?. Climatic influences on lichen growth and abundance, and on soil properties that influence the availability of 137Cs for plant uptake, are hypothesized to have a larger impact on long-term transfer of radiocaesium in the soil-plant/lichen-reindeer food chain than has been previously observed.  相似文献   

16.
In this paper a compartment model of the highly vulnerable Arctic terrestrial food chain "lichen-reindeer-man" is outlined. Based upon an analysis of measured (137)Cs and (90)Sr contents in lichen and reindeer meat from 1961 up to 2001, site specific model parameters for two regions in north-western Arctic Russia and for Kautokeino municipality in Arctic Norway have been determined. The dynamics of radionuclide activity concentrations in the "lichen-reindeer-man" food chain for all areas was satisfactorily described by a double exponential function with short-term and long-term effective ecological half-lives between 1-2 and 10-12 years, respectively, for both (137)Cs and (90)Sr. Using parameter values derived from the model, life-time internal effective doses due to consumption of reindeer meat by reindeer-breeders after an assumed single pulse deposit of 1 kBq m(-2) of (137)Cs were estimated to be 11.4 mSv (Kola Peninsula), 5 mSv (Nenets Autonomous Area), and 2 mSv (Kautokeino, Norway). Differences in vulnerability to radiocaesium deposition were due to differences in transfer between lichen and reindeer and in diet between the three regions.  相似文献   

17.
Trends in the dynamics of herbivore community related to trophic competition in summer have been analyzed on Wrangel Island. The results show that the trophic spectra overlap considerably, resources are partitioned on the principle “weak competitors after strong competitors,” and community dynamics in the absence of extermination depend on specific competitive advantages related to the width of food spectrum. We conclude that the dynamics of this insular community prior to the establishment of nature reserve on the island have been determined by human activities, as well as the structure of arctic herbivore communities in general.  相似文献   

18.
Concentrations of (137)Cs were determined in 747 lynxes killed in Norway during the period 1986-2001. Highly variable (137)Cs concentrations and aggregated transfer coefficient values were observed, probably caused by variable (137)Cs concentrations in prey and the lynx's extensive home ranges and roaming distances. Adult lynxes had higher (137)Cs concentrations than sub-adults, and lynxes killed in regions with extensive reindeer grazing areas were more contaminated than others. A model with (137)Cs deposition density, the year lynxes were killed, age, and extent of reindeer grazing area accounted for 50% of the variability in observed (137)Cs concentrations. The analyses were equivocal regarding the influence of stomach content on (137)Cs concentrations in lynx muscle, i.e., on the lynx's specialization in prey species. Gender was not significant. Information on caesium retention in lynx and better estimates of deposition densities in lynxes' home ranges are important for further elucidation of factors influencing (137)Cs contamination in lynxes.  相似文献   

19.
Calendar     
The WHO Regional Office for Europe organized a working group in Schloss Reisenburg, Federal Republic of Germany, on 9–12 June 1987, to discuss one important result of the Chernobyl nuclear accident in April 1986, namely the wide distribution of radiocaesium. Its possible health hazards, being a beta-emitter, are long-term because of the long half-lives (about 2 years for 134Cs and about 30 years for 137Cs). Radiocaesium has been shown to concentrate in plants (e.g. spinach and tea) and in animals and animals products (e.g. reindeer and sheep, and their respective milk products).Therefore, it was considered important to examine the rate of deposition in Europe, environmental pathways through soil, flora and fauna to man, the related metabolism and accumulation in man and radiotoxicity and, consequently, the possible health effects.  相似文献   

20.
During the last 50 years, a large amount of information on radionuclide accumulators or "sentinel-type" organisms in the environment has been published. Much of this work focused on the risks of food-chain transfer of radionuclides to higher organisms such as reindeer and man. Until the 1980s and 1990s, there were few published data on the radiocesium ((134)Cs and (137)Cs) accumulation by mushrooms. The present review of published data for (134,137)Cs accumulation by mushrooms in nature discusses the aspects that promote (134,137)Cs uptake by mushrooms and focuses on mushrooms that demonstrate a propensity for use in the environmental biomonitoring of radiocesium contamination. Transfer factors (TF, as dry weight concentration in fruiting body divided by concentration in substrate) ranged up to 24 (unitless), and aggregate transfer factors (T(ag), as Bq(137)Cs/kg dw in fruiting body divided by the aerial deposition as Bq/m(2)) ranged up to 8m(2)/kg dw.  相似文献   

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