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91.
Aleksi Lehikoinen Lluís Brotons John Calladine Tommaso Campedelli Virginia Escandell Jiri Flousek Christoph Grueneberg Fredrik Haas Sarah Harris Sergi Herrando Magne Husby Frederic Jiguet John Atle Kls ke Lindstrm Romain Lorrillire Blas Molina Clara Pladevall Gianpiero Calvi Thomas Sattler Hans Schmid Pivi M. Sirki Norbert Teufelbauer Sven Trautmann 《Global Change Biology》2019,25(2):577-588
Mountain areas often hold special species communities, and they are high on the list of conservation concern. Global warming and changes in human land use, such as grazing pressure and afforestation, have been suggested to be major threats for biodiversity in the mountain areas, affecting species abundance and causing distribution shifts towards mountaintops. Population shifts towards poles and mountaintops have been documented in several areas, indicating that climate change is one of the key drivers of species’ distribution changes. Despite the high conservation concern, relatively little is known about the population trends of species in mountain areas due to low accessibility and difficult working conditions. Thanks to the recent improvement of bird monitoring schemes around Europe, we can here report a first account of population trends of 44 bird species from four major European mountain regions: Fennoscandia, UK upland, south‐western (Iberia) and south‐central mountains (Alps), covering 12 countries. Overall, the mountain bird species declined significantly (?7%) during 2002–2014, which is similar to the declining rate in common birds in Europe during the same period. Mountain specialists showed a significant ?10% decline in population numbers. The slope for mountain generalists was also negative, but not significantly so. The slopes of specialists and generalists did not differ from each other. Fennoscandian and Iberian populations were on average declining, while in United Kingdom and Alps, trends were nonsignificant. Temperature change or migratory behaviour was not significantly associated with regional population trends of species. Alpine habitats are highly vulnerable to climate change, and this is certainly one of the main drivers of mountain bird population trends. However, observed declines can also be partly linked with local land use practices. More efforts should be undertaken to identify the causes of decline and to increase conservation efforts for these populations. 相似文献
92.
93.
Aleksi Lehikoinen Martin Green Magne Husby John Atle Kålås Åke Lindström 《Journal of avian biology》2014,45(1):3-14
Large‐scale multi‐species data on population changes of alpine or arctic species are largely lacking. At the same time, climate change has been argued to cause poleward and uphill range shifts and the concomitant predicted loss of habitat may have drastic effects on alpine and arctic species. Here we present a multi‐national bird indicator for the Fennoscandian mountain range in northern Europe (Finland, Sweden and Norway), based on 14 common species of montane tundra and subalpine birch forest. The data were collected at 262 alpine survey plots, mainly as a part of geographically representative national breeding bird monitoring schemes. The area sampled covers around 1/4 million km2, spanning 10 degrees of latitude and 1600 km in a northeast–southwest direction. During 2002–2012, nine of the 14 bird species declined significantly in numbers, in parallel to higher summer temperatures and precipitation during this period compared to the preceding 40 yr. The population trends were largely parallel in the three countries and similar among montane tundra and subalpine birch forest species. Long‐distance migrants declined less on average than residents and short‐distance migrants. Some potential causes of the current decline of alpine birds are discussed, but since montane bird population sizes may show strong natural annual variation due to several factors, longer time series are needed to verify the observed population trends. The present Fennoscandian monitoring systems, which from 2010 onwards include more than 400 montane survey plots, have the capacity to deliver a robust bird indicator in the climate‐sensitive mountainous regions of northernmost Europe for conservation purposes. 相似文献
94.
Interaction effects between weather and space use on harvesting effort and patterns in red deer
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Inger M. Rivrud Erling L. Meisingset Leif E. Loe Atle Mysterud 《Ecology and evolution》2014,4(24):4786-4797
Most cervid populations in Europe and North America are managed through selective harvesting, often with age‐ and sex‐specific quotas, with a large influence on the population growth rate. Less well understood is how prevailing weather affects harvesting selectivity and off‐take indirectly through changes in individual animal and hunter behavior. The behavior and movement patterns of hunters and their prey are expected to be influenced by weather conditions. Furthermore, habitat characteristics like habitat openness are also known to affect movement patterns and harvesting vulnerability, but how much such processes affect harvest composition has not been quantified. We use harvest data from red deer (Cervus elaphus) to investigate how weather and habitat characteristics affect behavioral decisions of red deer and their hunters throughout the hunting season. More specifically, we look at how sex and age class, temperature, precipitation, moon phase, and day of week affect the probability of being harvested on farmland (open habitat), hunter effort, and the overall harvest numbers. Moon phase and day of week were the strongest predictors of hunter effort and harvest numbers, with higher effort during full moon and weekends, and higher numbers during full moon. In general, the effect of fall weather conditions and habitat characteristics on harvest effort and numbers varied through the season. Yearlings showed the highest variation in the probability of being harvested on farmland through the season, but there was no effect of sex. Our study is among the first to highlight that weather may affect harvesting patterns and off‐take indirectly through animal and hunter behavior, but the interaction effects of weather and space use on hunter behavior are complicated, and seem less important than hunter preference and quotas in determining hunter selection and harvest off‐take. The consideration of hunter behavior is therefore key when forming management rules for sustainable harvesting. 相似文献
95.
Aim
PTSD symptoms were pervasive among children and adolescents after experiencing or exposure to traumatic events. Screening and diagnosis of PTSD symptoms is crucial in trauma-related research and practice. The 13-item Children''s Revised Impact of Event Scale (CRIES) has been demonstrated to be a valid and reliable tool to achieve this goal. This study was designed to examine the psychometric properties of the 13-item CRIES in a sample of Chinese debris flood victims.Methods
A total of 268 participants (145 girls, 123 boys) aged 8–18 years were recruited from an integral part of a service oriented project, supported by the Institute of Psychology, Chinese Academy of Sciences following the debris flood. The participants were given the 13-item CRIES 3 months after the debris flood.Results
The results of confirmatory factor analysis indicated that a two-factor structure (intrusion+arousal vs avoidance) emerged as the model best fit in total sample, boys and girls subsamples, respectively. The scale was also demonstrated to have good internal consistency (Cronbach''s alpha = 0.83).Conclusion
The study confirmed the good psychometric properties of the CRIES and its'' applicability to Chinese children and adolescents. Moreover, these findings imply that the CRIES factor structure is stable across age, gender, and different types of trauma. 相似文献96.
97.
Tillaar RV Sæterbakken A 《Journal of strength and conditioning research / National Strength & Conditioning Association》2012,26(11):2962-2969
ABSTRACT: Van den Tillaar, R, and S?terbakken, A. The sticking region in three chest-press exercises with increasing degrees of freedom. J Strength Cond Res 26(11): 2962-2969, 2012-The purpose was to investigate the effect of 3 chest-press exercises with different degrees of freedom upon the sticking region and muscle activity in maximal attempts. It was hypothesized that, with increasing degrees of freedom, the sticking region (the weakest region during the lift) would be longer because the muscles need to use a part of their ability to control these increasing degrees of freedom during the exercise. Furthermore, the prime movers would have the same muscle activity, but the biceps muscle activity would increase when the degrees of freedom increases because of the enhanced control of the upward movement. Eleven male subjects (age 22.6 ± 1.7 years, body mass 78.6 ± 8.0 kg, stature 1.80 ± 0.07 m) with at least 1 year of bench press training experience participated in this study. Every subject was tested in 1 repetition maximum (1RM) in the 3 chest-press exercises. During the attempts, kinematics and muscle activity were recorded and analyzed in 4 different regions (downward, presticking, sticking, and poststicking). The participants achieved the highest 1RM strength using the free barbell (106.4 ± 15.5 kg), followed by the Smith machine (103.6 ± 14.8 kg) and dumbbells (89.5 ± 13.7 kg). Furthermore, muscle activity differences (electromyographic) between the 3 different exercises and the muscle activation between the 4 different regions were found. The length of the different lifting regions together with muscle activity was different between the exercises. However, the differences found did not follow the line of increasing degrees of freedom that would result in a longer sticking region. Therefore, it is possible to choose to train a particular chest press exercise with the purpose of training a particular muscle more than the others. 相似文献
98.
Many deer populations in Europe and North America have increased in abundance over the last decades. The increasing populations potentially entail both ecological and economic challenges and opportunities, but in practice we still know little about the extent to which these opportunities are being exploited in different management systems. The Norwegian red deer population has increased in density and expanded rapidly since the 1950s. Traditionally, red deer hunting has been undertaken by the local landowner and his relatives and friends. The present large population raises the question whether attracting other hunters could provide a higher economic return for the landowners and, if so, if they are interested in providing such hunting opportunities. We designed a survey to learn more about the landowners, both with respect to the present level of hunting income as well as economic costs of, for example, forest and agricultural damage; we also sought to understand their interest in increasing their income from red deer hunting and potential obstacles to realizing such an increased economic benefit. The results indicate that landowners on average think that red deer populations on their land result in higher costs than income but are nevertheless satisfied with the way things are. This highlights that increased numbers of deer need not automatically lead to more income for landowners and that the potential for income may be hindered by cultural factors such as reluctance to allow access to non-local hunters. 相似文献
99.
van Dijk J Gustavsen L Mysterud A May R Flagstad Ø Brøseth H Andersen R Andersen R Steen H Landa A 《The Journal of animal ecology》2008,77(6):1183-1190
1. Wolves Canis lupus L. recolonized the boreal forests in the southern part of the Scandinavian peninsula during the late 1990s, but so far there has been little attention to its effect on ecosystem functioning. Wolf predation increases the availability of carcasses of large prey, especially moose Alces alces L., which may lead in turn to a diet switch in facultative scavengers such as the wolverine Gulo gulo L. 2. Using 459 wolverine scats collected during winter-spring 2001-04 for DNA identity and dietary contents, we compared diet inside and outside wolf territories while controlling for potential confounding factors, such as prey density. We tested the hypothesis that wolverine diet shifted towards moose in the presence of wolves, while taking into account possible sexual segregation between the sexes. Occurrence of reindeer, moose and small prey was modelled against explanatory covariates using logistic mixed-effects models. Furthermore, we compared diet composition and breadth among habitats and sexes. 3. Occurrence of reindeer, moose and small prey in the diet varied with prey availability and habitat. As expected, diet contained more moose and less reindeer and small prey in the presence of wolves. Their diet in tundra consisted of 40% reindeer Rangifer tarandus L., 39% moose and 9% rodents. In forest with wolf, their diet shifted to 76% moose, 18% reindeer and 5% rodents; compared to 42% moose, 32% reindeer and 15% rodents in forest without wolf. This diet switch could not be explained by higher moose density in wolf territories. Female diet consisted of more small prey than for males, but there was a tendency for females to use the highly available moose carrion opportunistically and to hunt less on small prey within wolf territories. 4. Our study highlights how wolves increase scavenging opportunities for wolverines, and how sexual differences in diet may also apply to large scavengers. Due to their more restricted home range, female wolverines are forced to rely more on hunting small prey. The relatively high occurrence of wolf kills, however, forms an important food source to wolverines in this area. The recolonization of wolves may therefore have contributed to the consequent recolonization of wolverines into the same area. 相似文献
100.
The enzymic and chemically induced decomposition of glucosinolates 总被引:19,自引:0,他引:19
While the myrosinase-glucosinolate system has been reviewed in recent years by a number of authors, little attention has been paid to the enzymic and non-enzymic degradation of glucosinolates. Non-enzymic degradation processes are particularly important in the processing of brassica vegetables with respect to both flavour and in the role of glucosinolates as precursors of anticancer compounds in the diet. This review highlights early empirical work on glucosinolate degradation along with more recent aspects related to current research on mechanism of glucosinolate degradation in plants, microbes and animals. 相似文献