The natural upper boundary of a forest（forest line） in mountain environments is an indicator of climate conditions. An increase in global average temperatures has resulted in an upward advance of the forest line. Th...The natural upper boundary of a forest（forest line） in mountain environments is an indicator of climate conditions. An increase in global average temperatures has resulted in an upward advance of the forest line. This advance may result in fragmentation of the alpine ecosystem and a loss of biodiversity. Therefore, it is important to identify potential areas where current forests can advance under scenarios of future climate change. I used expert knowledge and cartographic modeling to create a hybrid cartographic model considering five topographic variables to predict areas where forest line can expand in the future.The prediction accuracy of the model is around 82%. The model is able to predict areas above the current forest line that are suitable or unsuitable for future forest advance.Further inclusion of high-resolution satellite imagery and digital elevation models, as well as field-based information into the model can help to improve the model accuracy.展开更多
The article is based on collection of small terrestrial mammals(Soriculus nigrescens,Episoriculus caudatus, Neodon sikimensis,Alticola stoliczkanus, Niviventer eha and Ochotona roylei) collected in the Barun Valley, e...The article is based on collection of small terrestrial mammals(Soriculus nigrescens,Episoriculus caudatus, Neodon sikimensis,Alticola stoliczkanus, Niviventer eha and Ochotona roylei) collected in the Barun Valley, east Nepal in the pre-monsoon period of 1973.Zoogeographic and ecological characteristics and altitudinal stratification of these species are analysed, depending both on abiotic(geomorphological and climatic) and biotic(vegetation, and human presence and activities)factors. All the captured mammals were examined for ecto- and endoparasities. Infestations of Trombiculid mites and Ixodid ticks were tightly linked to the local habitat where these ectoparasites must survive during their nonparasitic phase. Analysis of their occurrence completes the reconstruction of migration routes during the expansion of small mammals into the Barun Valley and the exacerbating influence of human activities(summer pasturing,mountaineering expeditions and trekking parties).An indicator of anthropogenic influence was the occurrence of synantropic flies. The potential medical importance of these findings is discussed.It is assumed a possible occurrence of arboviruses transmitted by ticks and also rickettsioses(transmitted by ticks and chigger mites). As far bacteriological infections, plague cannot be excluded.展开更多
The frequent occurrence of geopolitical crises in the post-financial crisis era is driving the rethinking behind whether the global crude oil market is still a highly connected"great pool".Using the spillove...The frequent occurrence of geopolitical crises in the post-financial crisis era is driving the rethinking behind whether the global crude oil market is still a highly connected"great pool".Using the spillover network model suggested by Baruník and Krehlík(2018),and the daily data of 31 global crude oil markets from 2009 to 2019,this study examines the return and volatility spillover effects and their timevarying behavior in six crude oil market segments at different timescales.The findings indicate that heterogeneity exists in the co-movements between global crude oil markets in the post-financial crisis era.In the medium term,both return and volatility spillover effects are not significant,which makes the diversified portfolio strategy useful.Prices in the Europe and Central Asian regions take the lead in return spillovers.In contrast,Asia-Pacific regional prices contribute the most in terms of volatility spillovers.Long-term volatility spillovers increase sharply when confronted with oil-related events in the postfinancial crisis era.Therefore,policymakers should take effective measures to prevent any large-scale risk transmission in the long run.展开更多
文摘The natural upper boundary of a forest（forest line） in mountain environments is an indicator of climate conditions. An increase in global average temperatures has resulted in an upward advance of the forest line. This advance may result in fragmentation of the alpine ecosystem and a loss of biodiversity. Therefore, it is important to identify potential areas where current forests can advance under scenarios of future climate change. I used expert knowledge and cartographic modeling to create a hybrid cartographic model considering five topographic variables to predict areas where forest line can expand in the future.The prediction accuracy of the model is around 82%. The model is able to predict areas above the current forest line that are suitable or unsuitable for future forest advance.Further inclusion of high-resolution satellite imagery and digital elevation models, as well as field-based information into the model can help to improve the model accuracy.
文摘The article is based on collection of small terrestrial mammals(Soriculus nigrescens,Episoriculus caudatus, Neodon sikimensis,Alticola stoliczkanus, Niviventer eha and Ochotona roylei) collected in the Barun Valley, east Nepal in the pre-monsoon period of 1973.Zoogeographic and ecological characteristics and altitudinal stratification of these species are analysed, depending both on abiotic(geomorphological and climatic) and biotic(vegetation, and human presence and activities)factors. All the captured mammals were examined for ecto- and endoparasities. Infestations of Trombiculid mites and Ixodid ticks were tightly linked to the local habitat where these ectoparasites must survive during their nonparasitic phase. Analysis of their occurrence completes the reconstruction of migration routes during the expansion of small mammals into the Barun Valley and the exacerbating influence of human activities(summer pasturing,mountaineering expeditions and trekking parties).An indicator of anthropogenic influence was the occurrence of synantropic flies. The potential medical importance of these findings is discussed.It is assumed a possible occurrence of arboviruses transmitted by ticks and also rickettsioses(transmitted by ticks and chigger mites). As far bacteriological infections, plague cannot be excluded.
基金the financial support from the National Natural Science Foundation of China(No.71922013)。
文摘The frequent occurrence of geopolitical crises in the post-financial crisis era is driving the rethinking behind whether the global crude oil market is still a highly connected"great pool".Using the spillover network model suggested by Baruník and Krehlík(2018),and the daily data of 31 global crude oil markets from 2009 to 2019,this study examines the return and volatility spillover effects and their timevarying behavior in six crude oil market segments at different timescales.The findings indicate that heterogeneity exists in the co-movements between global crude oil markets in the post-financial crisis era.In the medium term,both return and volatility spillover effects are not significant,which makes the diversified portfolio strategy useful.Prices in the Europe and Central Asian regions take the lead in return spillovers.In contrast,Asia-Pacific regional prices contribute the most in terms of volatility spillovers.Long-term volatility spillovers increase sharply when confronted with oil-related events in the postfinancial crisis era.Therefore,policymakers should take effective measures to prevent any large-scale risk transmission in the long run.
