Controls on the regional distribution of landslide dams and implications for fluvial landform evolution in Bhutan and its surrounding area

The regional distribution of landslide dams can provide valuable insights into the interactions among various factors,including lithology,topography,climate,and fluvial landforms in tectonically active mountains.Himalayan rivers are frequently impacted by large-scale landslide damming,which profoundly influence fluvial geomorphology.In this study,we identified 1652 landslide dams in four major rivers of Bhutan and its surrounding area by remote sensing interpretation.Notably,approximately 71%of these landslide dams are found in regions composed of quartzite or gneiss.Fault-related tectonic activity plays a significant role in governing the distribution of these landslide dams,as approximately 83%of the mapped landslide dams are found within a 10 km radius of the nearest fault.The majority of the identified landslide dams are situated in areas with relatively modest local relief,ranging from 227 m to 327 m.These dams tend to cluster in the tributaries,and the stream power of almost 95%of them is typically below 1×10^(6) kg m^(2) s^(-3).Our data,combining the erosion rate and kernel density map of the landslide dams,reveals that regions with high erosion rates do not consistently align with the major high-density distribution of landslide dams.It is shown that the distribution of landslide dams is strongly influenced by the valley form.In comparison to U-shaped valleys,V-shaped valleys exhibit a higher density of landslide dams.Intriguingly,we also find a positive correlation between the landslide-dam distribution density and the erosion rate only in relatively arid regions with mean annual rainfall less than 500 mm.Moreover,the length of the upstream reach protected by the knickpoint associated with both lithology and landslide damming is about three times longer than that protected by the knickpoint associated only with landslide damming.

尾凤蝶属昆虫研究概况

对尾凤蝶属(Bhutanitis)昆虫的研究主要集中在形态描述和分类方面,其次是生物学特性研究,仅有少数涉及到分子生物学和保护生物学等方面。分子生物学和保护生物学研究将是今后该属昆虫的研究重点。

Extremely high prevalence of Helicobacter pylori infection in Bhutan

AIM: To revealed the prevalence of Helicobacter pylori (H. pylori ) infection in the Bhutanese population. METHODS: We recruited a total of 372 volunteers (214 females and 158 males; mean age of 39.6 ± 14.9 years) from three Bhutanese cities (Thimphu, Punaka, and Wangdue). The status of H. pylori infection was determined based on five different tests: the rapid urease test (CLO test), culture, histology, immunohistochemistry (IHC), and serum anti H. pylori -antibody. RESULTS: The serological test showed a significantly higher positive rate compared with the CLO test, culture, histology and IHC (P < 0.001, P < 0.001, P=0.01, and P=0.01, respectively). When the subjects were considered to be H. pylori positive in the case of at least one test showing a positive result, the overall prevalence of H. pylori infection in Bhutan was 73.4%. The prevalence of H. pylori infection significantly decreased with age (P < 0.01). The prevalence of H. pylori infection was lower in Thimphu than in Punakha and Wangdue (P=0.001 and 0.06, respectively). The prevalence of H. pylori infection was significantly higher in patients with peptic ulcers than in those with gastritis (91.4% vs 71.3%, P=0.003). CONCLUSION: The high incidence of gastric cancer in Bhutan may be attributed to the high prevalence of H. pylori infection.

Antibiotics resistance rate of Helicobacter pylori in Bhutan

AIM:To survey the antibiotic resistance pattern of Helicobacter pylori(H.pylori)strains isolated from Bhutanese population.METHODS:We isolated 111 H.pylori strains from the gastric mucosa of H.pylori-infected patients in Bhutan in 2010.The Epsilometer test was used to determine the minimum inhibitory concentrations(MICs)of amoxicillin(AMX),clarithromycin(CLR),metronidazole(MNZ),levofloxacin(LVX),ciprofloxacin(CIP),and tetracycline(TET).RESULTS:Nineteen of the isolated H.pylori strains were susceptible to all antibiotics tested.The isolated strains showed the highest rate of antibiotic resistance to MNZ(92/111,82.9%).Among the 92 MNZresistant strains,74 strains(80.4%)showed high-level resistance(MIC≥256 g/mL).Three strains were resistance to LVX(2.7%).These strains were also resistance to CIP.None of the strains showed resistance to CLR,AMX and TET.CONCLUSION:CLR-based triple therapy is a more effective treatment approach over MNZ-based triple therapy for H.pylori infection in Bhutan.

Geographical distribution of the incidence of gastric cancer in Bhutan

AIM: To estimate the prevalence of gastric cancer(GC) in a cohort of patients diagnosed with GC and to compare it with patients diagnosed with all other types of gastro-intestinal(GI) cancer during the same period.METHODS: Between 2008 and 2013,five-year period,the medical records of all GI cancer patients who underwent medical care and confirm diagnosis of cancer were reviewed at the National Referral Hospital,Thimphu which is the only hospital in the country where surgical and cancer diagnosis can be made. Demographic information,type of cancer,and the year of diagnosis were collected.RESULTS: There were a total of 767 GI related cancer records reviewed during the study period of which 354(46%) patients were diagnosed with GC. There were 413 patients with other GI cancer including; esophagus,colon,liver,rectum,pancreas,gall bladder,cholangiocarcinoma and other GI tract cancers. The GC incidence rate is approximately 0.9/10000 per year(367 cases/5years per 800000 people). The geographic distribution of GC was the lowest in the south region of Bhutan 0.3/10000 per year compared to the central region 1.4/10000 per year,Eastern region 1.2/10000 per year,and the Western region 1.1/10000 per year. Moreover,GC in the South part was significantly lower than the other GI cancer in the same region(8% vs 15%; OR = 1.8,95%CI: 1.3-3.1,P = 0.05). Among GC patients,38% were under the age of 60 years,mean age at diagnosis was 62.3(± 12.1) years with male-to-female ratio 1:0.5. The mean age among patients with all other type GI cancer was 60 years(± 13.2) and male-tofemale ratio of 1:0.7. At time of diagnosis of GC,342(93%) were at stage 3 and 4 of and by the year 2013; 80(23%) GC patients died compared to 31% death among patients with the all other GI cancer(P = 0.08).CONCLUSION: The incidence rate of GC in Bhutan is twice as high in the United States but is likely an underestimate rate because of unreported and undiagnosed cases in the villages. The high incidence of GC in Bhutan could be attributed to the high prevalence of Helicobacter pylori infection that we previously reported. The lowest incidence of GC in Southern part of the country could be due to the difference in the ethnicity as most of its population is of Indian and Nepal origin. Our current study emphasizes on the importance for developing surveillance and prevention strategies for GC in Bhutan.

Plant diversity of the Kangchenjunga Landscape, Eastern Himalayas

The Kangchenjunga Landscape (KL) in the Eastern Himalayas is a transboundary complex shared by Bhutan, India, and Nepal. It forms a part of the ‘Himalayan Biodiversity Hotspot’ and is one of the biologically richest landscapes in the Eastern Himalayas. In this paper, we use secondary information to review and consolidate the knowledge on the flora of the KL. We reviewed 215 journal articles, analysed the history of publications on the flora of the KL, their publication pattern in terms of temporal and spatial distribution and key research areas. Our review shows that the landscape has a long history of botanical research that dates back to the 1840s and progressed remarkably after the 1980s. Most of the studies have been carried out in India, followed by Nepal and Bhutan. The majority of these have been vegetation surveys, followed by research on ethnobotanical aspects and Non-Timber Forest Products (NTFPs). This paper describes the forest types and characteristic species of the KL and details the species richness, diversity and dominant families of seed plants. A total of 5198 species of seed plants belonging to 1548 genera and 216 families have been recorded from the landscape, including 3860 dicots, 1315 monocots and 23 gymnosperms. Among families, Orchidaceae is the most diversely represented family in terms of species richness. This paper also draws attention to the threatened and endemic flora of the KL, including 44 species that are threatened at national and global level and 182 species that are endemic. Finally, the paper reviews the major challenges facing the KL, the conservation efforts and practices that are currently in place and recommends systematic and comprehensive floral surveys, particularly long-term data collection and monitoring and transboundary collaboration, to address the existing knowledge gaps on floral diversity of the KL.

Birds of the Kangchenjunga Landscape,the Eastern Himalaya:status,threats and implications for conservation

Birds are reliable and widely used indicators for conservation planning and monitoring. We reviewed birds of the Kangchenjunga Landscape, a transboundary complex shared by Bhutan, India and Nepal in the Eastern Himalaya. Using 119 literature, we analyzed the bird survey efforts in the landscape, their taxonomic representation, global threat status, distribution patterns, and habitat preferences. We also discussed the potential threats and conservation challenges and documented current conservation efforts and government policies. Most of the bird surveys are carried out in India followed by Nepal and Bhutan. A total of 618 bird species belonging to 19 orders and 77 families are recorded. Passeriformes is the dominant order that constitutes 62% of the total records listed from the landscape. Among the families, Muscicapidae is the most common and diversely represented family. There are 41 species of birds that are categorized as threatened under IUCN Red List. Of the total birds occurring in the landscape, the highest number of bird species(95%) was documented from India, followed by Nepal(55%) and Bhutan(34%). Of them, 24% of the species were found to occur in the tropical zone. Forested habitat is widely used by 63% of the total species followed by wetlands(16%). Despite promising policies and legal provisions, the landscape faces numerous challenges including habitat loss and fragmentation, hunting and trapping, unsustainable extraction of natural resources, invasive alien species, unregulated tourism and global climate change. We suggest protection and management of birds through strengthening Important Bird and Biodiversity Areas, reduction in forest encroachment and habitat destruction, conservation awareness programmes and comprehensive bird surveys with long term monitoring to assess the impact of environmental change as some of the approaches to conserve the rich avifaunal diversity of the landscape.

三尾褐凤蝶小陇山栖息地蝶类资源

对甘肃小陇山境内三尾褐凤蝶(Bhutanitis thaidina Blanchard)栖息地内蝴蝶资源进行调查,发现区内各种蝶类10科58属74种,与三尾褐凤蝶有共同寄主的4种,有共同蜜源植物的50种,既有共同寄主又有共同蜜源植物的3种。三尾褐凤蝶与区内其它蝴蝶之间并无明显竞争关系,其它蝴蝶一定种群数量的分布有益于三尾褐凤蝶生存和种群恢复。

三尾褐凤蝶蜜源植物资源调查

对小陇山林业实验局张家庄林场黑河省级自然保护区内三尾褐凤蝶(Bhutanitis thaidina Blanchard)访花蜜源植物进行调查,发现区内可供三尾褐凤蝶访花的蜜源植物9种,为甘肃丁香(Syringa buxifoliaNakai)、东陵八仙花(Hydrangea bretschneideri Dipp)、南川绣线菊(Spiraea rosthornii Pritz.)、山梅花(Philadelphus incanus Kochne)、绣线梅(Neillia sinensis Oliv.)、魁蓟(Cirsium leo Nakai et Kitag)、毛蕊老鹳草(Geranium eriostemon Fisch)、紫花碎米荠(Cardamine tangutorum O. E. Schulz)和峨参(Anthriscus sylvestris(L.) Hoffm. Gen.)。

Cultural Landscape in World Heritage Conservation and Cultural Landscape Conservation Challenges in Asia

UNESCO was the first United Nations agency to deal with landscapes at a global scale,notably through the World Heritage Convention.In 1992,‘Cultural Landscapes’became a new category on the World Heritage List combining works of nature and of humankind:cultural landscapes often illustrate a specific relation between people and nature and can reflect techniques of sustainable land use,fostering strong links between culture and sustainable development.Initiatives such as the UNESCO-Greece Melina Mercouri International Prize highlight outstanding examples of safeguarding activities at the world’s major cultural landscapes and offer opportunities to share good practices and create synergies.Cultural landscapes face numerous threats across the world,and especially in Asia,with its growing infrastructure development and urbanisation.This article shares some of the knowledge and experience garnered by UNESCO through its conservation and management activities at cultural landscapes in Asia(Bamiyan Valley in Afghanistan,Bhutan,Silk Roads heritage corridors)and highlights the urgent need for a cultural-historical-natural territory approach to address the pressing challenges for the conservation of Cultural Landscapes in Asia.Finally,the article advocates for a strong focus on the peoples and communities that inhabit these territories and their involvement at all stages.

The COVID-19 vaccination campaign in Bhutan: strategy and enablers

Bhutan has reported a total of 2596 COVID-19 cases and three deaths as of September 15,2021.With support from India,the United States,Denmark,the People’s Republic of China,Croatia and other countries,Bhutan was able to conduct two rounds of nationwide vaccination campaign.While many countries struggle to overcome vaccine refusal or hesitancy due to complacency,a lack of trust,inconvenience and fear,escalated in some countries by anti-vaccine groups,Bhutan managed to inoculate more than 95%of its eligible populations in two rounds of vaccination campaign.Enabling factors of this successful vaccination campaign were strong national leadership,a well-coordinated national preparedness plan,and high acceptability of vaccine due to effective mass communication and social engagement led by religious figures,volunteers and local leaders.In this short report,we described the national strategic plan and enabling factors that led to the success of this historical vaccination campaign.