The household responsibility contract system and the question of grassland protection. A case study from the Chang Tang, northwest Tibet Autonomous Region

The implementation of the Household Responsibility Contract System (HRCS) for grassland is ongoing in the pastoral area of Tibetan Autonomous Region (TAR). The main purposes of the HRCS are to reverse the degradation of the rangeland, promote sustainable development of grassland and to increase nomadic production to transform traditional animal husbandry into a more modern development. In this thesis I have address two main questions: 1) Does the Household Responsibility Contract System really protect grassland? 2) Is HRCS compatible with the intended development of the Chang Tang conservation area? HRCS implements a shilft from a common management system to an individual management system. Thus, the starting point for this argument is the comparison of the two management systems and their suitability and adaptability to TAR’s pastoral area in relation to my study area, the Shenchen township pastoral area. I attempt to demonstrate how common property systems have traditionally served and benefited the Shenchen nomads, and how they have traditionally co-existed with the wildlife using this system. I have compared my study area to those areas where the grassland policy has already been implemented in other pastoral areas in China. I analyze how HRCS is working in my particular area; especially in the Chang Tang conservation area and whether it is having an effect on nomad’s culture and environment

Local knowledge production, transmission, and the importance of village leaders in a network of Tibetan pastoralists coping with environmental change

Includes bibliographical references.Changing climate, social institutions, and natural resource management policies are reshaping the dynamics of social-ecological systems globally, with subsistence-based communities likely to be among the most vulnerable to the impacts of global change. These communities’ local ecological knowledge is increasingly recognized as a source of adaptive capacity for them as well as a crucial source of information to be incorporated into scientific understanding and policy making. We interviewed Tibetan pastoralists about their observations of environmental changes, their interpretations of the causes of these changes, and the ways in which they acquire and transmit this knowledge. We found that community members tended to agree that changing climate is driving undesirable trends in grassland and livestock health, and some also viewed changing management practices as compounding the impacts of climate change. However, those nominated by their peers as experts on traditional, pastoral knowledge observed fewer changes than did a more heterogeneous group of people who reported more ways in which the environment is changing. Herders mostly discussed these changes among themselves and particularly with village leaders, yet people who discussed environmental changes together did not necessarily hold the same knowledge of them. These results indicate that members of the community are transferring knowledge of environmental change primarily as a means for seeking adaptive solutions to it, rather than for learning from others, and that local leaders can serve as critical brokers of knowledge transfer within and beyond their communities. This highlights not only the interconnectedness of knowledge, practice, and power, but also points toward the important role that local governance can have in helping communities cope with the impacts of global change.Published with support from the Colorado State University Libraries Open Access Research and Scholarship Fund

Phylogeography and allopatric divergence of cypress species (Cupressus L.) in the Qinghai-Tibetan Plateau and adjacent regions

Additional files can be found at http://www.biomedcentral.com/1471-2148/10/194Background Although allopatric speciation is viewed as the most common way in which species originate, allopatric divergence among a group of closely related species has rarely been examined at the population level through phylogeographic analysis. Here we report such a case study on eight putative cypress (Cupressus) species, which each have a mainly allopatric distribution in the Qinghai-Tibetan Plateau (QTP) and adjacent regions. The analysis involved sequencing three plastid DNA fragments (trnD-trnT, trnS-trnG and trnL-trnF) in 371 individuals sampled from populations at 66 localities. Results Both phylogenetic and network analyses showed that most DNA haplotypes recovered or haplotype-clustered lineages resolved were largely species-specific. Across all species, significant phylogeographic structure (NST > GST, P < 0.05) implied a high correlation between haplotypes/lineages and geographic distribution. Two species, C. duclouxiana and C. chengiana, which are distributed in the eastern QTP region, contained more haplotypes and higher diversity than five species with restricted distributions in the western highlands of the QTP. The remaining species, C. funebris, is widely cultivated and contained very little cpDNA diversity. Conclusions It is concluded that the formation of high mountain barriers separating deep valleys in the QTP and adjacent regions caused by various uplifts of the plateau since the early Miocene most likely promoted allopatric divergence in Cupressus by restricting gene flow and fixing local, species-specific haplotypes in geographically isolated populations. The low levels of intraspecific diversity present in most species might stem from population bottlenecks brought about by recurrent periods of unfavorable climate and more recently by the negative impacts of human activities on species' distributions. Our findings shed new light on the importance of geographical isolation caused by the uplift of the QTP on the development of high plant species diversity in the QTP biodiversity hotspot.Publisher PDFPeer reviewe

Screening for snow/snowmelt in SNPP VIIRS aerosol optical depth algorithm

The Visible Infrared Imaging Radiometer Suite (VIIRS) on board the Suomi National Polar-orbiting Partnership (S-NPP) spacecraft provides validated daily global aerosol optical depth (AOD) retrievals; however, a close examination of the VIIRS aerosol product identified residual snow and snowmelt contamination, resulting generally in an overestimation of AOD. The contamination was particularly evident over Northern Hemisphere high-latitude regions during the spring thaw. To improve the product performance, we introduced a new empirical snow and snowmelt screening scheme that combines a normalized difference snow index (NDSI)- and brightness temperature (BT)-based snow test, a snow adjacency test and a spatial homogeneity test (a.k.a. spatial filter). Testing of retrievals for 18 May 2014 indicated that, compared to the previous, visible reflectance anomaly (VRA)-based snow test, the new NDSI- and BT-based snow test screened out an additional 3.44&thinsp;% of VIIRS AOD retrievals, most of which were over high latitudes experiencing snowmelt. The new snow adjacency test and the homogeneity test degraded another 5.57&thinsp;% and 0.26&thinsp;%, respectively, otherwise good-quality AOD retrievals. For the VIIRS–AERONET (Aerosol Robotic Network) matchups over Northern Hemisphere high-latitude regions during 3 years of spring (2013–2015), the new scheme also effectively screened out a significant number of the matchups that had anomalously high positive biases attributable to snow and snowmelt contamination. The new snow and snowmelt screening scheme was transferred to the Interface Data Processing Segment (IDPS) VIIRS aerosol algorithm on 22 June 2015. Subsequently no significant snow and snowmelt contamination was found during spring 2016. The scheme is also implemented in the new Enterprise VIIRS aerosol algorithm in the National Oceanic and Atmospheric Administration (NOAA) Enterprise Processing System (EPS) that became operational in 2017.</p

CDOM absorption properties of natural water bodies along extreme environmental gradients

We present absorption properties of colored dissolved organic matter (CDOM) sampled in six different water bodies along extreme altitudinal, latitudinal, and trophic state gradients. Three sites are in Norway: the mesotrophic Lysefjord (LF), Samnangerfjord (SF), and Røst Coastal Water (RCW); two sites are in China: the oligotrophic Lake Namtso (LN) and the eutrophic Bohai Sea (BS); and one site is in Uganda: the eutrophic Lake Victoria (LV). The site locations ranged from equatorial to subarctic regions, and they included water types from oligotrophic to eutrophic and altitudes from 0 m to 4700 m. The mean CDOM absorption coefficients at 440 nm [ a CDOM (440) aCDOM(440) ] and 320 nm [ a CDOM (320) aCDOM(320) ] varied in the ranges 0.063–0.35 m −1 −1 and 0.34–2.28 m −1 −1 , respectively, with highest values in LV, Uganda and the lowest in the high-altitude LN, Tibet. The mean spectral slopes S 280−500 S280−500 and S 350−500 S350−500 were found to vary in the ranges of 0.017–0.032 nm −1 −1 and 0.013–0.015 nm −1 −1 , respectively. The highest mean value for S 280−500 S280−500 as well as the lowest mean value for S 350−500 S350−500 were found in LN. Scatter plots of S 280−500 S280−500 versus a CDOM (440) aCDOM(440) and a CDOM (320) aCDOM(320) values ranges revealed a close connection between RCW, LF, and SF on one side, and BS and LV on the other side. CDOM seems to originate from terrestrial sources in LF, SF, BS, and LV, while RCW is characterized by autochthonous-oceanic CDOM, and LN by autochthonous CDOM. Photobleaching of CDOM is prominent in LN, demonstrated by absorption towards lower wavelengths in the UV spectrum. We conclude that high altitudes, implying high levels of UV radiation and oligotrophic water conditions are most important for making a significant change in CDOM absorption properties.publishedVersio

Gender-specific association between blood cell parameters and hyperuricemia in high-altitude areas

BackgroundHyperuricemia is a common metabolic disorder linked to various health conditions. Its prevalence varies among populations and genders, and high-altitude environments may contribute to its development. Understanding the connection between blood cell parameters and hyperuricemia in high-altitude areas can shed light on the underlying mechanisms. This study aimed to investigate the relationship between blood cell parameters and hyperuricemia in high-altitude areas, with a particular focus on gender differences.MethodsWe consecutively enrolled all eligible Tibetan participants aged 18–60 who were undergoing routine medical examinations at the People’s Hospital of Chaya County between January and December 2022. During this period, demographic and laboratory data were collected to investigate the risk factors associated with hyperuricemia.ResultsAmong the participants, 46.09% were diagnosed with hyperuricemia. In the male cohort, significant correlations were found between serum uric acid (SUA) levels and red blood cell (RBC) count, creatinine (Cr). Urea, alanine transaminase (ALT), and albumin (ALB). Notably, RBC exhibited the strongest association. Conversely, in the female cohort, elevated SUA levels were associated with factors such as white blood cell (WBC) count. Urea, ALT, and ALB, with WBC demonstrating the most significant association. Further analysis within the female group revealed a compelling relationship between SUA levels and specific white blood cell subtypes, particularly neutrophils (Neu).ConclusionThis study revealed gender-specific associations between SUA levels and blood cell parameters in high-altitude areas. In males, RBC count may play a role in hyperuricemia, while in females, WBC count appears to be a significant factor. These findings contribute to our understanding of metabolic dynamics in high-altitude regions but require further research for comprehensive mechanistic insights

The late Eocene rise of SE Tibet formed an Asian ‘Mediterranean’ climate

Southeastern (SE) Tibet forms the transition zone between the high interior Tibetan Plateau and the lowlands of southwest China. So understanding the elevation history of SE Tibet, a biodiversity hotspot, enlightens our understanding of the interactions between tectonics, monsoon dynamics and biodiversity. Here we reconstruct the uplift history of the Markam Basin, SE Tibet, during the middle−late Eocene based on U − Pb dating, plant fossil assemblages, and stable and clumped isotope analyses. Our results suggest that the floor of the Markam Basin was at an elevation of 2.6 ± 0.9 km between 42 Ma and 39 Ma, where the mean annual air temperature (MAAT) was 13.2 ± 2.4 °C. The basin then rose rapidly to 3.8 (+0.6/−0.8) km before 36 Ma. Integrated with existing paleoelevation data, we propose that the high plateau boundary (∼3.0 km) of SE Tibet formed during the late Eocene. Numerical climate modeling with realistic paleo-landscapes shows that with the rise of SE Tibet, a Mediterranean-like climate developed in the region characterized by bi-modal precipitation with two wet seasons in boreal spring and autumn. The high topographic relief of SE Tibet, coupled with this distinctive Mediterranean-like climate system, helped develop the high biodiversity of the Hengduan Mountains

BCG coverage and the association between selected factors and the immunization coverage among children under the age of two years in rural and semi-rural Lhasa District, Tibet

Aim: Tuberculosis (TB) is a worldwide pandemic. The BCG vaccine still remains the standard for TB prevention in most countries because of its efficacy in preventing life-threatening forms of TB in infants and young children, and BCG is the only vaccine available. To achieve a high BCG coverage, it is important to investigate the BCG coverage in populations and the factors which affect the immunization status. Thus giving us clues for improving the coverage. Few such studies have been conducted in Tibet. The aim of the present study is to estimate the BCG immunization coverage and to investigate the association between the BCG coverage and the selected factors in children less than two years of age in semi-rural and rural areas of Lhasa District. Methods: The present cross-sectional study was carried out among children less than two years of age in Quxu County (N=484) and in Damxung County (N=496) of Lhasa District, Tibet. In Quxu County we selected all the children less than two years of age and in Damxung County we used multi- stage sampling method to select the sample. The questionnaire consists of core question regarding socio-demographic characteristic of household, the knowledge and belief of mothers related to the immunization and TB, accessibility of health services and the BCG immunization history of children. BCG vaccination scar were checked on the children’s shoulder and recorded. Results: The BCG coverage in the semi-rural area Quxu County was 77%, and that of rural-area Damxung County was 61%. In Quxu County the high BCG coverage was significantly associated with short walking time from home to nearest health facility (OR=3.1; CI, 2.0-4.8), ever vaccinated in health facility (OR=2.5 ; CI, 1.6-4.0), receiving outreaching services (OR=12.0; CI, 7.0-20.6), frequency of outreaching services once per month (OR=7.4; CI 3.7-14.9) or once per two to four months (OR=6.3; CI 2.8-14.5), knowing the time of next outreaching services (OR=2.0; CI, 1.1-3.6), hospital delivery (OR=1.8 ; CI, 1.1-2.7), type of delivery assistance (health worker) (OR=2.0; CI 1.3-3.1), and. In terms of cost of transportation, high BCG coverage were associated with inexpensive cost of transportation (OR=4.6; CI, 1.8-11.6). In Damxung County, the factors significantly associated with high BCG coverage of children were receiving outreaching services (OR=3.8; CI, 2.0-7.2), and knowing the time of next outreaching services (OR=2.7; CI, 1.6-4.5). There was a clear relation between high BCG coverage and frequency of outreaching services, compared to services once or twice per year the odds were as follows once per two to four months (OR=2.7; CI, 1.6-4.5), and monthly (OR=5.7; CI, 3.0 -11.0). Conclusions: BCG coverage was significantly higher in semi-rural area Quxu County (77%) than in the rural-area of Damxung County (61%). In order to increase the immunization coverage in the rural and semi-rural area of Tibet, the frequency of the outreaching services should be increased, as well as more polite information about the time of such services should be given. To establish more health facilities to reduce the travel distance for the mothers or to set up transportation free of charge or to a low cost would be helpful. To encourage the mothers to give birth at hospitals would also increase immunization coverage. However, for many families in Tibet, this will be too expensive. At the same time, birth at hospitals would help in decreasing the mother and child mortality in Tibet