Spatial and temporal variability in vegetation cover of Mongolia and its implications     

Sumiya VANDANDORJ  Batdelger GANTSETSEG  Bazartseren BOLDGIV 《干旱区科学》2015,7(4):450-461

In this paper, we attempted to determine the most stable or unstable regions of vegetation cover in Mongolia and their spatio-temporal dynamics using Terra/MODIS Normalized Difference Vegetation Index(NDVI) dataset, which had a 250-m spatial resolution and comprised 6 periods of 16-day composited temporal resolution data(from 10 June to 13 September) for summer seasons from 2000 to 2012. We also used precipitation data as well as biomass data from 12 meteorological stations located in 4 largest natural zones of Mongolia. Our study showed that taiga and forest steppe zones had relatively stable vegetation cover because of forest characteristics and relatively high precipitation. The highest coefficient of variation(CV) of vegetation cover occurred frequently in the steppe and desert steppe zones, mainly depending on variation of precipitation. Our results showed that spatial and temporal variability in vegetation cover(NDVI or plant biomass) of Mongolia was highly dependent on the amount, distribution and CV of precipitation. This suggests that the lowest inter-annual CV of NDVI can occur during wet periods of growing season or in high precipitation regions, while the highest inter-annual CV of NDVI can occur during dry periods and in low precipitation regions. Although the desert zone received less precipitation than other natural zones of the country, it had relatively low variation compared to the steppe and desert steppe, which could be attributed to the very sparse vegetation in the desert.  相似文献   

Metagenetics of fairy rings reveals complex and variable soil fungal communities     

Siyu XU  Ke DONG  Sangseob LEE  Matthew Chidozie OGWU  Sainbileg UNDRAKHBOLD  Dharmesh SINGH  Dagvatseren ARIUNZAYA  Orsoo ENKHMANDAL  Laura A. SPENCE  Anarmaa SHARKHUU  Brenda B. CASPER  Jonathan M. ADAMS  Bazartseren BOLDGIV 《土壤圈》2023,33(4):567-578

Although fairy rings are widely observed, little is known about the community processes associated with them. Here, we studied fairy rings in a natural grassland in northern Mongolia by sampling soils outside (future stage), directly under (present stage), and within (past stage) the rings, to represent different time stages during the expansion of fairy rings. Soil DNA was extracted for amplicon sequencing of the fungal ITS1 region. The present stage had reduced fungal diversity and different fungal communities toward the other stages. Most strikingly, there was an increase in the pathogenic fungus Gibberella baccata in the present stage of most rings and the saprotrophic fairy ring fungus Lepista luscina in several. However, no mushrooms of Lepista had been recorded from any of these rings during several years of observation. Known fairy ring fungi were not found in the present stage of every ring, even in some known rings to have previously displayed mushrooms of such species. It is possible that these fungi occurred or were more abundant at the unsampled leading edge of the ring. The increase in G. baccata is intriguing, but its importance, if any, is unclear. It is also unclear whether consortia of fungi or other microbes might be present in these rings. The absence or low abundance of the previously reported fairy ring fungal species suggests that their presence is transient, with rapid replacement by other fungi. No differences in soil parameters were found between the fairy ring stages, except for aluminum. There is a need for broader sampling, including analysis of non-fungal biota, to understand the functional diversity of fairy ring fungi and the consequences for plant communities.  相似文献   

Discrepancies between self‐reported tick bites and evidence of tick‐borne disease exposure among nomadic Mongolian herders     

Sukhbaatar Lkhagvatseren  Kathryn M. Hogan  Bazartseren Boldbaatar  Michael E. von Fricken  Benjamin D. Anderson  Laura A. Pulscher  Luke Caddell  Pagbajabyn Nymadawa  Gregory C. Gray 《Zoonoses and public health》2019,66(5):480-486

Twenty‐six per cent of Mongolians live pastoral lifestyles, increasing their likelihood of exposure to ticks and placing them at a higher risk for contracting tick‐borne diseases (TBDs). Anaplasma spp. and Rickettsia spp. have been identified in ticks, livestock and humans in Mongolia, but no known qualitative research has been conducted investigating the association between nomadic herder characteristics, tick bite history and exposure to TBDs. To better understand the association between self‐reported tick bites and symptoms versus actual exposure to TBDs, this study paired serological data with 335 surveys administered to Mongolian herders, ages 12–69, from 2014 to 2015. Logistic regression results identified no significant associations between reported tick bites or symptoms with serological evidence of Anaplasma spp. and Rickettsia spp. controlling for age, gender and aimag. Among the 335 respondents who were seropositive to either Anaplasma spp. or Rickettsia spp., 32.9% self‐reported experiencing abnormal symptoms such as redness, inflammation, headache, arthritis or fever after being bitten. Alternatively, 17.3% (58/335) of individuals reported experiencing symptoms following a tick bite in instances where serological results indicated no exposure to Anaplasma spp. or Rickettsia spp. Results also identified inconsistencies in reporting and seroprevalence among different age groups, with children having the highest reporting and treatment seeking rates but low levels of exposure in comparison with other groups. While survey results showed that individuals were aware of peak tick seasons and tick species that inhabit specific areas, 58% of heads of households (49/84) were unaware that ticks can cause disease in livestock or dogs. This study suggests that herders are an at‐risk population in Mongolia with gaps in awareness of TBD risk. Increased surveillance paired with focused outreach to prevent TBDs targeted to the herder population is encouraged.  相似文献   

Cytokine responses in camels (Camelus bactrianus) vaccinated with Brucella abortus strain 19 vaccine     

Odbileg R  Purevtseren B  Gantsetseg D  Boldbaatar B  Buyannemekh T  Galmandakh Z  Erdenebaatar J  Konnai S  Onuma M  Ohashi K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(2):197-201

In the present study, we determined the levels of cytokines produced by camel (Camelus bactrianus) peripheral blood mononuclear cells (PBMCs) in response to live attenuated Brucella abortus (B. abortus) S19 vaccine. Seven camels were vaccinated with commercial B. abortus S19 vaccine, and their cytokine responses were determined using a real-time PCR assay. Cytokine responses to B. abortus S19 were examined at 6 hr, 48 hr and 1, 2 and 3 weeks post-vaccination. Serological tests were performed to further confirm these immune responses. The results revealed that IFN-gamma and IL-6 were upregulated during the first week post-vaccination. Low level expressions of IL-1alpha, IL-1beta, TNFalpha and IL-10 and no expression of IL-2 and IL-4 were observed compared with the control camels. The findings showed that B. abortus stimulates cell-mediated immunity by directly activating camel Th1 cells to secrete IFN-gamma. This quantification of cytokine expression in camels is essential for understanding of Camelidae disease development and protective immune responses. This is the first report of in vivo camel cytokine quantification after vaccination.  相似文献