85 research outputs found

    Intermediate disturbance on rangelands : Management applicability of the intermediate disturbance hypothesis across Mongolian rangeland ecosystems

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    The current growing body of evidence for diversity-disturbance relationships suggests that the peaked pattern predicted by the intermediate disturbance hypothesis (IDH) may not be the rule. Even if ecologists could quantify the diversity-disturbance relationship consistent with the IDH, the applicability of the IDH to land management has rarely been addressed. We examined two hypotheses related to the generality and management applicability of the IDH to Mongolian rangeland ecosystems: that the diversity-disturbance relationship varies as a function of landscape condition and that some intermediate scales of grazing can play an important role in terms of sustainable rangeland management through a grazing gradient approach. We quantified the landscape condition of each ecological site using an ordination technique and determined two types of landscape conditions, relatively benign and harsh environmental conditions. At the ecological sites characterized by relatively benign environmental conditions, diversity-disturbance relationships were generally consistent with the IDH and maximum diversity was observed at some intermediate distance from the source of the grazing gradient. In contrast, the IDH was not supported at most but not all sites characterized by relatively harsh environmental conditions. The intermediate levels of grazing were generally located below the ecological threshold representing the points or zones at which disturbance should be limited to prevent drastic changes in ecological conditions, suggesting that there is little “conundrum” with regard to intermediate disturbance in the studied systems in terms of land management. We suggest that the landscape condition is one of the primary factors that cause inconsistencies in diversity-disturbance relationships. The ecological threshold can extend its utility in rangeland management because it also has the compatibility with the maintenance of species diversity. This study thus suggests that some intermediate scales of grazing and ecological thresholds are mutually supportive tools for sustainable management of Mongolian rangelands

    Effect of biorationals and Predatory Mites incontrolling the Two-Spotted Spider Mite (Tetranychus urticae L) on Eggplant field in the Greenhouse

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    The Two-Spotted Spider Mite (TSSM) is a prevalent mite pest found worldwide and is extensively distributed in Mongolian greenhouses. In this study, we conducted a field experiment using predatory mites and botanical pesticides on eggplants infested by TSSM. We observed promising results in terms of reducing pest populations and achieving overall improved outcomes. The experiment took place in a 120 sq.m. greenhouse located at the "Agropark" training-research center of the Mongolian University of Life Sciences. The aim of this experiment was to test the effectiveness of the following treatments in controlling Two-Spotted Spider Mite (TSSM): Treatment A (predatory phytoseiid mites at a ratio of 1:5), Treatment B (predatory phytoseiid mites + Neem), Treatment C (Neem alone), Treatment D (Neem + BEB), and Treatment E (untreated control). The experiment utilized a total of 20 plots, each with a size of 6 square meters, and 24 plants were grown in each plot, resulting in a total of 480 plants. Each plot was replicated four times. To assess TSSM control, mortality rates of TSSM were calculated for each treatment as follows: - Treatment A (Predatory phytoseiid mites): 44.4% to 94.7% - Treatment B (Predatory phytoseiid mites - 1:5 + Neem - 30ml/4.5L of water): 76.3% to 96.3% - Treatment C (Neem - 30ml/4.5L of water): 61.8% to 90.8% - Treatment D (Neem - 30ml/4.5L of water + BEB - 20ml/10L of water): 68.6% to 88.2%. The combination of all these treatments have shown apromising results in controlling TSSM in the greenhouse, significantly reducing the TSSM population, according to our research findings. However, it is important to release the predatory mites after a 5-day interval following the application of botanicals (Neem). We recommend a release of predatory mites (Phytoseiilus persimilis and Amblyseius swirskii) either alone or in combination with botanicals for controlling TSSM in the greenhouse, because it is effective and a safe plant protection measurement to use in the greenhouse

    Alterations in Interleukin-6 and Other Parameters during Open-Heart Surgery

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    Objectives: Cardiopulmonary bypass (CPB) using a heart-lung machine to perform open-heart surgery is known to be associated with numerous pathophysiologic changes in body systems. Soon after beginning extracorporeal circulation, an activation process of certain plasma protein systems occurs as blood contacts the foreign surfaces of the cardiopulmonary bypass circuit. During cardiac surgery with CPB, there is a systemic inflammatory reaction involving an enhanced release of inflammatory cytokines. In this study, we investigated the occurrence of systemic inflammatory response syndrome (SIRS) and the mechanisms that lead to the protraction of SIRS in patients who are operated under CPB. Methods: Blood samples from 27 patients (12 females and 15 males, aged 18-63 years) who underwent CPB were collected before and at several time points after surgery and analyzed for plasma levels of proinflammatory cytokines and white blood cells (WBC). Results: In patients with SIRS, the duration of CPB, interleukin-6 (IL-6) count, and WBC count after aortic declamping were significantly higher. The occurrence of SIRS was significantly correlated with the highest recorded level of IL-6 (OR 1.01, 95% CI 1.00-1.01, p<0.05) and the duration of CPB (r = 0.578, p<0.001). Conclusion: The study findings suggest that the duration of CPB and cytokinemia characterized by high IL-6 levels may play an important role in the development of the SIRS

    Resource Variations across the Landscape Mediate the Impact of Grazing on Vegetation in Mongolian Rangeland under High Climatic Variability

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    Assessment of grazing-induced degradation of arid and semi-arid rangelands with stochastic rainfall regimes is challenging. For the last two decades, rangeland ecologists have been discussing the relative importance of biotic and abiotic factors in controlling vegetation dynamics. According to the non-equilibrium concept, which emerged as a new paradigm to describe ecosystems in highly variable and poorly predictable environments, vegetation dynamics are driven primarily by abiotic factors such as rainfall, rather than by internal biotic regulation (e.g. grazing impact). Although a number of studies have emphasized the non-equilibrium nature of most rangelands, they have produced inconsistent results and there is still no consensus on the relative importance of grazing impact. Alternatively, recent studies have suggested that a continuum of systems exists, rather than a stark dichotomy between equilibrium and non-equilibrium rangelands. Moreover, theoretical studies have predicted that, in addition to climatic variability, resource variations occurring in space and time as a result of landscape heterogeneity should be taken into account in assessments of grazing impact. However, there have been few empirical studies of the role of resource variations in either mitigating or enhancing the impacts of grazing on vegetation. This study explores the impact of grazing strategies on vegetation in Mongolian rangelands under high climatic variability. Specifically, it is focused on key resource areas, defined in terms of the key factor determining livestock population, and thus the ability to forage during drought. Based on the prediction proposed by Illius and O’Connor (1999) that animal numbers are regulated in a density-dependent manner by the limited forage availability in key resource areas, we established and examined the hypothesis that grazing impacts would be greater in key resource areas than in other areas even in Mongolian rangelands

    Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia

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    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross sectional study recruited a total of 50 women, 40–60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.–11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17–99) μg/m3, and 100 (95% CI: 67–187) μg/m3 in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39–297) μg/m3 and 127.8 (95% CI: 86–190) μg/m3 in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant difference in increased BLL could be due to occupational or frequent exposure to other sources of indoor or outdoor air pollution that were not measured. Blood lead levels from our study population are the  study measurements published on women aged 40–60 years of age in Mongoli

    Environmental Factors Controlling Leaf Emergence in Caragana microphylla, a Deciduous Shrub of the Mongolian Steppe

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    Abstract: We examined the effect of temperature and rainfall on the timing of leaf emergence in Caragana microphylla, a representative deciduous shrub found in the Mongolian steppe over a three-year period. Two peaks of leaf emergence were identified, the first of which appeared to be induced by temperature, while the second was controlled by rainfall

    Phylogenetic conservatism and biogeographic affinity influence woody plant species richness–climate relationships in eastern Eurasia

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    Mechanisms underlying species richness patterns remain a central yet controversial issue in biology. Climate has been regarded as a major determinant of species richness. However, the relative influences of different evolutionary processes, (i.e. niche conservatism, diversification rate and time for speciation) on species richness–climate relationships remain to be tested. Here, using newly compiled distribution maps for 11 422 woody plant species in eastern Eurasia, we estimated species richness patterns for all species and for families with tropical and temperate affinities separately, and explored the phylogenetic signals in species richness patterns of different families and their relationships with contemporary climate and climate change since the Last Glacial Maximum (LGM). We further compared the effects of niche conservatism (represented by contemporary‐ancestral climatic niches differences), diversification rate and time for speciation (represented by family age) on variation in the slopes of species richness–climate relationships. We found that winter coldness was the best predictor for species richness patterns of most tropical families while Quaternary climate change was the best predictor for those of most temperate families. Species richness patterns of closely‐related families were more similar than those of distantly‐related families within eudicots, and significant phylogenetic signals characterized the slopes of species richness–climate relationships across all angiosperm families. Contemporary‐ancestral climatic niche differences dominated variation in the relationships between family‐level species richness and most climate variables. Our results indicate significant phylogenetic conservatism in family‐level species richness patterns and their relationships with contemporary climate within eudicots. These findings shed light on the mechanisms underlying large‐scale species richness patterns and suggest that ancestral climatic niche may influence the evolution of species richness–climate relationships in plants through niche conservatism.publishedVersio
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