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•We quantified pelagic microplastic pollution in Lake Hovsgol, Mongolia.•Lake Hovsgol is more polluted with microplastics than Lakes Huron and Superior.•Microplastics came from ...consumer goods; no microbeads/few pellets were observed.•Microplastics were sourced from population centers and distributed by the winds.•Without waste management, even small populations can heavily pollute large lakes.
Despite the large and growing literature on microplastics in the ocean, little information exists on microplastics in freshwater systems. This study is the first to evaluate the abundance, distribution, and composition of pelagic microplastic pollution in a large, remote, mountain lake. We quantified pelagic microplastics and shoreline anthropogenic debris in Lake Hovsgol, Mongolia. With an average microplastic density of 20,264 particles km−2, Lake Hovsgol is more heavily polluted with microplastics than the more developed Lakes Huron and Superior in the Laurentian Great Lakes. Fragments and films were the most abundant microplastic types; no plastic microbeads and few pellets were observed. Household plastics dominated the shoreline debris and were comprised largely of plastic bottles, fishing gear, and bags. Microplastic density decreased with distance from the southwestern shore, the most populated and accessible section of the park, and was distributed by the prevailing winds. These results demonstrate that without proper waste management, low-density populations can heavily pollute freshwater systems with consumer plastics.
Abstract
Little is known about the diversity and distribution patterns of moths along latitudinal gradients. We studied macro-moths in Mongolia along an 860 km latitudinal climatic gradient to gain ...knowledge on community composition, alpha, beta, and gamma diversity as well as underlying factors, which can be used as baseline information for further studies related to climate change. We identified 236 species of moths of ten families. Our study shows that the diversity of moths increased with the latitude, i.e., low species richness in the south and higher richness in the north. Moth community composition changed along the gradient, and we revealed a breakpoint of beta diversity that divided grassland and desert communities. In the desert, beta diversity was driven by species loss (i.e., nestedness), and few tolerant species existed with high abundance. In contrast, in the grassland, beta diversity was driven by species replacement with more unique species, (i.e., species which occurred only in one site). We found the lowest species diversity in the transitional zones dominated by few generalist species such as
Agrotis ripae
and
Anarta trifolii.
Low precipitation and an increasing number of grazing goats are drivers of species loss. We suggest different conservation strategies regarding the contrasting patterns of beta diversity in desert and grassland.
The Eneolithic Botai culture of the Central Asian steppes provides the earliest archaeological evidence for horse husbandry, ~5500 years ago, but the exact nature of early horse domestication remains ...controversial. We generated 42 ancient-horse genomes, including 20 from Botai. Compared to 46 published ancient- and modern-horse genomes, our data indicate that Przewalski's horses are the feral descendants of horses herded at Botai and not truly wild horses. All domestic horses dated from ~4000 years ago to present only show ~2.7% of Botai-related ancestry. This indicates that a massive genomic turnover underpins the expansion of the horse stock that gave rise to modern domesticates, which coincides with large-scale human population expansions during the Early Bronze Age.
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•Moths followed a dynamic equilibrium model.•Grazing did not affect moth diversity in desert, but in grassland.•Specialist and generalist moths showed different responses in ...contrasting biomes.•At intermediate vegetation richness species turnover dominated.•In grassland, more indicator species were found than in desert.
Intensive land use, e.g. pastoralism, decreases biodiversity and leads to homogenization of habitats. However, the effect of land-use changes differs under varying climatic conditions. Thus, it is essential to study how land use affects biodiversity on a large scale. Moreover, species respond differently to environmental changes depending on whether they are specialists or generalists. We studied macro-moths in Mongolian pastures under two different grazing regimes (grazed and less grazed plots) in ten study sites that belong to two distinct biomes along a large-scale latitudinal gradient from desert to steppe. We explored 1) how livestock grazing affects macro moth diversity, species composition, and species richness, 2) how specialist and generalist moths respond to grazing in desert (Desert and xeric shrublands) and grassland (Temperate grasslands, savannas & shrublands). Moths are sensitive to environmental changes and suitable bioindicators. We also revealed a) indicators of grazing and b) indicators representative for certain sections of the latitudinal gradient. Totally, we recorded 80 species in the desert and 202 species in grassland in 2018 and 2019, which were DNA barcoded. In the desert, grazing did not affect macro-moth diversity, whereas grassland was negatively affected. However, not all moth families showed the same response to grazing. Species diversity, species richness, and abundance of Erebidae, Geometridae, and Noctuidae were significantly higher in the less grazed plots. Further, species dissimilarity between grazed and less grazed plots was mainly due to species replacement rather than species loss. In the desert, the species richness of both specialist and generalist moths did not differ between grazed and less grazed plots; in contrast, in grassland, the species richness of both groups was higher in less grazed plots. We found two indicator species of grazing in the desert: Hyles chuvilini in less grazed, and Cucullia splendida in grazed pasture. In grassland, we found ten indicator species exclusively for less grazed pastures: Catarhoe cuculata, Euxoa ochrogaster, Lacanobia thalassina, Megalycinia strictaria, Mythimna comma, Polia bombycina, Rhyacia simulans, Sideridis kitti, Sideridis egena, and Smerinthus caecus. These indicator species can be used as references for habitat quality and for moths' dispersal due to climate change in future studies. Among the environmental variables, plant species richness, altitude, and livestock number were the most important variables. Species composition of high altitudes in the desert was distinct, and higher species richness in this area indicated that high altitudes could serve as a refuge area during global warming and should receive conservation management.
Climate change is affecting virtually all environments in the world today. The Central Asian mountains, where livestock herding is the main source of livelihood, are among the environments predicted ...to be most affected. In this paper, we use meteorological records and herder perceptions to improve the understanding of climate change and examine how different climate change scenarios will affect herder livelihoods in the Tost-Tosonbumba Nature Reserve of southern Mongolia. Herders with generation-long herding experience perceived that there had been changes in all eight meteorological variables examined in this study between 1995 and 2015, including winter temperature, summer temperature, summer precipitation, frequency of intense rain, frequency of drizzle rain, wind speed, number of windy days, and snow cover. Herder perceptions and meteorological data showed the same patterns for 3 of the 8 variables at
α
= 0.05 and for 5 of the 8 variables at
α
= 0.10. Herders also predicted that all 9 climate change scenarios presented would have negative impacts on their practices and livelihoods. Our work suggests that herder perceptions of climate change can provide important information on changes in the climate and insights on factors that put their livelihoods at risk.
Abstract
Climate change is projected to increase the aridity of semi-arid ecosystems, including Mongolian grasslands (MG), which provide ecosystem services that support food supply and pastoralist ...lifestyle. Here, we conducted a grid-scale (0.5° × 0.5°) probabilistic risk assessment of MG under climate change for 40 years (1976–2015) based on probability theory. We evaluated changes of risk (impacts) and vulnerability of MG to drought between the recent two decades R20 = 1996–2015 and the previous two decades P20 = 1976–1995. The risk is quantified as the product of the probability of hazardous drought and ecosystem vulnerability. The probability of hazardous drought is defined from the Standardized Precipitation–Evapotranspiration Index. Vulnerability is defined as the expected differences of key ecosystem variables between years with and without hazardous conditions. The ecosystem variables are productivity (peak aboveground biomass, net primary productivity, and leaf area index) and root-zone plant-available soil moisture, simulated with a process-based vegetation model Organizing Carbon and Hydrology in Dynamic Ecosystems-Grassland Management validated with field observations of biomass and soil moisture. Results reveal that MG experienced more frequent hazardous droughts with rapid warming and slight drying during R20 aggravated by ever-increasing grazing intensity (34% compared to P20), which resulted in a reduction in soil water availability and grassland productivity, particularly in northeastern areas (20%–65%). The risk of drought to productivity increased by 10% between P20 and R20 over extended areas, particularly in northcentral and northeast Mongolia. The increase in the risk to MG was mainly caused by climate change-induced increase in the probability of hazardous drought and, to a lesser extent, by the increasing vulnerability. Recent droughts modify the risk to grasslands, particularly in northcentral and northeast Mongolia, suggesting that these regions need strategic management for both adaptation and ecosystem conservation to cope with climate change impacts.
The bio-geographical composition and spatial distribution patterns of dytiscid assemblages in Mongolia are relatively unexplored. In this study, we compiled a list of 99 dytiscid species belonging to ...20 genera and five subfamilies recorded in Mongolia and investigated species richness, spatial distribution and bio-geographical composition of the Mongolian dytiscid fauna. This study encompasses the information of currently recorded species and their geographic localities in Mongolia based on our own data and literature sources. We examined how dytiscid species richness was related to sub-basins of surface water network, as well as to geographical elevations within Mongolia. The majority of the Mongolian dytiscid fauna was associated with the sub-basins belonging to Arctic Ocean (80 species, 80.8%) and Central Asian Inland (60 species, 60.6%) basins. Only a few species of dytiscids belonged to the remaining river basins. Species richness of dytiscids and total area of sub-basins were not correlated, but species composition of dytiscids differed significantly among the sub-basins. We observed that most of the species (77 species or 77.8% of total fauna) were recorded in a wide range of elevations and mid-altitudes (1000-2000 m a.s.l.) and showed the greatest diversity of dytiscids. Regarding the bio-geographical composition, species with wide geographical distributions (27.3% of dytiscids), were Palearctic species, while species of Arctic origin (21.2%) together with Boreal elements (16.2%) comprised a large proportion of the dytiscid fauna in Mongolia.
The Mongolian Gobi-Eastern Steppe Ecosystem is one of the largest remaining natural drylands and home to a unique assemblage of migratory ungulates. Connectivity and integrity of this ecosystem are ...at risk if increasing human activities are not carefully planned and regulated. The Gobi part supports the largest remaining population of the Asiatic wild ass (Equus hemionus; locally called "khulan"). Individual khulan roam over areas of thousands of square kilometers and the scale of their movements is among the largest described for terrestrial mammals, making them particularly difficult to monitor. Although GPS satellite telemetry makes it possible to track animals in near-real time and remote sensing provides environmental data at the landscape scale, remotely collected data also harbors the risk of missing important abiotic or biotic environmental variables or life history events. We tested the potential of animal born camera systems ("camera collars") to improve our understanding of the drivers and limitations of khulan movements. Deployment of a camera collar on an adult khulan mare resulted in 7,881 images over a one-year period. Over half of the images showed other khulan and 1,630 images showed enough of the collared khulan to classify the behaviour of the animals seen into several main categories. These khulan images provided us with: i) new insights into important life history events and grouping dynamics, ii) allowed us to calculate time budgets for many more animals than the collared khulan alone, and iii) provided us with a training dataset for calibrating data from accelerometer and tilt sensors in the collar. The images also allowed to document khulan behaviour near infrastructure and to obtain a day-time encounter rate between a specific khulan with semi-nomadic herders and their livestock. Lastly, the images allowed us to ground truth the availability of water by: i) confirming waterpoints predicted from other analyses, ii) detecting new waterpoints, and iii) compare precipitation records for rain and snow from landscape scale climate products with those documented by the camera collar. We discuss the added value of deploying camera collars on a subset of animals in remote, highly variable ecosystems for research and conservation.
Globally, soil respiration is one of the largest fluxes of carbon to the atmosphere and is known to be sensitive to climate change, representing a potential positive feedback. We conducted a number ...of field experiments to study independent and combined impacts of topography, watering, grazing and climate manipulations on bare soil and vegetated soil (i.e., ecosystem) respiration in northern Mongolia, an area known to be highly vulnerable to climate change and overgrazing. Our results indicated that soil moisture is the most important driving factor for carbon fluxes in this semi-arid ecosystem, based on smaller carbon fluxes under drier conditions. Warmer conditions did not result in increased respiration. Although the system has local topographical gradients in terms of nutrient, moisture availability and plant species, soil respiration responses to OTC treatments were similar on the upper and lower slopes, implying that local heterogeneity may not be important for scaling up the results. In contrast, ecosystem respiration responses to OTCs differed between the upper and the lower slopes, implying that the response of vegetation to climate change may override microbial responses. Our results also showed that light grazing may actually enhance soil respiration while decreasing ecosystem respiration, and grazing impact may not depend on climate change. Overall, our results indicate that soil and ecosystem respiration in this semi-arid steppe are more sensitive to precipitation fluctuation and grazing pressure than to temperature change.
•Field experiment on topography, watering, grazing and climate in northern Mongolia•Measured soil moisture and temperature, and bare and vegetated soil respiration•Respiration responses to chambers differed between upper and lower slopes•Grazing enhanced bare soil respiration but decreased vegetated soil respiration•Soil respiration in semi-arid steppe more sensitive to moisture than temperature
Climate change is expected to modify plant assemblages in ways that will have major consequences for ecosystem functions. How climate change will affect community composition will depend on how ...individual species respond, which is likely related to interspecific differences in functional traits. The extraordinary plasticity of some plant traits is typically neglected in assessing how climate change will affect different species. In the Mongolian steppe, we examined whether leaf functional traits under ambient conditions and whether plasticity in these traits under altered climate could explain climate‐induced biomass responses in 12 co‐occurring plant species. We experimentally created three probable climate change scenarios and used a model selection procedure to determine the set of baseline traits or plasticity values that best explained biomass response. Under all climate change scenarios, plasticity for at least one leaf trait correlated with change in species performance, while functional leaf‐trait values in ambient conditions did not. We demonstrate that trait plasticity could play a critical role in vulnerability of species to a rapidly changing environment. Plasticity should be considered when examining how climate change will affect plant performance, species' niche spaces, and ecological processes that depend on plant community composition.
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