Papers by Bazartseren Boldgiv
Grazing and ecosystem service delivery in global drylands
Science
Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem service... more Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure.
Metagenetics of fairy rings reveals complex and variable soil fungal communities
Pedosphere
Mongolian journal of biological sciences, 2011
This paper discusses about a phenomenon newly called as the "coauthorship hitchhiking," a term we... more This paper discusses about a phenomenon newly called as the "coauthorship hitchhiking," a term we coined to denote the inclusion of coauthors in peer-reviewed publications without signifi cant intellectual input from these coauthors to the published works. We feel that this phenomenon has become fairly common due to increasing international research interest in Mongolia as international authors include Mongolian researchers as coauthor(s) in their publications. Collaborative work is important and indeed required to advance knowledge frontier, but it needs signifi cant input from all coauthors to be a truly collaborative research output, namely a scientifi c publication. Although the coauthorship hitchhiking is benefi cial to career of individual researchers, it is detrimental to overall improvement of scientifi c thinking in the country. The authorship should be limited to those who have substantially contributed to the work and who have a shared responsibility for the results.
Effects of grazing on macro-moth assemblages in two different biomes in Mongolia
Ecological Indicators, 2021
Scientific Reports, 2021
Little is known about the diversity and distribution patterns of moths along latitudinal gradient... more 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...
Journal of Vegetation Science, 2019
QuestionsWe asked how plant community composition responded to experimentally produced warmer and... more QuestionsWe asked how plant community composition responded to experimentally produced warmer and drier climate conditions at the landscape scale with existing variation in local species composition and environmental conditions. We aimed to identify changes in community composition overall and the species with greatest response in abundance, and hypothesized that locally restricted species may be more sensitive to warming than more widespread species within the landscape based on the assumption that they have a narrower niche breadth with respect to environmental conditions.LocationSemiarid, northern Mongolian steppe.MethodsOpen‐top passive warming chambers (OTCs) elevated temperatures at two slope locations that differed in elevation, degree of slope, environmental conditions, and species composition. The OTC treatment was crossed with watering on the drier upper slope. Community composition differences among treatments were examined using canonical analysis of principal coordinate...
Environmental Earth Sciences, 2017
In addition to the total amount of precipitation, the number, type and duration of rain events pl... more In addition to the total amount of precipitation, the number, type and duration of rain events play a critical role in hydrological cycle, land surface processes, vegetation and land cover dynamics in such semi-arid regions as Mongolia where water availability is the main determinant of ecosystem functioning and services. However, only a limited number of studies have so far focused on certain aspects of changes in rain types and durations for Mongolia as a whole, while a relatively large number of studies have examined trends observed in total annual precipitation for the country. In the present study, we evaluated changes in not only the amount, but also in the number and total duration of rain types using the data on start-to-end times of all rain events from 55 meteorological stations scattered throughout Mongolia between 1981 and 2014, a period for which this type of analysis was made possible for the first time. Our study confirms that there has been no significant change in the amount of mean summer precipitation for almost all parts of the country for the last 34 years, with only a few stations showing a significant decreasing trend. In terms of rain types, the number and duration of convective rains have increased, while those of stratiform rain events have decreased over Mongolia, a trend that is more pronounced around Khangai mountain area in central Mongolia and south-eastern desert steppe and eastern steppe, suggesting a possible transition from stratiform rains to convective rains. The findings of this research imply that increasing temperature and altered rain type ratios may affect each other as the decreasing number and duration of stratiform rain events allow for progressively longer sunshine period, possibly feeding back to the increased temperature. The release of this latent heat fuelling the upward movement of moisture and producing the convective rains could be one of the reasons of the significant rise in convective rain frequency for the study period. The observed changes in rain patterns have significant implications in ecosystem functioning and resource management. Keywords Precipitation patterns Á Mongolia Á Convective rain Á Stratiform rain Á Number and duration of rain events This article is part of a Topical Collection in Environmental Earth Sciences on ''Water in Central Asia'', guest edited by Daniel Karthe,
Ecological Indicators, 2017
Overgrazing has become an ecological problem in the wide steppes of Mongolia due to rapid livesto... more Overgrazing has become an ecological problem in the wide steppes of Mongolia due to rapid livestock growth in the last two decades. Species diversity and productivity of biological communities, along with information on the presence and absence of certain species, can be indicators of environmental health to assess the state of pasture. Moths have been used as indicator species in various studies as they are abundant in many different habitats and sensitive to environmental changes. We used moths as indicators for pasture degradation in the Mongolian steppe for the first time. In this study, we investigated how overgrazing affected moth species diversity, identified indicator species for degraded pasture and collected baseline data to study distribution and migration of moths under future climate change. To accomplish these objectives, we compared moth diversity in plots with different grazing intensity in two locations in central Mongolia. Species diversity of moths was two times higher in lightly grazed plots than in medium-grazed and heavily grazed plots. Thus we conclude that pasture degradation affected moth diversity negatively. As a result of indicator species analysis we identified four indicator species for heavily grazed plots (Leucoma salicis, Autographa buraetica, Mythimna impura and Pelochrista arabescana) and seven indicator species for lightly grazed plots (Panchrysia dives, Gastropacha quercifolia, Selagia argyrella, Lymantria dispar, Mythimna conigera, Stigmatophora micans and Perconia strigillaria). The meadow moth Loxostege sticticalis was most abundant in all plots. In this study we collected a total of 115 species from Ikhtamir and Undurshireet as baseline data in order to study distribution and migration of moths under future climate change.
Journal of Species Research, 2013
Typical of large, oligotrophic lakes, Lake Hövsgöl, Mongolia, exhibits complex morphometry which ... more Typical of large, oligotrophic lakes, Lake Hövsgöl, Mongolia, exhibits complex morphometry which should support a spatially heterogeneous community of benthic macroinvertrates. The lake also exhibits a broad range of land uses. Based on the variation in land use and complex physical habitat of the lake (e.g. substrate variation and presence of affluent streams in bays), we asked two questions. First, does density of total benthic macroinvertebrates vary between different bays in Lake Hövsgöl? Second, does density of individual benthic taxa vary by bay? Samples collected in 1997, the last year for benthic sampling of the lake, were designed to test for variation in macroinvertebrate density between bays and can now be used to establish baseline variation in density for future studies. A total of 56 Ponar grab samples were analyzed from six bays in Lake Hövsgöl. Results of a general linear model analysis of variance showed that total density of macroinvertebrates varied only slightly between bays of the lake, but that most individual taxa showed significant variation between bays. Variation in density for most taxa was linked to substrate composition rather than other geographic or physical variables in the lake. Recent increases in grazing intensity and ecotourism along the shores should be managed to reduce the nutrient load into the lake to avoid impairment of the benthic biota of this unique, ancient ecosystem.
Climatic Change, 2016
Increases in extreme record-breaking daily precipitation events have accompanied warming temperat... more Increases in extreme record-breaking daily precipitation events have accompanied warming temperatures, causing increased flooding in many areas of the World, but are not well documented for arid and semi-arid regions. In semi-arid Mongolia, where warming has been over 2 °C from 1940 to 2008, nomadic herders described their concerns over an increase in the number of hot days and a shift from multi-day gentle rains to heavy rains lasting less than one hour that damage their pastures, animals, gers and people, suggesting a transition from stratiform rains to convective storms. The brief intense rains described by the herders, are not seen in daily precipitation data typically reported by meteorological stations, and here the correlation between fine-scale rainfall readings and thunderstorm activity were used to hindcast brief heavy rains. From 2008 to 2012, an automated weather station in Dalbay Valley at Lake Hövsgöl, Mongolia, recording at 5-min intervals, detected at least 40 heavy sub-daily summer rains each lasting less than 40 min. Heavy rains in Dalbay were correlated with thunderstorm activity and were 2.5 times more likely to occur when thunderstorms were reported within the previous 24 h at the Hatgal meteorological station (80 km to the southwest
Journal of Vegetation Science, 2015
Questions: How does plant productivity and community composition in the mountain steppe of northe... more Questions: How does plant productivity and community composition in the mountain steppe of northern Mongolia respond to increased precipitation? Do these changes differ with the timing of precipitation? Location: Mountain steppe at ecotone between steppe and taiga, Dalbay Valley, Lake H€ ovsg€ ol International Long Term Ecological Research Site (ILTER), northern Mongolia (51°01.405 0 N 100°45.600 0 E). We experimentally applied water, representing a 25% increase in growing season precipitation, to plots at the drier end of a topographic moisture gradient in mountain steppe vegetation. In one treatment, supplemental water was applied weekly for four growing seasons. A second treatment started in year 2, in which three times the weekly supplement of water was applied once every 3 wk for three growing seasons. Vascular plant species presence and percentage cover were used to assess water treatment effects on forb and graminoid composition. Plant species biomass and percentage cover in year 4 was used to determine treatment effects on total productivity, and on the abundances of legumes, non-leguminous forbs and graminoids, separately. Lichen, litter and root biomass, plant available N, P and K, and seedling demography were also examined in year 4. Weekly watering changed the relative abundances of forbs and increased the total abundance of legumes and non-leguminous forbs measured either as percentage cover or biomass. The 3-wk watering treatment did not induce the same changes in forb composition or abundance of functional groups but produced less compositional change in graminoids compared to controls. Neither treatment increased total productivity. Three-week watering increased plant available P and decreased litter. Seedling emergence, survival and size increased with one or both watering treatments. In mountain steppe, precipitation increases will produce immediate changes in composition and abundance of forbs, including legumes, but not in graminoids or total productivity. The steppe is more responsive to regular incremental increases in precipitation than to less frequent, larger storms whose effect would be timing-dependent within the short, temperature-limited growing season. Longer term investigations need to be conducted to explore if further lagged responses to water addition occur.
Science, 2015
Grassland diversity and ecosystem productivity The relationship between plant species diversity a... more Grassland diversity and ecosystem productivity The relationship between plant species diversity and ecosystem productivity is controversial. The debate concerns whether diversity peaks at intermediate levels of productivity—the so-called humped-back model—or whether there is no clear predictable relationship. Fraser et al. used a large, standardized, and geographically diverse sample of grasslands from six continents to confirm the validity and generality of the humped-back model. Their findings pave the way for a more mechanistic understanding of the factors controlling species diversity. Science , this issue p. 302
Community-level pollination: Biotic and abiotic determinants and temporal variation
ABSTRACT Background/Question/Methods Community-level pollination studies have increasingly used n... more ABSTRACT Background/Question/Methods Community-level pollination studies have increasingly used network analysis to describe the visitation of pollinator species to plant species. Many focus on network topology rather than the basic biotic and abiotic factors shaping plant-pollinator interactions. Our work is motivated by sources of variation in plant-pollinator interactions: time, temperature, and availability of different flowering species. This pursuit holds great potential to enhance our understanding of factors determining pollination services. Moreover, while most plant-pollinator interaction studies have been conducted in warm or temperate climates, our study takes place in the cold-climate steppe mountain in northern Mongolia. The data were collected within a valley from permanent observations plots set up at two elevations, 1670 m and 1800 m a.s.l. We counted the total number of available flowers for each plant species and observed pollinators during three diurnal periods, which was repeated 11 times across the summer. Additionally, we measured air temperature at the two elevations. At each elevation we determined how pollinator visitation varies diurnally and throughout the summer months. We also constructed a hypothetical path model to determine how much of the variation in pollinator visitation can be explained by air temperature and floral abundance. Results/Conclusions Pollinator visits varied throughout the day and throughout the season. Visits were highest in frequency during the mid-afternoon time period (1200-1530) at both elevations. There was a large amount of variation in pollinator visitation throughout the summer at both elevations; at the lower elevation, pollinator visitation was highest during the last two weeks of July while at the higher elevation, visitation was highest slightly earlier, during the first two weeks of July. Path analysis showed that, in the higher elevation, temperature and floral abundance both significantly explained pollinator visitation, (β = 0.42 and β = 0.37, respectively), but at the lower elevation, only temperature was significant (β = 0.66). Visitation frequency and the biotic and abiotic factors contribution to pollinator visitation vary within the landscape. Studies should be aware of landscape-wide variation and account for this when studying plant-pollinator interactions.
Climate change and grazing interact to alter flowering patterns in the Mongolian steppe
Oecologia, 2014
Socio-economic changes threaten nomadic pastoralism across the world, changing traditional grazin... more Socio-economic changes threaten nomadic pastoralism across the world, changing traditional grazing patterns. Such land-use changes will co-occur with climate change, and while both are potentially important determinants of future ecosystem functioning, interactions between them remain poorly understood. We investigated the effects of grazing by large herbivores and climate manipulation using open-top chambers (OTCs) on flower number and flowering species richness in mountain steppe of northern Mongolia. In this region, sedentary pastoralism is replacing nomadic pastoralism, and temperature is predicted to increase. Grazing and OTCs interacted to affect forb flowering richness, which was reduced following grazing removal, and reduced by OTCs in grazed plots only. This interaction was directly linked to the soil moisture and temperature environments created by the experimental treatments: most species flowered when both soil moisture and temperature levels were high (i.e. in grazed plots without OTCs), while fewer species flowered when either temperature, or moisture, or both, were low. Removal of grazing increased the average number of graminoid flowers produced at peak flowering in Year 1, but otherwise grazing removal and OTCs did not affect community-level flower composition. Of four abundant graminoid species examined individually, three showed increased flower number with grazing removal, while one showed the reverse. Four abundant forb species showed no significant response to either treatment. Our results highlight how climate change effects on mountain steppe could be contingent on land-use, and that studies designed to understand ecosystem response to climate change should incorporate co-occurring drivers of change, such as altered grazing regimes.
Focus on Geography, 2002
The International Association of Theoretical and Applied Limnology (Societas Internationalis Limn... more The International Association of Theoretical and Applied Limnology (Societas Internationalis Limnologiae Theoreticae et Applicatae, SIL) promotes and communicates new and emerging knowledge among limnologists to advance the understanding of inland aquatic ecosystems and their management.
Emerging Infectious Diseases, 2013
dence of genetically distinct hantaviruses (family Bunyaviridae) in multiple species of shrews an... more dence of genetically distinct hantaviruses (family Bunyaviridae) in multiple species of shrews and moles (order Soricomorpha, families Soricidae and Talpidae) across 4 continents (1-7) suggests that soricomorphs, rather than rodents (order Rodentia, families Muridae and Cricetidae), might be the primordial hosts (6,7). Recently, the host range of hantaviruses has been further expanded by the discovery that insectivorous bats (order Chiroptera) also serve as reservoirs (8,9). Conjecturing that Mouyassué virus in the banana pipistrelle (Neoromicia nanus) in Côte d'Ivoire (8) and Magboi virus (MGBV) in the hairy split-faced bat (Nycteris hispida) in Sierra Leone (9) represent a much broader geographic distribution of bat-borne hantaviruses, we analyzed tissues from bats captured in Mongolia and Vietnam. Total RNA was extracted from 51 lung tissues, collected in RNAlater Stabilization Reagent (QIAGEN, Valencia, CA, USA), from insectivorous bats, representing 7 genera and 12 species, captured in Mongolia and Vietnam. cDNA was then prepared by using PrimeScript II 1st strand cDNA Synthesis Kit (Takara Bio, Otsu, Shiga, Japan) for reverse transcription PCR (RT-PCR), and using oligonucleotide primers previously designed for amplification of soricid-and talpidborne hantaviruses (1-7). A novel hantavirus, designated Xuan Son virus (XSV), was detected in 1 of 5 Pomona roundleaf bats (Hipposideros pomona) by using a heminested large (L)-segment primer set
Effects of experimental warming on soil temperature, moisture and respiration in northern Mongolia
ABSTRACT Mean annual air temperature in the Lake Hövsgöl region of northern Mongolia has increase... more ABSTRACT Mean annual air temperature in the Lake Hövsgöl region of northern Mongolia has increased by 1.8 °C over the last 40 years, greater than global average temperature increases. A decrease of soil moisture due to changes in precipitation regime is also predicted over the northern region of Mongolia. Warmer temperatures generally result in higher soil CO2 efflux, but responses of soil efflux to climate change may differ among ecosystems due to response variations in soil temperature and moisture regime. The objectives of our study were to examine the environmental responses (soil temperature and moisture) to experimental warming, and to test responses of soil CO2 efflux to experimental warming, in three different ecozones. The experimental site is located in Dalbay Valley, on the eastern shore of Lake Hövsgöl in northern Mongolia (51.0234° N 100.7600° E; 1670 m elevation). Replicate plots with ITEX-style open-top passive warming chambers (OTC) and non-warmed control areas were installed in three ecosystems: (1) semi-arid grassland on the south-facing slope not underlain by permafrost, (2) riparian zone, and (3) larch forest on the north-facing slope underlain by permafrost. Aboveground air temperature and belowground soil temperature and moisture (10 and 20 cm) were monitored using sensors and dataloggers. Soil CO2 efflux was measured periodically using a portable infra-red gas analyzer with an attached soil respiration chamber. The warming chambers were installed and data collected during the 2009 and 2010 growing seasons. Passive warming chambers increased nighttime air temperatures; more so in grassland compared to the forest. Increases in daytime air temperatures were observed in the grassland, but were not significant in the riparian and forest areas. Soil temperatures in warmed plots were consistently higher in all three ecozones at 10 cm depth but not at 20 cm depth. Warming chambers had a slight drying effect in the grassland, but no consistent effect in forest and riparian areas. Measured soil CO2 efflux rates were highest in riparian area, and lowest in the grassland. Initial results of soil efflux measurements suggest that the effect of warming treatment significantly depends on the ecosystem type: soil efflux rates differed between warming treatments in forest plots, but not in riparian and grassland plots.
Lake Khovsgol the Blue Pearl of Mongolia
Focus, 2002
... affected by loss of forest trees in their watersheds or by commercial and intensive sports fi... more ... affected by loss of forest trees in their watersheds or by commercial and intensive sports fishing. ... can guess from evidence that Khovsgol is a rarity among the world's lakes, an "ancient" lake. Khovsgol is in the Baikal Rift system, and similar tectonic basins hold the doxen oldest ...
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Papers by Bazartseren Boldgiv