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Climate change will affect the way biodiversity influences the stability of plant communities. Although biodiversity, associated species asynchrony, and species stability could enhance community stability, the understanding of potential nonlinear shifts in the biodiversity-stability relationship across a wide range of aridity (measured as the aridity index, the precipitation/potential evapotranspiration ratio) gradients and the underlying mechanisms remain limited. Using an 8-year dataset from 687 sites in Mongolia, which included 5496 records of vegetation and productivity, we found that the temporal stability of plant communities decreased more rapidly in more arid areas than in less arid areas. The result suggests that future aridification across terrestrial ecosystems may adversely affect community stability. Additionally, we identified nonlinear shifts in the effects of species richness and species synchrony on temporal community stability along the aridity gradient. Species synchrony was a primary driver of community stability, which was consistently negatively affected by species richness while being positively affected by the synchrony between C3 and C4 species across the aridity gradient. These results highlight the crucial role of C4 species in stabilizing communities through differential responses to interannual climate variations between C3 and C4 species. Notably, species richness and the synchrony between C3 and C4 species independently regulated species synchrony, ultimately affecting community stability. We propose that maintaining plant communities with a high diversity of C3 and C4 species will be key to enhancing community stability across Mongolian grasslands. Moreover, species synchrony, species stability, species richness and the synchrony between C3 and C4 species across the aridity gradient consistently mediated the impacts of aridity on community stability. Hence, strategies aimed at promoting the maintenance of biological diversity and composition will help ecosystems adapt to climate change or mitigate its adverse effects on ecosystem stability., (Global Change Biology© 2024 The Author(s). Global Change Biology published by John Wiley & Sons Ltd.)

Climate change is causing more frequent and intense heatwaves. Therefore, it is important to understand how heatwaves affect the terrestrial carbon cycle, especially in grasslands, which are especially susceptible to climate extremes. This study assessed the impact of naturally occurring, simultaneous short-term heatwaves on CO 2 fluxes in three ecosystems on the Mongolia Plateau: meadow steppe (MDW), typical steppe (TPL), and shrub-grassland (SHB). During three heatwaves, net ecosystem productivity (NEP) was reduced by 86 %, 178 %, and 172 % at MDW, TPL, and SHB, respectively. The changes in ecosystem respiration, gross primary production, evapotranspiration, and water use efficiency were divergent, indicating the mechanisms underlying the observed NEP decreases among the sites. The impact of the heatwave in MDW was mitigated by the high soil water content, which enhanced evapotranspiration and subsequent cooling effects. However, at TPL, insufficient soil water led to combined thermal and drought stress and low resilience. At SHB, the ecosystem's low tolerance to an August heatwave was heavily influenced by species phenology, as it coincided with the key phenological growing phase of plants. The potential key mechanism of divergent NEP response to heatwaves lies in the divergent stability and varying importance of environmental factors, combined with the specific sensitivity of NEP to each factor in ecosystems. Furthermore, our findings suggest that anomalies in soil environment, rather than atmospheric anomalies, are the primary determinants of NEP anomalies during heatwaves. This challenges the conventional understanding of heatwaves as a discrete and ephemeral periods of high air temperatures. Instead, heatwaves should be viewed as chronologically variable, compound, and time-sensitive environmental stressors. The ultimate impact of heatwaves on ecosystems is co-determined by a complex interplay of environmental, biological, and heatwave features., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Larix gmelinii is an important ecological construction tree species in northern China, and its carbon storage and distribution characteristics are of great significance for evaluating the carbon balance and climate effect of forest ecosystems. However, at present, there is a lack of systematic research on the carbon storage of L. gmelinii forests and its change with forest age. In this paper, the biomass and carbon density of L. gmelinii forests at different ages and the distribution of carbon storage in vegetation and soil were analyzed by means of sample plot investigation and model simulation in the northern forest area of Daxing'anling, Inner Mongolia. The influence of forest age on the carbon storage and carbon pool distribution characteristics of L. gmelinii forests and the mechanism of influencing factors were also discussed. Results show that: (1) As forest age increased, the total amount of carbon pools initially increased and then decreased, and the distribution structure of carbon pools showed a trend of transferring from soil to trees. The proportion of soil carbon pools gradually decreased (72.72-51.87%), while the proportion of tree carbon pools gradually increased (23.98-39.33%). The proportion of shrub and grass carbon pools was also relatively stable (0.51-0.53%). (2) Soil carbon pool was affected by the input and output of soil organic matter, soil depth, soil carbon content, and soil bulk density, shrub-grass carbon pool was affected by undergrowth light conditions and soil moisture, litter carbon pool was affected by litter input and output, and the carbon pool of trees was affected by the growth rate and carbon balance of trees. This study provides scientific basis and management suggestions for the carbon storage capacity of L. gmelinii forests and the mitigation of climate change. [ABSTRACT FROM AUTHOR]

The Belt and Road Initiative (BRI) offers great opportunities for China and Mongolia to collaborate on tackling climate change. However, few studies have focused on China--Mongolia collaboration on climate change under the BRI's sustainable development framework; in particular, studies have neglected the factors and feasibility of collaboration. Focusing on China and Mongolia, this study first discusses the evolution of legislation in China and Mongolia in the context of dealing with climate change and then explores the factors that influence China--Mongolia collaboration on climate change mitigation from the perspectives of climate environmental governance and energy development at the domestic level. Subsequently, the paper analyzes the Paris Agreement to identify international factors that can influence climate change cooperation between the two countries. Finally, based on the results of this analysis, this paper identifies geopolitical relations, the energy supply, technology and investment, and the demand for a transition to sustainable development as the main driving forces for China and Mongolia to collaborate on climate change mitigation under the BRI. Finally, the paper concludes that collaboration between the two countries is highly feasible. [ABSTRACT FROM AUTHOR]

The freshwater Buir Lake in Khalkh Gol soum, Dornod aimag, is located (47° 51' 47° N, 117° 51' 29° E) on the border of Mongolia and Inner Mongolia, China. The northwest and northeast part of the lake is swampy, and is flat in the rest part. This research paper reveals the lithology and some major elements content (SiO2, Al2O3, TiO2, Fe2O3, MgO, K2O, Na2O, MnO and P2O5) of the core sediments and their distribution along the depth and the Chemical Index of Alteration (CIA), which will be a significant factor in restoring environmental change. According to the data of analysis of major elements of Buir Lake sediments, the concentration of SiO2 ranges from 42.92 to 58.29%; Al2O3 = 9.25-12.83%; Fe2O3 = 3.66-4.79%; TiO2 = 0.46-0.62%; MnO = 0.08-0.13%; CaO = 5.73-11.56%; MgO = 1.34-1.81%; Na2O = 0.72-1.50%; K2O = 1.58-2.31%; and P2O5 = 0.14-0.26% respectively. The chemical index of alteration is basically the same as the distribution of SiO2, Al2O3, TiO2, Fe2O3, MgO, K2O and Na2O in the sediments of the lake, but their content at 32.5 cm interval of the core sharply decreases and also increases. This is perhaps due to global climate change. The content and distribution patterns of water-soluble elements, such as CaO, MnO, and P2O5, are negatively correlated with the chemical index of alteration. These lead to conclude that major elements of Buir Lake sediment and Chemical Index of Alteration are closely related to climatic changes in eastern Mongolia pertaining to the Upper Pleistocene and the Holocene epochs. [ABSTRACT FROM AUTHOR]

Herders in Mongolia have adapted to changing environmental conditions over thousands of years through innovations in pasture and herd management practices, knowledge, collective institutions and mobility strategies, yet they now face unprecedented climate risks threatening their livelihoods, economies and ways of life. This paper presents the results of a study into how herder communities adapt to climate change and the potential role an ecosystem services approach could play in informing the development of effective adaptation strategies. The findings are based on semi-structured interviews with herders, key informants, focus group discussions and a survey of nomadic households in Northeast Mongolia. The benefits of pasture ecosystem services have changed considerably due to climatic and socio-economic changes in the Mongolian steppe resulting in degradation of the pastureland and water resources. The ways that traditional ecological knowledge and practices can support adaptation to climate change are explored. In particular, the seasonal movement of nomads represents a valuable form of knowledge and practice of adaptation in response to the changes in temperate dryland ecosystems. To continue to maintain mobility as part of adaptation strategies other adaptation actions are required, such as the implementation of an appropriate livestock insurance systems that addresses climate and weather risks, and restoration of dryland ecosystem services, notably through reforestation and improvement of water supplies. Further changes in the pastureland ecosystems may lead to further adaptations in nomadic livelihoods, leveraging nomadic herders' knowledge of local ecosystem services. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

Background: Photodegradation of plant litter plays a pivotal role in the global carbon (C) cycle. In temperate forest ecosystems, the exposure of plant litter to solar radiation can be significantly altered by changes in autumn phenology and snow cover due to climatic change. How this will affect litter decomposition and nutrient dynamic interacting with forest canopy structure (understorey vs. gaps) is uncertain. In the present study, we conducted a field experiment using leaf litter of early-fall deciduous Betula platyphylla (Asian white birch) and late-fall deciduous Quercus mongolica (Mongolian oak) to explore the effect of change in autumn solar radiation on dynamics of litter decomposition in a gap and understorey of a temperate mixed forest. Results: Exposure to the full-spectrum of not only significantly increased the loss of mass, C, and lignin, but also modified N loss through both immobilization and mineralization during the initial decomposition during autumn canopy opening, irrespective of canopy structure and litter species. These effects were mainly driven by the blue-green spectral region of sunlight. Short-term photodegradation by autumn solar radiation had a positive legacy effect on the later decomposition particularly in the forest gap, increasing mass loss by 16% and 19% for Asian white birch and Mongolia oak, respectively. Conclusions: Our results suggest that earlier autumn leaf-fall phenology and/or later snow cover due to land-use or climate change would increase the exposure of plant organic matter to solar radiation, and accelerate ecosystem processes, C and nutrient cycling in temperate forest ecosystems. The study provides a reference for predictive research on carbon cycling under the background of global climate change. [ABSTRACT FROM AUTHOR]

The greenery of floodplain meadows in arid regions, such as Mongolia, is influenced by climate, hydrology, and land use. In this study, we analyzed the NDVI (Normalized Difference Vegetation Index) of two floodplain meadows located along the South Tamir and Tamir Rivers using LANDSAT images. Our goal was to observe NDVI spatial changes, variations, and mean values in mid-August every six years from 1991 to 2015 and to identify the factors driving these differences. To achieve this, we conducted variance analysis to identify changes in NDVI and implemented Principal Component Analysis to determine the influence of hydro-meteorological factors and grazing intensity. Our findings indicate a significant decrease in greenness, as measured by pixel-scale NDVI, during the late summer period. This decrease was consistently observed, except for a series of harsh winters that followed relatively dry summers, resulting in a disastrous event called dzud, which led to the death of livestock. The decrease in NDVI was amplified by lower precipitation in June, higher temperatures and wind speed in July, and increased precipitation in August, along with a higher frequency of days with convective rain. Our findings have important implications for managing grazing in Mongolia's grasslands, promoting sustainable land use, and mitigating sandstorms. The variance and average values of NDVI at the pixel level can serve as reliable markers of sustainable pasture management in areas where other vegetation measures are limited. [ABSTRACT FROM AUTHOR]

Desertification is a transnational, cross-regional, and global eco-environmental problem that seriously restricts sustainable socioeconomic development. As Mongolia is a typical arid and semi-arid region, the evolution of desertification in the country is closely related to major global issues such as climate change, global carbon cycling, and biodiversity. In this article, we analyze the background, development process, limitations, and other aspects of Mongolia's desertification prevention and control policies and regulations and conclude that Mongolia needs to formulate a "Desertification Prevention and Control Law." In particular, it needs to clarify the responsibility subjects, beneficiaries, interest compensation subjects, and illegal punishment subjects for prevention and control, as well as the responsibilities and obligations of relevant legal subjects. The research results show that it is important to form a solution mechanism in legal research on the joint prevention and control of desertification between Mongolia and China. We propose a concept of best future practice, highlighting the urgent need to establish a framework for the joint prevention and control of desertification via a cooperative mechanism between Mongolia and China and for the two countries to jointly promote global cooperation in combating this important environmental issue. [ABSTRACT FROM AUTHOR]

The paper is focused on changes in biodiversity, the environment, and human activity in the Uvs Nuur Basin during the last three millennia based on biological and geochemical proxies from the lake Bayan Nuur. Regions with high biodiversity and relatively low anthropogenic pressures are typically the most vulnerable to both climate change and human activities. One such area is the Uvs Nuur Basin located on the north of the Great Lake Depression of Mongolia. The main objective of this study is to assess changes in the past biodiversity of the lake's microflora and microfauna, and surrounding vegetation biodiversity in the Uvs Nuur Basin, and to determine the main drivers of diversity change. Based on the analysis of pollen and chironomids we conclude that the most humid and afforested phase was between 1400 and 1800 CE. We assume that the Little Ice Age in the Uvs Nuur Basin was humid with mean annual precipitation ca. 305 mm/year and mean July temperature about 13°C. Conversely, the warmest and most arid period was between 650 and 1350 CE with mean annual precipitation ca. 280 mm/year and mean July temperature of about 16°C, attributed to the Medieval Warm Period. The biodiversity of terrestrial plants, chironomids, and Cladocera positive react to changes in annual precipitation and July temperature, whereas diatoms do not correlate directly to the climatic factors. The diversity and the evenness of plants are strongly correlated with the change in the leading biomes. The calculated species turnover suggests no significant changes in plant and Cladocera taxa composition, but significant changes in diatom and chironomid communities. This may be explained by the instability of lake ecology due to the fluctuation of the salinity and acidity of the water. An additional aim was to assess if dung fungi in lacustrine sediments reflect changes in human population density around the lake. We found that neither historical sources of human presence nor the influx of coprophilous fungi are correlated with the inferred climate changes. Coprophilous fungi can be used as individual or additional sources of assessment for the peopling and human-related herbivore density including overgrazing of the studied area. [ABSTRACT FROM AUTHOR]

Droughts have become more severe and frequent due to global warming. In this context, it is widely accepted that for drought assessments, both water supply (rainfall) and demand (standardized precipitation evapotranspiration index, SPEI) should be considered. Using SPEI, we explored the spatial-temporal patterns of dry and wet annual and seasonal changes in five sub-regions of East Asia during 1902–2018. These factors are linked to excess drought frequency and severity on the regional scale, and their effect on vegetation remains an important topic for climate change studies. Our results show that the SPEI significantly improved extreme drought and mostly affected the SPEI-06 and SPEI-12 growing seasons in East Asia during 1981–2018. The dry and wet annual SPEI trends mostly affect the five sub-regions of East Asia. The annual SPEI had two extremely dry spells during 1936–1947 and 1978–2018. Japan, South Korea, and North Korea are wet in the summer compared to other regions of East Asia, with drought frequency occurring at 51.4%, respectively. The mean drought frequencies in China and Mongolia are 57.4% and 54.6%. China and Mongolia are the driest regions in East Asia due to high drought frequency and duration. The spatial seasonal analysis of solar radiation (SR), water vapor pressure (WVP), wind speed (WS), vegetation condition index (VCI), temperature condition index (TCI), and vegetation health index (VHI) have confirmed that the East Asia region suffered from maximum drought events. The seasonal variation of SPEI shows no clear drying trends during summer and autumn seasons. During the winter and spring seasons, there was a dry trend in East Asia region. During 1902–1990, a seasonal SPEI presented diverse characteristics, with clear wet trends in Japan, Mongolia, and North Korea in four different growing seasons, with dry trends in China and South Korea. During 1991–2018, seasonal SPEI presented clear dry trends in Japan, Mongolia, and North Korea in different growing seasons, while China and South Korea showed a wet trend during the spring, autumn, and winter seasons. This ecological and climatic mechanism provides a good basis for the assessment of vegetation and drought-change variations within East Asia. An understandings of long-term vegetation trends and the effects of rainfall and SPEI on droughts of varying severity is essential for water resource management and climate change adaptation. Based on the results, water resources will increase under global warming, which may alleviate the water scarcity issue in the East Asia region. [ABSTRACT FROM AUTHOR]

Wildfire is the main natural disturbance in forest ecosystems; it controls and modifies vegetation compositions, landscape properties and global carbon cycle. Estimates of areas burned by wildfires vary greatly depending on the environmental conditions, data availability and methods used. This paper aims to develop a framework for reconstructing time series of burned areas in the taiga-steppe transition zone using MODIS composites. The estimated accuracy of the developed mapping algorithm and other statistical indications denote that the clear land surface composites of MODIS data in spring (Julian dates, JD 97-177), logistic regression and MODIS active fire product can be integrated successfully for reconstructing burned areas in the taiga-steppe transition zone. Time series of burned areas between 2000 and 2012 derived from the MODIS spring composite algorithm were validated using Landsat-based burned areas, showing average omission and commission errors of 18% and 31%. Compared with the MCD45A1 burned area product, the developed algorithm significantly improved the prediction of burned areas and successfully separated late-season from early-season burns. The derived long-term burned areas will assist in understanding the complex relationships among forest dynamics, forest recovery and fire in the vulnerable boreal forest ecosystem as well as its transition zone under climate change in northern Mongolia and Central Asia. [ABSTRACT FROM AUTHOR]

The imminent threat of Mongolian montane forests facing extinction due to climate change emphasizes the pressing need to study these ecosystems for sustainable development. Leveraging multispectral remote sensing data from Landsat 8 OLI TIRS (2013–2021), we apply Tsallis non-extensive thermodynamics to assess spatiotemporal fluctuations in the absorbed solar energy budget (exergy, bound energy, internal energy increment) and organizational parameters (entropy, information increment, q-index) within the mountain taiga–meadow landscape. Using the principal component method, we discern three functional subsystems: evapotranspiration, heat dissipation, and a structural-informational component linked to bioproductivity. The interplay among these subsystems delineates distinct landscape cover states. By categorizing ecosystems (pixels) based on these processes, discrete states and transitional areas (boundaries and potential disturbances) emerge. Examining the temporal dynamics of ecosystems (pixels) within this three-dimensional coordinate space facilitates predictions of future landscape states. Our findings indicate that northern Mongolian montane forests utilize a smaller proportion of received energy for productivity compared to alpine meadows, which results in their heightened vulnerability to climate change. This approach deepens our understanding of ecosystem functioning and landscape dynamics, serving as a basis for evaluating their resilience amid ongoing climate challenges. [ABSTRACT FROM AUTHOR]

The incidence of plague has rebounded in the Americas, Asia, and Africa alongside rapid globalization and climate change. Previous studies have shown local climate to have significant nonlinear effects on plague dynamics among rodent communities. We analyzed an 18-year database of plague, spanning 1998 to 2015, in the foci of Mongolia and China to trace the associations between marmot plague and climate factors. Our results suggested a density-dependent effect of precipitation and a geographic location-dependent effect of temperature on marmot plague. That is, a significantly positive relationship was evident between risk of plague and precipitation only when the marmot density exceeded a certain threshold. The geographical heterogeneity of the temperature effect and the contrasting slopes of influence for the Qinghai-Tibet Plateau (QTP) and other regions in the study (nQTP) were primarily related to diversity of climate and landscape types. [ABSTRACT FROM AUTHOR]

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According to records of 17 meteorological stations distributed in the study area, climate change of the middle Inner Mongolia in northern China was analyzed in this paper. Based on SPOT VGT data, combined with field investigation, local vegetation change was detected in the last 10 years. The results show that annual mean air temperature obviously rose, while precipitation slightly decreased in fluctuation in the study area during the last 50 years. Air temperature increasing rates are +0.318°C 10 year during 1960-2009 and +0.423°C 10 year during 1980-2009, while precipitation decreasing rates are −2.91 mm 10 year during 1960-2009. There were five different dry or wet periods from the 1960s to the 2000s in order, and the wetter 1990s and the drier 2000s changed dramatically in the study area. Local climate totally tend to warm-dry conditions during the last 50 years. According to coefficient of variation ( Cv) of yearly growing-season cumulative NDVI value and yearly NDVI maximum in pixel scale, vegetation had experienced huge temporal and spatial variation during the last 10 years. Recently, frequent droughts and dust storms seriously affected local agriculture and grazing activities, and resulted in heavy economic loss, especially over the drought period of 1999-2001. Faced with those drought disasters accompanied with strong dust storms, the local authorities proposed the enclosing-transferring strategy and made great efforts to adapt overt climate change and improve environment, including making selective emigration, decreasing livestock numbers, fencing grasslands and building forage production bases with irrigation instruments and actively adjusting industry structure. However, some effects and potential problems of this adaptation strategy still need to be comprehensively assessed further in longer time scales and aimed at different sub-regions. [ABSTRACT FROM AUTHOR]

Climate variability is a primary characteristic of arid and semi-arid areas where drought occurs frequently. As a disaster, drought is the result of both low precipitation and social factors. If the institutions governing grassland use fail to deal with drought, grassland degradation and herder poverty will result. Based on a case study conducted in Hexigten Banner of eastern Inner Mongolia, we found that drought impacts caused by climate variability were aggravated by resource use conflicts. A series of social and economic changes in pastoral societies, including grassland segmentation, sedentarization, increased buying-in of fodder, decrease in cooperation amongst herders, and industrial development, have made herders more vulnerable to drought. Less fodder production, increased costs, and heavy debt within a disrupted community make a herder's life unsustainable. The paper points out that changes driven by policy makers may aggravate herders' vulnerability and that an alternative approach of adaptation should be developed. [ABSTRACT FROM AUTHOR]

Rising temperatures are expected to increase wildfire activity in many regions of the world. Over the last 60 years in Mongolia, mean annual temperatures have increased ~2°C and the recorded frequency and spatial extent of forest and steppe fires have increased. Few long records of fire history exist to place these recent changes in a historical perspective. The purpose of this paper is to report on fire history research from three sites in central Mongolia and to highlight the potential of this region as a test case for understanding the relationships between climate change, fire and land use. We collected partial cross-sections from fire-scarred trees and stumps at each site using a targeted sampling approach. All three sites had long histories of fire ranging from 280 to 450 years. Mean Weibull fire return intervals varied from 7 to 16 years. Fire scars at one protected-area site were nearly absent after 1760, likely owing to changes in land use. There is limited synchrony in fire occurrence across sites, suggesting that fire occurrence, at least at annual time scales, might be influenced by local processes (grazing, human ignitions, other land-use factors) as well as regional processes like climate. Additional data are being collected to further test hypotheses regarding climate change, land use and fire. [ABSTRACT FROM AUTHOR]

The study area, the middle part of Inner Mongolia including Hohhot city, Baotou city, Wulanchabu city, Ordos city, Bayannaoer city and Wuhai city, is one of typical eco-geographical transition zones in China. Using monthly precipitation data (1961–2003) from 45 meteorological stations in the study area, this paper analyzes characteristics and tendencies of annual and seasonal rainfall variations, and reveals multi-time scales structures of these time series through wavelet analyses; also, the periods of annual and seasonal precipitation series are identified, and the periodical oscillations and points of abrupt change at the principal period scale are discovered. The results show that annual precipitation varies in a large range, and has an ascending tendency at an increasing rate of 1.482 mm/10a; the multi-time scales periodical oscillations are clear; differences in tendencies, ranges and decadal precipitation anomalies exist within each decade during 1961–2000. The seasonal allocation of overall annual precipitation is extremely uneven; in terms of tendencies of seasonal precipitation, winter and spring have upward trends while summer and autumn have downward tendencies; distinctions in tendencies, ranges and decadal precipitation anomalies among each seasons are in existence within each decade during 1961–2000. The periodical oscillations of each seasonal precipitation time series are also evident. The research results not only provide convincing evidence for global climate change research, but also facilitate the understanding of specific natural process and pattern to make steps to rehabilitate and reconstruct vegetation, and contribute to fulfill the sustainability of water management. [ABSTRACT FROM AUTHOR]

The Inner Mongolia grassland of China is representative of semi-arid grasslands in temperate zones. Studying land surface processes in this region will improve the understanding of regional climate formation and the feedback with global climate change. Satellite remote sensing provides an excellent opportunity to study land-atmosphere interactions at the regional scale. It is necessary to develop feasible and reasonable remote sensing-based methods to map surface energy fluxes for a specific study area. In this paper, previously published algorithms and empirical formulae were tested with Landsat 7 ETM+ data to derive the regional distributions of land surface reflectance, surface temperature, NDVI and land surface energy fluxes (net radiation, soil heat flux, sensible heat flux and latent heat flux) over the upper Xilin River watershed in Inner Mongolia, China. A new land use/land cover classification was developed and applied for regionalization analysis. Validation of remote sensing derived surface reflectance, surface temperature, net radiation and sensible heat flux with field measurements shows differences of about 13, 4, 1, and 28%, respectively. This study provides valuable guidance for further investigation of the whole watershed. [ABSTRACT FROM AUTHOR]

Evaluating the variations in terrestrial water storage anomalies (TWSA) associated with climate forcing and human activities in the Mongolian Plateau is crucial for assessing water scarcity and predicting potential pressures on water resources in the future. In this study, we assessed the impacts of climatic and anthropogenic drivers on the change in TWSA on the Mongolian Plateau by using the Independent Component Analysis (ICA) to examine Gravity Recovery and Climate Experiment (GRACE) based TWSA data and comparing the ICA modes with hydrometeorological data and statistical data related to human activities. The results showed that TWSA in the Mongolian Plateau has experienced significant depletion (−2.3 ± 0.62 mm/year) from 2002 to 2017, with a severe decline (−3.4 ± 0.78 mm/year) in Inner Mongolia, China, and a moderate depletion rate in Mongolia (1.44 ± 0.56 mm/year). The results of the statistical analysis indicated that climate change was the dominant driver for the decline in TWSA from 2002 to 2007, resulting in a decrease in TWSA in Mongolia and Inner Mongolia at rates of −5.17 ± 1.13 mm/year and −5.01 ± 2.0 mm/year, respectively. From 2008 to 2017, the intensity of human activities has increased in Mongolia, but climate-driven effects greatly offset the anthropogenic changes, leading to an increasing trend in TWSA in Mongolia during this period. Nevertheless, in Inner Mongolia, the anthropogenic water depletion, such as irrigation, coal mining, and grazing, outweighed the climate contributions on the variations in TWSA, causing the TWSA in Inner Mongolia to decline at a rate of 1.08 ± 0.54 mm/year during 2007–2011. [ABSTRACT FROM AUTHOR]

Primary productivity response to climatic drivers varies temporally, indicating state-dependent interactions between climate and productivity. Previous studies primarily employed equation-based approaches to clarify this relationship, ignoring the state-dependent nature of ecological dynamics. Here, using 40 y of climate and productivity data from 48 grassland sites across Mongolia, we applied an equation- free, nonlinear time- series analysis to reveal sensitivity patterns of productivity to climate change and variability and clarify underlying mechanisms. We showed that productivity responded positively to annual precipitation in mesic regions but negatively in arid regions, with the opposite pattern observed for annual mean temperature. Furthermore, productivity responded negatively to decreasing annual aridity that integrated precipitation and temperature across Mongolia. Productivity responded negatively to interannual variability in precipitation and aridity in mesic regions but positively in arid regions. Overall, interannual temperature variability enhanced productivity. These response patterns are largely unrecognized; however, two mechanisms are inferable. First, time- delayed climate effects modify annual productivity responses to annual climate conditions. Notably, our results suggest that the sensitivity of annual productivity to increasing annual precipitation and decreasing annual aridity can even be negative when the negative time- delayed effects of annual precipitation and aridity on productivity prevail across time. Second, the proportion of plant species resistant to water and temperature stresses at a site determines the sensitivity of productivity to climate variability. Thus, we highlight the importance of nonlinear, state-dependent sensitivity of productivity to climate change and variability, accurately forecasting potential biosphere feedback to the climate system. [ABSTRACT FROM AUTHOR]

Trends for increased vegetation greenness based on satellite-derived data have been repeatedly published for the temperate grassland biome (including forest steppes) of eastern Inner Asia since 1982. Although this greening trend has been attenuated or partially reversed by drought in the early twenty-first century, linear increases in the Normalized Difference Vegetation Index (NDVI) or other parameters of vegetation greenness are nevertheless evident when the period since 1982 is regarded. However, the question arises whether these trends are part of a long-term trend driven by climate change, as simultaneously forests in the region show widespread drought-induced growth reductions and mortality outbreaks. Therefore, we hypothesized that the post-1982 greening trend was neither part of a long-term trend nor unprecedented. To test this hypothesis, we analyzed monthly maximum NDVI data from AVHRR time series and correlated these data with standardized tree-ring data of Larix sibirica from two regions of western Mongolia. We used linear regression to model the NDVI from tree-ring anomalies and to reconstruct the NDVI since 1940. These reconstructions show that the availability of satellite-based NDVI data coincidentally began during a dry period of low vegetation greenness in the early 1980s and was followed by a wet phase in the 1990s, producing the linear greening trend. No positive long-term trend in the reconstructed NDVI was observed from 1940 to 2010. This result rules out a recent climate change-driven greening trend for the grasslands and forest steppes of western Mongolia and calls into question its existence for all of eastern Inner Asia. [ABSTRACT FROM AUTHOR]

Transitional climate zone (TCZ) over East Asia is located between humid and arid regions, which is a highly sensitive and disaster-prone region especially under global climate change. Due to limited water resources, the atmospheric moisture availability has a dominant control on the precipitation variability. Hence, this study is motivated to reveal the key teleconnection patterns and associated moisture processes that govern the interannual variability of the summer precipitation over TCZ. In order to better diagnose moisture budget, the Lagrangian particle dispersion model FLEXPART is employed for quantifying contribution from moisture sources. Above all, the observational analysis highlights two critical modes, one is Eurasian teleconnection (EU) and the other is Circumglobal Teleconnection (CGT). As regards EU pattern, positive EU phase corresponds to ample precipitation in TCZ. In the presence of positive phase, it underlines a "+-+-" pattern of geopotential height anomalies stretching from western Europe to Mongolia plateau. In the context, the cyclonic flow and low pressure over Mongolia plateau act to enhance moisture flux from the west and the south and to prompt upward motions. Further moisture diagnoses illuminate largest increase of moisture uptake in monsoon dominated region, followed by the westerlies dominated region. However, the eventual contribution of summer monsoon is a little bit less than that of westerlies, due to the grand loss en route. In addition, the local evaporation exerts little impact. CGT propagates along the mid-latitude westerly jet, which is positively coupled with the precipitation in TCZ. Under the positive phase, there is an ascending motion over TCZ, which bears great resemblance to the EU case. However, unlike the result of moisture attribution in EU case, the southerly monsoon has the largest contribution followed by local effect, while the westerlies have little impact due to the cancellation of wetting and drying regimes along the pathway. [ABSTRACT FROM AUTHOR]

Extreme weather events are happening more frequently as a result of global climate change. Dust storms broke out in the spring of 2017 in China and drastically impacted the local air quality. In this study, a variety of data, including aerosol vertical profiles, surface particle concentration, meteorological parameters, and MODIS–derived aerosol optical depth, as well as backward trajectory analysis, were employed to analyze two dust events from April to May in Beijing. The dust plumes were mainly concentrated below 0.8 km, with peak PM10 values of 1000 μg·m−3 and 300 μg·m−3 in the two cases. The aerosols showed different vertical distribution characteristics. The pure dust in case 1 from 4 to 5 May 2017 had a longer duration (2 days) and presented a larger aerosol extinction coefficient (2.27 km−1 at 355 nm and 1.25 km−1 at 532 nm) than that of the mixed dust in case 2 on 17 April 2017 (2.01 km−1 at 355 nm and 1.33 km−1 at 532 nm). The particle depolarization ratio (PDR) remained constant (0.24 ± 0.03 in case 1) from the surface to 0.8 km in height. In contrast, the PDR profile in the mixed dust (case 2) layer was split into two regions—large values exceeding 0.15 above 0.6 km and small values of 0.11 ± 0.03 below 0.6 km. The influence of meteorological information on aerosol distribution was also investigated, and wind was predominant through the observing period. The pure dust in case 1 was mainly from Mongolia, with strong northwest winds, while the near-surface mixed pollution was caused by the combination of long-transported sand and local emission. Furthermore, lidar-derived profiles of dust mass concentrations in the two cases were presented. This study reveals the vertical characteristics of dust aerosols in the production and dissipation of localized dust events and confirms the efficacy of thorough observations with multiple approaches from the ground to space to monitor dust events in real time. [ABSTRACT FROM AUTHOR]

During the urbanization process in Mongolia, Ulaanbaatar (UB) became the most dominant metro-city in the nation and the most popular migration destination. We examined the changes in migration to UB during the economic transition of 2002–2017 and explored driving forces using the dataset from the Mongolia National Labor Survey. The results confirmed that relatively higher wages and lower unemployment positively influenced migration toward UB. Using the multinomial logistic regression, we find a 1% increase in the expected wage increases the likelihood of migration to core UB by 6.75%; a 1% increase in relative income increases the odds of migration to core UB by 3.17%; and a 1% increase in the expected unemployment rate decreases the odds of migration to core UB and peri-UB by 1.14% and 1.64%, respectively. We also confirmed the impact of environmental change and climate extremes on migration destination choice, as well as the influence of several demographic variables. [ABSTRACT FROM AUTHOR]

Mt. Munkhkhairkhan is the most crucial region for understanding climate and glaciation changes in Mongolia. This study investigated the relationship between glacial area changes and the climate elements of Mt. Munkhkhairkhan in the Mongolian-Altai Mountains using a remote sensing approach, in-situ observations, the Mann–Kendall (MK) test, Innovative Trend Analysis Method (ITAM), Sen's slope estimator test, and statistical analysis. The study results showed that for the last 30 years, the annual average air temperature of Mt. Munkhkhairkhan has been slightly increasing. Total annual precipitation (mainly snow) in the mountain area decreased from 1990 to 2000, but since 2000, a significant increase in precipitation levels has appeared. For the last 30 years, the glacial area has decreased by 32% to 11.7 km2. Multiple regression results showed a strong correlation between Temperature, Precipitation, and Glaciers (Multiple R = 0.69, R2 = 0.48). Ruther indicated that Temperature (t = −2.332, p = 0.036) and Precipitation (t = −3.212, p = 0.007) were significant predictors in the model. Air temperature and precipitation explained 48 percent of the change in the glacier area, and R = 0.69 is a strong correlation. The glaciers and snow area in the study area have changed due to climate warming and precipitation changes and are located in arid and semi-arid regions of Central Asia. This study of Mt. Munkhairkhan shows that climate change significantly impacts glaciers and snow. [ABSTRACT FROM AUTHOR]

Understanding the climatically suitable habitat of species plays a vital role in the sustainable use and management of target species. Calligonum mongolicum Turcz., a native shrub species found in desert areas of Central Asia, is generally considered as one of the top four tree species for desertification control. However, previous works on suitable habitat simulation had focused mainly on either the national or specific geographical scales rather than entire biota scales, which have underestimated the climatic tolerance of the species. Furthermore, the uncertainty outcomes of climate change were largely ignored. With these questions, the arid regions of Central Asia were selected as our research background area. Occurrence data of C. mongolicum were obtained from various sources, such as the Global Biodiversity Information Facility, the Chinese Virtual Herbarium, and the iPlant website. The maximum entropy model (MaxEnt) was used to simulate the suitable habitat change dynamics under various climate change scenarios [5 general circulation models (GCMs) × 3 shared socioeconomic pathways (SSPs)]. The uncertainty of climate change induced by GCMs and SSPs were decomposed by the two-way ANOVA method. Our results show that hydrological-related variables are more important for the species' habitat suitability than thermal-related variables. The climatic threshold for the core suitable habitat was 1–30 mm for precipitation of the coldest quarter, 14–401 mm for annual precipitation, −16.01–12.42 °C for mean temperature of the driest quarter, 9.48–32.63 °C for mean temperature of the wettest quarter, and −25.01–−9.77 °C for the minimum temperature of the coldest month. The size of suitable habitat was about 287.4 × 104 km2 under the current climate condition, located in China and Mongolia. Climate change has less impact on the total area size, but it has bigger impacts on the gain area and loss area sizes. The loss area is mainly located in the southeast boundaries, whereas the gain area is mainly located in Mongolia and the Qinghai-Tibet Plateau. The decomposition uncertainty of climate change indicates that GCMs could explain 14.5%, 66.4%, and 97.0% of total variation, respectively, and SSPs could explain 85.5%, 33.6%, and 3.0% of the total variation for gain, loss, and total habitat sizes, respectively. Our work clearly demonstrates that while C. mongolicum has great planting potential in Central Asia under various climate change scenarios, the sensitive areas possess large uncertainties requiring long-term climate monitoring for afforestation projects. [ABSTRACT FROM AUTHOR]

The frequency and intensity of fires are increasing because of warmer temperatures and increased droughts, as well as climate-change induced fuel distribution changes. Vegetation in environments, such as those in the mid-to-high latitudes and high elevations, moves to higher latitudes or elevations in response to global warming. Over the past 40 years, the Mongolian Plateau has been arid and semi-arid, with a decrease in growing season vegetation in the southwest and an increase in growing season vegetation in the northeast. The northward movement of vegetation has brought fires, especially in the Dornod, Sukhbaatar, and Kent provinces near the Kent Mountains, and has become more obvious in the past 20 years. The occurrence of a dead fuel index (DFI) with high probability is distributed in northern Mongolia, the border area between China and Mongolia, and the forest-side meadow-steppe region of the Greater Khingan Mountains. These findings suggest that vegetation is moving northward because of climate change and this presents a challenge of future warming spreading fire northward, adding material to the study of the relationship between the northward movement of global vegetation and fires. [ABSTRACT FROM AUTHOR]

Hulun Lake is the largest lake in northeastern China, and its basin is located in China and Mongolia. This research aims to analyze the dynamic changes in the water volume of Hulun Lake and to estimate the groundwater recharge of the lake during the past 60 years. Multi-source data were used, and water-level-data-interpolation extrapolation, water-balance equations, and other methods were applied. The proportion of the contribution of each component to the quantity of water in Hulun Lake during the last 60 years was accurately calculated. Evaporation loss was the main component in the water loss in Hulun Lake. In the last 60 years, the average annual runoff into the lake was about 1.202 billion m3, and it was the factor with the largest variation range and the leading factor affecting the changes in the quantity of water in Hulun Lake. There was groundwater recharge in Hulun Lake for a long period, and the average annual groundwater recharge was about 776 million m3 (excluding leakage). The contribution ratio of the river water, groundwater, and precipitation to the recharging of Hulun Lake was about 5:3:2. The changes in the quantity of water in Hulun Lake are affected by climate change and human activities in China and Mongolia, especially those in Mongolia. [ABSTRACT FROM AUTHOR]

Snow is one of the important water sources for vegetation growth in the Mongolian Plateau, and temporal and spatial changes to it have a profound impact on terrestrial vegetation phenology. In recent years, due to global climate change, the snow associated with the different vegetation types of the Mongolian Plateau has changed substantially, and the mechanism of the resulting change in the vegetation growth date needs to be studied. To address this issue, we used the modified Carnegie Ames Stanford Approach (CASA) model was to estimate the start of growing season net primary productivity (SOSNPP) for different types of vegetation over the Mongolian Plateau from 2001 to 2019. An extensive study of the spatial changes in the SOSNPP and the responses reflected by the winter snow cover fraction (SCFWinter), spring snow melting date (SMDSpring), and SOSNPP to influencing factors is of great significance for ecosystem maintenance. We observed: (1) Different vegetation types exhibited similar changes; SCFWinter underwent a significant decrease of −0.2%, and SMDSpring followed a slow downward trend of −0.59 day of the year (DOY)/year for the whole study area. (2) In the Mongolia Plateau, SOSNPP showed a trend of significant decrease of −0.53 DOY/year. (3) The local hydrothermal condition coupling relationship effect on different vegetation types. Spring temperature (TEMSpring) has a direct effect on vegetation SOSNPP, with a path coefficient of −0.09 in the Mongolian Plateau. SCFWinter and SMDSpring were shown through a path analysis to employ different effects on vegetation SOSNPP. SMDSpring has a direct effect on vegetation SOSNPP, with a path coefficient of 0.53. (4) The SMDSpring and PRESpring factors have a significant impact on vegetation SOSNPP, and they account for 21.11% and 21.26% of the whole study area SOSNPP, respectively. This study is expected to promote the examination of the snow phonological parameters of different related vegetation types and theoretical research on SOSNPP. [ABSTRACT FROM AUTHOR]

The daily and seasonal activity patterns of snow leopards (Panthera uncia) are poorly understood, limiting our ecological understanding and hampering our ability to mitigate threats such as climate change and retaliatory killing in response to livestock predation. We fitted GPS-collars with activity loggers to snow leopards, Siberian ibex (Capra sibirica: their main prey), and domestic goats (Capra hircus: common livestock prey) in Mongolia between 2009 and 2020. Snow leopards were facultatively nocturnal with season-specific crepuscular activity peaks: seasonal activity shifted towards night-sunrise during summer, and day-sunset in winter. Snow leopard activity was in contrast to their prey, which were consistently diurnal. We interpret these results in relation to: (1) darkness as concealment for snow leopards when stalking in an open landscape (nocturnal activity), (2) low-intermediate light preferred for predatory ambush in steep rocky terrain (dawn and dusk activity), and (3) seasonal activity adjustments to facilitate thermoregulation in an extreme environment. These patterns suggest that to minimise human-wildlife conflict, livestock should be corralled at night and dawn in summer, and dusk in winter. It is likely that climate change will intensify seasonal effects on the snow leopard's daily temporal niche for thermoregulation in the future. [ABSTRACT FROM AUTHOR]

Locally known as dzuds, extreme winter weather events that are believed to arise from the interaction of hydrometeorological and climate drivers and socioeconomic forces have become increasingly frequent in Mongolia in the past few decades. As they cut off access to forage, these extreme events are associated with mass livestock deaths. Since the socioeconomic changes in the 1990s, and due to climate change, Mongolia has weathered major dzuds in 1999–2000, 2000–2001, 2001–2002, and 2009–2010. They wiped out about 4 million (11.6%), 5 million (18.5%), 3 million (12.3%), and 10 million (22%) heads of livestock, respectively. As a result, the country has been facing the challenge of examining these complex phenomena, finding ways to reduce their risk, and building resilience against them. This study adopts a systems approach to review key research and trace the occurrence of dzuds in Mongolia, understand why measures to reduce their risk have failed, and what can be done to fix this. Specifically, we focus on two dzud events that occurred 10 years apart in 1999–2000 and 2009–2010 and examine the effectiveness of social responses and countermeasures taken to tackle them. We find that a lack of accountability mechanisms and failure to treat dzud as a systemic issue have hindered efforts to reduce risk and minimize mortality. Our findings highlight the need for inclusive, integrated, and accountable handling of dzuds. [ABSTRACT FROM AUTHOR]

The effects of the present global climate change appear more pronounced in high latitudes and alpine regions. Transitions zones, such as the southern fringe of the boreal region in northern Mongolia, are expected to experience drastic changes as a result. This area is dry and cold with forests forming only on the north-facing slopes of hills and grasslands distributing on the south-facing slopes, making it difficult for continuous forests to exist. However, in the Hovsgol Lake Basin, there is a vast continuous pure forest of Siberian larch (Larix sibirica). In other words, the lake water thawing/freezing process may have created a unique climatic environment that differs with the climate of the adjacent Darhad Basin, where no lake exists. Thus, in order to compare the effect of the thawing/freezing dynamics of lake water and the active layer on the thermal regime at each basin, respectively, temperatures were simultaneously measured. The Darhad Basin has similar latitude, topography, area, and elevation conditions. As expected, the presence of the lake affected the annual temperature amplitude, as it was 60% of that in the Darhad Basin. The difference in the seasonal freeze–thaw cycles of the lake and the active layer caused a significant difference in the thermal regime, especially in winter. [ABSTRACT FROM AUTHOR]

Mass livestock mortality events during severe winters, a phenomenon that Mongolians call dzud, cause the country significant socioeconomic problems. Dzud is an example of a compound event, meaning that multiple climatic and social drivers contribute to the risk of occurrence. Existing studies argue that the frequency and intensity of dzud events are rising due to the combined effects of climate change and variability, most notably summer drought and severe winter conditions, on top of socioeconomic dynamics such as overgrazing. Summer droughts are a precondition for dzud because scarce grasses cause malnutrition, making livestock more vulnerable to harsh winter conditions. However, studies investigating the association between climate and dzud typically look at a short time frame (i.e., after 1940), and few have investigated the risk or the recurrence of dzud over a century-scale climate record. This study aims to fill the gaps in technical knowledge about the recurrence probability of dzud by estimating the return periods of relevant climatic variables: summer drought conditions and winter minimum temperature. We divide the country into three regions (northwest, southwest, and east Mongolia) based on the mortality index at the soum (county) level. For droughts, our study uses as a proxy the tree-ring-reconstructed Palmer drought severity index (PDSI) for three regions between 1700–2013. For winter severity, our study uses observational data of winter minimum temperature after 1901 while inferring winter minimum temperature in Mongolia from instrumental data in Siberia that extend to the early 19th century. Using a generalized extreme value distribution with time-varying parameters, we find that the return periods of drought conditions vary over time, with variability increasing for all the regions. Winter temperature severity, however, does not change with time. The median temperature of the 100-year return period for winter minimum temperature in Mongolia over the past 300 years is estimated as -26.08 ∘ C for the southwest, -27.99 ∘ C for the northwest, and -25.31 ∘ C for the east. The co-occurrence of summer drought and winter severity increases in all the regions in the early 21st century. The analysis suggests that a continued trend in summer drought would lead to increased vulnerability and malnutrition. Prospects for climate index insurance for livestock are also discussed. [ABSTRACT FROM AUTHOR]

The Great Lakes region of western Mongolia includes a diversity of lake ecosystems, from alpine freshwater to lowland, saline lakes, which increasingly face environmental threats from excessive grazing and climate change. We assessed environment-species relationships and patterns of biodiversity of non-biting midges (Diptera: Chironomidae) in 55 western Mongolian lakes using surface-floating pupal exuviae. Overall, the gamma diversity of chironomids from these lakes was high with 117 taxa, but alpha diversity was relatively low. Results from canonical correspondence analysis indicated that chironomid communities were most strongly related to salinity and water temperature. Indicator species analysis identified 12 taxa which were indicative of four lake salinity categories: freshwater, subsaline, hyposaline, and mesohaline. Most of the variation in the chironomid communities could be attributed to the loss of taxa in lakes with higher salinity. Observations also suggested that groundwater upwelling along the margins of lakes with extreme salinity could possibly allow small populations of chironomids to survive in littoral zones. Climate change and watershed disturbance are already altering water quality in western Mongolian lakes, and our results establish a baseline for chironomid communities along gradients of salinity and temperature by which future studies may be compared. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents new data on climatic, lake level and environmental changes in the Darhad Basin, northern Mongolia, during the Late Glacial and Early to Middle Holocene. Two cores, DN1 and DN2, from Lake Dood were investigated using the following proxies: grain size, total carbon (TC), total inorganic carbon (TIC), total organic carbon (TOC), total nitrogen (TN), total sulfur (TS), δ13C, δ18O and diatom. Our reconstructions indicate that dramatic climatic and environmental changes occurred several times since ca 14 ka cal BP. A cold and dry climate of the Late Glacial changed to a relatively cold and wet climate starting around 9.5 ka cal BP in response to an Early Holocene humidization. A generally warm and humid climate prevailed in the region at ca. 7.8–5.8 ka cal BP. Later on after 5.8 ka cal BP the climate became cooler and drier. The Darhad paleolake, the predecessor of Lake Dood, disappeared during the Late Glacial to Early Holocene times and started to reappear since ca. 9.5 ka cal BP. Lake Dood fluctuated considerably in response to changes in precipitation or/and in ground ice melting between 9.5 and 5.8 ka cal BP and started to decrease at 5.8 ka cal BP. [Copyright &y& Elsevier]

The repeated expansion of East Asian steppe cultures was a key driver of Eurasian history, forging new social, economic, and biological links across the continent. Climate has been suggested as important driver of these poorly understood cultural expansions, but paleoclimate records from the Mongolian Plateau often suffer from poor age control or ambiguous proxy interpretation. Here, we use a combination of geochemical analyses and comprehensive radiocarbon dating to establish the first robust and detailed record of paleohydrological conditions for Lake Telmen, Mongolia, covering the past ~ 4000 years. Our record shows that humid conditions coincided with solar minima, and hydrological modeling confirms the high sensitivity of the lake to paleoclimate changes. Careful comparisons with archaeological and historical records suggest that in the vast semi-arid grasslands of eastern Eurasia, solar minima led to reduced temperatures, less evaporation, and high biomass production, expanding the power base for pastoral economies and horse cavalry. Our findings suggest a crucial link between temperature dynamics in the Eastern Steppe and key social developments, such as the emergence of pastoral empires, and fuel concerns that global warming enhances water scarcity in the semi-arid regions of interior Eurasia. [ABSTRACT FROM AUTHOR]

This study used the Innovative trend analysis method, Mann-Kendall, and Sen's slope estimator test to investigate the mean annual precipitation, annual mean air temperature, and river discharge at selected stations of the sub-basin. The results showed that the trend of annual precipitation trend was significantly increased in Nizhneangarsk station (ф = 0.88 and Z = –0.64) and Bolshoe Goloustnoe (ф = 0.24 and Z = 1.14*) whereas, the other stations showed a decreasing trend. The most decreasing trend was observed in the Ust Barguzin station (ф = –0.68, Z = –2.38**, and β = –0.95). The average air temperature has increased by 1.7°C from 1970 to 2019. All stations showed an increasing trend of annual air temperature during the study period. The most increasing condition was observed in the Ulan Ude station (ф = 9.20***, Z = 7.78***, and β = 0.04). The river discharge showed an increasing trend in Utulik River, Upper Angara River, and Barguzin rivers. The most decreasing is in the Selenga river gauge station (ф = –2.25**, Z = –2.16**, and β = –2.96**). The warming rates in the Selenga river sub-basin of the study area were higher than those in the other four sub-basins and the global climate change more affects the semi-arid region. [ABSTRACT FROM AUTHOR]

Climate change caused by land use/cover change (LUCC) is becoming a hot topic in current global change, especially the changes caused by the grassland degradation. In this paper, based on the baseline underlying surface data of 1993, the predicted underlying surface data which can be derived through overlaying the grassland degradation information to the map of baseline underlying surface, and the atmospheric forcing data of RCP 6.0 from CMIP5, climatological changes caused by future grassland changes for the years 2010-2020 and 2040-2050 with the Weather Research Forecast model (WRF) are simulated. The model-based analysis shows that future grassland degradation will significantly result in regional climate change. The grassland degradation in future could lead to an increasing trend of temperature in most areas and corresponding change range of the annual average temperature of -0.1°C- 0.4°C, and it will cause a decreasing trend of precipitation and corresponding change range of the annual average precipitation of 10 mm-50 mm. This study identifies lines of evidence for effects of future grassland degradation on regional climate in Mongolia which provides meaningful decision-making information for the development and strategy plan making in Mongolia. [ABSTRACT FROM AUTHOR]

Abstract: Knowledge about the dynamics of modern glaciers is relevant for evaluating climatic change. However, there is very little and conflicting information about the extent of modern glaciers in northwestern Mongolia. Thus, the aim of this paper is to present detailed data about the extent of modern glaciers in the Turgen–Kharkhiraa Mountains in the northwestern part of the Mongolian Altai and to distinguish three main phases of ice extent: in 1991, in 1948, and back to the Holocene glacial epoch including the so-called Little Ice Age (LIA) — a worldwide cooling period beginning in the 16th century and lasting until the end of the 19th century (). Based on field work, topographic maps and aerial photographs of this region, the investigations have shown glacier retreat in 1991, since 1948, as compared to Holocene glaciations including the so-called Little Ice Age period. Using the toe-to-summit altitude (TSAM) method, the overall modern snowline can be calculated at about 3537–3559masl; the area of present glaciers can be calculated to be 33.8km2 for the Turgen Mountains and 39.5km2 for the Kharkhiraa Mountains. This is more than 25% of the glaciated area of Mongolia. The LIA snowline was about ∼80m lower (3461–3480masl), whereby the glaciated areas during the LIA was 76.8km2 and 80.8km2 in the two mountain systems, respectively. In conclusion, there has been a remarkable glacier retreat from this Holocene and Little Ice Age compared to the glaciation in 1948 and 1991. This glacier retreat coincides with an increase in the snowlines. [Copyright &y& Elsevier]

Abstract: Multi-proxy records (geochemistry, clay mineralogy and paleontology) from three sediment cores from Lake Hovsgol, northwest Mongolia, provide paleoenvironmental changes in continental Asia from the last glacial to the present (during the last 29calka BP). This paper presents the first continuous δ13C and δ18O dataset for ostracod shells (Cytherissa lacustris) from Lake Hovsgol sediments. A positive shift in ostracod δ13C values (from +0.5‰ to +3.2‰) began at ca. 21calka BP, and was associated with a decrease in δ13C values of total organic carbon (from −24.7‰ to −27.3‰) and an increase in the mass accumulation rate of total organic carbon (MAR-TOC). These results suggest that increased lake productivity led to the 13C-enrichment of dissolved inorganic carbon in Lake Hovsgol. In addition, decreases in clay content and the illite crystallinity index (full width at half maximum of the 10Å peak) began at ca. 21calka BP, indicating an increase in surface runoff and a change in sources of clastic materials in the watershed. The highest δ18Oostracod values (up to −4.8‰) at 16–15calka BP indicate the increases in precipitation from the East Asian monsoon. The total pollen amount increased, and Betula, Alnus, and Salix were dominant (up to 53%, 30%, and 6%, respectively) after 16–15calka BP. These findings indicate that broad-leaved trees expanded around Lake Hovsgol. In addition, fossil diatom valves appeared after 16–15calka BP, suggesting climate amelioration, and increased input of soil-derived nutrients and dissolved silica. Between 10 and 5calka BP (Holocene climate optimum), productivity was high in and around the lake (MAR-TOC, up to 47.3mg/cm2 kyr; MAR-diatoms, up to 14.4×108 valves/cm2 kyr; total pollen concentration, up to 9.0×105 grains/cm3). Environmental changes during the last 29kyr in and around Lake Hovsgol are clearly associated with fluctuations in summer insolation and East Asian monsoon intensity. [Copyright &y& Elsevier]

• The ecosystem carbon pool of late-successional and pioneer forests was compared. • Larch, birch and mixed larch-birch stands were studied in the southern boreal zone. • Biomass C stock density was reduced by 7 and 19% in mixed or birch forest. • Soil organic C density remained stable despite disturbance. The boreal forest biome is prominent for its high organic carbon pools, the stability of which is important for climate change mitigation. Natural and anthropogenic disturbance is converting boreal forests from late-successional conifer stands to broadleaved pioneer forests. The present paper analyzes how the degradation of Larix sibirica forest to mixed Betula platyphylla-L. sibirica stands or finally to monospecific B. platyphylla forest affects organic carbon stock density in Mongolia's boreal forests, which are representative of large forest areas at the southern fringe of this biome in Inner Asia. Conversion of larch forest to mixed forest with 60% larch and 40% birch resulted in the reduction of carbon stock density by 7%, whereas the complete replacement of larch by birch reduced ecosystem carbon stock density by 19%. These reductions only referred to biomass stocks, whereas the soil organic carbon stock remained stable indicating that losses during and after the disturbance were offset by carbon sequestration in the highly productive initial stages of pioneer forests. The magnitude of carbon stock degradation by conversion into broadleaved pioneer forest suggests that the existing estimate of 1.5–1.7 Pg C for the total organic carbon pool in Mongolia's boreal forest is not substantially affected by the present level of forest conversion resulting in a share of 6.4% of birch in Mongolia's total forest area, but could become more relevant with progressive degradation of late-successional forests. [ABSTRACT FROM AUTHOR]

Forest growth in most parts of the boreal zone is originally limited by low temperatures and low nitrogen availability. Due to the rapid climate warming at high latitudes, an increasing forest area is switching to drought limitation, especially in continental and southern parts of the boreal forest. Studies addressing this issue were mostly dendrochronological and remote‐sensing analyses focusing on climatic effects, but not answering the question whether drought is effective alone or in combination with nitrogen shortage at limiting the forests' productivity and vitality. Here we show in a case study from larch forests of Mongolia with a combination of stable isotope analyses, tree‐ring analysis and bioindication of the local variability of livestock densities using epiphytic lichens that, in the studied highly drought‐prone forests at the southern fringe of the boreal forest in Inner Asia, the trees' vulnerability to drought is modified by nitrogen fertilization from livestock kept in the vicinity and the edge of the forests. The most likely mechanism behind this drought‐nitrogen interaction is the reduction of stomatal conductance, which is known to be induced by low nitrogen levels in plants. Nitrogen fertilization by the livestock could, thus, shorten the times of stomatal closure and thereby increase tree growth, which we measured as radial stem increment. Even though the underlying mechanisms, which were so far examined in angiosperms, should be experimentally tested for conifers, our results indicate that focusing on water alone is not enough to understand the climate change response of drought‐limited boreal forests. [ABSTRACT FROM AUTHOR]

The Tarvagatai Nuruu National Park, situated in the northern Khangai Mountains in central Mongolia, is dominated by a forest-steppe ecosystem. An extreme continental and semi-arid climate is characteristic for forest-steppe ecosystems in Central Asia and their vegetation is very sensitive to climatic changes and human impacts by pastoralism and tree-logging. In the selected study area, nowadays human impact is exceptionally low, and it has potentially also been in the past. The focus of this paper was to reconstruct vegetation variability, climate dynamics, intensity of human impact and fire dynamics by applying a broad multi-proxy approach on a lacustrine sediment core from a small closed lake in the study area. The analyses include reconstructions of pollen, spores, non-pollen palynomorphs, and charcoal distribution as well as XRF-scanning. Overall, the radiocarbon-dated lacustrine sediment core reveals stable, long-term environmental conditions since the early Holocene (9570 cal yr BP). Palynological results indicate that vegetation varies on a comparably low level. We assume that nomadic pastoralism played a tangential role on the vegetation changes in the study area. Higher values of coprophilous fungi between 9570 and 8350 cal yr BP suggest the highest wildlife activity during the early Holocene. Hence, our multi-proxy data reveal a surprisingly stable vegetation composition and only slight climatic changes in north-central Mongolia for the entire Holocene. An initial moist and warm period from 9570 to 4180 cal yr BP was followed by a period of slightly drier and potentially cooler conditions from 4180 until 430 cal yr BP. The latest period from 430 cal yr BP to present was moist and warm. Fires were in general relatively rare except from a strong phase of fire activity between 3550 and 2960 cal yr BP. • A new multi-proxy record (pollen, NPPs, macro charcoal, XRF-data) from north-central Mongolia. • Detailed high-resolution Holocene palaeoecological record covering the last 9600 cal yr BP. • Reconstructed stable vegetation reflects limited human impact on the vegetation dynamics since the Early Holocene. • Values of coprophilous fungal spores during the early Holocene provide a baseline of wildlife activities. • Extensive fire episode from 3550 to 2960 cal yr BP. [ABSTRACT FROM AUTHOR]

• High spatial resolution data has a higher accuracy in acquiring SOS. • The SOS changes are mainly affected by spring temperature and winter precipitation. • At lower elevations, advancing SOS increased spring and summer growth. • At higher elevations, delayed SOS leads to decreased spring growth and increased summer growth. • The effect of SOS on vegetation growth weakens from the spring to summer seasons. Vegetation spring phenology in mountains has undergone profound changes due to climate change. In this paper, which made use of the Harmonic Analysis of Time Series (HANTS) smoothing algorithm and logistic models, the start of the vegetation growing season (SOS) inferred from MODIS datasets with different spatial resolutions from 2001 to 2018 was extracted. The MODIS data closest to the ground-truth observation data were then selected to reflect spring phenology. Combined with temperature and precipitation data, the spatio-temporal patterns and elevation-dependent change mechanisms of the SOS and its legacy effect on vegetation growth in the mountains of northwest Mongolia was examined and the following results were obtained: (1) Compared with the MOD13A1 and MOD13A2 datasets, the high spatial resolution MOD13Q1 dataset provided stronger correlations and the lowest errors with ground-truth observation data. (2) In this study, the SOS usually occurred between 120 and 152 day-of-year (DOY) with the earlier SOS detected in the low-elevation areas. Later SOS occurred mostly in the higher elevation areas. (3) The spatio-temporal variations in the SOS are mainly influenced by both spring temperature and winter precipitation, with increasing precipitation in winter tending to delay the SOS, while increasing spring temperature tended to advance the SOS. (4) At elevation gradient, the spring temperature showed a significant negative effect on SOS at all elevations, except between 1037 m and 1137 m and 3337 m to 3437 m above sea level (ASL), with a significant positive correlation between SOS and winter precipitation between 1337 m and 2937 m ASL. It is expected that spring temperature is closely linked to the heat accumulation of plants, while winter precipitation indirectly affects the temperature in spring. (5) In lower elevation areas (below 1437 m ASL), the SOS was found to be negatively correlated with spring and summer growth, with advancing SOS leading to increased vegetation growth during spring and summer. In higher elevation areas (above 1437 m ASL), the SOS was significantly negatively correlated with spring growth and positively correlated with summer growth. Hence, delayed SOS leads to decreased spring growth and increased summer growth. Also, we found the effect of SOS on vegetation growth gradually weakened from spring to summer. These findings can help to determine the mechanisms and functional consequences of spring phenological changes in mountain regions. [ABSTRACT FROM AUTHOR]

Desertification and the expansion of deserts are regarded as a major threat to human livelihoods and ecosystem services, as well as achieving Sustainable Development Goals. Humans have been recognized as significant agents in the expansion of desert‐like conditions, through the agency of desertification/land degradation, and through contributions to global climate change. Yet, how desertification changes and whether human or climate change drives these processes and trends over the whole Mongolia Plateau is still not clear. Here we first use MODIS data for 2000–2019 to assess the long‐term vegetation changes across the Mongolian Plateau, both in Inner Mongolia of PR China and the Mongolian People's Republic. We then appied a General Linear Model to analyze the additional climate and human attribute data sets to explore relationships between the observed desert extent reduction and their potential drivers. Results show that from 2000–2019, desert extent declined by over 7%, comprised of an almost 11% reduction in Inner Mongolia and 5% reduction in Mongolia, and a reduction in the degree of desert conditions, as measured by vegetation cover grades, across the whole region (37.5% decline ‐ one grade in PR China, 28.75% in Mongolia). The majority of desert area reduction occurs in the northern and eastern areas of the Mongolia Plateau. We found that the main drivers of changing desert extent is not because of a reduction in human pressures on the land, but an increasing trend of both precipitation and temperature, which explains over 75% of all the observed changes. Besides, urbanization, and a reduction of population pressures on the land, contribute to most of the remaining changes. Our results suggest that although the climate has been the primary driver of changing desert area and severity, human interventions have played an important role, although the way it intervenes and the intensity varies in Inner Mongolia and Mongolia. Human's active response to land degradation in the desert contributes to more land restoration in Inner Mongolia than in Mongolia. [ABSTRACT FROM AUTHOR]

Climate change is predicted to cause increasingly frequent and intense storms. Northern Mongolia is already warming at a rate twice the global average, and thunderstorms, defined as intense, short, patchy rains associated with thunder, lightning and high precipitation rates, are becoming more frequent. Because Mongolia's fish populations are lightly exploited, Mongolia provides a model system in which to study the effects of storms on fish behaviour and fishing vulnerability. The impacts of thunderstorm‐related hydrological changes on fishes' vulnerability to two fishing gears were evaluated. Two thunderstorm‐related factors, turbidity and river stage, reduced catch rates of the salmonids lenok Brachymystax lenok (Pallas) and Baikal grayling Thymallus baicalensis Dybowski. Fly‐fishing gear was more effective than spinning gear in this fishery and retained higher catch rates in extreme conditions. These gear‐specific effects suggest that turbidity and rising river stage affect fishing vulnerability by influencing feeding behaviour. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]