Eurasian Steppe Research Articles

Sublethal effects of chlorantraniliprole on biological characteristics, detoxifying enzyme activity and gene expression profile in the Allium mongolicum Regel leaf beetle Galeruca daurica (Coleoptera: Chrysomelidae)

AbstractAllium mongolicum Regel leaf beetle, Galeruca daurica (Coleoptera: Chrysomelidae) is rampantly harmful in Inner Mongolia grassland. However, the current management strategies for this pest still heavily rely on chemical control using traditional insecticides or those with novel action. In the study, we conducted an indoor bioassay to evaluate the sublethal effects of chlorantraniliprole on the biological characteristics. Additionally, we assessed the activity of detoxification enzymes, specifically the primary enzymes carboxylesterase (CarE) and cytochrome P450, and insect's secondary metabolic enzymes, namely glutathione S‐transferase (GST) and uridine diphosphate glycosyltransferase (UGT), as well as its gene expression profile. The developmental period of the 3rd instar larvae of G. daurica was significantly prolonged after treatment with chlorantraniliprole, which negatively affected the hatching, pupation and diapause rates as well as their body weight. The larvae showed different dynamics of the enzyme activities within 24 h of chlorantraniliprole treatment. Different sublethal concentrations of chlorantraniliprole showed an inducing effect on the activities, while no significant difference in activity was observed for P450. Expression profiling of detoxifying enzyme genes screened by transcriptome data has revealed that 6 CarE, 2 GST, 7 UGT and 31 P450 genes were up‐regulated. In conclusion, chlorantraniliprole's sublethal effect on 3rd instar G. daurica larvae resulted in a deceleration of their growth and developmental processes and significantly increased the activity levels of CarE, GST and UGT. The detoxifying proteins encoded by up‐regulation genes may involve in the detoxification metabolism of chlorantraniliprole. Our results provide a basis for understanding the molecular mechanisms of chlorantraniliprole action and detoxification in this key grassland insect pest.

Drought intensity and post-drought precipitation determine vegetation recovery in a desert steppe in Inner Mongolia, China

Extreme drought events are expected to increase in frequency and severity, posing significant threats to ecosystems worldwide. While considerable research has been concentrated on the effects of climate extremes on the stability of grasslands, the process by which grassland productivity may recover after extreme drought events are still not well understood. Here, we conducted a four-year (2019–2022) recovery investigation after four-year's (2015–2018) extreme drought treatments of different intensities (control, press and pulse) to explore the vegetation recovery of desert-grassland ecosystems Inner Mongolia, China. Press drought involved a 66 % reduction in natural precipitation from May to August, while pulse drought reduced it by 100 % during June and July. We found that both press and pulse droughts led to a sharp decrease in aboveground net primary productivity (ANPP) after four years, primarily due to reduced growth, density, and productivity of annual and perennial plants. However, ANPP under pulse drought could recover fully after four years of stopping of drought treatment, and it could not under press drought. Additionally, community structure (i.e., species richness, plant density, and height) fully recovered within 1 year after the end of the two extreme drought treatments. Both plant density and height contributed to the ANPP recovery after press and pulse droughts. Structural equation modeling (SEM) results further revealed that the reduction in ANPP during the extreme drought was primarily due to a decrease in plant density caused by reduced soil water content. The recovery of ANPP in pulse drought was directly caused by increased soil water content in the post-extreme drought. These results suggest that drought intensity and precipitation determine ANPP recovery in a degraded desert steppe. Our findings are crucial for deepening understanding of the processes and mechanisms of ecosystem recovery after extreme drought, as well as for the successful management and protection of grassland ecosystems.

Spatial-temporal variations of vegetation coverage and its driving force in Inner Mongolia grassland, China

Inner Mongolia grassland is rich in natural vegetation and mineral resources. Based on Landsat5/7/8 NDVI data, we used pixel binary model to invert vegetation coverage of Inner Mongolia grassland area, investigated the stability, spatial distribution, and future evolution trend of vegetation coverage by using Sen+MK and Hurst index, and analyzed the driving factors of the spatial differentiation of vegetation coverage by the optimal parameters-based geographical detector. The results showed that vegetation coverage of Inner Mongolia grassland showed an increasing trend from 2006 to 2020, and the overall spatial pattern was high in the east and low in the west, mainly with great fluctuation. The regions with slight or obvious improvement characteristics (64.8%) were much more than those with slight or severe degradation characteristics (23.2%). Compared with that in the past 15 years, the proportion of degraded vegetation in the future is expected to increase to 36.6%. The central part of Xilin Gol League and Wulanqab in the central grassland area, the western part of Hulunbuir and Erdos in the eastern grassland area, and Wuhai in the western grassland area were at the risk of degradation, which should be paid more attention. Precipitation was the dominant factor of spatial differentiation in Inner Mongolia grassland, while soil type, land use, and air temperature had the most significant synergistic effect.

Heavy grazing causes plant cluster fragmentation of sparse grasses.

Cleistogenes songorica, as a clustered grass, is the main grassland flora of the Stipa breviflora desert grassland. Some studies have shown that the constructive species of S. breviflora (sparse cluster type) is prone to cluster fragmentation; however, research on C. songorica is relatively rare. Then will the C. songorica plant population (dense cluster type) also have cluster fragmentation under the influence of intense grazing? To answer this question, we used variance analysis and geo-statistical methods. The spatial distribution of C. songorica in S. breviflora desert steppe in Inner Mongolia was measured under four grazing intensities (no grazing, CK, 0 sheep·ha-1·half year-1; light grazing, LG, 0.93 sheep·ha-1·half year-1; moderate grazing, MG, 1.82 sheep·ha-1·half year-1; and heavy grazing, HG, 2.71 sheep·ha-1·half year-1) and four scales (10 cm × 10 cm, 20 cm × 20 cm, 25 cm × 25 cm, 50 cm × 50 cm). We then analyzed C. songorica whether fragmentation was present. The results showed that increased grazing intensity is associated with increased density and decreased height, coverage, and standing crop of C. songorica. The spatial distribution of C. songorica was affected by structural factors, and spatial heterogeneity decreased with increased spatial scale. With increased grazing intensity and spatial scale, the patch area of C. songorica gradually increased and tended toward band distribution. In summary, increased grazing intensity and spatial scale led to weakened heterogeneity of C. songorica spatial distribution and increased consistency.

Anatomy of xylem and phloem in stems and roots of Populus sibirica and Ulmus pumila from semi-arid steppe in Mongolia

The present study focuses on the cambium and the anatomy of secondary tissues (xylem – wood and phloem) of Siberian poplar (Populus sibirica) and Siberian elm (Ulmus pumila) grown in a plantation in the semi-arid Mongolian steppe. Stem and root microcores from both species were collected and subsequently processed to obtain cross-sections for light microscopy by paraffin embedding, sectioning with a rotary microtome, and staining with safranin and astra blue. The results present the anatomy of the secondary xylem and phloem of stems and roots of both species, along with the characteristics of the youngest xylem and phloem annual rings. We discuss the critical aspects which need to be considered when using the microcoring methodology, along with the need for further studies on wood and phloem formation of less-commonly studied tree species and their characteristics when grown in semi-arid environments.

Funeral Practice of the Sapalli Culture in the Reflection of Vedic Texts

Northern Bactria in the Bronze Age became the arena of complex processes of interaction between the local population and the world of the Eurasian steppes. During this period, the early urban agricultural Sapalli culture, where the contacts of the two traditions were reflected not only in material but also in spiritual culture, developed and functioned on the territory of the south of modern Uzbekistan. Based on the results of studies of the burial grounds of Bustan VI–VII, the first-time attempt to verify the funeral rite with the written sources of the ancient Indo-Aryans and Indo-Iranians was made in the present work. The chosen approach made it possible to solve simultaneously several problems: to clarify the path of advancement of the Indo-Aryan tribes to India; trace one of the ideological foundations of the formation of the Bactrian civilization; illustrate the impact on the local environment of the steppe ethnos represented by the Andronovo population, identified with the Indo-Aryans. The results of the realized work allow us to speak about the significant presence of the Aryan tradition in Sapalli society and the emergence of new forms of funeral rituals. The changed mythological and ritual statements in cosmogonic representations have established as their main constant the maintenance of universal balance and order, carried out through a system of sacrifices, the highest of which at the final stage of life was a person.

Environmental and Cultural Transformations at the Turn of the Late Bronze and Early Iron Age in the Steppe Belt of Eurasia

At the turn of the Late Bronze and Early Iron Age in the steppe belt of Eurasia there were significant cultural transformations which probably had been connected with Rapid Climatic Cycles (RCC) in this time, around 3,2 ka calBP. The correlation of data obtained on the base of radiocarbon dating, paleoclimatic reconstructions and cultural and historical chronology for eastern and western zones of the Great Steppe allowed us to reconstruct these processes. In the Late Bronze period bearers of the Кarasuk culture spread in the steppe zone of the Southern Siberia from Central Kazakhstan to Mongolia and Northern Chine. Formation of the Late Bronze Age cultures Sabatinovka and Belozerka Active cultures took place during period of favorable environment. Then the bearers of the early Hallstattian Carpathian-Danubian cultures and the Cimmerian nomads appeared in the beginning of the Early Iron Age during the aridization episode. Since the middle of 9th century BC expansion of the nomadic Scythian cultures within the whole steppe belt began because of wet climatic conditions.

Russia and Mongolia in the civilizational and geopolitical paradigms of Central Eurasia development

The relationship between Russia and Mongolia in the civilizational and geo-political paradigms of Central Eurasia development is extremely important for political science, sociology and regional studies. The authors’ definition of Central Eurasia differs from the generally accepted neutral interpretation due to its connection with a specific civilizational space - three local civilizations - the historically summarized limits of their dominant influence. The article considers the following limits of the influence of the Mongolian, Russian and Chinese civilizations from ancient times to the present: the great steppe empires (from the state of the Xiongnu to the Great Mongol Empire of Genghis Khan) with the center in Mongolia, the Russian Empire and the socialist camp with the center in Russia (USSR), and the economic corridor Russia-Mongolia-China with centers in three countries. The recognition of the taxonomic equilibrium of Russia, China and Mongolia as the cores of the Russian, Chinese and Mongolian civilizations, united by the space of Central Eurasia, allows to reconsider the Russian-Mongolian relations from ancient times to the present. The authors admit the existence of the world civilization hidden in Inner Asia and based on more than two thousand years of the nomads’ written history - the Mongolian civilization. The authors develop a new scientific direction - civilizational political science which considers the interaction between societies through the intertwined civilizational world order. The authors believe that civilizations cover the entire global space; introduce the concept “cascade of the civilizational boundaries”, which requires a combination of modeling methods and geoinformation technologies with cultural-historical ideas; consider the historical tradition of relations between Russia, Mongolia and China in the Eurasian region as being revived in the new context of trilateral cooperation.

Nitrogen addition and mowing had only weak interactive effects on macronutrients in plant-soil systems of a typical steppe in Inner Mongolia

Effective management of macronutrients is pivotal in the optimization and provisioning of ecosystem services in grassland areas, particularly in degraded grasslands. In such instances where mowing and nitrogen (N) fertilization have emerged as predominant management strategies, nutrient management is especially important. However, the precise effects of these concurrent practices on the distribution of macronutrients in plant-soil systems remain unclear. Here we evaluated the effects of 12 years of N addition (2, 10, and 50 g N m−2 year−1) and mowing on the concentrations and pools of six macronutrients (i.e., N; phosphorus P; sulfur S, calcium Ca, magnesium Mg, and potassium K) in three plant components (aboveground plants, litter, and belowground roots) at the community level and in the soil in a typical steppe in Inner Mongolia. Our results revealed that N addition generally raised the N concentration in the entire plant-soil system, regardless of whether plots were mowed. Higher N addition (10 and 50 g N m−2 year−1) also led to higher concentrations of P (+22%, averaging two N addition rates), S (+16%), K (+22%), Ca (+22%), and Mg (+24%) in plants but lower concentrations of these nutrients in the litter. Similar decreases in K (−9%), Ca (−46%), and Mg (−8%) were observed in the roots. In light of the observed increases in vegetation biomass and the lack of pronounced changes in soil bulk density, we found that the ecosystem N enrichment resulted in increased pools of all measured macronutrients in plants, litter, and roots (with the exception of Ca in the roots) while concurrently decreased the pools of P (−20%, averaging two higher N addition rates), S (−12%), K (−10%), Ca (−37%), and Mg (−19%) in the soil, with no obvious effect of the mowing practice. Overall, mowing exhibited a very limited capacity to alleviate the effects of long-term N addition on macronutrients in the plant-soil system. These findings highlight the importance of considering the distribution of macronutrients across distinct plant organs and the dynamic nutrient interplay between plants and soil, particularly in the context of long-term fertilization and mowing practices, when formulating effective grassland management strategies.

Grazing decreased soil organic carbon by decreasing aboveground biomass in a desert steppe in Inner Mongolia

The mechanisms through which stocking rates affect soil organic carbon in desert steppe landscapes are not fully understood. To address this research gap, we investigated changes in the biomass of Stipa breviflora plant communities and soils in a desert steppe. Through our research findings, we can establish an appropriate stocking rate for Stipa breviflora desert steppe. The establishment serves as a theoretical foundation for effectively maintaining elevated productivity levels and increasing the carbon sink, thereby offering a valuable contribution towards mitigate climate change.This study examined the effects of different stocking rates on soil organic carbon input, sequestration, and output and found: (1) For soil organic carbon input, the aboveground and litter biomass of plant communities decreased with increasing stocking rate. (2) Grazing treatments did not affect soil organic carbon retention. (3) Regarding soil organic carbon output, the grazing treatments exhibited no significant alteration in soil respiration when compared to the no grazing. In summary, the primary mechanisms through which increasing stocking rates affect the soil organic carbon pool are decreased inputs from plants and increased output through wind erosion. Therefore, decreasing grazing intensity is key to improving soil organic carbon retention in the desert steppe.

Inner Mongolia grasslands act as a weak regional carbon sink: A new estimation based on upscaling eddy covariance observations

Clarifying temporal and spatial variations of carbon exchanges of arid and semi-arid grasslands, the most widespread terrestrial ecosystem in the Northern China, is critical to evaluate regional and national carbon balance. However, estimating the carbon sequestration capability of arid and semi-arid grasslands still remains a challenge due to large interannual variability and high sensitivity to human activities. In this study, based on 696 site-months of long-term eddy covariance observations from 7 sites, we estimated the regional carbon fluxes of the arid and semi-arid grasslands in Inner Mongolia, China with the random forest (RF) approach. The estimated carbon fluxes encompassed net ecosystem productivity (NEP), gross primary productivity (GPP) and ecosystem respiration (ER), at a spatial resolution of 0.1°×0.1°. We found that Inner Mongolia grasslands acted as a weak carbon sink with a mean NEP of 2.43 ± 6.71 Tg C y−1 from 1982 to 2018. Fluctuations of precipitation during the peak growing season and leaf area index were the most important drivers for the interannual variations of regional carbon fluxes. During the dry period of 1999 to 2011, the grasslands switched from carbon sink to source resulting from a great drought-induced reduction in GPP than ER. Comparison of our RF carbon fluxes with the global datasets (FLUXCOM, CMIP6 models, and atmospheric inversion data of JenaCO2) showed that these products had limited agreement in terms of spatial and temporal variations, particularly for interannual variabilities of carbon fluxes, which highlights the importance of local long-term observations for regional evaluation and simulation of carbon budget.

Construction and Practice of Livelihood Efficiency Index System for Herders in Typical Steppe Area of Inner Mongolia Based on Super-Efficiency Slacks-Based Measure Model

Inner Mongolia is one of the main animal husbandry production bases in China, with herders being the main animal husbandry producers. A systematic analysis of the efficiency of herding households’ livelihoods and the influencing factors is of great importance to formulate effective policies to support herding households’ livelihoods, enhance their social adaptability, and alleviate the vulnerability of poor people in herding areas. This study used a typical steppe of Inner Mongolia as the research area. It used the interview data of herding households from 2021, constructed the evaluation index system of herding households’ livelihood efficiency, analyzed the redundancy of the inputs and outputs of herding households’ livelihoods, and examined the key factors affecting herding households’ livelihood efficiency. The results indicate that (1) the pure technical effectiveness of the livelihood efficiency of typical grassland herding households in Inner Mongolia is the highest; the comprehensive technical efficiency and scale efficiency are low. The scale return of most herders’ livelihoods shows a decreasing state. (2) According to the results of the model, under the premise of the output not being reduced, reducing the amount of social capital input can effectively save resources. Without increasing the input, the room for improvement in the living level is the most obvious. (3) The pasture area, the communication network, and the access to information have significant negative effects on the efficiency of herders’ livelihoods; infrastructure and water supply have significant positive impacts. In summary, we built a model for evaluating the livelihood efficiency of herders in typical grassland areas of Inner Mongolia, which can provide a reference for the revitalization work of pastoral areas and related research in the future.

Understanding the drivers of ecosystem multifunctionality in the Mongolian steppe: The role of grazing history and resource input

Predicting the comprehensive driver of ecosystem multifunctionality is crucial for effective grassland management. However, the underlying biotic and abiotic mechanisms of ecosystem multifunctionality under global change and land use remain poorly understood. In this study, a 3-year field experiment was conducted in a semi-arid steppe in Inner Mongolia to investigate the relative importance of different biotic and abiotic factors in regulating aboveground ecosystem multifunctionality (AEM) and belowground ecosystem multifunctionality (BEM) in response to resource input after long-term grazing. The experiment involved three grazing intensities (1.5 low, 4.5 moderate, and 9.0 high sheep/ha) with a 7-year difference in grazing history. Precipitation (W) and nitrogen deposition (N) were manipulatively increased during the growing season. The study focused on exploring the effects of various biotic factors (e.g. species richness, functional diversity, plant functional groups) and abiotic factors (e.g. soil environment variables) on AEM and BEM. The results revealed asymmetric responses of AEM and BEM to resource input. Resource input enhanced AEM, but not BEM. However, increasing grazing intensity substantially reduced BEM, though we noted that AEM and BEM decreased the most under moderate grazing. Interestingly, the study found consistent responses of single ecosystem functions and ecosystem multifunctionality to resource input across the three grazing blocks. Structural equation modeling (SEM) analysis indicated that species richness primarily enhanced AEM, while soil environment played a major role in promoting BEM across different grazing history intensities and the whole grazed system. Multiple biotic and abiotic factors with varying relative importance in different grazing history scenarios controlled AEM and BEM. Species richness exhibited a strong influence on AEM and BEM, but within a narrow effect threshold range, whereas soil environment had a lesser effect size but a wider threshold range. This study provides the first evidence that grazing history and resource enrichment jointly regulate AEM and BEM. The findings highlight the importance of considering biodiversity conservation, soil health, and land use history in management practices aimed at maintaining ecosystem multifunctionality under climate change and human activities scenarios.

Nomadic ungulate movements under threat: Declining mobility of Mongolian gazelles in the Eastern Steppe of Mongolia

Increasing habitat fragmentation and disturbance threaten long-distance movements of ungulates. While the effects of impermeable barriers on ungulate migrations have been well researched, quantitative evidence for gradual, long-term changes of mobility remains rare.We investigated changes in movement behavior of Mongolian gazelle Procapra gutturosa using GPS tracking data collected from 62 gazelle individuals between 2007 and 2021. We quantified 16-day displacement distances as a metric for long-distance movements before using linear mixed models, generalized additive models and quantile regressions to assess how anthropogenic and environmental factors affected gazelle movement behavior.Long-distance 16-day movements decreased by 36 %, from 142 km in 2007 to 92 km in 2021. Changes in mobility were affected by increasing vehicle numbers in Mongolia, but could not be explained by concurrent changes in other environmental factors like temperature, precipitation or vegetation greenness. Gazelle movement decreased close to roads, and gazelles stayed further away from roads during the snow-free season, when traffic likely is most intense.Conserving landscape permeability is essential for maintaining populations of highly mobile species. Our study provides evidence for a gradual decline in gazelle mobility over fifteen years as a response to increasing anthropogenic impact. The transportation infrastructure permeating the Eastern Steppe does not pose physical barriers, yet our findings suggest that increasing traffic volume may create semipermeable barriers to gazelle movement. As human activity is increasing, interactions between ungulates and vehicle traffic need to be closely monitored to identify and mitigate semipermeable barrier effects before landscape permeability is severely altered.

Contribution of cultural heritage values to steppe conservation on ancient burial mounds of Eurasia.

Civilizations, including ancient ones, have shaped global ecosystems in many ways through coevolution of landscapes and humans. However, the cultural legacies of ancient and lost civilizations are rarely considered in the conservation of the Eurasian steppe biome. We used a data set containing more than 1000 records on localities, land cover, protection status, and cultural values related to ancient steppic burial mounds (kurgans); we evaluated how these iconic and widespread landmarks can contribute to grassland conservation in the Eurasian steppes, which is one of the most endangered biomes on Earth. Using Bayesian logistic generalized regressions and proportional odds logistic regressions, we examined the potential of mounds to preserve grasslands in landscapes with different levels of land-use transformation. We also compared the conservation potential of mounds inside and outside protected areas and assessed whether local cultural values support the maintenance of grasslands on them. Kurgans were of great importance in preserving grasslands in transformed landscapes outside protected areas, where they sometimes acted as habitat islands that contributed to habitat conservation and improved habitat connectivity. In addition to steep slopes hindering ploughing, when mounds had cultural value for local communities, the probability of grassland occurrence on kurgans almost doubled. Because the estimated number of steppic mounds is about 600,000 and similar historical features exist on all continents, our results may be applicable at a global level. Our results also suggested that an integrative socioecological approach in conservation might support the positive synergistic effects of conservation, landscape, and cultural values.

Zhuravlevo complex of the of Borki 1 hillfort in the Lower Ishim River Basin

At the end of the Late Bronze Age, there were events taking place in the history of the Eurasian steppes that manifested the beginning of the formation of cultures of the Scythian type. These processes, in many aspects triggered by the climate changes, spread into both southern taiga and forest-steppe territories of Western Siberia. In understanding the processes of the transitional period from the Bronze to Early Iron Age and beginning of the Early Iron Age in the southern taiga and forest-steppe Ishim River Basin, a major role pertains to the materials of the multi-layered hillfort of Borki 1, in the study of which, as well as of the cultures of the concerned period in ge-neral, a significant contribution was made by E.M. Danchenko (1991, 1996). The site is located nearby the village of Borki of Vikulovo District, Tyumen Oblast. This paper aims at the analysis and introduction into the scientific discourse of the materials of the Zhuravlevo type from the excavation trench of 2014 with the clean archaeological layer of the beginning of the Early Iron Age. During this period, the fortified platform of the hillfort was overbuilt with dwellings of the above-ground type, probably timber crib. The Zhuravlevo ware of the settlement finds its closest similarities in the materials of the sites of the Lower Ishim Basin: the settlement of Borovlyanka 2, hillfort of Lastochkino Gnezdo 1, fortified settlement of Maray 4, as well as the sites of Yamsysa 7, Kip 3, Novonikolskoe 3 and others in the southern-taiga Ishim-Irtysh area. Differences in the pottery and material culture assemblages even within a range of the Zhuravlevo complexes, not to mention the later ones of the Bogochanovo type, which have certain continuity with the aforementioned complexes, help to reveal evolutionary development of the culture of the transitional period in the Lower Ishim Basin and to raise the issue of the revision of its chronology and peri-odization. Giving the studies of E.M. Danchenko credit for unification of the Zhuravlevo and Bogochanovo types within the framework of the Bogochanovo Culture of the Early Iron Age, we believe that it would be more logical to consider earlier, Zhuravlevo, materials as a stage in the development of the Krasnoozerka Culture. The existence of the latter we tend to define from the mergence of the Suzgun and Atlym complexes to the formation of the steady Sargatka Culture. In spite of certain dissimilarities in the ware originating from the forest-steppe territories of the Lower Tobol River Basin, Ishim-Irtysh interfluve, Baraba and the Ob River Basin, it still seems that the pro-cesses of the development of the cultures of the concerned period in these regions have similarity in many as-pects. There is a notable uniformity in the bronze assemblages of the sites of these and much wider territories. Products, similar to those found at the hillfort of Borki 1, are present in the complexes of the steppe belt of Eurasia from Tuva to the Circumpontic area and date to, most likely, the period within the 8th–6th cc. BC.

Phosphorus Coupled with High Nitrogen Addition Exerts a Great Influence on Soil Bacterial Community in a Semiarid Grassland.

Nitrogen (N) and phosphorus (P) addition, either individually or in combination, has been demonstrated to enhance plant productivity in grassland ecosystems. Soil bacterial community, which is the driver of litter decomposition and nutrient cycling, is assumed to control responses of terrestrial ecosystem structure and function to N and P addition. Using a high-throughput Illumina MiSeq sequencing platform, we conducted a 9-year field experiment of N (0, 5, 10, and 20 g N m-2 yr-1) and P (0 and 10 g P m-2 yr-1) additions in the Inner Mongolian steppes to elucidate long-term effects of N and P addition on soil bacterial richness, diversity and composition. We found that N addition reduced the relative abundance of Acidobacteria, Chloroflexi, and Nitrospirae, while increased that of Bacteroides. The results showed that the bacterial biomarker was enriched in P addition treatments, either individually or combined with N addition. Both N and P addition altered the bacterial community structure, while only N addition greatly decreased bacterial richness and diversity. More importantly, we showed that all of these effects were most significant in N3P treatment (20 g N m-2 yr-1 and 10 g P m-2 yr-1), implying that P coupled with a high-level N addition exerted a great influence on soil bacterial community. Structural equation models revealed that N and P addition had a great direct effect on soil bacterial community and an indirect effect on it mainly by changing the litter biomass. Our findings highlighted that severe niche differentiation was induced by P along with a high-level N, further emphasizing the importance of simultaneously evaluating response of soil bacterial community to N and P addition, especially in the context of increasing anthropogenic nutrient additions.

Pro et contra of frontier interpretation of Sintashta antiquities (Bronze Age in the Southern Urals)

The practice of archaeological research often illustrates situations where the sum of facts does not corre-spond to the cultural-historical approach; it is impossible to squeeze this sum into the framework of the term “ar-chaeological culture”. Deviations from his canonical understanding of the term may relate to the duration of the phenomenon, its spatial distribution or the degree of stereotyping of material culture and rituals. The frontier can be one of the options for interpreting such non-standard groups of archaeological objects. The purpose of the study is to test the possibilities of using the concept for the interpretation of the Sintashta sites of the Bronze Age of the Southern Urals (the turn of 3rd — 2nd millennium cal BC) in the light of new data from a comprehensive study (paleogenetics, chronology, etc.). Sintashta settlements and cemeteries are located on the compact territory of the northern steppe: settlements in the Trans-Urals, the burial ground — on both sides of the Ural Mountains. Previous studies have accumulated a huge amount of data on all major aspects, but the general concept remains debatable. The new data comes from mass radiocarbon dating, which allowed to use Bayesian modeling. New data of mass radiocarbon dating confirm the brevity of the functioning of the Sintashta settlements and burial grounds, as well as the possibility of partial synchronization of this tradition with others. Paleogenetic analyzes (more than 50 samples) have shown the heterogeneity of the Sintashta population. Peleogenetic data made it possible to diagnose traces of a subtratian population absorbed by the main migratory group. In material culture, The evidences in material culture are not traced. The same data confirmed a special scenario for the formation of necropolises, weakly associated with the consanguinity of the buried individuals. Only 1/5 of the deceased turned out to be relatives of the first and second degree. The new data significantly complement the previously formulated crite-ria, which allow us to consider the group of Sintashta sites as a reflection of the situation of the frontier. The Sin-tashta society in the frontier was formed as complex society. But it did not have the prospect of forming statehood.

Grazing mediates the biodiversity effects on multifunctionality in grasslands

AbstractBiodiversity loss by grazing pressure has threatened multiple ecosystem functions simultaneously (ecosystem multifunctionality, EMF) in grasslands. Therefore, detecting the relation between EMF and biodiversity under human intervention would provide guidance on the optimization of sustainable grassland management. However, little is known about how grazing effects grassland EMF by mediating biodiversity under different grazing intensities. Here, species and functional diversity were investigated along a longitudinal gradient in Inner Mongolia grassland, and its EMF was quantified comprehensively on six ecosystem functions by an averaging approach, threshold approach and multiple threshold approach to assess the impact of grazing intensity on EMF. There was a significantly lower average EMF index and above‐ground biomass under heavy grazing (HG) than under light grazing (LG). The threshold approach‐based EMF and average EMF index were positively related to species diversity and functional diversity, and species diversity was a stronger driver of EMF than functional diversity. Compared with LG, the slope of the positive relation between EMF and species diversity significantly weakened by 40%–86% under moderate grazing (MG) and decreased by 30%–100% under HG, and reversed to a negative relation between functional diversity and EMF under HG. Additionally, species diversity was more negatively influenced by soil pH and sand content, while functional diversity was more negatively influenced by grazing intensity, indicating that functional diversity was more sensitive to intensive grazing. This study highlights the role of grazing intensity for driving multiple ecosystem functions, and reinforces the significance of managing both species diversity and functional diversity for sustaining productive functional grasslands.

Network complexity and community composition of key bacterial functional groups promote ecosystem multifunctionality in three temperate steppes of Inner Mongolia

Network complexity and community composition of key bacterial functional groups promote ecosystem multifunctionality in three temperate steppes of Inner Mongolia