Meadow Steppe Research Articles

Consecutive annual mowing reduces soil respiration and increases the proportion of autotrophic component in a meadow steppe

BcakgroundSoil respiration (Rs), as the second largest CO2 emissions of terrestrial ecosystems, is sensitive to disturbance and consequent environmental changes. Mowing is strategically implemented as an management approach and has the potential to influence carbon cycling in meadow steppes. However, it remains unclear how and why Rs and its heterotrophic (Rh) and autotrophic (Ra) components respond to consecutive mowing and associated ecological consequences. Here, we conducted a field mowing experiment in a meadow steppe in 2018 and monitored Rs, Rh, and Ra from 2019 to 2022.ResultsWe observed a significant reduction in Rs by 4.8% across four years, primarily attributed to a decrease in Rh. This decline in Rs intensified over time, indicating an accumulative effect of mowing. In addition, mowing induced an generally increasing Ra/Rs ratio over the experimental years with a simultaneous increase in the ratio of belowground to aboveground biomass (BGB/AGB). Furthermore, structural equation modeling results revealed that the decline in Rs was largely ascribed to reduced microbial biomass carbon (MBC) under mowing, while the increased Ra/Rs was primarily explained by the enhanced BGB/AGB. Partial regression analysis suggested that the biotic factor of microbial biomass dominated changes in soil respiration induced by mowing rather than abiotic soil temperature.ConclusionsOur findings showed that consecutive mowing decreased Rs and raised Ra/Rs in meadow steppe by decreasing plant biomass and altering the proportion of biomass allocation. This observed decline in Rs would help to reduce CO2 concentration in atmosphere as well as alleviate global warming. However, considering the concurrent lower microbial biomass, the potential positive impacts of mowing on climate and ecosystem function should be reevaluated in future grassland management practices.

Net Primary Production of Steppe Ecosystems and the Reasons for its Spatial Variability

The purpose of the article is to analyze the values change of net primary production: aboveground (ANP), belowground (BNP) and total (NPP) for meadow, true and dry steppes. The investigated meadow and true steppes are located between 36 and 116° E, 47 and 56° N. In Tyva, the production of dry steppes is determined on various elements of the relief – from the upper part of the mountain to the depressions located in the bottom of the slope. The value of ANP in the meadow steppes varies from west to east from 10.2 to 3.1, in the true steppes from 5.8 to 0.7 t/ha per year and depends on many factors, including air temperature, precipitation, and soil properties. The soil properties are defined by a set of conditions: the position of the ecosystem on the relief, which leads to different soil moisture. Both, the meadow and true steppes, have irregularities in the decrease of the ANP value from west to east. In some cases, in a series of meadow steppes instead of a decrease, an increase of ANP is observed, which is explaining by changes in soil conditions. The first increase from 4.8 (63° E) to 6.1 t/ha per year (73° E) occurs when Luvic Chernozem (Loamic) is replaced by Inclinigleyic Chernozem (Loamic), as a result of additional soil moistening. The second increase of ANP from 3.6 (75° E) to 6.6 t/ha per year (90° E) is observed when the soil changes from Tonguic Chernozem (Siltic) to Haplic Chernozem (Siltic, Pachic). The increases of ANP were observed in the true steppes: 1) when Skeletic Kastanozem (Siltic) changed to Calcic Chernozem (Siltic), 2) when Haplic Solonetz (Loamic) changed to Calcic Chernozem (Loamic), 3) when soil changes from Mollic Leptosol (Siltic) to Calcic Chernozem (Siltic). The value of BNP in meadow and true steppes in the soil layer of 0–30 cm generally decreases from west to east from 26.8 to 7.7 t/ha per year, varying without a visible pattern. In Tyva, due to the change in the relief, ANP of dry steppes varies from 3.7 to 1.7, BNP – from 27.0 to 8.7 t/ha per year. Consequently, the amount of aboveground production of grass ecosystems is determined not only by air temperature and precipitation, but also by the properties of soils, which vary in structure, Corg content, nutrients, and watering.

Non-linear response of plant caloric value to N addition and mowing treatments in a meadow steppe

BackgroundCaloric value is an important indicator of grassland ecosystem function, but the response of caloric value to nitrogen (N) addition and mowing is still unclear. We explored the adaptive changes of plant caloric value and energy standing crop along a N addition gradient after six-year NH4NO3 addition and mowing treatments in an Inner Mongolian temperate meadow steppe in northern China.ResultsWe found that the response of plant caloric value to N addition at different organizational levels was diverse. The caloric value of legumes increased linearly with N addition rates. The caloric value of grasses exhibited a non-linear response trend, initially increasing followed by saturation or decrease, with a N response threshold present. Due to the dominance of grass species, the caloric value at the community level followed a similar pattern to that of the grasses along the N addition gradient. Under mowing, the caloric value of plants at each organizational level increased and usually mowing enhanced the N response threshold. Amongst these, the N response threshold of Leymus chinensis increased from 3.302 to 5.443 g N m−2 yr−1, grasses increased from 4.414 to 5.746 g N m−2 yr−1, and community increased from 5.373 to 9.216 g N m−2 yr−1. Under non-mowing treatment, the N response thresholds of the most dominant species, Leymus chinensis, and community energy standing crop were 10.001 and 15.119 g N m−2 yr−1, respectively. Under mowing, the energy standing crops showed a linear increasing trend.ConclusionsN response thresholds of plant caloric value and energy standing crop vary at different organizational levels (community > functional group > species). The results reveal varying regulatory capabilities of plants on the ecological environment at different organizational levels. These findings enhance our understanding of plant-environment interactions in grassland ecosystems under N deposition from an energy perspective, which is of great significance to clarify the response mechanism of grassland ecosystem structure and function to N deposition.

Comprehensive assessment of the climatic and vegetation impacts of wind farms on grasslands: A case study in inner Mongolia, China

Although wind power contributes to the reduction of greenhouse gas emissions, it also has significant impacts on the local climate and vegetation. Exploring these impacts is important for the sustainable development of wind power. Therefore, based on moderate-resolution imaging spectroradiometer (MODIS) data and other remote sensing data from 2003 to 2022, this paper investigated the impacts of 101 grassland wind farms (WFs) in Inner Mongolia on land-atmosphere water and heat exchange, vegetation growth, ecosystem primary productivity, and vegetation structural characteristics during the growing season and revealed the spatial distribution patterns of the impacts of WFs as well as differences between different types of grasslands. The results indicated that WFs increased the nighttime land surface temperature (LST), decreased evapotranspiration (ET), inhibited vegetation growth, decreased gross primary productivity (GPP), and reduced the leaf area index (LAI) in growing season grasslands. This effect varied across different types of grasslands and showed significant complexity. In terms of land-atmosphere water and heat exchange, nighttime LST increases and ET decreases were significant in the typical steppe but not in the meadow steppe. In terms of vegetation change, meadow steppe had the most inhibited vegetation growth and the greatest reduction in GPP. In terms of the impact range, WFs on typical steppe and meadow steppe have opposite effects on vegetation growth and ecosystem primary productivity inside and outside of them, i.e., they inhibit vegetation growth and reduce GPP inside the WF areas but promote vegetation growth and increase GPP outside the WF areas. Compared with previous studies, this study analyzed multiple climate and vegetation indicators based on many WF samples, which reduced the uncertainty associated with a single sample and provided more comprehensive and comparable observations of different types of grasslands. These findings can help to balance the relationship between wind power development and ecological protection.

Differential responses of soil phosphorus fractions to varied nitrogen compound additions in a meadow steppe

Nitrogen (N) addition can greatly influence soil inorganic phosphorus (Pi) and organic phosphorus (Po) transformations. However, whether and how the N compound forms may differentially affect the soil P fractions remain unclear. Here, we investigated the responses of soil Pi (labile Pi, moderately-occluded Pi, and recalcitrant Pi) and Po fractions (labile Po and stable Po) to varying addition rates of three N compounds ((NH4)2SO4, NH4NO3, and urea) in a meadow steppe in northern China. Our studies revealed that with increasing N addition rate, soil labile and moderately-occluded Pi increased, accompanied by decreases in soil recalcitrant Pi. This shift was attributed to N-induced soil acidification, which accelerated the conversion of recalcitrant Pi into labile and moderately-occluded Pi. Soil labile Po decreased with increasing rate of N addition, whilst soil stable Po was not affected. Regardless of the compound forms, N addition increased soil Olsen-P, suggesting a potential alleviation of P limitation in this grassland ecosystem. The effect of N addition on soil labile Pi was significantly greater with addition of urea than with addition of either (NH4)2SO4 or NH4NO3, indicating that urea was more efficient in enhancing soil P availability. Addition of (NH4)2SO4 imposed a more pronounced positive effect on soil moderately-occluded Pi than the addition of either NH4NO3 or urea, mainly due to the greater mobilization of recalcitrant Pi as a result of higher soil acidification strength of (NH4)2SO4. These findings underscore the importance of considering the distinct effects of different N compounds when studying grassland soil P dynamics and availability in response to N addition.

ISSUES OF LIVESTOCK FARMING IN THE RESEARCH OF B. KH. KARMISHEVA

It is known that in the late 19th and early 20th centuries, animal husbandry developed in its own way, as one of the important industries along with agriculture. The favorable climate of the southern oasis and the availability of wide pastures are important in this. The scientific study of this area has been widely analyzed in the studies of ethnographers such as B. Karmisheva, K. Shoniyozov, I. Hidoyatov, N. Borozna. Among them, the work of B. Kh. Karmisheva is also important, the scientist distinguishes four types of animal husbandry in his works. These are the portable method, the plowing-pasture method, the plowing method and the plowing method. The article reveals the specific aspects, differences, similarities, and gradual development of these methods over time. In addition, an attempt was made to reveal the types of livestock, their distribution by regions and breeds. In the course of the article, it was emphasized that the economic activities and traditional activities of the residents of the Central Asian region have ancient historical experiences and are distinguished by their own characteristics. It has been shown on the basis of various sources that the inhabitants of the oasis are considered one of the peoples with an ancient sedentary culture, which preserved and improved the traditions of their ancestors for thousands of years. B.Kh. Karmisheva said that the descendants of large tribes such as Transoxiana Turks, Kungyrot, Lokai, Karluq, Turks, who came from the Dashti Kipchak, from the tribes that were formerly nomads, were herdsmen. It tries to reveal on the basis of field materials that they were driven to the steppe meadows, and how cattle breeding affected their way of life.

Gradient variations in rhizospheric soil exchangeable cations across a forest-steppe transect

The forest-steppe ecotone (FSE) is vulnerable to climate change and valuable to predict ecosystem succession. Although species diversity covaries with climatic factors and changes gradually across FSE transects, aligning with “Whittaker’s hierarchy theory”, whether soil nutrients follow a similar distribution pattern remains unclear. We studied the ecological gradient changes in effective cation-exchange capacity (ECEC, sum of exchangeable Ca2+, Mg2+, K+ and Na+) in the near-neutral-pH rhizosphere and bulk soils along the north–south zonal transect of the Hulunbuir FSE, China. The 230-km transect includes hierarchical transitions from two closed forests through two FSE to four meadow steppes. For both rhizosphere and bulk soils, soil ECEC were the highest in meadow steppes followed by closed forests and FSE area. ECEC were inversely correlated with soil water content but positively with soil pH. Therefore, the distribution of ECEC along the forest-steppe transect did not conform to a hierarchical distribution and decoupled from vegetation transitions, possibly due to the fact that the distribution of soil pH, plant uptake and leaching break the uniformity of ECEC variation along the gradient. In closed forests and FSE ecosystems, the ECEC and exchangeable Ca2+ in rhizosphere soils were higher than those in bulk soil, indicating that rhizosphere processes may alleviate cation limitation in these ecosystems. The study substantially improves our understanding of soil nutrient mobilization and soil fertility across forest-steppe ecotones which helps projecting ecosystem succession. It further highlights the critical role of rhizosphere processes in modulating hierarchical vegetation transition along environmental gradients and provides avenues for future research opportunities.

Glomalin-Related Soil Protein Plays Different Roles in Soil Organic Carbon Pool Maintaining among Different Grassland Types

Glomalin-related soil protein (GRSP) is an important component of soil organic carbon (SOC), which can promote long-term SOC sequestration. However, GRSP distribution characteristics and its contribution to the SOC pool among different grassland types remain poorly understood. Therefore, six grassland types (alpine meadow, mountain meadow, temperate meadow steppe, temperate steppe, temperate desert steppe, and temperate desert) were chosen to evaluate the contribution of GRSP to the SOC pool and the factors that influence GRSP accumulation in the Irtysh River Basin in China. The results revealed that GRSP (EE-GRSP, T-GRSP) accumulated more in the 0–10 cm soil layer than in the 10–20 cm soil layer (p < 0.05). GRSP content was higher in alpine grasslands (15.69 mg·g−1) than in desert grasslands (5.45 mg·g−1). However, their contribution to the SOC pool exhibited an opposite trend, whereas GRSP-C/SOC even accounted for 11.88% in the desert grasslands. The redundancy analysis (RDA) showed that SOC was the top important positive regulator for GRSP accumulation both in the two layers (explanatory rate > 80%). Besides the SOC factor, the two soil layers had different factors in regulating GRSP accumulation. Changes in GRSP content in the 0–10 cm soil layer were more strongly associated with mean annual temperature (MAT), sand content, soil water content (SWC), and silt content. In contrast, in the 10–20 cm soil layer, GRSP content was more influenced by SWC, electrical conductivity (EC), and pH (p < 0.05). Additionally, the main factor in the GRSP content variation was the interaction between climate and soil in the two soil layers (explanatory rate > 80%). Our findings underscore the critical role of GRSP in facilitating SOC sequestration within desert grasslands and elucidate the primary factors driving GRSP distribution across varying soil depths.

Phytochemical Characteristics and Antimicrobial Effects of Nonea rossica (Boraginaceae) Extracts.

Phytochemical characteristics and antimicrobial properties of extracts were studied in Nonea rossica Steven (Boraginaceae), which is widespread in Russia. The aerial part (herb) of N. rossica was harvested from a steppe meadow in the Novosibirsk region during flowering. The qualitative composition of biologically active compounds (BACs) was determined by thin-layer chromatography. Quantitative assays were carried out by spectrophotometry; flavonoids, hydroxycinnamic acids, and coumarin-like compounds were measured with reference to rutin, caffeic acid, and coumarin, respectively. Antimicrobial activity was determined by the serial dilution method. Gram-positive bacterial (Staphylococcus aureus ATCC 6538 FDA 209P and Bacillus cereus ATCC 10702) and fungal (Candida albicans NCTC 885-653) strains were used as test cultures. Phenolic BACs (hydroxycinnamic acids, flavonoids, and coumarins) were detected, and their quantitative contents determined. The highest yield of phenolic BACs was achieved using 40-70% ethanol as an extractant. Antimicrobial activity against S. aureus and B. cereus and antifungal activity against C. albicans were detected in N. rossica herb extracts prepared using 40-70% ethanol. The extracts were tested for the contents of caffeic acid and coumarin. Synergistic interactions of these compounds determined the bactericidal and fungistatic properties of the extracts.

Long-term grassland diversity-productivity relationship regulated by management regimes in northern China

Grasslands are the most extensively distributed terrestrial ecosystems on Earth, providing a range of ecosystem services that are vital for sustaining human life and critical for sustainable development at the global scale. However, the relationship between the two most important attributes of grassland, plant diversity, and productivity, remains controversial even after many years of research. Here, we develop an analysis of covariance (ANCOVA) model based on decadal-scale experimental data from a degraded meadow steppe in northeastern Inner Mongolia, China to quantify the response of aboveground biomass (AGB) to plant species diversity under varying management regimes. We report that AGB responds negatively to the plant diversity in fallow grasslands and positively in grazing grasslands, transiting from negative to positive in mowing grasslands as mowing became more frequent. We show that the changing diversity-productivity relationships are driven by changes in species composition of the plant community, given the significant productivity gap between rare and non-rare species. This highlights the role of management in regulating the diversity-productivity relationships in grasslands. These results not only provide provocative insights into the relationships between plant diversity and productivity but also support more sustainable use and management of grassland resources.

Responses in species diversity in the Hulunbuir grassland to phosphorus addition under nitrogen-limiting and non-limiting conditions.

The phenomenon of nitrogen deposition resulting in species loss in terrestrial ecosystems has been demonstrated in several experiments. Nitrogen (N) and phosphorus (P), as major nutrients required for plant growth, exhibit ecological stoichiometric coupling in many ecosystems. The increased availability of nitrogen can exacerbate the ecological effects of phosphorus. To reveal the ecological effects of phosphorus under nitrogen-limiting and non-limiting conditions, we conducted a controlled N-P interaction experiment over 5 years in the Hulunbuir meadow steppe, where two nitrogen addition levels were implemented: 0g N·m-2·a-1 (nitrogen-limiting condition) and 10g N·m-2·a-1 (nitrogen-non-limiting condition), together with six levels of phosphorus addition (0, 2, 4, 6, 8, and 10g P·m-2·a-1). The results showed that nitrogen addition (under nitrogen-non-limiting conditions) significantly decreased species diversity in the steppe community, which was exacerbated under phosphorus addition. Under nitrogen-limiting conditions, phosphorus addition had no marked impact on species diversity compared to the control; however, there were substantial differences between different levels of phosphorus addition, exhibiting a unimodal change. Under both experimental nitrogen conditions, the addition of 6g P·m-2·a-1 was the threshold for affecting the community species diversity. Nitrogen addition reduced the relative biomass of legumes, bunch grasses, and forbs, but substantially increased the relative biomass of rhizomatous grasses. In contrast, phosphorus addition only markedly affected the relative biomass of forbs and rhizomatous grasses, with the former showing a unimodal pattern of first increasing and then decreasing with increasing phosphorus addition level, and the latter exhibiting the opposite pattern. The different responses of rhizomatous grasses and other functional groups to nitrogen and phosphorus addition were observed to have a regulatory effect on the changes in grassland community structure. Phosphorus addition may increase the risk of nitrogen deposition-induced species loss. Both nitrogen and phosphorus addition lead to soil acidification and an increase in the dominance of the already-dominant species, and the consequent species loss in the forb functional group represents the main mechanism for the reduction in community species diversity.

Alpine meadow and alpine steppe plant-soil network in Qinghai-Tibet Plateau, China

Alpine meadow and alpine steppe are crucial ecosystem types in the Qinghai-Tibet Plateau. However, due to ecosystem fragility and human disturbance, the nutrient imbalance between plant and soil leads to grassland degradation. From a systematic perspective, there needs to be a comprehensive understanding of the plant and soil traits within these two ecosystem types. This study addressed this gap by constructing plant-soil trait networks for alpine meadow and alpine steppe, identifying bridge traits, and comparing the stability and distinctions of the two trait networks. The results demonstrated a significant difference in the distribution of network structure edge weights between the alpine meadow and steppe. In the network of alpine meadow, the soil organic carbon was responsible for linking plant and soil traits, exhibiting the highest impact. Conversely, the network of alpine steppe revealed an increasing negative correlation between plant and soil traits. The results of bridge traits agreed with the optimal distribution hypothesis. The bridge traits of the alpine meadow were aboveground traits (AGB or PlantC), while those of the alpine steppe were belowground traits (BGB and RootN). Based on our findings, different management measures could be taken. The alpine meadow could be primarily restored through natural processes, and climate warming would enhance its carbon sequestration capacity. The alpine steppe ecosystem exhibits low nitrogen availability, which could be augmented through fertilisation or the return of yak manure.

Temporal stability responses to nitrogen addition in Xizang alpine grasslands: A community composition perspective

Plant community composition typically undergoes progressive changes along environmental gradients. However, most experimental studies have focused on individual communities, so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients. Along a rainfall gradient on the northern Xizang Plateau, we conducted an 8-year nitrogen (N) addition experiment in four alpine grasslands (alpine desert steppe, ADS; alpine steppe, AS; alpine meadow steppe, AMS; and alpine meadow, AM) and used two-way ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands. We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients, while there was no change in AS and a gradual increase in ADS. The temporal stability showed different patterns of gradual decreases in ADS and AM, and a unimodal trend in AMS with increasing N gradients. However, N addition had no effect on the temporal stability of AS. Dominant species stability was the controlling factor for alpine grasslands along the transect, while the effect of asynchrony gradually increased with decreasing precipitation. These findings highlight that community composition, especially the dominant species, along the environmental gradient can mediate the effects of N inputs on community temporal stability. Thus, the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.

ISSUES OF LIVESTOCK FARMING IN THE RESEARCH OF B. KH. KARMISHEVA

It is known that in the late 19th and early 20th centuries, animal husbandry developed in its own way, as one of the important industries along with agriculture. The favorable climate of the southern oasis and the availability of wide pastures are important in this. The scientific study of this area has been widely analyzed in the studies of ethnographers such as B. Karmisheva, K. Shoniyozov, I. Hidoyatov, N. Borozna. Among them, the work of B. Kh. Karmisheva is also important, the scientist distinguishes four types of animal husbandry in his works. These are the portable method, the plowing-pasture method, the plowing method and the plowing method. The article reveals the specific aspects, differences, similarities, and gradual development of these methods over time. In addition, an attempt was made to reveal the types of livestock, their distribution by regions and breeds. In the course of the article, it was emphasized that the economic activities and traditional activities of the residents of the Central Asian region have ancient historical experiences and are distinguished by their own characteristics. It has been shown on the basis of various sources that the inhabitants of the oasis are considered one of the peoples with an ancient sedentary culture, which preserved and improved the traditions of their ancestors for thousands of years. B.Kh. Karmisheva said that the descendants of large tribes such as Transoxiana Turks, Kungyrot, Lokai, Karluq, Turks, who came from the Dashti Kipchak, from the tribes that were formerly nomads, were herdsmen. It tries to reveal on the basis of field materials that they were driven to the steppe meadows, and how cattle breeding affected their way of life.

Technogenic transformation of the Lena River floodplain near Yakutsk and assessment of landscape disturbance

The Tuymaada Valley located in the Yakutsk region represents the most developed region within the Lena River fllodplain. Landscape studies conducted here between 2016 and 2022 revealed a significant level of technogenic transformation: 30.4 % of its sites showed a high and moderate degree of disturbance. The primary driver of landscape development was the transformation of forested areas into meadows due to centuries of grazing in the floodplain. The current trend in evolution involves replacing agricultural stows with residential ones, leading to an increase in mechanical disturbances to the landscape structure. Water protection dams have removed significant areas of the left bank floodplain from the flood zone. Consequently, some of its stows become swamped, while others transform into dry wastelands with low-value steppe meadows. Currently, at the investment justification stage, the issue of providing comprehensive protection for the entire left bank of the Tuymaada valley from the adverse effects of floods and inundations is under consideration. For its continued growth, it is essential to implement not just protective measures but also environmental and improvement measures for both existing and new urban, rural, and economic-technical zones on the developing technogenic terrace.

Spatial distribution and drivers of arbuscular mycorrhizal fungi on the Tibetan Plateau.

Arbuscular mycorrhizal fungi (AMF) are pivotal in plant resource acquisition, mediating plant interactions, and influencing soil carbon dynamics. However, their biogeographical distribution in Tibetan alpine grasslands remains understudied. In this research, we examined the distribution pattern of AMF communities and their key determinants along a 2000-km transect across the Tibetan plateau, encompassing 7 alpine meadows and 8 alpine steppes. Our findings indicate that AMF community diversity and composition exhibit similarities between alpine meadows and alpine steppes, primarily influenced by latitude and evapotranspiration. At the genus level, Glomus predominated in both alpine meadow (36.49%±2.67%) and alpine steppe (41.87%±2.36%) soils, followed by Paraglomus (27.14%±3.69%, 32.34%±3.28%). Furthermore, a significant decay relationship of AMF community was observed over geographical distance. Null model analyses revealed that random processes predominantly (>50%) drove the assembly of AMF communities. In summary, our study elucidates the spatial distribution pattern of AMF in Tibetan plateau grasslands and underscores the significant influence of geographical and climatic factors on AMF community dynamics.

Species richness and dominant functional groups enhance aboveground biomass, with no effect on belowground biomass in Qinghai-Tibet Plateau's grasslands

Understanding the role of plant diversity in maintaining grassland ecosystem functioning is of great importance in ecological research. Despite decades of research, ecologists have struggled to understand the biodiversity-ecosystem functioning relationships and how the dominance of plant functional groups impacts ecosystem function. In attempting to understand (i) the temporal patterns of above- and below-ground biomass (AGB and BGB) and species richness, (ii) whether species richness is consistently associated with AGB and BGB, and (iii) the relative contributions of plant functional groups (forb, grass, legume, and sedge) in stabilizing ecosystem function, we used biomass productivity data of meadow steppe and alpine meadow in the Qinghai-Tibet Plateau (QTP) for the period 2015–2019. Our results show that AGB for both grasslands increased, but BGB stayed steady over 5 years. The rising tendency of AGB was caused by the upward trend of AGB in forbs and grasses, which are the dominant functional groups in QTP, stressing the importance of dominant functional groups to ecosystem functioning. The biodiversity-ecosystem functioning relationships were significantly positive for AGB, stable for BGB, and negative for the BGB:AGB ratio, which highlights the crucial role of higher species richness in ecosystem functioning. Significant differences in mean species richness among sites (9–19 species in meadow steppe and 8–22 species in alpine meadow) highlight the varying levels of species diversity across sites in the QTP. While 42% of the sites showed stable species richness, the reported increasing trends in species richness at 58% of the sites indicate the potential for ecological changes or processes in these areas. AGB in both grasslands increased, while BGB remained stable with increasing precipitation. The top soil layer (0–10 cm) dominated the observed BGB in both grasslands, as abundant nutrients in the top layer provide favorable conditions for root proliferation. In meadow steppe, AGB formed an isometric relationship with BGB, indicating that AGB increased with BGB. This study concludes that species richness influenced ecosystem functioning, and forbs and grasses dominated biomass productivity, of which the topsoil layer contributed three-quarters of BGB. Our study (i) provides empirical evidence of stable to increasing species richness in both grasslands over 5 years, and (ii) highlights the role of greater species richness in enhancing ecosystem functioning. These findings serve as a scientific reference for policymaking regarding ecosystem stability.

СHERNOZEM SCIENCE - THE SCIENCE ABOIT CHERNOZEM

The article outlines views on the modern scientific and practical significance of chernozem, emphasizing its special role in the history of science and humanity. The main attention is paid to the issues of geographical distribution, genesis, composition, structure, properties, rational use, restoration, preservation and protection. Problems related to the manifestation of degradation processes are considered: erosion, deflation, compaction, dehumification, destructuring, etc. Emphasis is placed on the role and importance of chernozems in the world of soils as a phenomenon of nature, ideal soil, feeder and means of work. In the Cenozoic period, three events stand out - not destructive, but creating, large in their progressive consequence. In the world of plants, this is the development of angiosperm families and genera, and among them cereals, which played a prominent role in the composition of specific herbaceous and cereal phytocenoses, and later in the food base of humans and domestic animals. Mammals began to predominate in the animal world, primates appeared, as a result of their long evolution, the first humanoids appeared already in the anthropogenic period. In the world of soils, the formation of chernozems began. The initial stage is the expansion of cereals and the formation on extensive, but mainly loess plains of meadow and grass-cereal steppes, under which chernozems began to form - soils of the "gathering" type, in contrast to the already existing podzolic and feralitic soils of the "dispersive" type, which are characterized by weak accumulation humus and dispersion - removal of chemical elements - biogens and many trace elements. Based on the analysis of extensive scientific research and publications about chernozem and its importance in society, it is expedient to develop a doctrine about chernozem and to single out a separate direction in the development of the science of soil science - chernozemology. Black geology is a field of soil science that studies the formation (genesis), structure, composition and properties, patterns of geographical distribution, processes of interaction with the external environment, which determine the formation and development of the main property - fertility, ecological and social functions, aesthetic value, ways of rational use, reproduction, preservation and protection. The question of chernozem and its degradation in the modern world is not only agronomic, ecological, economic, legal, aesthetic, but also political. Radical and tough decisions are needed so that the quiet crisis of the planet does not turn into a loud one in the foreseeable future. Evaluating the global importance of chernozem in the world of soils, it is advisable to develop a special course "Chernozem Science" for students of natural and agricultural specialties of higher educational institutions of Ukraine. Key words: chernozem, natural phenomenon, degradation, erosion, morphology, properties, ideal of perfection, aesthetic value.

Vegetation cover is a crucial key to the success of ecological restoration in the desertified steppe of Inner Mongolia

In this study, we analyzed the environmental factors influencing the restoration process of the degraded ecosystem in the Inner Mongolian steppe, the largest steppe ecosystem in Asia, which is experiencing rapid desertification, and evaluated the effects of restoration on the damaged ecosystem in China. For this purpose, we selected degraded steppe areas left to desertification in the Hulunbuir region, four restored sites where vegetation was artificially introduced for restoration, and reference ecosystems, including a non-desertified area with the dominant Pinus sylvestris var. mongolica community and a meadow steppe area. We conducted analyses and monitoring of plant community characteristics and soil environmental factors to assess the progress of restoration. The results showed that the introduction of indigenous woody plants in the degraded areas led to a proportional increase in vegetation cover, plant biodiversity, and species abundance over time. The primary external forces driving the succession of vegetation in the restored sites were soil factors including organic matter content, temperature and total nitrogen levels, which were associated with an increase in vegetation cover. These results can be interpreted as an increase in vegetation cover leading to an increase in litter production. This in turn reduces soil temperature and evaporation, subsequently enhancing the activity of soil microorganisms. Over time, the species composition, structural diversity of communities, and ecosystem functions in the restored sites gradually became more similar to those of the reference ecosystems. This indicates that vegetation restoration in this area has been very successful. In particular, the positive change in local residents’ awareness regarding the necessity of restoration has been considered a crucial contribution to the success of restoration in the degraded areas. It has led to a decrease in perceived anthropogenic threats to the restored sites. These results indicate that the introduction of native woody plants is crucial and can increase vegetation cover and species composition complexity and local residents’ positive perception of restoration for the successful restoration of desertified drylands.

Soil environmental anomalies dominate the responses of net ecosystem productivity to heatwaves in three Mongolian grasslands

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 CO2 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.