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Soil mesofauna play pertinent roles in soil processes. For example, microarthropods strongly influence rates of microbial decomposition. The relationship between mesofauna and their environment are understudied in low Arctic ecosystems compared to other regions. A more detailed grasp of these soil assemblages is necessary for understanding the current functioning of these ecosystems. We characterized the soil mesofauna community across different low Arctic habitats to determine which soil properties commonly correlated with soil fauna would best explain their distribution, abundance, and diversity. Samples were taken near five different lakes in northern Finland, in both alpine meadows and sub-alpine birch forests, across a span of available soil habitats (measured by pH, salinity, organic and nitrogen content, soil moisture). Total abundance of the mesofauna community was influenced by a combination of soil factors, but most individual taxa, as well as measures of diversity were best explained by models of one or two influential soil parameters. Poduromorpha springtails and Oribatid mites were best modeled by measures of resource availability, although only Oribatids were significantly, positively related to these resources. All mites and Entomobryomorphid springtails were positively influenced by physicochemical soil moisture and/or salinity. Salinity, in particular, had a strong influence on overall mesofauna community composition. Our results provide further insight into soil fauna assemblages in Northern Finland and further, more extensive research would contribute to a more comprehensive foundation. This will allow for better monitoring of community changes and responses in the face of climate change in the low Arctic. [ABSTRACT FROM AUTHOR]

Accurate estimation of livestock carrying capacity (LCC) and implementation of an appropriate actual stocking rate (ASR) are key to the sustainable management of grazing adapted alpine grassland ecosystems. The reliable determination of aboveground biomass is fundamental to these determinations. Peak aboveground biomass (AGBP) captured from satellite data at the peak of the growing season (POS) is widely used as a proxy for annual aboveground biomass (AGBA) to estimate LCC of grasslands. Here, we demonstrate the limitations of this approach and highlight the ability of POS in the estimation of ASR. We develop and trail new approaches that incorporate remote sensing phenology timings of grassland response to grazing activity, considering relations between biomass growth and consumption dynamics, in an effort to support more accurate and reliable estimation of LCC and ASR. The results show that based on averaged values from large-scale studies of alpine grassland on the Qinghai-Tibet Plateau (QTP), differences between AGBP and AGBA underestimate LCC by about 31%. The findings from a smaller-scale study that incorporate phenology timings into the estimation of annual aboveground biomass reveal that summer pastures in Haibei alpine meadows were overgrazed by 11.5% during the study period from 2000 to 2005. The methods proposed can be extended to map grassland grazing pressure by predicting the LCC and tracking the ASR, thereby improving sustainable resource use in alpine grasslands. [ABSTRACT FROM AUTHOR]

A plethora of names has been applied to upper Cambrian and Lower Ordovician lithostratigraphic units distributed from western Utah to southeastern and central Nevada. We report comprehensive stratigraphic analysis utilizing lithologic, conodont, brachiopod, sequence stratigraphic, and carbon isotope data from several ranges in southeastern Nevada. Those data demonstrate that upper Cambrian to Lower Ordovician strata in that area belong to a variety of depositional systems that can be integrated into a comprehensive and functional depositional model that span carbonate tidal flat to shallow marine carbonate ramp to shelf to deep marine settings. Most of these strata should be placed within a single lithostratigraphic nomenclature based on the well-known Notch Peak Formation and House Limestone of western Utah. Strata of the Whipple Cave Formation in the South Egan Range, Nevada are reassigned to the three members of the Notch Peak Formation. Strata assigned to the Nopah Formation and Pogonip Group by geologic mappers who worked in the Delamar Mountains, Meadow Valley Mountains, Sheep Range, and Arrow Canyon Range in Nevada are reassigned to the Notch Peak Formation and overlying House Limestone. Coeval strata farther west record a deeper marine depositional setting and are appropriately assigned to the Windfall Formation and Goodwin Limestone. Conodonts and sequence stratigraphic packages identified from slope deposits of the Hales Limestone at Tybo Canyon in the Hot Creek Range allow correlation to the Notch Peak Formation and House Limestone in western Utah. [ABSTRACT FROM AUTHOR]

Background and aims: Planting artificial grassland has been widely implemented to restore the extremely degraded alpine meadow. However, the restoration effect of different planting patterns of artificial grassland on the alpine plant and soil is poorly understood. Methods: Three typical native grass species (Elymus nutans, Poa pratensis L. cv. Qinghai, Festuca sinensis) were planted in two patterns: P. pratensis monoculture and mixed sowing containing all three species. The plant, soil physicochemical properties, and soil bacterial community under two different planting patterns in the degraded alpine meadow of Qilian Mountain were evaluated. Results: The aboveground, belowground biomass, coverage, Shannon-winner, and richness diversity of the mixed sowing grassland was approximately 144%, 111%, 113%, 144%, and 205% higher than that of the monoculture grassland. Furthermore, the mixed sowing grassland significantly increased the soil total nitrogen and water content than monoculture grassland. The soil bacterial Chao1 and ACE diversity in mixed sowing was significantly lower than in monoculture grassland. Soil bacterial species network analysis revealed a higher complexity of the mixed plot than the monoculture. The redundancy analysis (RDA) model suggested that plant characteristics caused more variation in the soil bacterial community than in soil physicochemical characteristics. Conclusions: The results show that mixed sowing had more positive restoration on plant and soil than monoculture, and could be recommended for the restoration of degraded alpine meadow. [ABSTRACT FROM AUTHOR]

Background: Ticks are blood-feeding significant arthropods that can harbour various microorganisms, including pathogens that pose health risks to humans and animals. Tick-symbiont microorganisms are believed to influence tick development, but the intricate interactions between these microbes and the relationships between different tick-borne microorganisms remain largely unexplored. Results: Based on 111 tick pool samples presenting questing and engorged statuses including 752 questing tick and 1083 engorged tick from cattle and goats, which were collected in two types of geographic landscape (semi-desert and alpine meadow). We observed significant variations in the composition of tick-borne microorganisms across different environments and blood-engorgement statuses, with a pronounced divergence in symbionts compared to environmental bacteria. Metabolic predictions revealed over 90 differential pathways for tick-borne microorganisms in distinct environments and more than 80 metabolic variations in response to varying blood engorgement statuses. Interestingly, nine pathways were identified, particularly related to chorismate synthesis and carbohydrate metabolism. Moreover, microbial network relationships within tick-borne microorganism groups were highly distinct across different environments and blood-engorgement statuses. The microbial network relationships of symbionts involve some pathogenic and environmental microorganisms. Regression modelling highlighted positive correlations between the Coxiella symbiont and related pathogens, while some environmental bacteria showed strong negative correlations with Coxiella abundance. We also identified commensal bacteria/pathogens in bacterial cooccurrence patterns. Furthermore, we tested pathogenic microorganisms of each tick sample analysis revealed that 86.36% (1601/1855) of the tick samples carried one or more pathogenic microorganisms, The total carrier rate of bacterial pathogens was 43.77% ((812/1855). Most blood samples carried at least one pathogenic microorganism. The pathogens carried by the ticks have both genus and species diversity, and Rickettsia species are the most abundant pathogens among all pathogens. Conclusion: Our findings underscore that the bacterial pattern of ticks is dynamic and unstable, which is influenced by the environment factors and tick developmental characteristics. [ABSTRACT FROM AUTHOR]

Plant diversity can significantly affect the grassland productivity and its stability. However, it remains unclear how plant diversity affects the spatial stability of natural grassland productivity, especially in alpine regions that are sensitive to climate change. We analyzed the interaction between plant (species richness and productivity, etc.) and climatic factors (precipitation, temperature, and moisture index, etc.) of alpine natural grassland on the Qinghai-Tibetan Plateau. In addition, we tested the relationship between plant diversity and spatial stability of grassland productivity. Results showed that an increase in plant diversity significantly enhanced community productivity and its standard deviation, while reducing the coefficient of variation in productivity. The influence of plant diversity on productivity and the reciprocal of productivity variability coefficient was not affected by vegetation types. The absolute values of the regression slopes between climate factors and productivity in alpine meadow communities with higher plant diversity were smaller than those in alpine meadow communities with lower plant diversity. In other words, alpine meadow communities with higher plant diversity exhibited a weaker response to climatic factors in terms of productivity, whereas those with lower plant diversity showed a stronger response. Our results indicate that high plant diversity buffers the impact of ambient pressure (e.g., precipitation, temperature) on alpine meadow productivity, and significantly enhanced the spatial stability of grassland productivity. This finding provides a theoretical basis for maintaining the stability of grassland ecosystems and scientifically managing alpine grasslands under the continuous climate change. [ABSTRACT FROM AUTHOR]

Meconopsis biluoensis, a new species of Papaveraceae in an alpine meadow from Yunnan, Southwest China, is described and illustrated. Morphologically, it resembles Meconopsis georgei, while it is distinct in acaulescent and hispid with clearly expanded bases on the leaves. A genus‐level molecular phylogenetic analysis supported the closest relationship between M. biluoensis and M. georgei. In a finer population‐level molecular phylogenetic analysis using ribosomal DNA (rDNA) and the chloroplast genome, individuals from M. biluoensis and M. georgei were clearly separated, and the extremely short branch length indicated that the two species had a very short differentiation time. The species has currently been assessed as "endangered" (EN) due to its small‐sized population and narrow distribution following the IUCN categories and criteria. [ABSTRACT FROM AUTHOR]

Backgrounds: Climate change is well-known to alter the structure and function of grassland ecosystems, and multifunctionality contributes to a comprehensive understanding of the impacts of climate change on ecosystem functions. Warming and humidification are predicted to be the climate change trend on the northeastern Qinghai-Tibetan Plateau. However, understanding of how long-term warming and increased precipitation affect ecosystem multifunctionality in alpine meadows is still limited. Methods: Here, we conducted an 8-year field experiment involving warming and increased precipitation in an alpine meadow to explore how warming, increased precipitation, and their interaction affect ecosystem multifunctionality. Results: The results indicated that increased precipitation had a positive effect on ecosystem multifunctionality. However, warming and the interaction of warming and precipitation had no significant effects on it. Warming decreased species richness and plant coverage. Increased precipitation enhanced aboveground carbon (C), nitrogen (N), and phosphorus (P) pools of plant community, and soil moisture, but decreased soil pH. Aboveground P and N pools of plant community and microbial biomass nitrogen (MBN) were important predictors of ecosystem multifunctionality. Conclusion: This study demonstrated long-term increased precipitation can enhance ecosystem multifunctionality by indirectly affecting the individual functions (aboveground P and N pools of plant community and MBN), soil moisture, and pH in an alpine meadow. These findings highlighted that increased precipitation is more critical than warming for enhancing ecosystem multifunctionality in semi-arid alpine meadows. [ABSTRACT FROM AUTHOR]

Aims: Plant functional group (PFG) removal experiments are recognized as an effective way to explore the role of plant diversity and species traits in ecosystem functioning. To minimize soil physical disturbance in plant removal experiments, aboveground parts of targeted plant species are usually cut off without removing their roots from the soil. However, the potential effects of their remaining roots (partially as root litter) on soil nematode communities are still unclear. Methods: We used a three-year PFG removal experiment in a Qinghai-Tibet alpine meadow and set up root-ingrowth mesh bags for one year where removal target plants' roots existed only outside the mesh bags. Results: We found that nematode communities outside the mesh bags had higher nematode channel ratio and lower channel index values, indicating that the root litter outside the mesh bags increased energy flux to bacterial-feeding nematodes over fungal-feeding nematodes. The relative abundance of plant-feeding nematodes was higher inside than outside the mesh bags, probably because of a higher ratio of living roots inside the mesh bags. Non-metric multidimensional scaling showed that the structure of nematode communities inside and outside of mesh bags was generally differentiated except for the no-removal control treatment. Conclusions: We conclude that the remaining roots outside mesh bags could modify the relative abundance ratio of different nematode guilds and soil nematode community structures, suggesting legacy effects of target plants' roots in PFG removal experiments. [ABSTRACT FROM AUTHOR]

Although herbivores are well known to incur positive density‐dependent damage and mortality, thereby likely shaping plant community assembly, the response of belowground root feeders to changes in plant density has seldom been addressed. Locally rare plant species (with lower plant biomass per area) are often smaller with shallower roots than common species (with higher plant biomass per area) in competition‐intensive grasslands. Likewise, root feeders are often distributed in the upper soil layers. We hypothesized, therefore, that root feeders would incur negative density (biomass)‐dependent damage across plant species. To test this hypothesis, we investigated the diversity and abundance of plant and root feeder species in an alpine meadow and determined the diet of the root feeders using metabarcoding. Across all species, root feeder load decreased with increasing aboveground plant biomass, root biomass, and total plant biomass per area, indicating a negative density dependence of damage across plant species. Aboveground plant biomass per area increased with increasing individual plant biomass and root depth per area across species, suggesting that rare plant species were smaller in size and had shallower root systems compared to common plant species. Both root biomass per area and root feeder biomass per area decreased with soil depth, but the root feeder biomass decreased disproportionately faster compared to root biomass with increasing root depth. Root feeder load decreased with increasing root depth but was not correlated with the feeding preference of root feeder species. Moreover, the prediction derived from a random process incorporating vertical distributions of root biomass and root feeder biomass significantly accounted for interspecific variation in root feeder load. In conclusion, the data indicate that root feeders incur negative density‐dependent damage across plant species. On this basis, we suggest that manipulative experiments should be conducted to determine the effect of the negative density‐dependent damage on plant community structure and that different types of plant–animal interactions should be concurrently examined to fully understand the effect of plant density on overall herbivore damage across plant species. [ABSTRACT FROM AUTHOR]

Warming and precipitation anomalies affect terrestrial carbon balance partly through altering microbial eco-physiological processes (e.g., growth and death) in soil. However, little is known about how such processes responds to simultaneous regime shifts in temperature and precipitation. We used the 18O-water quantitative stable isotope probing approach to estimate bacterial growth in alpine meadow soils of the Tibetan Plateau after a decade of warming and altered precipitation manipulation. Our results showed that the growth of major taxa was suppressed by the single and combined effects of temperature and precipitation, eliciting 40-90% of growth reduction of whole community. The antagonistic interactions of warming and altered precipitation on population growth were common (~70% taxa), represented by the weak antagonistic interactions of warming and drought, and the neutralizing effects of warming and wet. The members in Solirubrobacter and Pseudonocardia genera had high growth rates under changed climate regimes. These results are important to understand and predict the soil microbial dynamics in alpine meadow ecosystems suffering from multiple climate change factors. [ABSTRACT FROM AUTHOR]

Climate change is significantly affecting mountain plant communities, causing dynamic alterations in species composition as well as spatial distribution. This raises the need for constant monitoring. The Tatra Mountains are the highest range of the Carpathians which are considered biodiversity hotspots in Central Europe. For this purpose, microwave Sentinel-1 and optical multi-temporal Sentinel-2 data, topographic derivatives, and iterative machine learning methods incorporating classifiers random forest (RF), support vector machines (SVMs), and XGBoost (XGB) were used for the identification of thirteen non-forest plant communities (various types of alpine grasslands, shrublands, herbaceous heaths, mountain hay meadows, rocks, and scree communities). Different scenarios were tested to identify the most important variables, retrieval periods, and spectral bands. The overall accuracy results for the individual algorithms reached RF (0.83–0.96), SVM (0.87–0.93), and lower results for XGBoost (0.69–0.82). The best combination, which included a fusion of Sentinel-1, Sentinel-2, and topographic data, achieved F1-scores for classes in the range of 0.73–0.97 (RF) and 0.66–0.95 (SVM). The inclusion of topographic variables resulted in an improvement in F1-scores for Sentinel-2 data by one–four percent points and Sentinel-1 data by 1%–9%. For spectral bands, the Sentinel-2 10 m resolution bands B4, B3, and B2 showed the highest mean decrease accuracy. The final result is the first comprehensive map of non-forest vegetation for the Tatra Mountains area. [ABSTRACT FROM AUTHOR]

The anatomical structure of roots determines their function. Coexisting species complementarily forage nutrients by roots themselves (e.g. root strategy) and their fungal partners (e.g. mycorrhizal strategy), leading to a trade‐off between root strategy and mycorrhizal strategy. However, few studies have specifically evaluated whether and how the root anatomical structures are involved in this trade‐off, especially for species in alpine ecosystems limited by extreme climate.Here, absorptive root anatomical and chemical traits and three key root traits commonly associated with nutrient foraging strategies, that is root strategy indicated by first‐order root length and root branching intensity and mycorrhizal strategy indicated by arbuscular mycorrhizal fungal colonization, were examined across 68 herbaceous species in alpine meadows of the Tibetan Plateau.We observed that absorptive roots with higher branching intensity had more protoxylem poles, thinner cortices and smaller cortical cells, whereas absorptive roots with higher mycorrhizal colonization and longer first‐order roots consistently had thicker cortices and larger cortical cells. Unexpectedly, root cortical traits responsible for nutrient uptake were decoupled from stelar traits specialized in water and nutrient transportation. The decoupling may be related to the non‐coordinated changes in soil water and nutrient availability in the meadows of the Tibetan Plateau. In addition, we found that root cortical thickness and stelar radius increased at a similar rate rather than well‐reported different rates with increasing root diameter.Synthesis: Our results demonstrate that root internal makeup plays an integral role in forming the diverse nutrient foraging strategies in below‐ground. These findings provide new insights into our understanding of plant coexistence and the responses of alpine meadows to climate change on the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

The ongoing climate change on the Tibetan Plateau, leading to warming and precipitation anomalies, modifies phosphorus (P) cycling in alpine meadow soils. However, the interactions and cascading effects of warming and precipitation changes on the key "extracellular" and "intracellular" P cycling genes (PCGs) of bacteria are largely unknown for these P‐limited ecosystems. We used metagenomics to analyze the individual and combined effects of warming and altered precipitation on soil PCGs and P transformation in a manipulation experiment. Warming and increased precipitation raised Olsen‐P (bioavailable P, AP) by 13% and 20%, respectively, mainly caused by augmented hydrolysis of organic P compounds (NaOH‐Po). The decreased precipitation reduced soil AP by 5.3%. The richness and abundance of the PCGs' community in soils on the cold Tibetan plateau were more sensitive to warming than altered precipitation. The abundance of PCGs and P cycling processes decreased under the influence of individual climate change factors (i.e., warming and altered precipitation alone), except for the warming combined with increased precipitation. Pyruvate metabolism, phosphotransferase system, oxidative phosphorylation, and purine metabolism (all "intracellular" PCG) were closely correlated with P pools under climate change conditions. Specifically, warming recruited bacteria with the phoD and phoX genes, which encode enzymes responsible for phosphoester hydrolysis (extracellular P cycling), strongly accelerated organic P mineralization and so, directly impacted P bioavailability in alpine soil. The interactions between warming and altered precipitation profoundly influenced the PCGs' community and facilitated microbial adaptation to these environmental changes. Warming combined with increased precipitation compensated for the detrimental impacts of the individual climate change factors on PCGs. In conclusion, warming combined with rising precipitation has boosting effect on most P‐related functions, leading to the acceleration of P cycling within microbial cells and extracellularly, including mineralization and more available P release for microorganisms and plants in alpine soils. [ABSTRACT FROM AUTHOR]

Meadows are the most important source of feed for extensive livestock farming in mountainous conditions, as well as providing many environmental services. The actual socioeconomic situation and climate change risk its conservation. That is why finding its optimal management is important. To do so, predictive models are a useful tool to determine the impact of different practices and estimate the consequences of future scenarios. Empirical models are a good analytical tool, but their applications in the future are limited. Dynamic models can better estimate the consequences of newer scenarios, but even if there are many dynamic models, their adaptation into grassland production estimation is scarce. This article reviews the most suitable predictive models for grass production in mountain meadows when data on agricultural management (mowing, grazing, fertilization) and forage value are available, considering the conservation of plant biodiversity. [ABSTRACT FROM AUTHOR]

The alpine meadow of the Qinghai–Tibetan Plateau is an essential terrestrial ecosystem that provides a livelihood for approximately 9.8 million local inhabitants and serves as a habitat for millions of livestock. Changing facets of the global environment, such as increased nitrogen deposition, have not only affected the abundance and quality of forgeable plants but have also increased the prevalence and severity of plant diseases caused by pathogens. However, whether or not and to what extent these pathogens affect the rangeland quality of the alpine meadow remains unclear. We conducted a factorial experiment with the exclusion of fungal and oomycete pathogens to investigate the impact of various pathogens on rangeland quality in an alpine meadow in the Qinghai–Tibetan Plateau. We measured forage production for each plant species, forage quality (including measurements of organic matter, crude protein, phosphorus, total phenolics, neutral detergent fiber (NDF), metabolizable energy, and digestibility) for 11 abundant species, and community composition. We found that fungal pathogen exclusion and the combination of fungal and oomycete pathogen exclusion primarily affected nutrient production by altering forage production rather than changing community composition or forage quality. Exclusion of both fungal and oomycete pathogens led to a significant increase in community forage production, although no significant effect was observed for individual exclusion of fungal or oomycete pathogens. Excluding either fungal pathogens alone or simultaneous exclusion of both fungal and oomycete pathogens significantly increased the metabolizable energy content of the community. In contrast, oomycete pathogen exclusion significantly decreased the forage metabolizable energy content of the community. The exclusion of both fungal and oomycete pathogens also considerably increased the yield of organic matter, total phenolics, NDF, digestible dry matter, and metabolizable energy. However, the direction and magnitude of the effect of fungal and oomycete pathogen exclusion varied widely across the different species studied. These results suggest that the interaction of fungal and oomycete pathogens constitutes an essential limiting factor in rangeland quality that has not been previously recognized. Greater attention should be placed on overall forage production rather than forage quality in the context of grassland pathogen control strategies. Furthermore, metabolizable energy content may serve as an effective indicator for predicting the impact of pathogenic activity on forage quality. [ABSTRACT FROM AUTHOR]

Low available soil nitrogen (N) limits plant productivity in alpine regions, and alpine plants thus resorb and reallocate N from senescing tissues to conserve this limited N during the non‐growing season. However, the destination and extent of N redistribution during plant senescence among above‐ and below‐ground organs, let alone other processes of translocation outside of plants and into the soil components, remain poorly understood.Utilizing 15N stable isotope as a tracer, we quantified N redistribution among above‐ and below‐ground plant organs and different soil components during senescence in an alpine meadow ecosystem, and explored the relationship between 15N partitioning among plant–soil N pools with seasonal fluctuations of plant functional traits.We found a substantial depletion of 15N in fine roots (−40% ± 2.8%) and above‐ground tissues (−51% ± 5.1%), and an enhanced 15N retention primarily in coarse roots (+79% ± 27%) and soil organic matter (+37% ± 10%) during plant senescence, indicating a dual role of roots with coarse roots acting as an N sink and fine roots as a source of N recycling during senescence. In parallel, we observed a temporal variation in plant functional traits, representing a shift from more acquisitive to more conservative strategies as the growing season ends, such as higher coarse root N and coarse root to fine root ratio. The seasonal trait variations were highly correlated with the 15N retention in coarse roots and soil organic matter. Particularly, 15N retention in particulate and mineral‐associated organic matter increased by 30% ± 12% and 24% ± 9%, respectively, suggesting a potential pathway through which fine root and microbial mortality contribute to 15N redistribution into soil N pools during senescence.Synthesis. N redistribution and seasonal plant trait fluctuation facilitate plant N conservation and ecosystem N retention in the alpine system. This study suggests a coupled above‐ground‐below‐ground N conservation strategy that may optimize the temporal coupling between plant N demand and ecosystem N supply in N‐limited alpine ecosystems. [ABSTRACT FROM AUTHOR]

Soil fungi are involved in the decomposition of organic matter, and they alter soil structure and physicochemical properties and drive the material cycle and energy flow in terrestrial ecosystems. Fungal community assembly processes were dissimilar in different soil layers and significantly affected soil microbial community function and plant growth. Grazing exclusion is one of the most common measures used to restore degraded grasslands worldwide. However, changes in soil fungal community characteristics during grazing exclusion in different types of grasslands are unknown. Here, we investigated the effects of a 9‐year grazing exclusion on soil properties, fungal community composition, and diversity in three grassland types (temperate desert, temperate steppe, and mountain meadow). The results showed that (1) in the 0–5 cm soil layer, grazing exclusion significantly increased the differences in SWC, SOC, KN, and N:P among the three grassland types, while the final pH, BD, TP, C:N, and C:P values were consistent with the results before exclusion. In the 5–10 cm soil layer, grazing exclusion significantly increased total phosphorus (TP) in temperate deserts by 34.1%, while significantly decreasing bulk density (BD) by 9.8% and the nitrogen: phosphorus ratio (N:P) by 47.1%. (2) The soil fungal community composition differed among the grassland types, For example, significant differences were found among the three grassland types for the Glomeromycota and Mucoromycota. (3) Under the influence of both grazing exclusion and grassland type, there was no significant change in soil fungal alpha diversity, but there were significant differences in fungal beta diversity. (4) Grassland type was the most important factor influencing changes in fungal community diversity, and vegetation cover and soil kjeldahl nitrogen were the main factors influencing fungal diversity. Our research provides a long‐term perspective for better understanding and managing different grasslands, as well as a better scientific basis for future research on grass–soil–microbe interactions. [ABSTRACT FROM AUTHOR]

The rapid loss of global biodiversity can greatly affect the normal functioning of ecosystems. However, how biodiversity losses affect plant community structure and soil nutrients is unclear. We conducted a field experiment to examine the short‐ and long‐term effects of removing plant functional groups (Gramineae, Cyperaceae, legumes, and forbs) on the interrelationships among the species diversity, productivity, community structure, and soil nutrients in an alpine meadow ecosystem at Menyuan County, Qinghai Province. The variations in the species richness, above‐ and belowground biomass of the community gradually decreased over time. Species richness and productivity were positively correlated, and this correlation tended to be increasingly significant over time. Removal of the Cyperaceae, legumes, and other forbs resulted in fewer Gramineae species in the community. Soil total nitrogen, phosphorus, organic matter, and moisture contents increased significantly in the legume removal treatment. The removal of other forbs led to the lowest negative cohesion values, suggesting that this community may have difficulty recovering its previous equilibrium state within a short time. The effects of species removal on the ecosystem were likely influenced by the species structure and composition within the community. Changes in the number of Gramineae species indicated that they were more sensitive and less resistant to plant functional group removal. Legume removal may also indirectly cause distinct community responses through starvation and compensation effects. In summary, species loss at the community level led to extensive species niche shifts, which caused community resource redistribution and significant changes in community structure. [ABSTRACT FROM AUTHOR]

Alpine meadows are key ecosystems that are facing increasing degradation due to climate change and anthropogenic disturbances. Despite tremendous efforts in ecological restoration and diverse communities rebuilding in alpine regions, restoration of extremely degraded alpine meadows (which have lost mattic epipedon) remains a major challenge for land managers. Here, we performed a field restoration experiment that combined seeding three grass species commonly (Elymus nutans, Poa annua, and Festuca sinensis) used in alpine meadow restoration with the application of grass clippings as mulch (bare land without mulching, 50% mulch cover, and 100% mulch cover) to ameliorate the soil surface conditions of degraded bare land. Soils covered with 50% and 100% mulching increased soil moisture, seedling density, plant cover, plant density, aboveground biomass, and belowground biomass, and reduced soil temperature during strong radiation days and insulated at night. In the three grass species seeding plots, mulching with grass clippings also improved seedling density, plant cover, plant density, and biomass. Moreover, 100% mulching had stronger restoration effect than 50% mulching. We further demonstrated that the improvement of surface microclimate in degraded alpine meadows by grass clipping mulching, that is, increasing soil moisture and regulating soil temperature, is an important reason for the success of grassland restoration. Mulching with grass clippings simulates the original mattic epipedon, improving the surface hydrothermal conditions and promoting ecological restoration facilitation. We encourage the application of locally available grass clippings after seeding as this can be an efficient, low‐cost, and sustainable approach for restoring extremely degraded high‐elevation alpine grassland ecosystems. [ABSTRACT FROM AUTHOR]

Grassland degradation can substantially reduce soil carbon sequestration capacity. However, the effects of grassland degradation on soil organic carbon (SOC) density remain unquantified in high‐altitude alpine meadows. In this study, the response and controlling mechanisms of topsoil (0–20 cm) organic carbon were explored in a field survey involving 11 pairs of healthy versus severely degraded plots of high‐altitude (above 4000 m) alpine meadows, as well as three short‐term (3–5 years) fencing restoration projects, across the source of the Yellow River in August of 2020 and 2021. The results showed that 0–20 cm root biomass, SOC content (SCC), and density (SCD) of healthy meadows averaged 533.7 ± 291.9 g/m2 (mean ± S.D), 21.17 ± 9.36 g/kg, and 4.54 ± 1.64 kg C/m2, respectively. Root biomass, SCC, and SCD were markedly reduced by 63.0%, 33.2%, and 17.6% in severely degraded grassland compared with healthy meadows. The SCC and SCD averaged 7.92 ± 2.21 g/kg and 2.2 ± 0.9 kg C/m2 in fencing plots, respectively, and were not significantly different from severely degraded meadows, suggesting a limited improvement in SOC from short‐term fencing restoration. Analysis of a piecewise structural equation model revealed that the effect of degradation on SCD (indicated by the difference in SCD between paired healthy and degraded meadows) was jointly regulated by the differential surface root biomass and site altitude, with a total positive effect of 0.39 and 0.26, respectively. Our findings indicate the losses of topsoil organic carbon stock caused by grassland degradation are root biomass‐ and altitude‐dependent, supporting the notion that antecedent prevention of degradation, more than subsequent restoration, should be the highest priority in the adaptive management of alpine meadows in harsh high‐altitude regions. [ABSTRACT FROM AUTHOR]

The species number of bryophytes is the second highest among land plants. Alpine grasslands on the Qinghai–Tibet Plateau (QTP) are the largest among global alpine biomes. However, bryophyte flora in alpine grasslands on the QTP remains poorly explored relative to its large geographic extent. A total of 347 plots were surveyed across the QTP, and 149 bryophyte taxa in 24 families and 49 genera were recorded in alpine grasslands. The largest family was Pottiaceae, followed by Bryaceae and Brachytheciaceae. The most species-rich genus was Bryum, followed by Didymodon and Brachythecium. The dominant species were Didymodon tectorus, Didymodon fallax, Bryum caespiticium, Didymodon constrictus, and Didymodon ditrichoides. The Jaccard similarity indexes of bryophyte compositions between alpine meadow and alpine steppe at the family, genus, and species levels were 0.375, 0.367, and 0.282, respectively. Turf was the most common life-form (75.2%), followed by weft (16.1%) and cushion (5.4%). Endemic species to China accounted for 8.05% of the total taxa. Bryophyte diversity in alpine grasslands on the QTP is exceptional and irreplaceable. The changes in species composition and life-forms between different grassland types reflect the adaptations of bryophytes to harsh environments. [ABSTRACT FROM AUTHOR]

Nitrogen availability limits the net primary productivity in alpine meadows on the Qinghai–Tibetan Plateau, which is regulated by ammonia-oxidizing microorganisms. However, little is known about the elevational patterns of soil ammonia oxidizers in alpine meadows. Here, we investigated the potential nitrification rate (PNR), abundance, and community diversity of soil ammonia-oxidizing microorganisms along the altitudinal gradient between 3,200 and 4,200 m in Qinghai–Tibetan alpine meadows. We found that both PNR and amoA gene abundance declined from 3,400 to 4,200 m but lowered at 3,200 m, possibly due to intense substrate competition and biological nitri fication inhibition from grasses. The primary contributors to soil nitrification were ammonia-oxidizing archaea (AOA), and their proportionate share of soil nitrification increased with altitude in comparison to ammonia-oxidizing bacteria (AOB). The alpha diversity of AOA increased by higher temperature and plant richness at low elevations, while decreased by higher moisture and low legume biomass at middle elevations. In contrast, the alpha diversity of AOB increased along elevation. The elevational patterns of AOA and AOB communities were primarily driven by temperature, soil moisture, and vegetation. These findings suggest that elevation-induced climate changes, such as shifts in temperature and water conditions, could potentially alter the soil nitrification process in alpine meadows through changes in vegetation and soil properties, which provide new insights into how soil ammonia oxidizers respond to climate change in alpine meadows. IMPORTANCE The importance of this study is revealing that elevational patterns and nitrification contributions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) communities were primarily driven by temperature, soil moisture, and vegetation. Compared to AOB, the relative contribution of AOA to soil nitri fication increased at higher elevations. The research highlights the potential impact of elevation- induced climate change on nitrification processes in alpine meadows, mediated by alterations in vegetation and soil properties. By providing new insights into how ammonia oxidizers respond to climate change, this study contributes valuable knowledge to the field of microbial ecology and helps predict ecological responses to environmental changes in alpine meadows [ABSTRACT FROM AUTHOR]

In alpine meadows, plants and soil microbes typically engage in competition for nitrogen (N) under N-deficient conditions. However, the acquisition and distribution of N among soil microbes and plants under alpine meadow degradation and climate warming induced by global climate change are still uncharacterized. In this study, we isotope labeled inorganic (NH4+-15N, NO3−-15N) and organic (glycine-15N) N in both degraded and non-degraded plots by using open-top chambers (OTC) to mimic increasing air temperatures. After 6 h, the 15N contents in soil microbes and plants were measured to investigate the effects of degradation and rising air temperature on N allocations in the ecosystems studied. Results showed that alpine meadow degradation significantly reduced soil microbial N accumulation by 52% compared to those in non-degraded plots. In non-degraded plots, warming significantly lowered the organic N levels of soil microbes by 49%, whereas in degraded ones, it reduced both NH4+-15N and NO3−-15N recovery by 80% and 45% on average but increased glycine-15N recovery by 653%. Meanwhile, warming decreased the plant recovery of NH4+-15N and NO3−-15N by 75% and 45% but increased the recovery of glycine-15N by 45% in non-degraded plots. Conversely, in degraded plots, warming markedly lowered NH4+-15N recovery by 40% but increased glycine-15N recovery by 114%. Warming mitigates the effects of alpine meadow degradation on nitrogen allocation among soil microbes and plants. In unwarmed plots, degradation significantly elevated the total 15N recovery ratio of soil microbes to plants by 60%. However, in warmed plots, the impact of degradation on this ratio was reduced. The responses of the 15N recovery ratio of soil microbes and plants to rising temperatures were closely related to alpine meadow quality. In non-degraded areas, warming enhanced the recovery ratio for NH4+-15N by 165% but reduced it for glycine-15N by 66%. Conversely, in degraded plots, warming decreased the recovery ratio for NH4+-15N by 66% but increased it for glycine-15N by 232%. This indicates that warming can increase carbon limitation for soil microbes in degraded alpine meadows, and the restoration of degraded alpine meadows should prioritize restoring carbon accumulation. [ABSTRACT FROM AUTHOR]

Background: In this study, we investigated the effects of alpine meadow in different phenological periods on ruminal fermentation, serum biochemical indices, and gastrointestinal tract microbes in grazing yak on the Qinghai-Tibetan Plateau. A total of eighteen female freely grazing yaks with an average age of 3 years old and a body weight of 130 ± 19 kg were selected. According to the plant phenological periods, yaks were randomly allocated to one of three treatments: (1) regreen periods group (RP, n = 6); (2) grassy periods group (GP, n = 6); and (3) hay periods group (HP, n = 6). At the end of the experiment, the blood, rumen fluids, and rectal contents were collected to perform further analysis. Results: The concentrations of total volatile fatty acid (TVFA), acetate, glucose (GLU), triglyceride (TG), cholesterol (CHO), high density lipoprotein (HDL), and low density lipoprotein (LDL) were higher in the GP group than in the HP group (P < 0.05). However, compared with the RP and GP groups, the HP group had higher concentrations of isobutyrate, isovalerate, valerate, and creatinine (CREA) (P < 0.05). The abundance of Prevotella in the rumen, and the abundances of Rikenellaceae_RC9_gut_group, Eubacterium_coprostanoligenes_group, and Prevotellaceae_UCG-004 in the gut were higher in the GP group compared with the HP group (P < 0.05). The HP had higher abundance of Eubacterium_coprostanoligenes_group in the rumen as well as the abundances of Romboutsia and Arthrobacter in the gut compared with the RP and GP groups (P < 0.05). Conclusions: Based on the results of rumen fermentation, serum biochemical, differential biomarkers, and function prediction, the carbohydrate digestion of grazing yak would be higher with the alpine meadow regreen and grassy due to the gastrointestinal tract microbes. However, the risk of microbe disorders and host inflammation in grazing yak were higher with the alpine meadow wither. [ABSTRACT FROM AUTHOR]

Nitrogen is the crucially sustainable element for most ecosystem including grassland. Fenced alpine meadow grassland (FG), lightly, moderately and heavily degraded (LD, MD and HD) alpine meadow in spring, summer and winter were studied to clear the effects of alpine meadow degradation on soil total nitrogen (TN), available nitrogen (AN), ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3–-N), inorganic nitrogen (IN) content and the ratio of inorganic nitrogen to available nitrogen (IN/AN), and to find practical management strategies on the background of alpine meadow degradation and ecological environment restoration in the Eastern Qilian Mountains area, northwest China. The results showed that soil total nitrogen contents of the alpine meadow types were at a low level, ranged from 1.60 g·kg−1 to 5.15 g·kg−1, but soil available nitrogen contents was at a high level, ranged from 373.2 mg·kg−1 to 650.8 mg·kg−1in the study area. Alpine meadow degradation can seasonally change soil nitrogen status. Degraded alpine meadow had more inorganic nitrogen than fenced meadow in surface soil. Degradation only changed soil NO3−-N profile distribution in winter and had no significant effect on profile distribution of TN, AN, NH4+-N and IN. There were significant interactions of alpine meadow types, seasons and soil depth on soil available nitrogen, NH4+-N, NO3–-N and inorganic nitrogen content. Although soil available nitrogen increased under degradation, nitrogen input is needed in the restoration of heavily degraded alpine meadow during the summer growing season to improve vegetation coverage because of the low soil inorganic nitrogen and IN/AN ratio in summer growing season in 10–20 cm and 20–30 cm depth. [ABSTRACT FROM AUTHOR]

Understanding animals' selection of microhabitats is important in both ecology and biodiversity conservation. However, there is no generally accepted methodology for the characterization of microhabitats, especially for vegetation structure. We studied microhabitat selection of three Vipera snakes by comparing grassland vegetation structure between viper occurrence points and random points in three grassland ecosystems: V. graeca in mountain meadows of Albania, V. renardi in loess steppes of Ukraine and V. ursinii in sand grasslands in Hungary. We quantified vegetation structure in an objective manner by automated processing of images taken of the vegetation against a vegetation profile board under standardized conditions. We developed an R script for automatic calculation of four vegetation structure variables derived from raster data obtained in the images: leaf area (LA), height of closed vegetation (HCV), maximum height of vegetation (MHV) and foliage height diversity (FHD). Generalized linear mixed models revealed that snake occurrence was positively related to HCV in V. graeca, to LA in V. renardi and to LA and MHV in V. ursinii, and negatively to HCV in V. ursinii. Our results demonstrate that vegetation structure variables derived from automated image processing significantly relate to viper microhabitat selection. Our method minimizes the risk of subjectivity in measuring vegetation structure, enables the aggregation of adjacent pixel data and is suitable for comparison of or extrapolation across different vegetation types or ecosystems. [ABSTRACT FROM AUTHOR]

The study of modern pollen, and vegetation can improve the accuracy of paleoenvironmental reconstruction based on fossil pollen data. A total of 188 pollen surface samples were collected from Southern Xinjiang (34°00′–43°00′N, 74°00′–94°00′E) in China, with an elevation range of 888–1530 m. Surface pollen and vegetation were studied in the northern region of the Kunlun Mountains and the southern region of the Tianshan Mountains. The results showed that the surface pollen assemblages on the southern slope of the Tianshan Mountains (3530–1124 m) were divided into three pollen zones, namely, montane steppe, montane desert steppe, and montane desert. These zones were dominated by Artemisia, Chenopodiaceae, and Ephedra pollen. The surface pollen assemblages in the eastern Pamir Plateau (4530–1287 m) could be divided into alpine meadow, montane desert steppe, and montane desert zones, which were predominantly characterized by Artemisia, Chenopodiaceae, and Asteraceae pollen. However, the Southern Tarim Basin (3548–888 m) comprised montane desert steppe and montane desert zones, which was dominated by Artemisia and Chenopodiaceae pollen. The geographic distribution of the surface pollen sites obtained using ArcGIS, the R-value, and Pearson correlation analyses indicated that the over-represented Picea and Pinus pollen were of external origin and were transported by wind, water (rivers), and ice (glacier movement). Over-representation of Ephedra and Nitraria pollen was mainly distributed in the montane desert and desert steppe zones, respectively. Pollen from Chenopodiaceae and Artemisia were over-represented and broadly distributed across Southern Xinjiang. Juglans pollen was concentrated in areas with walnut trees, strongly indicating the presence of local parent plants. According to the Hybrid Single-particle Lagrangian Integrated Trajectory model, more Pinus pollen was transported to the Pamir region by external airflows during spring and summer, resulting in its higher surface pollen content. Research elucidating the relationship between modern pollen and vegetation in southern Xinjiang could provide data describing the surface palynological database of Xinjiang for use in large-scale paleoenvironmental reconstructions. [ABSTRACT FROM AUTHOR]

Several studies have investigated how nitrogen (N) addition changes N competition between focal plant species and soil microorganisms; still, the impact on community-level plant-microbial N competition and the underlying mechanisms remain unclear. We conducted a short-term (4 h) 15N labeling experiment in an alpine meadow subjected to 7 years of NH4NO3 additions (0, 5, 10, and 15 g N m−2 year−1), by monitoring changes in soil properties (e.g., pH, Al3+, NH4+, NO3−), microbial biomass (MB), plant community composition, root traits (e.g., root length, root area, specific root length), as well as the plant (nine focal species and at the community level) and microbial N uptake. Change in the N competition between the nine focal plant species and microorganisms following N addition depended on the species. At the community level, the N addition rate did not affect plant-microbial competition for NH4+ and NO3− (P > 0.05). Nitrogen addition directly decreased NH4+ competition (β = − 0.700) but indirectly increased because of improved plant uptake due to increased N availability (β = 1.214). Competition for NO3− was dependent on microbial uptake (β = − 0.953) and was influenced by opposing effects of increased N availability (β = 1.342) and reduced MB (β = − 0.439). Thus, the effects of increased soil N availability and suppressed MB on plant and microbial N competition offset each other, while the plant community had a negligible impact. Such responses should be taken into account for better predictions of the effect of N addition on net primary productivity and ecosystem stability. [ABSTRACT FROM AUTHOR]

The impact of extreme climate events on vegetation growth and ecosystem function has garnered widespread attention, particularly in plateau regions, which are facing increasingly severe environmental pressures. This study employs the Events Coincidence Analysis (ECA) method to examine the impacts of extreme climate events on the Net Primary Productivity (NPP) of vegetation in plateau regions. Specifically, we focus on the unique phenomenon of asymmetric daytime and nighttime warming and evaluate the compounding effect of extreme precipitation with extreme temperature events. The results indicate that grassland NPP has higher overall sensitivity and Coincidence Rates (CR) to extreme precipitation events compared to extreme temperature events. Specifically, extreme drought events significantly negatively impact grassland NPP, and the sensitivity of NPP increases with the severity of extreme drought events. In lower elevations (<3200 m), grassland NPP shows a strong response to extreme precipitation events, with sensitivity decreasing with increasing elevation, especially for alpine meadows. Extreme high-temperature events contributed significantly to NPP in mid to high elevations (3000–5000 m). Compound extreme climate events amplify the average coincidence degree with NPP anomalies, with extreme precipitation events playing a major role in compound effects. The CR of compound climate events can reach above 0.6, reflected in the anomaly increase of NPP in temperate grasslands at higher elevations caused by compound events of extremely wet and extremely high temperatures. [ABSTRACT FROM AUTHOR]

We conducted a detailed field vegetation investigation combined with the collection of surface soil samples for pollen analysis in the alpine meadow and steppe vegetation zones (30 sites in each zone) in the hinterland of the Tibetan Plateau. Our objectives were to determine the source area of exotic pollen, the relationship between pollen percentages and the cover of the major plant taxa, and the characteristics of the pollen assemblages from surface soils and lake sediments and their vegetation significance. Our principal findings are: (i) the two vegetation zones are herbaceous although arboreal pollen types are present in the related pollen assemblages (2 and 16.8% in the alpine meadow and steppe zones, respectively); (ii) arboreal pollen is assumed to be transported mainly by the Indian monsoon from the forests of the southern Himalayan foothills or river valleys – the spatial distribution of the percentages and concentrations of arboreal pollen in the study sites shows that pollen concentrations have the strongest correlation with the Indian monsoon's variations; (iii) there are regional differences in (a) the relationship between pollen percentages and the cover of the main plant taxa and (b) the indicator plant taxa representative of pollen assemblages and vegetation types zones – the regional vegetation of the study region and pollen productivity variations between plant taxa are likely to be the main causes behind these differences; and (iv) the pollen assemblages from surface soils and lake sediments have similar characteristics and correspond well to the regional vegetation of the alpine meadow zone. In the alpine steppe zone, the pollen assemblages from surface soils and lake sediments are quite different, caused mainly by the over‐representation of Artemisia. Our study supplies a detailed description of pollen–vegetation relationships on the hinterland of the Tibetan Plateau and provides scientific references for interpreting stratigraphic pollen assemblages and reconstructing regional vegetation. [ABSTRACT FROM AUTHOR]

Question: Patchiness of herbaceous species is a common feature of degraded alpine grasslands on the Qinghai–Tibet Plateau; however, the impact of this phenomenon on vegetation, soil seed bank (SSB), and soil carbon (C) and nitrogen (N) is largely unknown. We asked how different herbaceous patches affect above‐ground vegetation, the SSB and soil organic C (SOC) and total N (TN) contents in alpine meadows. Location: An alpine meadow on the Qinghai–Tibetan Plateau, China. Methods: We used field and greenhouse experiments to evaluate above‐ground vegetation parameters, the SSB composition, and SOC and TN contents of four commonly distributed herbaceous patches (Leymus secalinus, Kobresia humilis, Leontopodium nanum and Pedicularis kansuensis) and non‐patch vegetation (control). Results: There were significant differences in the species composition of above‐ground vegetation, with the plant species richness, Shannon–Wiener index, Simpson index, and Pielou evenness index reduced in the four patches compared to the control. In addition, patches had increased above‐ground biomass (AGB) and a lower below‐ground biomass to above‐ground biomass ratio (BGB:AGB); while the species diversity indices did not change considerably among the patches. The species composition of the SSB in the four patches differed from that in the control and the seed density increased markedly, but the species richness and diversity of the SSB remained unaltered. Moreover, the contents of SOC, total C, TN, microbial biomass C, and microbial biomass N in the four patches were markedly lower than in the control. Conclusions: These findings suggest that patchiness of herbaceous species can alter the flora composition of alpine meadows and reduce plant species diversity, as well as the SOC and TN contents, which will adversely impact grassland biodiversity conservation and soil C sequestration, and then may intensify the degradation of alpine meadows on the Qinghai–Tibet Plateau. [ABSTRACT FROM AUTHOR]

On-going climate warming is threatening the ecological function of grassland ecosystems. However, whether warming has positive effects on community microhabitats and appearance, especially in degraded grasslands, remains elusive. To address this issue, we conducted a 2-year field experiment on the severely degraded alpine meadow and undegraded alpine meadow with no warming and warming treatments. Community coverage and height in degraded meadow significantly increased under warming, while these changes were not significant in undegraded meadow. Two-year warming increased the community height of degraded meadow and undegraded meadow by 56.55% and 10.99%, respectively. Warming also increased community coverage by 41.88% in degraded meadow and decreased community coverage by 3.01% in undegraded meadow. Moreover, the response of topsoil temperature to warming was stronger in degraded meadow (6.89%) than in undegraded meadow (− 0.26%), while the negative response of topsoil moisture to warming was weaker in degraded meadow (− 13.95%) than in undegraded meadow (− 20.00%). The SEMs further demonstrated that warming had positive effects on topsoil temperature and community height, while had negative effects on topsoil moisture both in degraded and undegraded meadows. Our results confirm that warming-induced soil drying is an important pathway affecting the community appearance in alpine meadows. These findings highlight that warming has positive effects on community height and coverage and is particularly effective in improving community coverage appearance in severely degraded alpine meadow with topsoil drying. [ABSTRACT FROM AUTHOR]

Buzz-pollination is used by some bees to expel pollen through vibrating flowers. Yet, little is known about the determinants influencing bee preferences among buzz-pollinated flowers. We studied five co-flowering, nectarless species of Pedicularis (Orobanchaceae) buzz-pollinated by bumblebees in an alpine meadow, to investigate bumblebee' flower preferences in response to fluctuations of floral abundance across five years. We also recorded and analyzed the buzzing frequencies produced by the three dominant bumblebee specie. Our results indicate that Bombus friseanus and B. lepidus visited different Pedicularis flowers using similar buzz frequencies and displayed an abundance-dependent flower preference across years. These two bumblebee species had staggered phenologies with distinct timing of peak abundances across the five years. In contrast, B. festivus used lower fundamental buzz frequencies, had a constant flower preference across years, but used different buzz frequencies across Pedicularis species. Although the amount of pollen released after bumblebee visitation varied across Pedicularis species, we found that after a single visit all bumblebees deposited similar amounts of pollen on stigmas. Our study indicates that bumblebees' flower preferences is sometimes, but not always, modulated by floral abundance, and that at least one bumblebee species was observed to produce buzzes of different frequencies in different plant species. Competition for floral resources among bumblebees and for pollination services among co-flowering Pedicularis species may structure plant-pollinator interactions and affect species coexistence. [ABSTRACT FROM AUTHOR]

The relationship between biodiversity and ecosystem multifunctionality (EMF) is critical to understanding the dynamics of ecosystem services. Several studies have investigated alterations in multiple ecosystem functions under grassland degradation and its relationship with taxonomic diversity. However, how multidimensional biodiversity (taxonomic, functional, and phylogenetic diversity) and abiotic factors mediate EMF in degraded alpine meadows has yet to be well been explored. In this study, alpine meadows with different degrees of degradation were investigated in Maqu County, Gansu Province, China. The average and multi‐threshold methods were used to quantify EMF, while structural equation modeling (SEM) was used for statistical analysis. The results show that: (1) Degradation of alpine meadows has altered the species composition and diversity of plant communities. (2) Taxonomic, functional, and phylogenetic diversity were all significantly and positively correlated with EMF, and species richness, functional richness and Faith's PD effectively drive EMF within thresholds of 22%–75%, 20%–86% and 42%–72%, with maximum effects of 0.29, 0.33 and 0.12, respectively. (3) Degradation of alpine meadows directly and significantly reduced EMF, and mediated indirectly through plant diversity and soil abiotic factors. The multifunctionality index for different degrees of degradation showed non‐degraded (60.89) > light degraded (37.84) > moderate degraded (−14.17) > heavy degraded (−48.55). The results of this study reveal the relative importance of multidimensional plant diversity in predicting EMF of degraded alpine meadows, and potential mechanisms by which plant diversity and abiotic factors mediate the effects of alpine meadow degradation on EMF. [ABSTRACT FROM AUTHOR]

The UN Decade on Ecosystem Restoration 2021–2030 has launched nature conservation, environmental protection, and ecosystem services' restoration on the global environmental policy agenda. However, particularly high mountain habitats being subject to erosion are up to now hardly restorable. Erosion with associated loss of vegetation, soil, and its fertility, is one of the most urgent environmental problems throughout the world. Consequently, we analyzed the soil seed bank of calcareous high‐mountain grassland in the European Alps to reveal the natural regeneration potential after shallow erosion events. We applied a chronosequence approach taking recently eroded grassland areas (<5 years) as well as areas with earlier erosion events (>5 up to 10 and >27 years) into account. Our results revealed that the vegetation of old eroded areas was not closely similar to the surrounding intact grasslands. However, it was well differentiated from the initial stages of young and intermediate eroded areas' vegetation and had higher plant cover and species richness. The old eroded areas' seed bank had higher seed density and species richness compared to younger areas. While typical mountain meadow species were present in the seedbank of eroded areas, the assessed indicator species of both, younger and older eroded areas did not resemble the ones of the aboveground vegetation. We conclude that the seed bank has important but limited potential for the restoration of the complete species range of calcareous eroded alpine grasslands. This implies that additional restoration measures are needed to reintroduce species absent from the seed bank. [ABSTRACT FROM AUTHOR]

Summary: Accurate measurements of soil nematode communities are important for an in-depth understanding of the ecological functions of soil nematodes. High throughput sequencing (HTS) has been reported extensively, but the concordance between HTS and morphological identification results is still lacking. To compare two methods, we selected bare patches (BP), short-term recovery patches (SP), middle-term recovery patches (MP) and long-term recovery patches (LP) of different restoration succession stages in three sample sites to survey the nematode characteristics. In addition to nematode community structure and community ecological function, common nematode genera in BP, SP, MP and LP were compared by two methods: HTS and morphological identification. The results show that the number of species identified in the morphological analysis was lower than using HTS. The soil nematode diversity in different recovery patches was LP > MP > SP > BP. The indices of Shannon-Wiener, Pielou, Simpson and species number of different recovery patches based on HTS reflected the biodiversity of nematode communities, which was consistent with the results of morphological identification. Of the common nematode genera, Coslenchus , Aphelenchus and Leptonchus showed a significant correlation by the two methods. Although both methods have limitations, the HTS provides a more effective means of observing soil nematode biodiversity levels for rapid insight across recovery patches in degraded alpine meadows of the Yellow River source region in our results. [ABSTRACT FROM AUTHOR]

Background and Aims: Human-driven nitrogen (N) deposition can alter soil biogeochemistry and plant communities, both critical to soil biota. However, understanding the relative impact of the relationship between nutrient resources and plants on soil communities has been hindered by a lack of experimental manipulations of both factors. We hypothesized that soil nematode communities would be structured predominantly by N addition via overall increased abundance, decreased diversity, and compositional shifts to dominance of r-selected bacterial-feeding nematodes. In contrast, we expected plant effects to be less evident and restricted to nematodes directly associated with plants. Methods: We used a long-term (18-yrs) experiment in moist meadow alpine tundra involving N addition and codominant plant (nitrophilic Deschampsia cespitosa and nitrogen-sensitive Geum rossii) removal. We characterized nematode communities via 18S rRNA metabarcoding and used soil biogeochemistry, plant, and microbial variables to determine factors shaping their communities. Results: The N addition treatment increased overall nematode abundance, decreased diversity, and affected the composition of all nematode trophic groups. Overall, nematode communities shifted to dominance of bacterial-feeding nematode taxa adapted to N-enriched environments. The likely drivers of this shift were increased soil nitrate and lower pH. The direct effects of codominant plants were more limited, with only changes in Geum rossii appearing to affect nematode responses. Conclusion: Overall, nematode communities in N-limited alpine ecosystems are highly sensitive to increases in N availability, irrespective of the nature of N preferences of codominant plants. The resulting nematode community restructuring could signify future shifts in soil functioning throughout alpine landscapes. [ABSTRACT FROM AUTHOR]

Climate warming, often accompanied by extreme drought events, could have profound effects on both plant community structure and ecosystem functioning. However, how warming interacts with extreme drought to affect community‐ and ecosystem‐level stability remains a largely open question. Using data from a manipulative experiment with three warming treatments in an alpine meadow that experienced one extreme drought event, we investigated how warming modulates resistance and recovery of community structural and ecosystem functional stability in facing with extreme drought. We found warming decreased resistance and recovery of aboveground net primary productivity (ANPP) and structural resistance but increased resistance and recovery of belowground net primary productivity (BNPP), overall net primary productivity (NPP), and structural recovery. The findings highlight the importance of jointly considering above‐ and belowground processes when evaluating ecosystem stability under global warming and extreme climate events. The stability of dominant species, rather than species richness and species asynchrony, was identified as a key predictor of ecosystem functional resistance and recovery, except for BNPP recovery. In addition, structural resistance of common species contributed strongly to the resistance changes in BNPP and NPP. Importantly, community structural resistance and recovery dominated the resistance and recovery of BNPP and NPP, but not for ANPP, suggesting the different mechanisms underlie the maintenance of stability of above‐ versus belowground productivity. This study is among the first to explain that warming modulates ecosystem stability in the face of extreme drought and lay stress on the need to investigate ecological stability at the community level for a more mechanistic understanding of ecosystem stability in response to climate extremes. [ABSTRACT FROM AUTHOR]

The degradation of alpine meadows on the Qinghai–Tibet Plateau is a major issue affecting both the ecology and the economy. Microorganisms play an important role in soil nutrient cycling and the regulation of ecosystem function. This study aimed to investigate the species composition and diversity of microbial communities and understand the response of microbial communities to changes in physicochemical properties resulting from meadow degradation. In this study, the soil bacterial and fungal communities' composition and diversity of alpine meadows of degradation gradient were sequenced by high-throughput sequencing. During the process of grassland degradation, there were 59 bacterial taxa and 29 fungal taxa showing significant differences. The relative abundance of meadow pathogenic fungi significantly increased (p < 0.05). PICRUSt2 analysis showed a decrease in synthesis-related functional gene abundance and an increase in metabolism-related functional gene abundance. FUNGuild analysis showed that symbiotic and saprophytic nutrient fungi decreased significantly (p < 0.05). The soil nutrient cycling was mainly influenced by the beta diversity of microbial communities. Grassland degradation affects soil structure, thereby affecting the diversity of soil microbial composition and functional soil nutrient content. This work reveals the response of microbial communities to the degradation of alpine meadows and their impact on nutrient cycling, providing theoretical support for the protection and sustainable development of alpine meadows. [ABSTRACT FROM AUTHOR]

Background: The alpine meadow is one of the most important ecosystems in the Qinghai-Tibet Plateau (QTP), and critically sensitive to climate change and human activities. Thus, it is crucial to precisely reveal the current state and predict future trends in the carbon budget of the alpine meadow ecosystem. The objective of this study was to explore the applicability of the Biome-BGC model (BBGC) in the Qinghai Lake Basin (QLB), identify the key parameters affecting the variation of net ecosystem exchange (NEE), and further predict the future trends in carbon budget in the QLB. Results: The alpine meadow mainly acted as carbon sink during the growing season. For the eco-physiological factors, the YEL (Yearday to end litterfall), YSNG (Yearday to start new growth), CLEC (Canopy light extinction coefficient), FRC:LC (New fine root C: new leaf C), SLA (Canopy average specific leaf area), C:Nleaf (C:N of leaves), and FLNR (Fraction of leaf N in Rubisco) were confirmed to be the top seven parameters affecting carbon budget of the alpine meadow. For the meteorological factors, the sensitivity of NEE to precipitation was greater than that to vapor pressure deficit (VPD), and it was greater to radiation than to air temperature. Moreover, the combined effect of two different meteorological factors on NEE was higher than the individual effect of each one. In the future, warming and wetting would enhance the carbon sink capacity of the alpine meadow during the growing season, but extreme warming (over 3.84 ℃) would reduce NEE (about 2.9%) in the SSP5-8.5 scenario. Conclusion: Overall, the alpine meadow ecosystem in the QLB generally performs as a carbon sink at present and in the future. It is of great significance for the achievement of the goal of carbon neutrality and the management of alpine ecosystems. [ABSTRACT FROM AUTHOR]

Species-abundance distribution (SAD) is essential in understanding the formation and maintenance mechanisms of species diversity. In alpine meadows, aspect affects almost all biological and ecological processes. Therefore, the soil ciliate data obtained by Illumina MiSeq sequencing were used to explore the characteristics of SADs to the soil ciliate communities on different aspects in alpine meadows (south aspect, southwest aspect, west aspect, northwest aspect, north aspect; SA, SWA, WA, NWA, NA, respectively). Statistical models: Log-series model (LSM) and Log-normal model (LNORM), Niche models: Broken stick model (BSM) and Geometric series model (GSM), and a neutral theory model: Meta-community zero-sum multinomial distribution model (MZSM) were selected to fit the soil ciliate data for analysis. The results showed that: (1) the number of common species increased and then decreased from SA to NA, the number of rare species changed in the opposite trend; (2) BSM and GSM were able to fit the SAD of overall soil ciliates species on different aspects, while MZSM was rejected on all aspects, indicating that the niche process dominated the formation of soil ciliate communities in the alpine meadows, and the resource allocation pattern was dominated by fixed allocation; (3) best-fit models for common species were GSM and BSM which were consistent with best-fit models for all species, while the best-fit model for rare species was LNORM, common species dominated the formation of SAD on different aspects and had an irreplaceable role in maintaining community productivity and stability. [ABSTRACT FROM AUTHOR]

We study studied the alpine meadow soil in Gannan Prefecture. Geostatistical analysis showed that Circular [soil total nitrogen (STN), soil total potassium (STK), soil available phosphorus (SAP)] model, index [bulk density (BD), soil water content (SWC), soil organic carbon (SOC), soil available nitrogen (SAN)] model and Gaussian [soil total phosphorus (STP), soil available potassium (SAK)] model is universal Kriging Method semi-variation function optimization fitting model. In the model, the spatial correlation is weak to medium, and SOC, STN, STP, STK, SAN, SAP, SAK, and SWC have specific spatial trend effects. Then principal component analysis was used to obtain three key factors (SOC, BD, and SWC) affecting soil quality, which accounted for 81.91% of the total variation of soil quality. These factors were taken as the minimum data set (MDS) and soil quality index (SQI) was calculated. According to SQI, the whole region was divided into three soil management zones (SMZs). Recommendations are made for different management areas to ensure resource conservation and reduce environmental footprint. [ABSTRACT FROM AUTHOR]

Simple Summary: Changes in precipitation patterns can significantly alter biological processes and associated ecosystem functions. This study aimed to investigate the impacts of rainfall intensity and timing on the structure of dung beetle assemblage and dung mass loss rate in a Tibetan alpine meadow. The results revealed that exposure to rainfall within a 2 h timeframe, regardless of rainfall intensity, significantly reduced the rate of dung mass loss. However, this decrease was not attributed to the activity of dung beetles. Earlier rainfall tended to decrease species richness of dung beetles, while heavier rainfall significantly decreased beetle abundance. These findings suggest that changes in precipitation patterns can influence both the assemblage of dung beetles and the rate of dung decomposition, but may also decouple their relationship under a certain circumstance. The variability in local biological processes and ecosystem functions deserves greater attention within a global climate change scenario. Changes in precipitation patterns, including rainfall intensity and rainfall timing, have been extensively demonstrated to impact biological processes and associated ecosystem functions. However, less attention has been paid to the effects of rainfall intensity and rainfall timing on the assembly of detritivore communities and the decomposition rate of detritus such as animal dung. In a grazed alpine meadow on the eastern Qinghai–Tibet Plateau, we conducted a manipulative experiment involving two levels of rainfall intensity (heavy rainfall, 1000 mL/5 min; light rainfall, 100 mL/5 min) and five levels of rainfall timing (0, 2, 4, 24, and 48 h after yak dung deposition). The aim was to determine the effects of rainfall intensity, timing, and their interaction on the assemblage of dung beetles and dung removal rate during the early stage (i.e., 96 h after yak dung deposition) of dung decomposition. Light rainfall significantly increased species richness in the treatment of 48 h after dung pats were deposited. Heavy rainfall significantly decreased beetle abundance in both the 0 h and 48 h treatments while light rainfall had no effect on beetle abundance. Dung mass loss was significant lower in the 2 h treatment compared to other treatments regardless of rainfall intensity. The structural equation model further revealed that the species richness of dung beetles and dung mass loss were significantly affected by rainfall timing but not by rainfall intensity. However, no significant relationships were observed between any variables examined. These findings suggest that changes in precipitation patterns can influence both the structure of dung beetles and the rate of dung decomposition but may also decouple their relationship under a certain circumstance. Therefore, it is crucial to pay greater attention to fully understand local variability between the biological processes and ecosystem functions within a global climate change scenario. [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 article represents a part of the researches done for the doctoral thesis, which aims at the knowledge of the vegetation in the basin of Pesceana river, Vâlcea county. This offers actual data regarding the types of habitats identified in the studied area and their typical vegetation. The phytocoenological observations developed between 2021-2023 in the basin of the Pesceana river permitted the identification of nine types of habitats of conservative interest, as: 91M0 – Pannonian-Balkanic turkey oak-sessile oak forests; 9130 – Asperulo-Fagetum beech forests; 91Y0 – Dacian oak - hornbeam forests; 91E0* - * Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae); 9170 – Galio-Carpinetum oak-hornbeam forests; 6440 – Alluvial meadows of river valleys of the Cnidion dubii; 6430 – Hydrophilous tall herb fringe communities of plains and of the montane to alpine levels; 6520 – Mountain hay meadows; 6240* - * Sub-Pannonic steppe grasslands.The article is focused on the description of four types of forest habitats, respectively the habitats of community interest 91M0; 9130; 91Y0 și 91E0*. The description of the habitats is followed by an analysis of the similarity on the account of the surveys done for every type of forest habitat. Also, the physical and chemical particularities of the soils in theses habitats identified at the studied area are highlighted The aim of the actual article is to identify, inventory and highlight the particularities that the forest habitats present in the studied area and the plant community typical for these habitats. [ABSTRACT FROM AUTHOR]

The intraspecific variations of phenotypic traits in the early life stages, such as seed germination and seedling establishment, are important components affecting species adaptation and differentiation. As one of the most common ways in which seeds are maintained, dry storage usually affects these traits, by either increasing or decreasing variation among populations. However, little is known about how the interaction between dry storage and population variation of a species affects the performance and adaptability of early life-cycle traits. In this study, we conducted experiments with seeds from ten populations of Elymus nutans along an altitudinal gradient on the eastern Qinghai-Tibet Plateau. Fresh seeds and seeds stored dry for 6 months were used to quantify the temperature thresholds for germination, determine seedling emergence and survival in two common gardens and examine the correlation between these traits and environmental conditions of population provenance. Dry storage increased germination percentage, germination speed and seedling emergence, and decreased intraspecific variation in germination traits of seeds (reduced by 33.36, 52.05 and 20.45% for T b, θT(50) and σ θ T , respectively). Dry storage had little effect on the intraspecific variation of seedling emergence and survival. In addition, the temperature threshold for germination cannot be used to predict seedling emergence and survival in either common garden, regardless of whether seeds were stored or not. These results indicated that it is feasible to use dry-stored seeds to evaluate and select suitable provenances in ecological restoration, and using dry-stored seeds in ecological restoration projects is expected to achieve better vegetation restoration results than fresh seeds. On the other hand, the status of seeds (fresh vs. dry stored) should be considered in an evaluation of the adaptive value of plant functional traits, especially in the early life stages, otherwise, inconsistent conclusions may be drawn. [ABSTRACT FROM AUTHOR]

Many fire‐prone forests are experiencing wildfires that burn outside the historical range of variation in extent and severity. These fires impact pollinators and the ecosystem services they provide, but how the effects of fire are mediated by burn severity in different habitats is not well understood. We used generalized linear mixed models in a Bayesian framework to model the abundance of pollinators as a function of burn severity, habitat, and floral resources in post‐fire, mid‐elevation, conifer forest, and meadow in the Sierra Nevada, California. Although most species‐level effects were not significant, we found highly consistent negative impacts of burn severity in meadows where pollinators were most abundant, with only hummingbirds and some butterfly families responding positively to burn severity in meadows. Moderate‐severity fire tended to increase the abundance of most pollinator taxa in upland forest habitat, indicating that even in large fires that burn primarily at high‐ and moderate‐severity patches may be associated with improved habitat conditions for pollinator species in upland forest. Nearly all pollinator taxa responded positively to floral richness but not necessarily to floral abundance. Given that much of the Sierra Nevada is predicted to burn at high severity, limiting high‐severity effects in meadow and upland habitats may help conserve pollinator communities whereas low‐ to moderate‐severity fire may be needed in both systems. [ABSTRACT FROM AUTHOR]

Background: Due to the effects of climate change and overgrazing in recent decades, alternative stable states in the alpine Kobresia meadow degradation process have coexisted in the same geographical and climatic environment, with variations occurring among microsites. Methods: We used a space‐for‐time substitution approach to explore the synergies of microsite variation according to its numerical characteristics and the proportion of each stable state at various stages of succession in alpine Kobresia meadows on the Qinghai–Tibetan Plateau. Results: (1) The highest average aboveground biomass in summer was 196.2 ± 20.3 g m−2, with significantly higher levels of biomass in ≤3.65 sheep unit ha−1 than in other levels of grazing intensity, while the parameters showed no significant differences among grazing intensity levels in >3.65 sheep unit ha−1. (2) The importance of plant functional groups, aboveground biomass, and niche breadth of Poaceae and Cyperaceae significantly decreased as the grazing intensity increased. (3) The effects of ≥0°C accumulated temperature, total precipitation, altitude, longitude, and latitude cumulatively contributed less than 20% of the variation in the distribution of functional group characteristics across microsites. Conclusions: (1) Overgrazing decreases primary production in alpine Kobresia meadows, but ecosystem responses regulate plant community structure and botanical components so as to partially counteract grazing disturbance. (2) Overgrazing changed the proportion of microsites, which in turn led to regime shift in the plant community and subsequent synergies between the microsites of plant communities and their stable states. [ABSTRACT FROM AUTHOR]