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Soil organic carbon (SOC) is an important component of the global carbon pool, whose accumulation and decomposition affect the balance of the global carbon cycle and climate change. However, understanding of the responses of SOC in alpine ecosystems to climate change is quite limited, especially in the seasonal-frozen soil zone. In order to understand the impact of soil moisture changes on the carbon cycle in alpine mountain ecosystems, we established two sample plots of the semi-shady and semi-sunny slopes in the subalpine meadow zone of the eastern part of Qilian Mountains, and collected soil samples to investigate the spatial and temporal changes of SOC and soil moisture and their relationships. The study indicated that the SOC content showed significant surface aggregation during the plant growing season, and that the influence of soil moisture on SOC was different in different slope directions and soil depths. The influence of soil moisture on SOC was greater on the semi-shady slope than on the semi-sunny slope. Among different soil layer depths, the soil moisture most significantly affected SOC in the soil layer of 20-40 cm. This study provides a theoretical basis for the study of carbon stocks and carbon cycling at high altitudes. [ABSTRACT FROM AUTHOR]

AbstractThis paper establishes a connection between rings, lattices and common meadows. Meadows are commutative and associative algebraic structures with two operations (addition and multiplication) with additive and multiplicative identities and for which inverses are total. Common meadows are meadows that introduce, as the inverse of zero, an error term a which is absorbent for addition. We show that common meadows are unions of rings which are ordered by a partial order that defines a lattice. These results allow us to extend some classical algebraic constructions to the setting of common meadows. We also briefly consider common meadows from a categorical perspective. [ABSTRACT FROM AUTHOR]

Urban green spaces can be important habitats for soil, plant, and pollinator diversity and the complementary ecosystem functions they confer. Most studies tend to investigate the relationships between plant diversity with either soil or pollinator diversity, but establishing their relationship across habitat types could be important for optimising ecosystem service provision via alternative management (for instance, urban meadows in place of short amenity grass). Here, we investigate soil–plant–pollinator relationships across urban grass and meadow habitats through a range of measured biodiversity (soil mesofauna and macrofauna, plants, aboveground invertebrates, and pollinators) and edaphic variables. We found significant effects of habitat type on available nutrients (plant and soil C:N ratios) but less clear relationships were observed between habitat type and diversity metrics. Soil–plant–pollinator interactions across habitat types and sites showed an interconnection, whereby flowering plant abundance increased alongside soil macrofauna abundance. Site characteristics that showed strong effects on plant and invertebrate diversity metrics were C:N ratios (plant and soil) and soil pH, suggesting a potential role of nutrient availability on soil–plant–pollinator associations. Our results suggest that a combination of short-mown grass, tall grass, and sown flowers can provide greater benefits for soil and pollination services as each habitat type benefits different taxa due to differing sensitivities to management practices. For example, pollinators benefit from sown flowers but soil fauna are sensitive to annual sowing. Our results also indicate that sown flowers may not optimise overall biodiversity as expected due to disturbance and the depleting role of tall, flowering plants on soil nutrient availability. Future research across a greater range of sites in urban landscapes would resolve the potential role of nutrient availability in modulating soil–plant–pollinator interactions in urban green spaces. [ABSTRACT FROM AUTHOR]

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]

Leatherjackets (Tipula spp.) are soil‐dwelling pests associated with agriculture. Land management decisions made at farm scale can have subsequent effects on their populations. Between 1980 and 2020, surveys were conducted across Scotland to collect field histories and larval population data from grassland farms. To assess the impact of management and bioclimatic factors on leatherjacket occurrence over time, this study investigated data from fields continuously sampled between 2009 and 2018. We utilized a Generalized Linear Mixed‐Effect Model on a dataset of 61 fields on 19 farms. Results indicated three significant factors affecting larval populations; field size, grazing type and application of insecticides or herbicides (referred to collectively as pesticides). Larval populations were significantly lower in fields that were larger in size and under sheep grazing, compared to no grazing. Pesticide application also caused a significant reduction in larval populations. Management variables were amalgamated to create a Management Intensity Index, revealing significantly increased larval populations under low‐management systems. These results, coupled with significant effects of bioclimatic variables, pinpoint predictive signals for high infestations and potential routes for control strategies. [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]

Eelgrass meadows have attracted much attention not only for their ability to maintain marine ecosystems as feeding grounds for marine organisms but also for their potential to store atmospheric and dissolved CO2 as blue carbon. This study comprehensively evaluated the bacterial and chemical data obtained from eelgrass sediments of different scales along the Japanese coast to investigate the effect on the acclimatization of eelgrass. Regardless of the eelgrass habitat, approximately 1% Anaerolineales, Babeliales, Cytophagales, and Phycisphaerales was present in the bottom sediment. Sulfate-reducing bacteria (SRB) were present at 3.69% in eelgrass sediment compared to 1.70% in bare sediment. Sulfur-oxidizing bacteria (SOB) were present at 2.81% and 1.10% in the eelgrass and bare sediment, respectively. Bacterial composition analysis and linear discriminant analysis revealed that SOB detoxified H2S in the eelgrass meadows and that the larger-scale eelgrass meadows had a higher diversity of SOB. Our result indicated that there were regional differences in the system that detoxifies H2S in eelgrass meadows, either microbial oxidation mediated by SOB or O2 permeation via the physical diffusion of benthos. However, since bacterial flora and phylogenetic analyses cannot show bias and/or causality due to PCR, future kinetic studies on microbial metabolism are expected. [ABSTRACT FROM AUTHOR]

Meadow podbels (dark-humus gleyic and gleyed podbels in the Russian soil classification system) in the west of their range experience deep and prolonged freezing manifested in cryogenic deformations of horizons and in their microstructures. Microfeatures of soils on permafrost are well known, and the objective of this study was to identify them in three profiles of meadow podbels taking into account particular features of their cryological and moisture regimes. Unlike northern permafrost-affected soils, meadow podbels have dark-humus horizons with weakly expressed cryogenic features; in eluvial horizons, these are platy microstructures and numerous humus-iron nodules of different size. In the textural horizons, there are specific microstructures: rounded or ellipsoidal aggregates with humus-iron nodules in the center and ooidal aggregates with iron impregnation in the center and optically oriented clay along the periphery. Typical microfeatures of gley in the lower clayey horizons are combined with partially deformed illuviation clay coatings. Unlike soils with permafrost, the separation of micromass and skeleton grains is weak, as well as their ring-shaped orientation. [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]

The expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket Saga pedo, currently listed as Vulnerable globally by the IUCN and included in Annex IV of the European Union Habitats Directive. Gathering information on its ecology and population size is challenging due to its low abundance and localized distribution. Additionally, the elusive and cryptic behavior of this species reduces the likelihood of its detection, potentially resulting in population underestimations. Thus, in this study, we aimed to (1) estimate S. pedo population size in relation to environmental variables and prey availability and (2) predict abundance of S. pedo in our study area for future monitoring in nearby territories. We found that the population of S. pedo in our study area consists of 197 (±115) individuals with a detection probability of 21.01% (±11.09). Detection probability of S. pedo further decreases on windy days. Moreover, we found that the investigated population of S. pedo occupies suboptimal areas, as highlighted not only by the predicted abundances but also by the association between S. pedo and other subfamilies of orthoptera that are ecologically very distant from our target species and mostly linked to mesophilic biotopes. Most of the individuals we observed are concentrated in small clearings completely within wooded matrices and therefore isolated from each other. Based on our results, it is possible that forest expansion toward open meadows represents the main threat to this population, transforming the clearings and xeric meadows (to which S. pedo is linked) into small and fragmented patches that are suboptimal and insufficient to host viable populations. [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]

Nematodes typically comprise the most abundant phylum in meiofaunal communities. We aim to characterize the specific ecological conditions that influence Nematoda communities in Posidonia oceanica grasslands focusing on three habitats: leaves, matte, and unvegetated adjacent sediment. We hypothesized that the constant flux of nutrients under the canopy would result in a higher concentration of metazoans compared to the unvegetated sediment outside; however, the hypothesis was not confirmed by the obtained results. The habitat heterogeneity played an important role in shaping the community, yielding a greater richness in the matte. The resource specificity of the leaves (microepiphytes) was also expected to shape the community by favoring nematodes capable of exploiting this resource (epistratum feeders with scraping-like structures), such as the family Chromadoridae that dominated this habitat. In addition, the high light exposure of the leaves explains the higher concentration of ocellated nematodes in this habitat. Organic carbon and nitrogen contents had an impact on the Nematoda community composition, meanwhile average grain size only affected the abundance of nematodes with elongated/filiform tails. [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]

Most farmland birds experience strong declines across Europe. These declines are typically associated with agricultural intensification but research on alternative local causes remains scarce. We investigated variation in reproductive success as a potential driver for the observed population declines in a fragmented population of the Meadow Pipit Anthus pratensis, a representative inhabitant of extensively managed mountain grasslands across Europe. Intense nest surveys in the entire Meadow Pipit metapopulation of the Northern Black Forest (SW Germany) between 2020 and 2022 provided information on reproductive success for 53 females distributed across nine habitat patches along an 18 km ridge of the Northern Black Forest. Hatching dates delayed by approx. 5.0 days per 100 m altitude and were almost 10 days later in a year with cold and rainy spring weather. Mean reproductive success per female and year (3.45 fledglings) was low compared to literature values (approx. 4.5) and may thus drive ongoing population declines. Mayfield nest survival estimates (approx. 51% across the nesting period) were comparably high, with most nest failures linked with predation or adverse weather. Low reproductive success further associated with comparably small clutch sizes and low fractions of second broods in habitat patches characterized by homogeneously dense swards. We suggest that restoration through extensive permanent cattle grazing coupled with succession control may be a key factor to increase population productivity. [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]

Simple Summary: Increased periods of drought and the resulting shortage of forage necessitate the development of new strategies to find forage alternatives for equine nutrition. Alfalfa (Medicago sativa) is a heat-tolerant and high-yielding plant that provides high levels of protein and minerals, such as calcium (Ca) and magnesium (Mg). Alfalfa hay (AH) is an adequate forage alternative to meadow hay that seems to positively impact the fermentation profile in the large intestine in horses. However, little is known about feeding wrapped alfalfa as an alternative forage source in equine diets. Furthermore, its preservation in the form of haylage minimises leaf losses compared with that of alfalfa hay. The aim of this study was to examine the nutrient composition and feed hygiene of alfalfa as well as investigate the feed intake, blood, urine and faecal parameters of horses fed alfalfa haylage (AS) compared with AH and meadow hay (MH). Voluntary feed intake, nutrient values and faecal quality support AS as a suitable forage source in equids. In addition, the intake of wrapped forage provides a dust-free feed, which may be beneficial for horses suffering from equine asthma. Furthermore, its preservation in the form of haylage minimises leaf losses compared with that of alfalfa hay. The aim of this study was to examine the nutrient composition and feed hygiene of alfalfa as well as investigate the feed intake, blood, urine and faecal parameters of horses fed alfalfa haylage (AS) compared with alfalfa hay (AH) and meadow hay (MH). A total of 11 geldings were fed ad libitum (2.1% dry matter (DM) of body weight (BW)) with alfalfa haylage, alfalfa hay and meadow hay (MH) in a Latin square design. On days 0 and 21 of the feeding period, blood samples were analysed for kidney and liver parameters. Faecal samples were analysed for pH, DM and short-chain fatty acids (SCFAs). Spontaneous urine was collected during the feeding period to analyse selected parameters. Forage was analysed in terms of feed hygiene and crude nutrients. In several feed samples of AS, AH and MH, the microbial reference ranges were exceeded for product-typical and spoilage-indicating bacteria and fungi. Crude nutrient analyses revealed a median crude protein content of 139 (138/142) g/kg DM for AS, which was similar to that in AH (127–135 g/kg DM) and substantially higher than in MH (79.1–87.7 g/kg DM). The calcium level in AS (11.3 g/kg DM) was significantly higher than that in MH (4.00–4.95 g/kg DM) but not compared with that in AH (9.80–10.4 g/kg DM). All blood parameters were within the reference ranges. Fractional excretion (FE)Ca for AS-fed horses ranged from 8.13 to 22.0%; the FECa for AH-fed horses ranged from 6.48 to 24.8%; the FECa for MH-fed horses ranged from 6.69 to 53.2%. No significant differences were found in faecal pH or SCFA content in AS-fed horses compared with AH-fed and MH-fed horses. We concluded that alfalfa haylage provides an alternative forage for equine nutrition. [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]

On the basis of the data received from the research experiment conducted with bird's-foot-trefoil, red clover and sainfoin, fertilized with humate fertilizers on the territory of the experimental field of Research Institute of Mountain Stockbreeding and Agriculture -- Troyan during the period 2013-2015, correlation dependencies and regression equations were constructed. A positive correlation dependence was established between: the phosphorus content and the height of fertilizer meadows with legumes (r = 0.90); the content of nitrogen-free extractable substances and the relative share of the stems (r = 0.86); and the crude protein and the percentage share of leaves (r = 0.80). This proves the positive effect of fertilizing with boron and molybdenum humate on growth and development of legumes, the accumulation of nutrients in the forage. The regression equations derived prove the possibility of predicting the crude protein content from the share of leaves in the grass stand (R² = 0.64), the phosphorus content from the height of the stems (R² = 0.81) and of the nitrogen-free extractable substances from the relative share of the stems (R² = 0.75), in the grass stands. Two-factor analysis of variance showed the high impact of the conditions of the year (η = 68.69) on the dry matter yield. [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]

Methane (CH4) is a powerful greenhouse gas with ongoing efforts aiming to quantify and map emissions from natural and managed ecosystems. Wetlands play a significant role in the global CH4 budget, but uncertainties in their total emissions remain large, due to a combined lack of CH4 data and fuzzy boundaries between mapped ecosystem categories. European floodplain meadows are anthropogenic ecosystems that originated due to traditional management for hay cropping. These ecosystems are seasonally inundated by river water, and straddle the boundary between grassland and wetland ecosystems; however, an understanding of their CH4 function is lacking. Here, we established a replicated outdoor floodplain‐meadow mesocosm experiment to test how water table depth (45, 30, 15 cm below the soil surface) and plant composition affect CH4 fluxes over an annual cycle. Water table was a major controller on CH4, with significantly higher fluxes (overall mean 9.3 mg m−2 d−1) from the high (15 cm) water table treatment. Fluxes from high water table mesocosms with bare soil were low (mean 0.4 mg m−2 d−1), demonstrating that vegetation drove high emissions. Larger emissions came from high water table mesocosms with aerenchymatous plant species (e.g. Alopecurus pratensis, mean 12.8 mg m−2 d−1), suggesting a role for plant‐mediated transport. However, at low (45 cm) water tables A. pratensis mesocosms were net CH4 sinks, suggesting that there is plasticity in CH4 exchange if aerenchyma are present. Plant cutting to simulate a hay harvest had no effect on CH4, further supporting a role for plant‐mediated transport. Upscaling our CH4 fluxes to a UK floodplain meadow using hydrological modelling showed that the meadow was a net CH4 source because oxic periods of uptake were outweighed by flooding‐induced anoxic emissions. Our results show that floodplain meadows can be either small sources or sinks of CH4 over an annual cycle. Their CH4 exchange appears to respond to soil temperature, moisture status and community composition, all of which are likely to be modified by climate change, leading to uncertainty around the future net contribution of floodplain meadows to the CH4 cycle. [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]

Background: Grasslands provide a wide range of ecosystem services (ESs). However, there is currently no method for easily diagnosing the level of ESs produced. Our aim was to develop ES indicators based on botanical surveys, which are readily available data and integrative of grassland spatiotemporal variability. Methods: Based on academic knowledge and expertise, we identified several simple vegetation criteria that we aggregated using a multicriteria analysis tool to construct indicators of the level of ESs provided by grasslands. In this study, the indicators were calculated from over 2000 botanical surveys spread over a wide biogeographical gradient. Results: Analyses of correlation between the various indicators show that "forage supply" and "diversity conservation" were not correlated. "Forage availability" and "nitrogen availability for the vegetation" were positively linked together and negatively linked to the robustness of the plant community to extreme events. A temporal approach highlights that the "biodiversity conservation" score decreased from 1970 to 2010 and that "nitrogen availability for the vegetation" was lower in 1970 and 1980 than in 2000 and 2010. Conclusions: These results show that our aggregation method based on a large data set of botanical surveys could be appropriate for studying temporal dynamics of ESs. [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]

Most terrestrial ecosystems are shaped by the pollination service provided by insects, foremost bees. As bees are also important pollinators of crop plants, they are key for both the pollination of wild plants and for agricultural production. Meadows and semi-natural habitats (SNHs) are important habitats for bees. However, there is limited knowledge on how land-use intensity of meadows affects wild bees and managed Western honey bees. Further, it is unknown whether SNHs adjacent to meadows affect bees in meadows. Here, we examined in a landscape dominated by grasslands, the effects of land-use intensity (nitrogen input, grazing intensity, mowing frequency), flower availability and adjacent SNHs on bee communities in meadows. We recorded more than 5000 individuals of 87 species of bees and found no effect of land-use intensity on wild and honey bees. Flowering plant species richness had a positive effect on bee species richness in one study year. Though we recorded more bee species in SNHs than meadows, overall and specifically in ecologically specialized bee species (e.g. parasitic bees, oligoleges), the availability of adjacent SNHs did not affect bee abundance and richness in meadows. We discuss why land-use intensity and SNHs adjacent to meadows did not affect bees in meadows and conclude that SNHs are important in sustaining functionally diverse bee communities in landscapes dominated by grasslands. [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]

Salt marshes provide valuable ecosystem services, which are influenced by their interaction with currents and waves. On the one hand, currents and waves exert hydrodynamic forces on salt marsh plants, which shapes the distribution of species within the marsh. On the other hand, the resistance produced by the plants can shape the flow structure, turbulence intensity, and wave dissipation over the canopy. Because marsh plants are flexible structures, their reconfiguration modifies the drag felt by the plants and the flow. While several previous studies have considered the flexibility of the stem, few studies have considered the leaf component, which has been shown to contribute the majority of plant resistance. This paper reports a unique dataset that includes laboratory measurements of both the force on an individual plant and the flow structure and wave energy dissipation over a meadow of plants. In the individual plant experiment, the motion of the plant and plant drag, free-surface displacement, and velocity profile were measured. The individual plant experiments considered both a live marsh plant (Spartina alterniflora) and a mimic consisting of 10 leaves attached to a central stem. For the meadow experiment, velocity profiles were measured both upstream and within the meadow, and free-surface displacement was measured along the model marsh plant meadow with high spatial and temporal resolution. These experiments used five water depths (covering both submerged and emergent conditions), three wave periods (from long wave to short waves), seven wave heights (from linear to nonlinear waves), and six current conditions (including pure current, pure wave, and combined current and wave). In summary, there are 102 individual plant tests and 58 meadow tests. The drag, free-surface displacement, and velocity are reported in the SMCW.mat and SMCW.nc files including the raw data, the phase averages, and the statistical values. A link to the plant motion videos is also provided. This dataset provides high-quality measurements that can be used to develop and validate models of plant motion, hydrodynamic drag on individual plants, vegetation-generated turbulence, the evolution of flow structure through a meadow, and the transformation and dissipation of waves over natural salt marshes. The dataset is available from Figshare with detailed instructions for reuse (10.6084/m9.figshare.24117144; Zhang and Nepf, 2023a). [ABSTRACT FROM AUTHOR]

Habitat disturbance affects not only the abundance, species richness and species composition of the local fauna, but also the body size of specific individuals and body size patterns in animal assemblages. Particularly large disturbances occur in agroecosystems, where many agricultural treatments are carried out. One of them, which is most commonly applied to grasslands and which significantly damages the habitat structure, is mowing. We examined the effect of mowing on mean, skewness and kurtosis of the body size in epigeic spider assemblages. The research was conducted on mesic meadows in eastern Poland, in an agricultural landscape typical for this region, consisting of a mosaic of meadows, fields and forests. Spiders were collected using pitfall traps in two sampling periods: the first before mowing and the second when part of the meadows had been mown. Mowing had no significant effect on mean body size, skewness and kurtosis of the body size in epigeic spider assemblages. However, after the cut, mown plots showed, on average, significantly smaller spider species than unmown plots. Both the value of skewness and kurtosis significantly increased after mowing but to the same extent on both the control and mown plots. The decrease in mean body size and increase in skewness in spider assemblages were mainly due to an increase in the number of small species from the Linyphiidae family. It is likely that these species began to migrate (via ballooning) during the second sampling session, following the start of haying, and were thus caught in traps more frequently. Our study showed no clear, significant changes in the body size structure of epigeic spiders in mown meadows compared to unmown ones, which may suggest that the mowing, where extensive farming is practised, does not have a long‐term significant negative impact on this group of invertebrates. [ABSTRACT FROM AUTHOR]

The arid sagebrush landscape of the Gunnison Basin, Colorado is home to the federally threatened Gunnison sage‐grouse (GUSG; Centrocercus minimus) and is expected to become hotter and drier with a changing climate. Wet meadows within the sagebrush ecosystem are a critical lifeline for wildlife and livestock, particularly during drought years, yet they occupy less than 2% of the landscape. Our objective was to enhance wet meadow drought resiliency by slowing the water down, reconnecting floodplains, and increasing wetland vegetation. Indirectly we also aimed to enhance GUSG habitat and improve rangeland condition. Between 2012 and 2020, we constructed nearly 900 low‐tech restoration structures (Zeedyk structures), across seven drainageways with wet meadows. Six of these years were drought years. We used a before‐after‐control‐impact design to assess vegetation response. Vegetation data were collected on 135 randomly selected treated and 30 control transects. We found that 75% of ephemeral units and all of perennial units achieved or surpassed the wetland plant cover management goal of a 4% yearly increase. This led to an average enhancement of 40% in wetland plant cover in the treated drainageways. There was a significant positive difference between treated and control transects in 50% of the drainageways, regardless of hydroperiod status. The low‐tech restoration structures were effective at rewetting perennial and ephemeral wet meadows within the arid landscape, even during a megadrought, and reduced non‐native invasive weeds in all but one of the treated units. Forbs and grasses critical to sage‐grouse and important to livestock operations increased in 67% of the units. [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]