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Background: Grazing livestock emits methane through rumen intestinal activity, however, its impact on plant growth in grassland while grazing still has not been explored in detail. Therefore, the study examined the effects of methane pulse spray (MPS), according to grazing intensity, at four grazing intensities (0, 3.6, 5.0, and 6.5 sheep·hm− 2 yr− 1) on seed germination and seedling growth of common vetch (Vicia sativa), while two irrigation rates (35 and 53 ml d− 1) were employed to simulate the precipitation. Results: The study revealed significant interactions between MPS and irrigation rate on seed germination and seedling growth parameters. Under moderate MPS intensities (0.74 and 1.04 mol m− 2), seed germination rate, potential, index, and vigor index improved, especially at higher irrigation rates (53 ml d− 1). Conversely, excessive MPS (1.33 mol m− 2) inhibited particularly at the germination rate and growth,. The seedling growth dynamics fitted a logistic model, with MPS advancing the rapid growth phase and increasing maximum growth rates. Conclusions: This study demonstrates that low to moderate levels of MPS from ruminants can promote seed germination and seedling growth of common vetch, while excessive MPS inhibits these processes. Irrigation enhances plant sensitivity to MPS, with wetter conditions (620 mm yr− 1) facilitating a more pronounced response. The findings introduce a new model elucidating plant responses to external perturbations, which can inform grazing management strategies in diverse ecosystems. In wetter regions, moderate grazing intensities may leverage MPS benefits, while arid regions require careful grazing regulation to maintain grassland-livestock balance. [ABSTRACT FROM AUTHOR]

Nitrogen (N) deposition rates have notably increased around the world, especially in high-altitude regions like the Qinghai–Tibetan Plateau (QTP). We conducted a six-year comprehensive experiment to simulate nitrogen deposition in an alpine grassland area near Qinghai Lake. Four levels of nitrogen depositions, i.e., 0 (CK), 8 kg N ha−1year−1 (N1), 40 kg N ha−1year−1 (N2), and 72 kg N ha−1year−1 (N3), with three replicates for each N treatment, were tested annually in early May and early July, with the meticulous collection of plant and soil samples during the peak growth period from 15 July to 15 August. We used the null model to evaluate the impact of environmental filtration and interspecific competition on the dynamics of the plant community was assessed based on the level of discrete species affinities within the plant community by constructing a phylogenetic tree. The results showed that the environmental filter was the predominant driver for the change of community's genealogical fabric. The N2 and N3 treatments increased the influence of soil factors on the change of plant community structure. Climatic factors played a crucial role on the change of plant community in the CK grassland area, while soil factors were dominant in the N1- and N3-treated grasslands. [ABSTRACT FROM AUTHOR]

The use of trait-based approaches to understand ecological communities has increased in the past two decades because of their promise to preserve more information about community structure than taxonomic methods and their potential to connect community responses to subsequent effects of ecosystem functioning. Though trait-based approaches are a powerful tool for describing ecological communities, many important properties of commonly-used trait metrics remain unexamined. Previous work with simulated communities and trait distributions shows sensitivity of functional diversity measures to the number and correlation of traits used to calculate them, but these relationships have yet to be studied in actual plant communities with a realistic distribution of trait values, ecologically meaningful covariation of traits, and a realistic number of traits available for analysis. To address this gap, we used data from six grassland plant communities in Minnesota and New Mexico, USA to test how the number of traits and the correlation between traits used in the calculation of eight functional diversity indices impact the magnitude of functional diversity metrics in real plant communities. We found that most metrics were sensitive to the number of traits used to calculate them, but functional dispersion (FDis), kernel density estimation dispersion (KDE dispersion), and Rao's quadratic entropy (Rao's Q) maintained consistent rankings of communities across the range of trait numbers. Despite sensitivity of metrics to trait correlation, there was no consistent pattern between communities as to how metrics were affected by the correlation of traits used to calculate them. We recommend that future use of evenness metrics include sensitivity analyses to ensure results are robust to the number of traits used to calculate them. In addition, we recommend use of FDis, KDE dispersion, and Rao's Q when ecologically applicable due to their ability to produce consistent rankings among communities across a range of the numbers of traits used to calculate them. [ABSTRACT FROM AUTHOR]

The encroachment of woody plants into grassland and the conversion of grasslands to woodlands is a worldwide phenomenon and has been regarded as a major global problem for decades. The rate of woody plant encroachment (WPE) varies across biomes and can be influenced by land use activities and climate conditions. As a result, the current study assessed the spatial distribution of woody plants and land use and land cover (LULC) change within the Letaba River catchment in the Limpopo province of South Africa's subtropical region. Landsat Thematic Mapper (TM) and Operational Land Imager (OLI) satellite data sets were used to map and quantify WPE and other LULC changes in the Letaba River catchment over a 30‐year period (1989–2019). Random forest classifier was used to determine of the rate of change of WPE and LULC within the study area. The results indicated that the Letaba River catchment has undergone a significant change with an increase in woody plant species. The woody plant cover had increased from 36,014 ha in the year 1989 to approximately 561,493 ha by 2019. Meanwhile, grassland has declined by 486,322 ha (33.7%) from 1989 to 2019. The overall classification accuracy (OA) ranged between 91.7% and 95.5%. The study findings will provide critical insights and baseline information about the state of WPE in semi‐arid environments, as well as provide catchment managers with the information they need to take the necessary actions to manage the rapid increase in woody plants. However, fire and herbivory are important factors that influences the WPE, and this might have also played an important role in the findings. The study suggests that WPE is an ongoing process and management strategies are required to mitigate and maintain the intensity of woody plants. [ABSTRACT FROM AUTHOR]

The timing and order of species arrival have been shown to be a significant factor in the assembly of biotic communities. Therefore, understanding priority effects, which refer to the impact of an early‐arriving species on a later‐arriving one, can help us better predict community assembly processes. However, little is known about the role of phylogenetic distance (PD) in priority effects and how they are mediated by the biogeographic history (BH) and the life stages (LSs) of interacting species.To shed light on the role of PD in priority effects, we conducted a multispecies greenhouse experiment. We created 10 allopatric and 10 sympatric species pairs, representing a PD gradient between early‐ and late‐arriving species from 5 to 270 Myr in evolutionary history and tested the priority effect of early‐arriving species on the late‐arriving species at multiple LSs.We found evidence of stronger competition between closely related species, as late‐arriving plants produced less above‐ground biomass when the PD was low. However, priority effects varied across the development of late‐arriving plants, as there were no effects on seedling emergence and survival, independent of PD. Regardless of PD, the pairs of allopatric and sympatric species did not differ in their responses.Synthesis. While many studies have produced contradictory results regarding the effect of PD on plant–plant interactions, our study provides experimental evidence that priority effects can be stronger when PD is small. This effect was independent of BH but varied across different LSs of late‐arriving plants. The dependence of the effect of PD on the LS of late‐arriving species highlights the importance of the timing of interactions for the assembly of plant communities, which could also have significant implications for the fields of invasion and restoration ecology. [ABSTRACT FROM AUTHOR]

Global warming may pose a threat to the productivity of grazed grasslands. In this study, we investigated changes in the warming response of aboveground regrowth with the repetition of simulated grazing in two Mongolian pasture species, Agropyron cristatum and Stipa krylovii. Plants were grown under warming or non-warming conditions and subjected to repeated clipping of aboveground parts three times at 4-week intervals. Aboveground parts collected at each clipping and whole plants harvested at the end of the experiment were dried and weighed. Specific leaf area (SLA) and the content of nitrogen (N) and crude fiber (CF) in leaves were measured to evaluate leaf morphology and pasture nutritional value. In both species, warming had little effect on regrowth when clipping was repeated one or two times. In A. cristatum, however, warming significantly diminished regrowth when clipping was repeated three times. Belowground biomass decreased with clipping–regrowth cycles only in A. cristatum, and the decline was enhanced by warming, implying that the depletion of belowground reserves contributed to the reduction of regrowth in this species. SLA and the N and CF contents were similar in the warming and non-warming treatments, indicating that warming had little effect on leaf morphology and pasture nutritive value in these Mongolian pasture species. Our results suggest that warming would likely have little effect on regrowth performance of grassland plants under lightly grazed conditions, but warming can decrease regrowth when grazing frequency is high, with the degree of decrease being species dependent. [ABSTRACT FROM AUTHOR]

Specific leaf area (SLA) and leaf dry matter content (LDMC) are key leaf functional traits often used to reflect plant resource utilization strategies and predict plant responses to environmental changes. In general, grassland plants at different elevations exhibit varying survival strategies. However, it remains unclear how grassland plants adapt to changes in elevation and their driving factors. To address this issue, we utilized SLA and LDMC data of grassland plants from 223 study sites at different elevations in China, along with climate and soil data, to investigate variations in resource utilization strategies of grassland plants along different elevational gradients and their dominant influencing factors employing linear mixed-effects models, variance partitioning method, piecewise Structural Equation Modeling, etc. The results show that with increasing elevation, SLA significantly decreases, and LDMC significantly increases (P < 0.001). This indicates different resource utilization strategies of grassland plants across elevation gradients, transitioning from a "faster investment-return" at lower elevations to a "slower investment-return" at higher elevations. Across different elevation gradients, climatic factors are the main factors affecting grassland plant resource utilization strategies, with soil nutrient factors also playing a nonnegligible coordinating role. Among these, mean annual precipitation and hottest month mean temperature are key climatic factors influencing SLA of grassland plants, explaining 28.94% and 23.88% of SLA variation, respectively. The key factors affecting LDMC of grassland plants are mainly hottest month mean temperature and soil phosphorus content, with relative importance of 24.24% and 20.27%, respectively. Additionally, the direct effect of elevation on grassland plant resource utilization strategies is greater than its indirect effect (through influencing climatic and soil nutrient factors). These findings emphasize the substantive impact of elevation on grassland plant resource utilization strategies and have important ecological value for grassland management and protection under global change. [ABSTRACT FROM AUTHOR]

Grassland aridification threatens biodiversity which supports ecosystem multifunctionality (EMF), but the relative roles of biota in maintaining EMF are poorly known. A new study in PLoS Biology finds complementarity of above- and belowground biodiversity and a trade-off between fungal and plant richness in driving EMF with aridity. Grassland aridification threatens biodiversity which supports ecosystem multifunctionality (EMF), but the relative roles of biota in maintaining EMF are poorly known. This Primer explores a new study in PLOS Biology that finds complementarity of above- and below-ground biodiversity and a trade-off between fungal and plant richness in driving EMF with aridity. [ABSTRACT FROM AUTHOR]

The study of the polarimetric target decomposition algorithm with physical scattering models has contributed to the development of the field of remote sensing because of its simple and clear physical meaning with a small computational effort. However, most of the volume scattering models in these algorithms are for forests or crops, and there is a lack of volume scattering models for grasslands. In order to improve the accuracy of the polarimetric target decomposition algorithm adapted to grassland data, in this paper, a novel volume scattering model is derived considering the characteristics of real grassland plant structure and combined with the backward scattering coefficients of grass, which is abstracted as a rotatable ellipsoid of variable shape. In the process of rotation, the possibility of rotation is considered in two dimensions, the tilt angle and canting angle; for particle shape, the anisotropy degree A is directly introduced as a parameter to describe and expand the applicability of the model at the same time. After obtaining the analytical solution of the parameters and using the principle of least negative power to determine the optimal solution of the model, the algorithm is validated by applying it to the C-band AirBorne dataset of Hunshandak grassland in Inner Mongolia and the X-band Cosmos-Skymed dataset of Xiwuqi grassland in Inner Mongolia. The performance of the algorithm with five polarimetric target decomposition algorithms is studied comparatively. The experimental results show that the algorithm proposed in this paper outperforms the other algorithms in terms of grassland decomposition accuracy on different bands of data. [ABSTRACT FROM AUTHOR]

A major factor hindering ecological restoration is uncertainty about which plant species will best establish. We account for this uncertainty in the design of seed mixes, though our developments are relevant to other planting mixes (e.g. root stock). We view seed mixes as being comprised of one or more species groups (e.g. shrubs, grasses, and nitrogen fixers). We mathematically establish that chances of relatively low densities decline as a species group's seeding rate (e.g. 100 seeds/m2) is divided more evenly among more species. This decline is sharpest if survival probabilities vary widely among species. To determine how much survival probabilities typically vary, we studied grasses commonly seeded in Great Plains grasslands and Mediterranean annual grasslands in the western United States. Survival probabilities varied extensively, so the chances of low densities declined markedly with increasing seeded species numbers. In the Great Plains, the chances of establishment failures (0 plants/m2) were 50% when the seeding rate was allocated to one species versus 0% when the seeding rate was divided evenly among five or more species. Similarly, in Mediterranean annual grasslands, the chances of very low densities (≤1.0 plants/m2) declined from 24% when one species was seeded to 0% when three or more species were seeded. The seeding rate for each plant group should be divided as evenly as possible among as many species as practical. Compared to increasing seeding rates to provide greater densities, dividing fixed rates more evenly among more species could prove less expensive. [ABSTRACT FROM AUTHOR]

Fire plays a key role in grasslands, determining the distribution and evolution of species and boundaries with neighboring ecosystems. Evidence of community-wide responses to fire is largely based on taxonomic and functional descriptors, while the phylogenetic dimension is overlooked. Here we evaluated how the taxonomic and phylogenetic structure of grassland plant communities responded to a time since fire (TSF) gradient. We sampled 12 communities in Southern Brazil under varying TSF and calculated taxonomic species richness (S) and dominance (D), phylogenetic diversity (PD), and mean phylogenetic distances (MPD). We used Structural Equation Models to test the relationships between the environmental gradient and community descriptors. Communities with longer TSF presented higher PD and MPD but lower species richness and increased taxonomic dominance. These sites were dominated by monocots, specifically C4 grasses, but also presented exclusive clades, whereas recently-burned sites presented lower taxonomic dominance and more species distributed in a wider variety of clades. Our results indicate that these scenarios are interchangeable and dependent on fire management. Fire adaptation was not constrained by phylogenetic relatedness, contrasting with previous findings for tropical savannahs and indicating that temperate and tropical non-forest ecosystems from South America respond differently to fire, possibly due to different evolutionary histories. [ABSTRACT FROM AUTHOR]

Grasslands are among the most imperilled ecosystems worldwide, and many have experienced degradation due to the loss of historical disturbance regimes and subsequent woody encroachment. Management practitioners often use physical and chemical management interventions in combination with fire to counter encroachment, altering aboveground structure and belowground function, respectively. This may disrupt the feedbacks that perpetuate encroachment and restore the herbaceous community. We use a large‐scale field experiment to assess the initial effects of different management interventions on woody vegetation persistence, abiotic habitat conditions, and herbaceous community composition. We evaluate these effects across seven sites spanning a natural soil moisture gradient to capture one aspect of environmental heterogeneity with which managers regularly contend. We found that chemical intervention, both with and without the addition of physical intervention, was most effective at reducing woody plant cover and abundance, and a second application reduced woody plant abundance by more than one application alone. We also found that any management intervention increased light availability and air temperature and decreased soil moisture, with the combination of physical and chemical interventions having the greatest effects. Finally, none of the management interventions affected herbaceous richness and functional group cover within the study period, indicating delayed or nonexistent effects on herbaceous community composition. Synthesis and application. Our findings suggest that management should focus on chemical intervention for the greatest effects on woody plant persistence and abiotic habitat conditions. Changes to herbaceous community composition may occur in the long term and seem likely since short‐term effects of management were successful in altering processes related to encroachment feedbacks. [ABSTRACT FROM AUTHOR]

The carbon density of subalpine-alpine grasslands (SGs) is significantly vital to sustaining the carbon cycle in global terrestrial ecosystems. However, on the Loess Plateau of China, it remains unclear how the geographical environment and plant functional groups affect the spatial variation pattern of plant carbon density in these grasslands. Here, nine typical SGs distributed in the eastern Loess Plateau with elevations ranging from 1720 to 3045 m were investigated. The biomass indices from grassland plants of different functional groups were investigated using plot surveys. The Kriging interpolation method was used to explore the spatial variation pattern of plant carbon density along geographical gradients. We found that (1) the total plant carbon density of SGs was 2676.825 g C/m2 on the eastern plateau, with 37.07%, 37.50%, and 25.43% contributed by the northern, central, and southern areas, respectively. Above- (666.338 g C/m2) and belowground (2010.488 g C/m2) carbon density accounted for 24.9% and 75.11% of the total, respectively. (2) At the horizontal scale, the plant carbon density in the northern SGs was high in the northwest and low in the southeast; in the central SGs, it was low in the northwest and high in the southeast; and in the southern SGs, it was high in the southwest and low in the northeast. At the vertical scale, plant carbon density in all SGs decreased with increasing altitude. (3) The carbon density of grasses, forbs, and sedges was 247.419 g C/m2, 26.073 g C/m2, and 23.471 g C/m2, respectively. With increased latitude, the carbon density of all functional groups (grasses, forbs, and sedges) decreased; the carbon density of forbs and grasses increased with increased longitude, while that of sedges decreased; and with increased altitude, the carbon density of all functional groups increased. In conclusion, the spatial variation pattern of plant carbon density in the SGs was not only influenced by the geographical environment but also by the plant functional groups at the horizontal and vertical scales on the eastern Loess Plateau of China. [ABSTRACT FROM AUTHOR]

Background: The species composition of and changes in grassland communities are important indices for inferring the number, quality and community succession of grasslands, and accurate monitoring is the foundation for evaluating, protecting, and utilizing grassland resources. Remote sensing technology provides a reliable and powerful approach for measuring regional terrain information, and the identification of grassland species by remote sensing will improve the quality and effectiveness of grassland monitoring. Methods: Ground hyperspectral images of a sericite–Artemisia desert grassland in different seasons were obtained with a Soc710 VP imaging spectrometer. First-order differential processing was used to calculate the characteristic parameters. Analysis of variance was used to extract the main species, namely, Seriphidium transiliense (Poljak), Ceratocarpus arenarius L., Petrosimonia sibirica (Pall), bare land and the spectral characteristic parameters and vegetation indices in different seasons. On this basis, Fisher discriminant analysis was used to divide the samples into a training set and a test set at a ratio of 7:3. The spectral characteristic parameters and vegetation indices were used to identify the three main plants and bare land. Results: The selection of parameters with significant differences (P < 0.05) between the recognition objects effectively distinguished different land features, and the identification parameters also differed due to differences in growth period and species. The overall accuracy of the recognition model established by the vegetation index decreased in the following order: June (98.87%) > September (91.53%) > April (90.37%). The overall accuracy of the recognition model established by the feature parameters decreased in the following order: September (89.77%) > June (88.48%) > April (85.98%). Conclusions: The recognition models based on vegetation indices in different months are superior to those based on feature parameters, with overall accuracies ranging from 1.76% to 9.40% higher. Based on hyperspectral image data, the use of vegetation indices as identification parameters can enable the identification of the main plants in sericite–Artemisia desert grassland, providing a basis for further quantitative classification of the species in community images. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal inoculation can promote plant growth, but specific research on the difference in the symbiosis effect of arbuscular mycorrhizal fungi and plant combination is not yet in-depth. Therefore, this study selected Medicago sativa L., Bromus inermis Leyss, and Festuca arundinacea Schreb., which were commonly used for restoring degraded land in China to inoculate with three AMF separately, to explore the effects of different AMF inoculation on the growth performance and nutrient absorption of different plants and to provide a scientific basis for the research and development of the combination of mycorrhiza and plants. We set up four treatments with inoculation Entrophospora etunicata (EE), Funneliformis mosseae (FM), Rhizophagus intraradices (RI), and non-inoculation. The main research findings are as follows: the three AMF formed a good symbiotic relationship with the three grassland plants, with RI and FM having more significant inoculation effects on plant height, biomass, and tiller number. Compared with C, the aboveground biomass of Medicago sativa L., Bromus inermis Leyss, and Festuca arundinacea Schreb. inoculated with AMF increased by 101.30–174.29%, 51.67–74.14%, and 110.67–174.67%. AMF inoculation enhanced the plant uptake of N, P, and K, and plant P and K contents were significantly correlated with plant biomass. PLS-PM analyses of three plants all showed that AMF inoculation increased plant nutrient uptake and then increased aboveground biomass and underground biomass by increasing plant height and root tillering. This study showed that RI was a more suitable AMF for combination with grassland degradation restoration grass species and proposed the potential mechanism of AMF–plant symbiosis to increase yield. [ABSTRACT FROM AUTHOR]

Grazing affects plant community characteristics and the relationship between above-ground biomass and diversity, which has become a hot topic in grassland ecosystem research in recent years. The present study investigated grassland vegetation in the Two Rivers pastoral area based on 60 sampling points using sampling methods. The effects of grazing on the structural characteristics of plant communities were analysed using the α-diversity index, and the relationship between species diversity and the above-ground biomass of plant communities, as well as their changes, was explored. The results showed that grazing disturbance decreased the number of family species in the grassland plant communities and the similarity between communities; grazing activities significantly decreased the above-ground biomass of the grassland plant communities; the height and cover also showed a decreasing trend (p < 0.01), but the density of the grassland plant communities improved (p < 0.01). The Margalef index, the Shannon–Wiener index, and the Simpson index of the grassland plant communities all showed different degrees of decrease after grazing, while the Alatalo index showed an increase; biomass was positively correlated with the Margalef, Shannon–Wiener, and Alatalo indices and negatively correlated with the Simpson index (p < 0.01). Therefore, in the management and maintenance of grasslands, the impact of grazing on the structural characteristics of plant communities should be taken into account, and reasonable response policies should be implemented according to the actual local situation. This study provides a theoretical basis for grassland maintenance and management and the sustainable development of ecosystems in the pastoral areas of the two river sources of the Altay Mountains. [ABSTRACT FROM AUTHOR]

Environmental change is disrupting mutualisms between organisms worldwide. Reported declines in insect populations and changes in pollinator community compositions in response to land use and other environmental drivers have put the spotlight on the need to conserve pollinators. While this is often motivated by their role in supporting crop yields, the role of pollinators for reproduction and resulting taxonomic and functional assembly in wild plant communities has received less attention. Recent findings suggest that observed and experimental gradients in pollinator availability can affect plant community composition, but we know little about when such shifts are to be expected, or the impact they have on ecosystem functioning. Correlations between plant traits related to pollination and plant traits related to other important ecosystem functions, such as productivity, nitrogen uptake or palatability to herbivores, lead us to expect non‐random shifts in ecosystem functioning in response to changes in pollinator communities. At the same time, ecological and evolutionary processes may counteract these effects of pollinator declines, limiting changes in plant community composition, and in ecosystem functioning. Despite calls to investigate community‐ and ecosystem‐level impacts of reduced pollination, the study of pollinator effects on plants has largely been confined to impacts on plant individuals or single‐species populations. With this review we aim to break new ground by bringing together aspects of landscape ecology, ecological and evolutionary plant–insect interactions, and biodiversity–ecosystem functioning research, to generate new ideas and hypotheses about the ecosystem‐level consequences of pollinator declines in response to land‐use change, using grasslands as a focal system. Based on an integrated set of seven hypotheses, we call for more research investigating the putative pollinator‐mediated links between landscape‐scale land use and ecosystem functioning. In particular, future research should use combinations of experimental and observational approaches to assess the effects of changes in pollinator communities over multiple years and across species on plant communities and on trait distributions both within and among species. [ABSTRACT FROM AUTHOR]

In this study, we selected four grassland plots in Altai forest area and used the field survey method of "two-valued occurrence" to obtain the occurrence data of each plant species in the plots so as to calculate the species diversity index value of the community as a whole and the species diversity index value of each plant species not present in the community and to make use of the difference between these two diversity indices to determine the role of each plant species in the overall species diversity of the community. The difference between these two diversity indices was used to investigate the role of each plant species in the overall species diversity of the community. The results show the following: (1) In the grassland of the Altai forest area in Xinjiang, Asteraceae, Poaceae, Fabaceae, Polygonaceae, and Rosaceae are the dominant families, among which the genera Puccinellia Parl, Taraxacum, Pharbitis, Lactuca, Geranium, and Alchemilla are the dominant genera. (2) The plant species with the greatest contribution to species diversity in the four grassland samples was not the first dominant species of the community, but rather the plant species whose dominance was in the second to sixth position. (3) The first dominant species was overwhelmingly dominant in the four sample plots, and it served to increase the overall diversity of the community. (4) The overall trend in the size of the role of species in diversity is unimodal, i.e., logarithmically increasing to a maximum as species dominance decreases and then exponentially or linearly decreasing and eventually converging to zero. The synthesis showed that it was not the first dominant species that played the largest role in species diversity in the different grassland communities and that the overwhelmingly dominant species reduced the species diversity of the community. [ABSTRACT FROM AUTHOR]

A negative dependence of the digestibility of grassland vegetation on the amount of grasses in the feed consumed, which is in turn associated with an increased content of silicon compounds in grasses, is found. Using the example of four species of herbivores (Przewalski's horse, American bison, Bactrian camel, and saiga), which differ in the specifics of digestion, the selectivity of their nutrition was studied in relation to two groups of plants differing in digestibility—grasses and forbs. Saigas, like other obviously highly selective consumers of easily digestible food, strictly select forbs with a low silicon content and high digestibility. With the dominance of low-digestible grasses on the grassland and their forced consumption, the saiga population is not viable. Horses and bison, like other representatives of equines and large ruminants, due to the characteristics of the digestive system, are able to assimilate low-digestible grass feeds successfully and are highly specialized in feeding on grasses. The exclusion of forbs from the diet of horses and bison is associated with the increased toxicity of this group of plants. Camels do not discriminate in the choice of grasses and forbs of different nutritional value and currently actively use fallow areas (on former arable land) dominated by weedy plants, which are avoided by other herbivores. Different specialization in the choice of forage plants when different species of animals graze together causes their division in the use of grassland feed resources, eliminates competition between them, and acts as a necessary factor in preserving the species diversity of grassland vegetation. [ABSTRACT FROM AUTHOR]

This study investigates the economic, social, and environmental impacts of dust storms on pastoralists' livelihoods in the Chaqakdo rangeland of West Iran. Data was collected through face‐to‐face interviews with 100 pastoralists in 2019. The research adopts a quantitative approach using Structural Equation Modeling (SEM). The results demonstrate a significant and positive relationship between pastoralists' livelihoods and the three independent variables (environmental, economic, and social), with the strongest correlation observed in environmental factors. The path coefficients indicate positive effects on pastoralists' livelihoods. Additionally, dust storms were found to have detrimental environmental effects, such as plant leaf pollution, reduced grazing, and decreased growth of grassland plants. Therefore, it is crucial to establish adaptive measures to mitigate the impacts of dust storms on pastoralists, considering their heavy reliance on the local pastures. [ABSTRACT FROM AUTHOR]

Simple Summary: Western Inner Mongolia is a principal part of the arid region in northwest China, covered mainly with semifrutex and frutex plants in the native grassland. Owing to the fact that epiphytic lactic bacteria (LAB) species are sensitive to the environment, the low nutrient concentrations, low water availability, and large changes in temperature around the phyllosphere in this region may lead to LAB species with special properties. However, limited information is available on the biodiversity and ensiling parameters of LAB on the forage plants in this region. This study was conducted to investigate the genotypic and phenotypic characteristics of LAB associated with forage plants in the region, and to screen for efficient strains for well-preserved alfalfa silage. A total of 73 strains belonging to 16 species were isolated, and most of strains could grow at 5–45 °C and in 6.0% NaCl, possessed good cryotolerance and osmotolerance. Lactiplantibacillus plantarum subsp. plantarum (GI19) and sucrose was the most effective combination for alfalfa ensiling, with a higher lactic acid content and lower pH, undesirable microorganism counts, and acetic acid and NH3-N contents. This additive could be used to produce quality alfalfa silage for the region to alleviate the shortage of feed in autumn and winter. This study was conducted to investigate the genotypic and phenotypic characteristics of lactic acid bacteria (LAB) associated with forage plants in the native grassland of western Inner Mongolia and to evaluate their effects on alfalfa silage fermentation. Forage plants and their spontaneous fermentation silages were analysed using culture-based techniques for LAB isolation; the phenotypic properties and 16S rDNA and pheS or rpoA gene sequences of the isolates were evaluated; alfalfa was ensiled with four additive combinations: Lactiplantibacillus plantarum subsp. plantarum (GI19), Lact. plantarum subsp. plantarum and Pediococcus pentosaceus (GI19+GI51), GI19 and 20 g/kg fresh matter of sucrose (GI19+S), and GI19+GI51+S, for 60 d. A total of 73 strains belonging to 16 species were isolated. All isolates grew at 5–45 °C and in 3.0% NaCl, and most of them grew in 6.5% NaCl. Enterococcus faecalis and Lact. plantarum were 26.03% and 17.81% of the total isolates, respectively. All additives improved the silage quality, while GI19+S was more effective for alfalfa ensiling with a higher lactic acid content and lower pH, undesirable microorganism counts, and acetic acid and NH3-N contents than remnant additives. In conclusion, the LAB species were diverse, and most of them possessed good cryotolerance and osmotolerance; GI19+S was the optimal inoculant for alfalfa fermentation improvement. [ABSTRACT FROM AUTHOR]

Grassland plants that endure livestock grazing exhibit a dwarf phenotype, which can be transmitted to clonal offspring. Yet to date, it remains poorly understood whether such transgenerational dwarf effects alter the plants' response to shade. Here, we conducted a common garden experiment under sunlight and shade conditions with clonal Leymus chinensis offspring, the parents of which had endured livestock overgrazing (OG) and non-grazing (NG) in the field, respectively. Plant morphological, physiological, and transcriptomic analyses were carried out. The results indicated that NG offspring showed greater shade avoidance than OG offspring. That is, NG offspring exhibited greater plasticity of vegetative height and leaf width, which may be contributed to their greater photosynthetic capacity and gibberellin (GA3) content compared with OG offspring when treated with shade. In addition, RNA-Seq profiling showed that differentially expressed genes in NG offspring were mainly enriched in RNA modification and metabolic processes, which facilitated rapid response to shade. Phytochrome interacting factors (PIFs) promoted downstream shade marker genes in NG offspring by significantly downregulating the expression of PHYC, SPY, and DELLA. Our findings suggest that light conditions should be taken into account to better understand transgenerational dwarf effects induced by livestock grazing on grassland ecosystems. These results provide new insights into the inducible factors of phenotypic variations in grassland plants that experience grazing. [ABSTRACT FROM AUTHOR]

Plant species with overlapping distributions are expected to experience the same historical events. In contrast, species with different preferred habitat types may exhibit incongruent phylogeographic patterns because of their habitat‐dependent demographic changes in spite of their overlapping distributions. On the western side of the Japanese Archipelago, boreal forest and non‐forest vegetation were dominant during the last glacial period; subsequently, temperate forests expanded, and open vegetation (e.g., grasslands) decreased. Such vegetation shifts can result in incongruent phylogeographic patterns among temperate forest and grassland species; however, few phylogeographic studies have investigated this hypothesis. Here, we evaluated the phylogeographic structure of two related Geranium species that occur in grassland (Geranium krameri) and temperate forest (Geranium shikokianum) habitats using chloroplast genome sequencing and nuclear genome‐wide single‐nucleotide polymorphisms genotyping. The phylogeographic structure was stronger for the temperate forest species than the grassland species, despite its currently scattered distribution for grassland species. The observed patterns indicate that the phylogeographic histories of these species were influenced by their habitat configurations since the last glacial period. During the ice age, grasslands in Japan were much more widespread than today; this would have enabled the grassland species to form a continuous distribution, leading to low divergence among regional populations. In contrast, the significant genetic divergence within the forest species can be attributed to the glacial isolation of regional populations. Our genetic results suggest that vegetation transitions have variously controlled the population dynamics of two species with overlapping distributions. [ABSTRACT FROM AUTHOR]

Community stability plays a crucial role in ensuring the consistent provision of ecosystem services despite environmental changes, including alterations in precipitation patterns. Over the past decades, significant progress has been made in understanding the responses of the stability of grassland plant communities and underlying mechanisms, defined as the ratio of the temporal mean biomass to the standard deviation. However, a crucial knowledge gap remains regarding whether the impacts of precipitation on the stability of grassland biomass are contingent upon specific contextual factors.Here, we examined the stability of above‐ and below‐ground biomass in adjacent grass‐ and shrub‐dominated communities through a 7‐year manipulation experiment involving seven precipitation levels: 20%, 40% and 60% decrease, as well as 20%, 40% and 60% increase in natural rainfall, in addition to ambient precipitation.We found that the stability of community biomass was influenced by three contextual factors including the magnitude and directionality of precipitation, above‐ and below‐ground biomass and the type of vegetation. In particular, higher and more intense precipitation resulted in higher stability of above‐ground biomass in both grass‐ and shrub‐dominated communities. Conversely, higher precipitation intensity led to decreased below‐ground biomass stability in grass‐dominated communities but increased below‐ground biomass stability in shrub‐dominated communities. Species stability and species asynchrony consistently played a positive role in explaining the stability of above‐ground biomass in both grass‐ and shrub‐dominated communities. However, species asynchrony negatively influenced below‐ground biomass stability in grass‐dominated communities without a comparable effect in shrub‐dominated communities. The preeminent contribution to the total community biomass was identified in the stability of below‐ground biomass, evident in both grass‐dominated and shrub‐dominated communities.Synthesis. This study highlights that while the specific effects of changes in precipitation may vary depending on the context, the fundamental processes governing biomass stability are consistent. These findings elucidate the desert steppe ecosystems' adaptive response to precipitation variations and emphasize their pivotal role in maintaining ecosystem functions under climatic perturbations. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Tall fescue (Festuca arundinacea Schreb.) is a perennial C3 grass species usually associated with the endophyte fungus Epichloë coenophiala that enhances tolerance to biotic and abiotic stresses. Given that the proportion of infected tall fescue plants in the grasslands of the Flooding Pampa (Argentina) has been progressively increasing, it is proposed that endophytes confer tolerance to the stresses characteristic of that environment, especially flooding. Plants from a naturalized population and a commercial cultivar were grown, both with and without endophyte (wild type and AR584 respectively). The plants were subjected to two submergence treatments (i.e., control and partial submergence) in two development stages (5‐leaf stage and beginning of the elongation of internodes). Plant performance (aerial and root biomass, root aerenchyma formation, total root length and root diameter, proportion of reproductive tillers, number of panicles and seeds produced) and endophyte transmission to progeny were evaluated. Endophytes did not alter the ecological fitness of plants under partial submergence. Independently of the water condition, the symbiosis was linked to low biomass in plants from the naturalized population, while the opposite occurred in plants from the cultivar. Partial submergence did not affect the germination of the seeds produced, nor the transmission of the endophyte to the seedlings that originated from them. Our work suggests that the invasion ability of tall fescue in the Flooding Pampa grasslands is not related to an endophyte‐mediated improvement of plants to tolerate water excess. [ABSTRACT FROM AUTHOR]

Diet selection, a core problem of foraging behavior, is a nutritional adaptation strategy formed in the long-term natural selection process by grazing herbivores and is significant for the sustainable management of grassland. Studies have mainly focused on the impacts of the individual and whole community spatial characteristics and herbivore body status on herbivore foraging behavior; thus, the response andmechanism of forage plants in different terrains to the diet selection of grazing herbivores remains unclear. Therefore, in this study, forage plants (gramineae, cyperaceae, legume, forbs, edible shrubs, and community) in different topographies (terrace, riparian zones, shady slope, half shady slope, half sunny slope, sunny slope) on the eastern Tibetan plateau were selected to study changes in nutrient andmineral content characteristics of forage plants, aswell as the difference in feeding bias of yaks for forage plants in different terrains by using an indoor cafeteria trial. A structural equation model was used to illustrate the impact of the forage plants in different terrains on the feeding bias of yak. The multi-criterion decision model TOPSIS showed that the nutritional value of gramineae was highest for the shaded slope, and that of cyperaceae and leguminosae was the highest for the terraces. The nutrient value of forbs and the whole community was highest for the sunny slope. Dry matter intake by yaks of leguminosae, forbs, and the whole plant community was significantly higher for terraces than for grasslands with other topographies, and all were significantly lower in riparian zones. Yak forage preference of leguminosae, forbs, and the whole community was the highest for the terrace and the lowest for the riparian zones. Structural equation modeling showed that for functional groups, the interactions between topography and functional groups were the drivers influencing yak forage preferences. Our study highlights the propensity of yaks to forage for plants in areas with different topographies. These results have provided a scientific basis for understanding the relationship between herbivores and plants in grasslands and for formulating scientific grazing management strategies, which are of considerable importance for sustainable grassland livestock husbandry. [ABSTRACT FROM AUTHOR]

Allelopathy has a profound impact on the germination and growth of plants, influencing the establishment of plant populations and shaping community ecological patterns. However, the allelopathic potential of many grassland species remains poorly understood. In this study, we prepared aqueous extracts from 17 herbaceous plants to investigate their allelopathic effects on the seed germination and seedling growth of Leymus chinensis, a dominant grassland species. Our results revealed that the response of L. chinensis to allelopathic compounds was dependent on the specific plant species, extract concentration, and target plant organ. Notably, Fabaceae plants exhibited a stronger allelopathic potential than Poaceae, Asteraceae, and other plant families. Moreover, we observed that root growth of L. chinensis was more sensitive to allelopathy than shoot growth, and seed germination was more affected than seedling growth. Generally, the germination of L. chinensis was strongly inhibited as the donor plant extract concentration increased. The leachate of Fabaceae plants inhibited the seedling growth of L. chinensis at concentrations ranging from 0.025 to 0.1 g mL−1. On the other hand, the leachate from other families' plants exhibited either inhibitory or hormetic effects on the early growth of L. chinensis, promoting growth at 0.025 g mL−1 and hindering it at concentrations between 0.05 and 0.1 g mL−1. These findings highlight the significant allelopathic potential of grassland plants, which plays a critical role in establishing plant populations and associated ecological processes. In addition, they shed light on the coexistence of other plants with dominant plants in the community. [ABSTRACT FROM AUTHOR]

Restoration of terrestrial ecosystems often requires re‐introduction of plants. In restored sites, the plants often face environments that differ from those of natural populations. This can affect plant traits, reduce performance and impose novel selection pressures. As a response, restored populations might rapidly evolve and adapt to the novel conditions. This may enhance population survival and contribute to restoration success, but has been rarely tested so far.Here, we focused on populations of three grassland species restored 20 years ago (Galium wirtgenii, Inula salicina and Centaurea jacea) by the transfer of green hay, and compared them with donor populations that were the source of the hay. We measured plants both in situ, and in a common garden under control and three stress conditions.In situ, plants in restored sites flowered earlier than plants in donor sites in two out of the three species. In the common garden, plants from the restored populations flowered earlier (in Galium) or showed increased plasticity of clonal propagation in response to clipping (in Inula). Both these traits suggest rapid adaptation to the contrasting mowing regimes in restored in comparison with the donor sites. In Centaurea, we detected no differentiation, neither in situ, nor in the common garden.Synthesis and applications. Grassland plants introduced into degraded habitats within the framework of ecological restoration may quite commonly evolve in response to novel selection pressures at restored sites. This rapid evolution likely increases the plant's adaptation to the new conditions of the restored grassland and thus enhances the likelihood of survival of the population and ultimately restoration success. While most practitioners do not consider evolution to be part of restoration, our finding highlights that restored populations of grassland species can be systems with considerable eco‐evolutionary dynamics. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation per se have been shown to be a major threat to global biodiversity and ecosystem function. However, little is known about how habitat loss and fragmentation per se alters the relationship between biodiversity and ecosystem function (BEF relationship) in the natural landscape context. Based on 130 landscapes identified by a stratified random sampling in the agro-pastoral ecotone of northern China, we investigated the effects of landscape context (habitat loss and fragmentation per se) on plant richness, above-ground biomass, and the relationship between them in grassland communities using a structural equation model. We found that habitat loss directly decreased plant richness and hence decreased above-ground biomass, while fragmentation per se directly increased plant richness and hence increased above-ground biomass. Fragmentation per se also directly decreased soil water content and hence decreased above-ground biomass. Meanwhile, habitat loss decreased the magnitude of the positive relationship between plant richness and above-ground biomass by reducing the percentage of grassland specialists in the community, while fragmentation per se had no significant modulating effect on this relationship. These results demonstrate that habitat loss and fragmentation per se have inconsistent effects on BEF, with the BEF relationship being modulated by landscape context. Our findings emphasise that habitat loss rather than fragmentation per se can weaken the positive BEF relationship by decreasing the degree of habitat specialisation of the community [ABSTRACT FROM AUTHOR]

Questions: Increased soil phosphorus (P) availability in fertilized grasslands can drive both community degradation and delayed community recovery upon agricultural abandonment. Beyond describing grassland community patterns along gradients in P availability, it remains unclear how individual species with different strategies respond to increasing phosphorus. Here we studied intraspecific variability of leaf functional traits in response to soil phosphorus, for species with contrasting resource‐use strategies. Methods: We set up a pot experiment with communities containing four species, assembled from a pool of 20 mesotrophic grassland species growing along a soil P gradient. Species selection included various growth forms (grasses vs forbs) and resource‐use strategies (acquisitive vs conservative resource use). We measured three variables characterizing the (a)biotic environmental context: bioavailable soil P concentration, total community biomass as a proxy for the intensity of competition, and the proportional biomass of a species in the community as a proxy for its competitive dominance. We investigated the effect of this environmental context on the expression of two leaf traits, specific leaf area (SLA) and leaf dry matter content (LDMC). Results: We found an acquisitive trait expression within species (increase in SLA and decrease in LDMC) in response to increased soil P supply and a conservative trait expression (decrease in SLA and increase in LDMC) in response to an increase in total community biomass. Importantly, the trait responses to the environmental context were generally consistent for species representing very different resource‐use strategies and growth forms. Conclusions: Species responded with a shift from an acquisitive to a conservative trait expression in response to limited resources; i.e., driven by a decrease in soil phosphorus concentration or an increase in total community biomass. Unexpectedly, the intraspecific variability in response to the changing environmental conditions was not clearly mediated by the species' strategy. These findings show that plant ecological strategies are probably not the main driver for intraspecific trait variability in an experimental grassland community. [ABSTRACT FROM AUTHOR]

Background The species composition of and changes in grassland communities are important indices for inferring the number, quality and community succession of grasslands, and accurate monitoring is the foundation for evaluating, protecting, and utilizing grassland resources. Remote sensing technology provides a reliable and powerful approach for measuring regional terrain information, and the identification of grassland species by remote sensing will improve the quality and effectiveness of grassland monitoring. Methods Ground hyperspectral images of a sericite–Artemisia desert grassland in different seasons were obtained with a Soc710 VP imaging spectrometer. First-order differential processing was used to calculate the characteristic parameters. Analysis of variance was used to extract the main species, namely, Seriphidium transiliense (Poljak), Ceratocarpus arenarius L., Petrosimonia sibirica (Pall), bare land and the spectral characteristic parameters and vegetation indices in different seasons. On this basis, Fisher discriminant analysis was used to divide the samples into a training set and a test set at a ratio of 7:3. The spectral characteristic parameters and vegetation indices were used to identify the three main plants and bare land. Results The selection of parameters with significant differences (P < 0.05) between the recognition objects effectively distinguished different land features, and the identification parameters also differed due to differences in growth period and species. The overall accuracy of the recognition model established by the vegetation index decreased in the following order: June (98.87%) > September (91.53%) > April (90.37%). The overall accuracy of the recognition model established by the feature parameters decreased in the following order: September (89.77%) > June (88.48%) > April (85.98%). Conclusions The recognition models based on vegetation indices in different months are superior to those based on feature parameters, with overall accuracies ranging from 1.76% to 9.40% higher. Based on hyperspectral image data, the use of vegetation indices as identification parameters can enable the identification of the main plants in sericite–Artemisia desert grassland, providing a basis for further quantitative classification of the species in community images.

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]

Current land use and extensive modifications of natural ecosystems across the state of Louisiana are generally similar to those across the southeastern USA where rainfall supports forest ecosystems. Both intentional and unintentional consequences of ecosystem modifications from the scales of water and sediment movement across a field edge to state-wide loss of functional grasslands are legacies from previous development across the state. While major investments and large-scale, long-term plans are aspects of some continuing ecological issues across the state, small-scale, volunteer-led restoration of native grassland plant communities in the Louisiana Coastal Prairie illustrates the value associated with the restoration of natural ecosystem function in drastically disturbed environments. As is now becoming increasingly recognized, Louisiana grasslands represent less obvious components of forest, woodland, and wetland landscapes across the state, where they have contributed essential wildlife habitat, and ecosystem functions. These are now largely missing from many landscapes across the state and region. The strategic restoration of grassland functions combining novel native grass pastures and fully functional native grassland plant communities as landscape components could provide both economic and ecosystem benefits. Specific native grassland seed resources are needed for various restoration activities to enhance ecosystem function at a range of scales across the state and region. [ABSTRACT FROM AUTHOR]

The edaphic and environmental changes in Bujagh grasslands have led to a gradual decline in the wintering waterbird populations in the associated national park. This has particularly affected forage habitats for birds, especially migratory geese. Our aim was to identify the reasons for the loss of habitat quality by examining the structure of the plant community and the edaphic factors that have been instrumental in shifting the grass community pattern to a Rush–Rubus type along the succession route. Bujagh National Park is surrounded by marine, riverine fresh water, and lagoon habitats, and the seasonal floodings of the Sefidrud and Ushmak rivers impact the grassland area along the deltaic pathway to the Caspian Sea. We used the TWINSPAN classification function to extract plant groups and their dominant species. Subsequently, we analyzed land cover changes in the study area over two times (2010 and 2020) to identify alterations in the coverage of main plants and land uses. Following the evaluation of unconstrained ordination methods and the selection of NMDS ordination, we compared the dominant species of groups to the main edaphic predictors. The results indicated that the chemicals and heavy metals in the soil did not play a direct role in the shift from grassland to Rush–Rubus plant type. However, these elements could have a significant impact on the evolution of the structure and the competitive capability among the main dominant species of the grass group. In conclusion, the dominance of the Rush–Rubus type is likely related to other unmeasured environmental and anthropogenic factors that support and enhance their reproductive attributes and herbal proliferation in the grassland territory. [ABSTRACT FROM AUTHOR]

The topicality of our research topic is justified by the significant change in traditional grassland management in the grassland areas of the Pannonian Basin. Due to several factors, the proportion of fallow grassland, and in parallel of over-exploited pastures, is continuously increasing. In the medium term (11 years), the effects of fallowing (Z), annual mowing (M), mowing and grazing (meadow treatment M + G), and permanent overgrazing (OG) as treatments on the population structure of grassland plants were investigated in a semi-natural grassland community in the Solonyec soil. It was found that the lowest degradation rates in the studied grassland biotope were obtained for the treatment presenting the utilisation pattern of mowing the main grassland phytomass followed by sheep grazing of the coltgrass. The highest degradation levels, which threatened the condition of the grassland community, were measured for the treatment presenting overgrazing with sheep at the end of the experimental period. [ABSTRACT FROM AUTHOR]

The work focused on the analysis of the vegetation cover of the grasslands according to the Fraction of Absorbed Photosynthetically Active Radiation (fAPAR index), in five different stages, during the same year (2022), on altitudinal levels, from three groups of mountains. 110 grasslands located in different environmental conditions were studied, from: the Banat Mountains, the Poiana Ruscă Mountains and part of the Southern Carpathians. Five Sentinel 2 satellite scenes were used, acquired on the following dates: 22.03, 16.05, 15.07, 08.09, 18.10 and the Digital Elevation Model, classified into 8 altitudinal levels, from 53-2473 m. The results show that the fAPAR values are different, lower in March when the vegetation is still stagnant and does not use solar radiation, maximum in July when the vegetation is very well represented and uses maximum solar radiation, and from August, a downward trend, along with the reduction of the physiological activity of the plants in the grasslands. Also, differences in average fAPAR values by mountain groups and similarities in altitudinal steps between mountain groups were noticed. [ABSTRACT FROM AUTHOR]

The speed of growth, as well as the height of plants on sown lawns, are important from the point of view of the possibility of obtaining a larger number of swaths if the growth is faster, and obtaining a higher yield, if the plants are of a higher age, at the same crop density. Sown lawns, usually called grass-leguminous mixtures in practice, comprise different types of grasses and legumes. Depending on the variety, growing conditions, vegetation cycle and the like, in principle, the plants of the first vegetation cycle (first cutting) reach the highest height. Considering the mentioned facts, the proposed research aimed to analyse the influence of the vegetation cycle and the mixture on the height of grasses and legume plants in the plant community under different defoliation regimes. The three-year research results showed that the height of the plants at mowing depended on the species (mixture), year (age of plants and weather conditions) and vegetation cycle. In general, the plants of all species are the lowest in the year of sowing. In the second and third years, the plants of the first cut are the tallest, with almost all mowing regimes. However, the tallest plants in the first swath are in the flowering phase of the plants, where among the tested species, the tallest plants are orchard grass in all mixtures (average 91.99 cm), followed by Italian ryegrass (average 82.77 cm). The lowest plants are bird's foot trefoil (average 48.97 cm). [ABSTRACT FROM AUTHOR]

The intensity of grazing on palatable species can vary depending on the neighboring plants in plant communities. We aimed to search for species whose biomass can have a positive effect on palatable plants near them in a grassland under grazing pressure by sika deer. We selected Iris sanguinea Hornem. as an indicator species of ease of being grazed because it is a palatable and past dominant species before the increase in deer density. We estimated the effects of the biomass of neighboring plant species, soil water content, and distance from the forest edge on the height of I. sanguinea. The height was remarkably and positively affected by the biomass of four graminoid species with larger biomass and slightly positively affected by the biomass of a toxic species. This study suggests that the biomass of less‐palatable species may have an important influence on the size of palatable species under grazing pressure by deer. [ABSTRACT FROM AUTHOR]

Large herbivores can exert pronounced top-down effects on plant communities in grassland ecosystems. Previous studies highlighted the importance of the composition and traits of living plants in regulating the impact of herbivores on plant community. However, there has been little consideration of whether and how plant litter, a ubiquitous "after-life" plant component, affects the outcome of herbivore grazing on grasslands. Here, we conducted a large-scale field experiment in temperate grasslands of northeastern China to investigate how standing plant litter influenced top-down effects of large herbivores (sheep; Ovis aries) on plant species richness, evenness, community composition, and productivity. We found that, in the presence of standing litter, sheep grazing significantly reduced living biomass of forbs by 56%, but have no effects on biomass of the dominant grass, Leymus chinensis. However, in the absence of standing litter, sheep shifted their diet preference from forbs to the grass L. chinensis, leading to a 36% decrease in the biomass of L. chinensis and a 21% decrease in total biomass. Such changes in foraging pressure on plant species led to competitive release that in turn significantly altered plant community composition and increased species evenness. Synthesis and applications. Our results demonstrate that standing litter can alter foraging behaviors of large herbivores and modifying the outcome of their top-down effects on plant community properties in grasslands. These cryptic but perhaps ubiquitous interactions between litter and herbivores may help us better understand the organization and dynamics of plant communities in the grazed grasslands, with important implications for developing effective management and conservation plans. [ABSTRACT FROM AUTHOR]

Simple Summary: Grasslands cover one-third of the world's land area and play a significant role in agriculture and ecological security. However, due to recent changes in precipitation patterns and land use, the coverage of grasslands is decreasing. The Hulunbuir steppe, one of the four major grasslands in the world, is also undergoing desertification caused by climate change and anthropogenic disturbances. To characterize the eco-functional diversity of plants in recently restored sites after the introduction of woody plants in natural grasslands, the competitor, stress tolerator, and ruderal (CSR) ecological strategies of plants were analyzed. As a result, the CSR ecological strategy in the temperate typical steppe was CSR and that in the woodland steppe was S/SR. The restored sites differed depending on the life-form of the introduced woody plants. The CSR ecological strategies observed over time in a restored site after the introduction of woody plants varied depending on the life-form of the introduced woody plants. This suggests the importance of selecting the life-form of woody plants for the success of ecological restoration in damaged grasslands. To reveal the changes in the life history characteristics of grassland plants due to vegetation restoration, plant species and communities were analyzed for their competitor, stress tolerator, and ruderal (CSR) ecological strategies after the introduction of woody plants in the damaged steppe grassland and were compared with those in reference sites in Hulunbuir, Inner Mongolia. As a result, it was found that the introduction of the woody plants (Corethrodeneron fruticosum, Caragana microphylla, Populus canadensis, and Pinus sylvestris var. mongolica) into the damaged land greatly increased the plant species diversity and CSR eco-functional diversity as the succession progressed. The plant strategies of the temperate typical steppe (TTS) and woodland steppe (WS) in this Asian steppe are CSR and S/SR, respectively, which means that the plants are adapted to disturbances or stress. As the restoration time elapsed in the damaged lands exhibiting (R/CR) (Corispermum hyssopifolium), the ecological strategies were predicted to change in two ways: (1) →R/CSR (Cynanchum thesioides, Astragalus laxmannii, etc.) → CSR in places (TSS) (Galium verum var. asiaticum, Saussurea japonica, etc.) where only shrubs were introduced, and (2) → S/SR (Allium mongolicum, Ulmus pumila, etc.) → S/SR in sites (WS) (Ulmus pumila, Thalictrum squarrosum, etc.) where trees and shrubs were planted simultaneously. The results mean that the driving force that causes succession in the restoration of temperate grasslands is determined by the life-form (trees/shrubs) of the introduced woody plants. This means that for the restoration of these grasslands to be successful, it is necessary to introduce woody tree species at an early stage. [ABSTRACT FROM AUTHOR]

Root functional traits are known to influence soil properties that underpin ecosystem functioning. Yet few studies have explored how root traits simultaneously influence physical, chemical, and biological properties of soil, or how these responses are modified by common grassland perturbations that shape roots, such as defoliation and fertilisation.Here, we explored how root traits of a wide range of grassland plant species with contrasting resource acquisition strategies (i.e. conservative vs. exploitative strategy plant species) respond to defoliation and fertilisation individually and in combination, and examined cascading impacts on a range of soil abiotic and biotic properties that underpin ecosystem functioning.We found that the amplitude of the response of root traits to defoliation and fertilisation varied among plant species, in most cases independently of plant resource acquisition strategies. However, the direction of the root trait responses (increase or decrease) to perturbations was consistent across all plant species, with defoliation and fertilisation exerting opposing effects on root traits. Specific root length increased relative to non‐perturbed control in response to defoliation, while root biomass, root mass density, and root length density decreased. Fertilisation induced the opposite responses. We also found that both defoliation and fertilisation individually enhanced the role of root traits in regulating soil biotic and abiotic properties, especially soil aggregate stability.Synthesis: Our results indicate that defoliation and fertilisation, two common grassland perturbations, have contrasting impacts on root traits of grassland plant species, with direct and indirect short‐term consequences for a wide range of soil abiotic and biotic properties that underpin ecosystem functioning. [ABSTRACT FROM AUTHOR]

In recent years, grassland ecosystems have faced increasingly severe desertification, which has caused continuous changes in the vegetation composition in grassland ecosystems. Therefore, effective research on grassland plant taxa is crucial to exploring the process of grassland desertification. This study proposed a solution by constructing a UAV hyperspectral remote sensing system to collect the hyperspectral data of various species in desert grasslands. This approach overcomes the limitations of traditional grassland survey methods such as a low efficiency and insufficient spatial resolution. A streamlined 2D-CNN model with different feature enhancement modules was constructed, and an improved depth-separable convolution approach was used to classify the desert grassland plants. The model was compared with existing hyperspectral classification models, such as ResNet34 and DenseNet121, under the preprocessing condition of data downscaling by combining the variance and F-norm2. The results showed that the model outperformed the other models in terms of the overall classification accuracy, kappa coefficient, and memory occupied, achieving 99.216%, 98.735%, and 16.3 MB, respectively. This model could effectively classify desert grassland species. This method provides a new approach for monitoring grassland ecosystem degradation. [ABSTRACT FROM AUTHOR]

Context: Plant communities are undergoing compositional changes that affect ecosystem function. These changes are not always uniform across the landscape due to heterogenous topographic and edaphic conditions. To predict areas most at risk of change, it is necessary to identify the landscape drivers affecting plant abundance. Objectives: Annual plants are increasing across the western USA, largely driven by non-native annual invasions. Here, we quantified change in annual plant abundance and identified landscape factors contributing to that change over the past 35 years. Methods: We focused on Willamette Valley (Oregon) grasslands because they represent a new example in this phenomenon. To understand the spatiotemporal patterns of annual plant abundances between 1986 and 2020, we combined a remote-sensing vegetation cover dataset from the rangeland analysis platform with gridded soils data and topographic variables. We determined the rate of change in percent cover for each 30 × 30 m pixel and regressed cover against heat load, soil depth and sand content for > 5975 hectares to determine areas most sensitive to rising annual cover. Results: We found a tendency toward increasing annual cover, with a median gain of + 15% cover among significantly increasing pixels. However, change was uneven across the landscape, with annual cover increasing markedly in areas with high heat load and shallower soils. Conclusions: We identified steep, south-facing slopes as being particularly sensitive to rising annual cover. Annual plant invasions may be lagging in this region compared to elsewhere in the western USA, but trends here suggest it may just be a matter of time. [ABSTRACT FROM AUTHOR]

Remobilization of carbon (C) and nitrogen (N) from roots and crowns to regrowing shoots is an important strategy for grassland plants to tolerate herbivory. While this remobilization is thought to terminate once plants have the capacity to photosynthesize again and to take up N from the soil, this has rarely been quantified.Here we investigated the remobilization of C and N to regrowing shoots of a perennial grassland under two defoliation frequencies (every 15 and 30 days) and two N fertilization levels (0 and 2.8 g m−2) by growing intact plant–soil cores for 60 days in a growth chamber. We measured the C remobilization from roots and crowns to regrowing shoots using a novel continuous 13C labelling method, and quantified the N remobilization to regrowing shoots and plant N uptake from soil with a 15N tracer method.Regrowing shoots relied strongly on below‐ground C reserves, where up to 52% of C in regrowing shoots came from below‐ground during the first 30 days after defoliation. Below‐ground C was still remobilized when plant shoots had fully regrown and retained full capacity to photosynthesize. Plants relied more on C remobilization with shorter times between defoliation events at the expense of root biomass, particularly without N fertilization. Large amounts of C remobilization were accompanied by large amounts of N remobilization (up to 89% of total shoot N) that were positively related, suggesting a coupled C and N transfer from roots and crowns to shoots.Synthesis. The unexpectedly high dependency on C and N remobilization occurred continuously after defoliation and did not terminate once plants were fully regrown. Our results indicate that remobilization of C and N from below‐ground has profound effects on long‐term productivity and C sequestration that needs to be considered for managing similar grasslands worldwide. [ABSTRACT FROM AUTHOR]

Background: Increased atmospheric nitrogen (N) deposition and altered precipitation regimes could change soil element availability and uptake by grassland plants. Identifying taxonomic or plant functional group-specific responses may provide a new perspective to explore the effects of N and water addition on community composition. Methods: Nitrogen addition and irrigation experiment was conducted using a split-plot design. We added 10 g N m− 2 yr− 1 twice per year and/or 15 mm of water once per week and cumulatively 180 mm during the growing season. We determined foliar concentrations of seven mineral nutrients (Ca, K, Mg, Cu, Zn, Mn, Fe) and one beneficial element (Na) in grassland plants. Results: Nitrogen addition as urea significantly decreased soil exchangeable Ca and Mg concentrations, but increased soil available Fe, Mn, and Zn concentrations, because of acidification. Under N addition, foliar Mn, Na concentrations increased, but foliar Fe concentrations decreased. Dicotyledons and sedges showed a stronger increase of foliar Mn and corresponding decrease of Fe concentrations than monocotyledons (without sedges) under N addition. Furthermore, Ca and K concentrations in monocotyledons and sedges increased, while that in dicotyledons remained unchanged under N addition. Conclusion: Our results suggest that the variations in foliar and soil element concentrations are mainly attributable to N-induced acidification. Meanwhile, irrigation increased the concentrations of base cations, weakening the impacts of N by alleviating soil acidification. The response of the nutrient concentrations in leaves to N addition varied among plant families and functional groups possibly contributing to changes in changes in plant community composition. [ABSTRACT FROM AUTHOR]

Winters are expected to warm more than summers in central and northern Europe, with largely unknown effects on grassland plant communities. By studying the interactions between winter warming and summer grazing, we aimed to disentangle their effects and give recommendations for future grassland management. Our study area Upper Teesdale, England has winter temperatures close to 0°C and a well-studied vegetation, known for its arctic-alpine species growing at their climatic warm range limits. We set up a winter warming experiment using open top chambers (ca. +0.5°C) from mid-September until mid-May 2019 to 2022 and excluded sheep grazing during summer in a fully factorial design. Graminoid biomass increased, and bryophyte biomass decreased with winter warming. There was little to no evidence that winter warming affected any of the other plant response variables we measured, neither did grazing nor the interaction between winter warming and grazing. Our experiment was relatively short in duration and treatments were realistic in magnitude, therefore the plant communities responded only slightly. Nevertheless, our data suggest a change towards more dominant vascular species and less bryophytes with winter warming, which might lead to lasting changes in the plant communities in the longer-term if not buffered by suitable grazing management. [ABSTRACT FROM AUTHOR]

The change grassland plant communities demonstrate with elevation has been one of the hot issues in ecological research, and there remain many unsolved problems. In order to further elucidate the rules of grassland plant community change with elevation, this study took the Burqin forest area as a research object, using field survey, redundancy analysis and grey correlation analysis to comprehensively assess the characteristics of change in grassland plant communities with elevation and the relationship of this evolution with environmental factors. The results showed that (1) the numbers of species, community biomass, community cover and community densities of grassland plant communities showed an "M" pattern with the increase in elevation. There were significant changes in the importance values and dominance of plants at different elevations; with increasing elevation, grassland plants became primarily dominated by cold-tolerant and well-adapted perennials. (2) The similarity coefficients of grassland plant communities at different elevations ranged from 0.06 to 0.62, i.e., from very dissimilar to moderately similar. (3) As the elevation increased, the Margalef species richness index, Shannon–Wiener diversity index, Simpson dominance index and Alatalo evenness index all showed an "M" pattern trend. (4) The degrees of correlation between temperature and precipitation and community biomass and species diversity were at a high level, and these were the most important environmental factors affecting the biomass and species diversity of grassland plant communities in the Burqin forest area. The results of this study can provide a theoretical basis for the rational utilization of grassland resources and for the sustainable development of grassland ecosystems in the Burqin forest area. [ABSTRACT FROM AUTHOR]

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For terrestrial plant communities, the increase in frequency and intensity of drought events is considered as one of the most severe consequences of climate change. While single‐species studies demonstrate that drought can lead to relatively rapid adaptive genetic changes, the evolutionary potential and constraints to selection need to be assessed in comparative approaches to draw more general conclusions. In a greenhouse experiment, we compare the phenotypic response and evolutionary potential of two co‐occurring grassland plant species, Bromus erectus and Trifolium pratense, in two environments differing in water availability. We quantified variation in functional traits and reproductive fitness in response to drought and compared multivariate genetic variance–covariance matrices and predicted evolutionary responses between species. Species showed different drought adaptation strategies, reflected in both their species‐specific phenotypic plasticity and predicted responses to selection indicating contrasting evolutionary potential under drought. In T. pratense we found evidence for stronger genetic constraints under drought compared to more favourable conditions, and for some traits plastic and predicted evolutionary responses to drought had opposing directions, likely limiting the potential for adaptive change. Our study contributes to a more detailed understanding of the evolutionary potential of species with different adaptive strategies in response to climate change and may help to inform future scenarios for semi‐natural grassland ecosystems. [ABSTRACT FROM AUTHOR]

Global warming intensifies the hydrological cycle and may result in changes in the frequency and intensity of precipitation events. However, a knowledge gap still exists about the general influences of intra‐annual precipitation variability on grassland plant diversity and ecosystem function at the global scale.Here, we synthesized field manipulative experiments from 66 publications to quantify the effects of intra‐annual precipitation variability increases (IPVI) on community biomass and plant diversity in grasslands worldwide.At the global scale, we found that IPVI generally increased grassland community above‐ground biomass (AGB) by 6.90%, and decreased grass biomass and soil ammonium content by 10.38% and 25.35% respectively. IPVI increased and decreased total AGB in arid and humid regions, respectively, and IPVI enhanced grassland below‐ground biomass and plant species richness in arid regions, but showed no effect in humid regions. Furthermore, moderate IPVI stimulated plant species richness and community biomass in arid grasslands, while extreme IPVI impaired them in mesic grasslands. Changes in total AGB under IPVI were related to changes in the biomass of plant functional groups, species richness and soil moisture. Structural equation modelling demonstrated that climate conditions (mean annual temperature and mean annual precipitation) and background soil properties (soil sand content and soil organic carbon content) jointly regulated grassland total AGB responses to IPVI across climate regions.Synthesis. Overall, our study shows divergent responses of grassland productivity and diversity to IPVI in arid and humid regions. Accounting for climate, edaphic properties and precipitation variability can help improve our ability to predict the responses of grassland ecosystems to future changes in precipitation at global scales. [ABSTRACT FROM AUTHOR]