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Abstract Trace elements are the essential mineral nutrients in grassland, however, we still know little about the distributions of trace elements in grassland with long‐term grazing exclusion. The contents, stocks, and proportions of iron (Fe), aluminum (Al), manganese (Mn), and boron (B) in green plant‐litter‐root‐soil were evaluated by enclosing for 18, and 39 years inside the fence (F18 and F39) and grazing outside the fence (F0) in Inner Mongolia grassland. The results showed that F18 and F39 decreased the stocks of Fe, Al, and Mn in green plant and root compared to F0 (p

Cesarean delivery is associated with diminished plasma levels of several birth-signaling hormones, such as oxytocin and vasopressin. These same hormones have been previously shown to exert organizational effects when acting in early life. For example, our previous work found a broadly gregarious phenotype in prairie voles exposed to oxytocin at birth. Meanwhile, cesarean delivery has been previously associated with changes in social behavior and metabolic processes related to oxytocin and vasopressin. In the present study, we investigated the long-term neurodevelopmental consequences of cesarean delivery in prairie voles. After cross-fostering, vole pups delivered either via cesarean or vaginal delivery were studied throughout development. Cesarean-delivered pups responded to isolation differently in terms of their vocalizations (albeit in opposite directions in the two experiments), huddled in less cohesive groups under warmed conditions, and shed less heat. As young adults, we observed no differences in anxiety-like or alloparental behavior. However, in adulthood, cesarean-delivered voles of both sexes failed to form partner preferences with opposite sex conspecifics. In a follow-up study, we replicated this deficit in partner-preference formation among cesarean-delivered voles and were able to normalize pair-bonding behavior by treating cesarean-delivered vole pups with oxytocin (0.25 mg/kg) at delivery. Finally, we detected minor differences in regional oxytocin receptor expression within the brains of cesarean-delivered voles, as well as microbial composition of the gut. Gene expression changes in the gut epithelium indicated that cesarean-delivered male voles have altered gut development. These results speak to the possibility of unintended developmental consequences of cesarean delivery, which currently accounts for 32.9 % of deliveries in the U.S. and suggest that further research should be directed at whether hormone replacement at delivery influences behavioral outcomes in later life.

Birth is a critical period for the developing brain, a time when surging hormone levels help prepare the fetal brain for the tremendous physiological changes it must accomplish upon entry into the extrauterine world. A number of obstetrical conditions warrant manipulations of these hormones at the time of birth, but we know little of their possible consequences on the developing brain. One of the most notable birth signaling hormones is oxytocin, which is administered to roughly 50% of laboring women in the United States prior to / during delivery. Previously, we found evidence for behavioral, epigenetic, and neuroendocrine consequences in adult prairie vole offspring following maternal oxytocin treatment immediately prior to birth. Here, we examined the neurodevelopmental consequences in adult prairie vole offspring following maternal oxytocin treatment prior to birth. Control prairie voles and those exposed to 0.25 mg/kg oxytocin were scanned as adults using anatomical and functional MRI, with neuroanatomy and brain function analyzed as voxel-based morphometry and resting state functional connectivity, respectively. Overall, anatomical differences brought on by oxytocin treatment, while widespread, were generally small, while differences in functional connectivity, particularly among oxytocin-exposed males, were larger. Analyses of functional connectivity based in graph theory revealed that oxytocin-exposed males in particular showed markedly increased connectivity throughout the brain and across several parameters, including closeness and degree. These results are interpreted in the context of the organizational effects of oxytocin exposure in early life and these findings add to a growing literature on how the perinatal brain is sensitive to hormonal manipulations at birth.

Prairie voles are among a small group of mammals that display long-term social attachment between mating partners. Many pharmacological studies show that signaling via the oxytocin receptor (Oxtr) is critical for the display of social monogamy in these animals. We used CRISPR mutagenesis to generate three different Oxtr-null mutant prairie vole lines. Oxtr mutants displayed social attachment such that males and females showed a behavioral preference for their mating partners over a stranger of the opposite sex, even when assayed using different experimental setups. Mothers lacking Oxtr delivered viable pups, and parents displayed care for their young and raised them to the weanling stage. Together, our studies unexpectedly reveal that social attachment, parturition, and parental behavior can occur in the absence of Oxtr signaling in prairie voles.

The Seriphidium transiliense desert pasture is an important spring-autumn pasture in northern Xinjiang, China, and has been subjected to grazing by livestock at different intensities, thus resulting in widespread deterioration of its biodiversity and ecosystem services. To understand the response mechanism of stoichiometric characteristics of desert vegetation to grazing, the leaf carbon (C), nitrogen (N), phosphorus (P) and C:N:P ratios of S. transiliense were studied under different grazing intensities. The results show that the control S. transiliense leaf C, N and P contents and C:N, C:P and N:P ratios were 458.79 ± 53.5 g/kg, 20.6 ± 7.18 g/kg, 2.83 ± 1.24 g/kg, 25.69 ± 11.08, 190.28 ± 75.65 and 8.21 ± 4.01, respectively. The differences in these characteristics varied with grazing intensity in accordance with sampling time, so both factors need to be considered comprehensively. General linear model (GLM) analysis indicated that grazing intensity had a strong main effect on S. transiliense leaf C, N, and P content, C:N ratio and N:P ratio. As grazing intensity increased, the leaf N content and N:P ratio increased (P < 0.01), and the C:N ratio decreased (P < 0.01). N content was the limiting factor for the growth of S. transiliense, but the grazing intensity, sampling year and growth season each affected the degree of N limitation. Our findings suggest that the remaining moderate stocking rate was essential for sustaining desert stabilisation in Xinjiang, and although S. transiliense could adapt its nutrient content and leaf stoichiometry to the grazing intensity, N was always the limiting element for the growth of S. transiliense.

Abstract Background Grasslands are the primary source of forage for ruminants. Legal restrictions on nitrogen fertilization force farmers to optimize nitrogen use efficiency (NUE) of grassland and protein quality in grass silage. Methods The present study included grassland data from 10 dairy farms in Flanders. For each grassland field, the presence of clover was determined based on the seed mixture composition. Soil and manure were sampled before the first application and analyzed to determine plant available N content. The annual NUE was calculated for each field possible (n = 28). Prewilted grass samples were taken just before ensiling (n = 65) and grass silage samples (n = 41) were collected from the same fields. Results Clover fields demonstrated improved NUE due to a lower nitrogen input from fertilizers compared to pure grassland fields (75 vs. 265 kg ha−1). The protein quality of the grass silage was positively correlated with the organic matter digestibility, sugar content, and dry matter content of the prewilted grass. Conversely, crude ash content had a negative effect. Conclusions These findings underscore the importance and potential of clover and the practical feasibility of optimizing grassland management to improve both NUE in grasslands and protein quality of the silage.

Abstract Background Mosquito-borne diseases are on the rise. While climatic factors have been linked to disease occurrences, they do not explain the non-random spatial distribution in disease outbreaks. Landscape-related factors, such as vegetation structure, likely play a crucial but hitherto unquantified role. Methods We explored how three critically important factors that are associated with mosquito-borne disease outbreaks: microclimate, mosquito abundance and bird communities, vary at the landscape scale. We compared the co-occurrence of these three factors in two contrasting habitat types (forest versus grassland) across five rural locations in the central part of the Netherlands between June and September 2021. Results Our results show that forest patches provide a more sheltered microclimate, and a higher overall abundance of birds. When accounting for differences in landscape characteristics, we also observed that the number of mosquitoes was higher in isolated forest patches. Conclusions Our findings indicate that, at the landscape scale, variation in tree cover coincides with suitable microclimate and high Culex pipiens and bird abundance. Overall, these factors can help understand the non-random spatial distribution of mosquito-borne disease outbreaks. Graphical Abstract

This paper presents the results of a study on the level of nitrate leaching from the 0–30 cm layer of grassland (GL) soil in the Lublin Voivodship during the winters of 2018/2019, 2019/2020 and 2020/2021. The amounts of leached nitrates were determined using the Burns model. For the calculations based on this model – directly and indirectly, the results determination of residual nitrate nitrogen, texture and organic matter in GL soils, obtained within the framework of agricultural monitoring of soils by the National Chemical and Agricultural Station (KSChR), and results of system meteorological measurements conducted by the Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB) were used. The analysed soil samples were taken from 39 permanent control and measurement grassland sites. The research discovered in particular that: – the average leaching of nitrate nitrogen from GL mineral soil in the three analysed periods was 16.2 and 5.1 kg N∙ha–1 from organic soil; – on average, in autumn during the entire study period, 55.3% of NO3-N leached from the 0–30 cm layer of GL mineral soil, and 27.3% from organic soil; – among different agronomic categories of mineral soil, the highest leaching of NO3-N was recorded from medium soil (17.4 kg N∙ha–1) and the lowest from heavy soil (11.5 kg N∙ha–1); – individually determined values of NO3-N leaching from soil varied significantly from 0 to 68.5 kg N∙ha–1 for mineral soil and from 0.1 to 23.65 kg N∙ha–1 for organic soil.

Abstract The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.

Abstract Background Grasslands in drylands are increasingly influenced by human activities and climate change, leading to alterations in albedo and radiative energy balance among others. Surface biophysical properties and their interactions change greatly following disturbances. However, our understanding of these processes and their climatic impacts remains limited. In this study, we used multi-year observations from satellites and eddy-covariance towers to investigate the response of albedo to variables closely associated with human disturbances, including vegetation greenness (EVI) and surface soil volumetric water content (VWC), as well as snow cover and clearness index (T a) for their potential relationships. Results EVI and VWC during the growing season were the primary factors influencing albedo. EVI and VWC were negatively correlated with albedo, with VWC’s total direct and indirect impacts being slightly smaller than those of EVI. During the non-growing season, snow cover was the most influential factor on albedo. VWC and Ta negatively affected albedo throughout the year. We estimated the impact of variations in EVI and VWC on climate to be in the range of 0.004 to 0.113 kg CO2 m−2 yr−1 in CO2 equivalent. Conclusions This study indicates the significant impacts of climate change and human disturbances on vulnerable grassland ecosystems from the perspective of altered albedo. Changes in vegetation greenness and soil properties induced by climate change and human activities may have a substantial impact on albedo, which in turn feedback on climate change, indicating that future climate policies should take this factor into consideration.

Societal Impact Statement Madagascar's children are taught that their ancestors destroyed the vast ancient forest, giving rise to modern grasslands, a misleading myth that continues to undermine people's relationship with nature. Replacing this myth with a more nuanced and accurate narrative around grassy ecosystems is fundamental to building a more positive relationship between Madagascar's people and ecosystems, a process that is necessary to build modern conservation practice and environmental governance. The data we present are consistent with a pre‐human grass flora in the region, suggesting the local grassy ecosystems should not be written off as fully anthropogenic and undesirable but are instead in need of recognition and further research attention. Summary Grassy ecosystems cover over a quarter of dry land, with mosaics of old‐growth and recently formed anthropogenic systems appearing superficially similar to an uninformed observer. Grasses are part of a deep web of historic relationships between grassy ecosystems and local people. We collect and compile the first list of grass species (Poaceae) in north‐west Madagascar in order to make an initial evidence assessment for a pre‐human grass flora. Field surveys and voucher specimen collections were carried out. Specimen identification was performed using morphological character comparison with reference specimens, literature and personal knowledge of grasses from other parts of Madagascar. Seventy species are recorded and assigned to 44 genera. The species list is compared with regional grass checklists from central and south‐central Madagascar. Thirty‐five grasses are unique to Mahajanga, comprising 19% of the multi‐region species pool analysed; the regional species richness is comparable to that of the highlands. The main subfamilies represented are the Panicoideae (64%) and Chloridoideae (29%). Seven species are endemic to Madagascar, reflecting their evolutionary origins on the island. Many of the species are found in multiple types of habitat and substrate, while others are restricted to limited areas and habitats, and local species richness varies significantly with habitat and soil. The main disturbance regimes driving species occurrence include fire and grazing, possibly partly reflecting similar disturbances prior to human arrival. The patterns observed in the grass flora of north‐western Madagascar are overall congruent with a pre‐human grass flora.

Abstract Worldwide, trees are colonizing rangelands with high conservation value. The introduction of trees into grasslands and shrublands causes large‐scale changes in ecosystem structure and function, which have cascading impacts on ecosystem services, biodiversity, and agricultural economies. Satellites are increasingly being used to track tree cover at continental to global scales, but these methods can only provide reliable estimates of change over recent decades. Given the slow pace of tree cover expansion, remote sensing techniques that can extend this historical record provide critical insights into the magnitude of environmental change. Here, we estimate conifer expansion in rangelands of the northern Great Plains, United States, North America, using historical aerial imagery from the mid‐20th century and modern aerial imagery. We analyzed 19.3 million hectares of rangelands in Montana, USA, using a convolutional neural network (U‐Net architecture) and cloud computing to detect tree features and tree cover change. Our bias‐corrected results estimate 3.0 ± 0.2 million hectares of conifer tree cover expansion in Montana rangelands, which accounts for 15.4% of the total study area. Overall accuracy was >91%, but the producer's accuracy was lower than the user's accuracy (0.60 vs. 0.88) for areas of tree cover expansion. Nonetheless, the omission errors were not spatially clustered, suggesting that the method is reliable for identifying the regions of Montana where substantial tree expansion has occurred. Using the model results in conjunction with historical and modern imagery allows for effective communication of the scale of tree expansion while overcoming the recency effect caused by shifting environmental baselines.

Dynamic changes in daily climatic features may induce a lag in the responses of ecosystems, representing a crucial mechanism in the climate-ecosystem interactions. However, the underlying mechanisms are not fully understood. With help of long term half-hourly data series (from 2006 to 2022) of carbon fluxes and climate from the Inner Mongolia no-grazing grassland ecosystem eddy covariance station, we conducted the following studies: (i) investigation of the lagged mechanisms between carbon flux and climatic factors, (ii) characterization of diurnal variation patterns that demonstrated the hysteresis between carbon flux and climatic factors, and (iii) assessment of the potential mechanisms underlying the diurnal variation in carbon flux. The results indicated that (i) there is a pronounced asynchrony between the carbon flux and climatic factors. Light saturation is crucial in the lagged relationship between net ecosystem exchange (NEE) and climatic factors. The lag times between NEE and climatic factors were separately explained by moisture and temperature conditions. (ii) Non-linear response relationships were observed between carbon flux and climatic factors. Under similar climatic conditions, the increasing stage of NEE consistently remained lower than the decreasing stage, presenting a distinctive hysteresis loop. (iii) Further investigations revealed the collaborative role of gross primary productivity (GPP) and ecosystem respiration (RECO) in the diurnal variation patterns of NEE. Specifically, the difference in light-use efficiency between the increasing and decreasing stages dominated the difference in GPP for both stages, whereas the difference in air temperature between the increasing and decreasing stages dominated the difference in RECO for both stages. The diurnal variation patterns of NEE were similar across the different parts of growing season. Results furthermore allowed to optimize the light-ues efficiency model, which exhibited remarkable accuracy in daily GPP estimation and effectively simulated the diurnal variation patterns between GPP and climatic factors. In summary, this study provides a theoretical basis for understanding lagged effects and diurnal variations in grassland ecosystems in response to climatic factors. These research findings are of great importance for predicting the future ecosystem carbon sink potential.

Livestock grazing may affect small mammalian herbivore-soil microbe interactions and their association with the structure and functions of the ecosystem. However, the role of factors such as vegetation and soil nutrients in regulating these impacts is not clear. Here we conducted a 9-year experiment in temperate steppe to study how Brandt’s vole (Lasiopodomys brandtii) affects the soil microbial community under different livestock grazing intensities. This experiment contained 12 field enclosures with three livestock grazing intensities: control (CK), light grazing (LG), and moderate grazing (MG). We found that vole activity does not significantly change soil microbial diversity under non-grazing conditions. However, under livestock grazing conditions, vole activity led to a significant reduction in soil bacterial diversity and an increase in fungal diversity, demonstrating the impacts of livestock grazing on rodents-soil microbe interactions. The activity of voles significantly altered soil bacterial community composition, with changes primarily attributed to variations in the relative abundance of the phyla Actinobacteria, Bacteroidetes, Firmicutes, Gemmatimonadetes, and Proteobacteria. The soil fungal community remained relatively stable despite vole activity, which can be attributed to the richness of fungal colonies in mycelium and their low sensitivity to changes in external conditions. Vole activity also influenced soil microbial functional groups, and the variations in these groups were further amplified by livestock grazing. Furthermore, the shift in the microbial community composition and diversity induced by vole activity were mainly associated with the reduction of plant aboveground biomass. Overall, our study suggested that livestock grazing enhanced the changes in the soil microbial community induced by rodents, underscoring the importance of managing livestock grazing regimes for grassland conservation.

As an essential nutrient element for biological growth and metabolism, sulfur is closely interlinked with the carbon and nitrogen cycles, and it is one of the limiting elements for grassland productivity. Here we investigated the spatial distribution of sulfur contents and 34S stable isotope along the North China Transect (NCT), with the aim to explore the shaping role of the aridity index (AI) gradient on sulfur cycling dynamic in arid and semi-arid grasslands. In the area with AI < 0.12, soil sulfur contents and sulfur isotopic compositions (δ34S) showed no correlation with AI, indicating that abiotic processes predominantly govern the sulfur cycle in this area. In the area where 0.12 ≤ AI < 0.32, both sulfur contents and δ34S values increased with rising AI, with microbial-mediated reduction being the primary sulfur cycling process. In the area with 0.32 ≤ AI < 0.60, soil sulfur contents continued to increase with higher AI, but δ34S significantly decreased as AI increased, suggesting plant uptake as the dominant sulfur cycling process in this area. This study demonstrated the significant impact of AI on sulfur dynamics, providing insights into the different drivers of sulfur cycling along the aridity gradient, and offering guidance for developing targeted strategies under global climate change.

Viruses are abundant, ubiquitous members of soil communities that kill microbial cells, but how they respond to perturbation of soil ecosystems is essentially unknown. Here, we investigate lineage-specific virus-host dynamics in grassland soil following "wet-up", when resident microbes are both resuscitated and lysed after a prolonged dry period. Quantitative isotope tracing, time-resolved metagenomics and viromic analyses indicate that dry soil holds a diverse but low biomass reservoir of virions, of which only a subset thrives following wet-up. Viral richness decreases by 50% within 24 h post wet-up, while viral biomass increases four-fold within one week. Though recent hypotheses suggest lysogeny predominates in soil, our evidence indicates that viruses in lytic cycles dominate the response to wet-up. We estimate that viruses drive a measurable and continuous rate of cell lysis, with up to 46% of microbial death driven by viral lysis one week following wet-up. Thus, viruses contribute to turnover of soil microbial biomass and the widely reported CO2 efflux following wet-up of seasonally dry soils.

The two major rainforests of the neotropics, the Amazon and Atlantic forests, show maximum expansion during the warm and wet conditions of interglacial periods, including the current Holocene. They are connected by a network of gallery forests through the Cerrado biome. However, the extent of their expansion during glacial periods, when they were more disjunct, is unknown. During glacial periods, a pollen assemblage comprising Podocarpus–Ilex–Hedyosmum–Myrsine displays higher frequencies in marine, continental and coastal Brazilian pollen records. This assemblage is observed today in the high-elevation grasslands of the Cerrado and Atlantic Forest biomes and in the coastal vegetation, the restinga, of southern Brazil. We therefore reviewed the possible migration routes for these species by tracking glacial period Podocarpus–Ilex–Hedyosmum–Myrsine assemblages in published pollen records. The marine pollen records provide evidence of a glacial expansion of restinga, its floristic composition being continuous with the dominant regional vegetation, a cold type of shrubby grassland. There appear to be two migration routes, one involving the expansion of high-elevation grassland taxa within the lowlands, and the other low-sea level stands of coastal restinga. We conclude that the Cerrado was a node of migration between the Amazon and Atlantic rainforests, linking the Andes to the central and coastal mountains of Brazil. The Brazilian mountain ranges represent refugia of ancient taxa that colonized the continent up to the Andes and modified the floristic composition of the two rainforests during the Pleistocene glacial periods.

Knowledge on biodiversity is fundamental for conservation strategies. The Brazilian Pampa region, located in subtropical southern Brazil, is neglected in terms of conservation, and knowledge of its biodiversity is fragmented. We aim to answer the question: how many, and which, species occur in the Brazilian Pampa? In a collaborative effort, we built species lists for plants, animals, bacteria, and fungi that occur in the Brazilian Pampa. We included information on distribution patterns, main habitat types, and conservation status. Our study resulted in referenced lists totaling 12,503 species (12,854 taxa, when considering infraspecific taxonomic categories [or units]). Vascular plants amount to 3,642 species (including 165 Pteridophytes), while algae have 2,046 species (2,378 taxa) and bryophytes 316 species (318 taxa). Fungi (incl. lichenized fungi) contains 1,141 species (1,144 taxa). Animals total 5,358 species (5,372 taxa). Among the latter, vertebrates comprise 1,136 species, while invertebrates are represented by 4,222 species. Our data indicate that, according to current knowledge, the Pampa holds approximately 9% of the Brazilian biodiversity in an area of little more than 2% of Brazil’s total land. The proportion of species restricted to the Brazilian Pampa is low (with few groups as exceptions), as it is part of a larger grassland ecoregion and in a transitional climatic setting. Our study yielded considerably higher species numbers than previously known for many species groups; for some, it provides the first published compilation. Further efforts are needed to increase knowledge in the Pampa and other regions of Brazil. Considering the strategic importance of biodiversity and its conservation, appropriate government policies are needed to fund studies on biodiversity, create accessible and constantly updated biodiversity databases, and consider biodiversity in school curricula and other outreach activities.

The growth and physiology of soil microorganisms, which play vital roles in biogeochemical cycling, are shaped by both current and historical soil environmental conditions. Here, we developed and applied a genome-resolved metagenomic implementation of quantitative stable isotope probing (qSIP) with an H218O labeling experiment to identify actively growing soil microorganisms and their genomic capacities. qSIP enabled measurement of taxon-specific growth because isotopic incorporation into microbial DNA requires production of new genome copies. We studied three Mediterranean grassland soils across a rainfall gradient to evaluate the hypothesis that historic precipitation levels are an important factor controlling trait selection. We used qSIP-informed genome-resolved metagenomics to resolve the active subset of soil community members and identify their characteristic ecophysiological traits. Higher year-round precipitation levels correlated with higher activity and growth rates of flagellar motile microorganisms. In addition to heavily isotopically labeled bacteria, we identified abundant isotope-labeled phages, suggesting phage-induced cell lysis likely contributed to necromass production at all three sites. Further, there was a positive correlation between phage activity and the activity of putative phage hosts. Contrary to our expectations, the capacity to decompose the diverse complex carbohydrates common in soil organic matter or oxidize methanol and carbon monoxide were broadly distributed across active and inactive bacteria in all three soils, implying that these traits are not highly selected for by historical precipitation. IMPORTANCE Soil moisture is a critical factor that strongly shapes the lifestyle of soil organisms by changing access to nutrients, controlling oxygen diffusion, and regulating the potential for mobility. We identified active microorganisms in three grassland soils with similar mineral contexts, yet different historic rainfall inputs, by adding water labeled with a stable isotope and tracking that isotope in DNA of growing microbes. By examining the genomes of active and inactive microorganisms, we identified functions that are enriched in growing organisms, and showed that different functions were selected for in different soils. Wetter soil had higher activity of motile organisms, but activity of pathways for degradation of soil organic carbon compounds, including simple carbon substrates, were comparable for all three soils. We identified many labeled, and thus active bacteriophages (viruses that infect bacteria), implying that the cells they killed contributed to soil organic matter. The activity of these bacteriophages was significantly correlated with activity of their hosts.

Viruses shape microbial communities, food web dynamics, and carbon and nutrient cycling in diverse ecosystems. However, little is known about the patterns and drivers of viral community composition, particularly in soil, precluding a predictive understanding of viral impacts on terrestrial habitats. To investigate soil viral community assembly processes, here we analyzed 43 soil viromes from a rainfall manipulation experiment in a Mediterranean grassland in California. We identified 5,315 viral populations (viral operational taxonomic units [vOTUs] with a representative sequence ≥10 kbp) and found that viral community composition exhibited a highly significant distance-decay relationship within the 200-m2 field site. This pattern was recapitulated by the intrapopulation microheterogeneity trends of prevalent vOTUs (detected in ≥90% of the viromes), which tended to exhibit negative correlations between spatial distance and the genomic similarity of their predominant allelic variants. Although significant spatial structuring was also observed in the bacterial and archaeal communities, the signal was dampened relative to the viromes, suggesting differences in local assembly drivers for viruses and prokaryotes and/or differences in the temporal scales captured by viromes and total DNA. Despite the overwhelming spatial signal, evidence for environmental filtering was revealed in a protein-sharing network analysis, wherein a group of related vOTUs predicted to infect actinobacteria was shown to be significantly enriched in low-moisture samples distributed throughout the field. Overall, our results indicate a highly diverse, dynamic, active, and spatially structured soil virosphere capable of rapid responses to changing environmental conditions.

Grassland is the basis for the development of grassland animal husbandry in China and an important part of the ecosystem. Grazing is the main way of grassland utilization, the most important factor of human interference with grassland, and has an important impact on grassland ecosystem service function. Through the related literature on the effect of grazing on grassland plants, we analyze the effect of grazing on plant communities and their diversity, organizational power, biomass, root system, etc., in order to provide some reference for studying the rational use of grassland and the management of degraded grassland. Currently, unreasonable grazing has caused the degradation of grassland and restricted the development of grassland economy. The next step should be to increase the research on zoned rotational grazing, seasonal grazing and reasonable livestock carrying capacity in combination with grassland management techniques such as fertilization, replanting and pine harrowing. [ABSTRACT FROM AUTHOR]

The savanna ecosystem is dominated by grasses, which are a key food source for many species of grazing animals. This relationship creates a diverse mosaic of habitats and contributes to the high grass species richness of savannas. However, how grazing interacts with environmental conditions in determining grass species richness and abundance in savannas is still insufficiently understood. In the Kruger National Park, South Africa, we recorded grass species and estimated their covers in 60 plots 50 × 50 m in size, accounting for varying proximity to water and different bedrocks. To achieve this, we located plots (i) near perennial rivers, near seasonal rivers, and on crests that are distant from all water sources and (ii) on nutrient‐rich basaltic and nutrient‐poor granitic bedrock. The presence and abundance of large herbivores were recorded by 60 camera traps located in the same plots. Grass cover was higher at crests and seasonal rivers than at perennial rivers and on basalts than on granites. The relationship between grass species richness and herbivore abundance or species richness was positive at crests, while that between grass species richness and herbivore species richness was negative at seasonal rivers. We found no support for controlling the dominance of grasses by herbivores in crests, but herbivore‐induced microsite heterogeneity may account for high grass species richness there. In contrast, the decrease in grass species richness with herbivore species richness at seasonal rivers indicates that the strong grazing pressure over‐rides the resistance of some species to grazing and trampling. We suggest that the relationships between grasses and herbivores may work in both directions, but the relationship is habitat‐dependent, so that in less productive environments, the effect of herbivores on vegetation prevails, while in more productive environments along rivers the effect of vegetation and water supply on herbivores is more important. [ABSTRACT FROM AUTHOR]

Montane grasslands must be managed effectively to conserve biodiversity since they play an important role in sustaining healthy and diversified ecosystems. A 9 km transect was used to assess plant and lepidopteran biodiversity in mountain meadows in Bilbor, Romania. Different management strategies were used in each plot. The identified plants were divided into three categories: Poaceae, Fabaceae, and other families. In the case of lepidoptera, diurnal butterfly species from three families were observed: Lycaenidae, Nymphalidae, and Pieridae. The number of plant species in the abandoned meadows was reduced, with a focus on those with low fodder value (Nardus stricta and Deschampsia flexuosa), as well as some invasive species (Vaccinium myrtillus). The implementation of protection and conservation measures resulted in species diversification, with an increase in the number of Poaceae (11 to 16 species) and Fabaceae (nine to fourteen species). In addition to providing more feed, the flora can benefit lepidopteran entomofauna. During the monitoring period, 29 species were identified from the three lepidopteran families. The most abundant species were Maniola jurtina L., Boloria selene Denis & Schif., Argynnis paphia L., Coenonympha pamphilus L. (Nymphalidae), Pseudophilotes schiffermuelleri Hemming (Lycaenidae), and Pieris mannii Mayer (Pieridae). Traditional mowing and grazing activities can help to maintain the structure and composition of these ecosystems, limiting biological succession to forest and sustaining floristic biodiversity. [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]

[Objective] The aims of this study are to identify drought events, drought frequency and drought intensity in grassland of Xilin Gol, to understand the meteorological drought field in Xilin Gol, and then to alleviate the environmental and economic problems caused by drought in Xilin Gol. [Methods] The month-by-month observation data of nine meteorological stations in Xilin Gol region from 1969 to 2018 were selected to calculate the effective drought index (EDI) . The spatial and temporal patterns of drought in Xilin Gol over the past 60 years were analyzed by combining Mann-Kendall test, empirical orthogonal function (EOF) decomposition and quantitative drought characterization methods. [Results] The annual average EDI index of Xilin Gol region decreased at the rate of 0.029/decade, and the drought trend increased significantly, with an average of 0.5 drought events per year. The frequency of normal occurrences in Xilin Gol ranged from 67.17 to 72.65%, and the frequency of severe droughts ranged from 0.02 to 0.99%, with a large variability in the frequency of different droughts, and the southwest and central regions being the regions with higher drought intensity. Contribution of variances of the previous two major characteristic vectors of Xilin Gol reached up to 52.75% and 14.38%, respectively, and the spatial mode showed a consistent type and southeast-northwest inversion phase type. [Conclusion] EDI index considering effective precipitation has more advantages in revealing the spatiotemporal variation trend of drought in grassland, and can be used to identify the spatiotemporal variation of meteorological drought. [ABSTRACT FROM AUTHOR]

Hourly automatic snow depth stations have enhanced insights into the dynamics and spatial variability of daily snowmelt. From 2021 to 2022, we gathered hourly snow depth measurements from six Hulun Buir grassland stations. Our analysis shed light on the dynamics of snowmelt and the key drivers in this northern region. We found that in northern China's mid-high latitude grasslands, winter snow cover persists for about 80 to 134 days. The transition to the melting phase in early March spans 5 to 12 days, with continuous and rapid phases. Snow under 3 cm quickly collapses. If the average temperature from 10:00 to 18:00 exceeds 0 °C, complete melting occurs within 36 h. Daily snow melting sees initial stability, swift decline, and gradual reduction, peaking between 11:00 and 14:00. Finally, thermal conditions primarily drive snow melt dynamics, with 14:00 ground temperature being pivotal. These findings shed light on snow dynamics and key factors in the mid-high latitude grasslands of northern China. [ABSTRACT FROM AUTHOR]

The leaf area index (LAI) of grassland is critical for estimating the balance of livestock and livestock production, understanding the dynamics of climate change, and providing feedback for achieving sustainable development. The currently available LAI products have some uncertainties and need to be further improved. Previous studies proposed that integrating the physical model and machine learning (ML) has great potential for the rapid and accurate retrieval of grassland LAI. However, there are few comparative studies on LAI forecast models for different grassland cover to assess the potential of the different hybrid models. Therefore, in this study, five hybrid models based on PROSAIL and ML including deep neural network (DNN), random forest (RF), gradient boosting regression tree (GBRT), support vector machine (SVR), and artificial neural network (ANN) and five mixed models averaging are applied to compare the performance with different forecast models for grassland LAI estimation in Tianzhu County. According to the multiple training, validation, and testing, the results demonstrate that five mixed models averaging and DNN model with a complex network structure are reliable and have higher accuracy and better performance than the estimates from the other four hybrid models, except for its computational efficiency. SVR achieves the best performance in computational efficiency, which it has great potentials to deliver near-real-time operational products for grassland LAI management. Our results show that the hybrid model based on machine learning algorithm coupled with physical process model has great application potential in grassland leaf area index inversion. [ABSTRACT FROM AUTHOR]

Grassland birds are globally imperiled. Those of endemic Neotropical savannas may be particularly threatened as knowledge of the ecology of many species is lacking, restricting our ability to take decisive conservation action. During the dry (non-breeding) season of 2010, we studied the population size, distribution, and habitat associations of the Cock-tailed Tyrant (Alectrurus tricolor), Black-masked Finch (Coryphaspiza melanotis), and Wedge-tailed Grass-finch (Emberiziodes herbicola) across a disturbance-mediated savanna–grassland gradient in Beni, Bolivia. We used distance sampling and surveyed structural and resource-specific habitat features at plots where birds were present versus random locations. Occupancy models identified fine-scale habitat associations. Cock-tailed Tyrant (7.1 ind./km2) specialized on open habitats in areas expected to be heavily inundated in the wet season, avoided trees, and selected tall grassy swards. Black-masked Finch (25.1 ind./km2) occurred across the gradient, associating with tall, forb-rich swards, sparse shrubs, and low levels of fruiting and seeding vegetation. Wedge-tailed Grass-finch (27.9 ind./km2) also occurred across the gradient, particularly associated with tall, forb-rich swards, abundant seeding grasses, and sparse shrubs. Our results offer the first quantitative abundance estimates for these species in Beni, provide vital baselines for future monitoring, and improve knowledge of the ecology and conservation management needs of these species. Importantly, our results suggest that populations of these three grassland birds may be best maintained in heterogenous, mosaic landscapes that can be produced by carefully managed burning and grazing. Further research in the breeding season would facilitate making stronger, more specific management recommendations. [ABSTRACT FROM AUTHOR]

Since its accidental introduction in 1951, the South African species Eragrostis plana has invaded a large part of the Pampa biome in South America, a highly diverse grassland ecosystem that has coexisted with livestock since its introduction at the beginning of the 17th century. E. plana, a perennial tussock grass with a deep and abundant root system, is resistant to frost and cattle grazing, and a successful competitor for environmental resources. The species is diploid, C4 dispersed endozoochorically, and flowers in late spring and early summer, with optimal germination occurring at 35°C and viability up to 39–40°C. It is allelopathic because it produces several phenols and alkaloids. Extreme soil disturbance or intense grazing favours initial invasion. Nonetheless, grazing exclusion enhances E. plana competition and affects the grassland community and diversity. E. plana is highly tolerant to interspecific competition, especially with grasses exhibiting a similar growth habit. Under water stress, it responds faster by increasing its root system by 66% more than native grass. Moreover, antioxidant system activity increases, and the species recovers quickly through osmolyte production. In non‐invaded fields, avoiding soil disturbance and intensive grazing are key strategies to preserving Biome Pampa. Nonetheless, in fields where the invasion has already occurred, grazing must be maintained, cattle quarantined practiced, along with strategies that reduce cover and prevent the spread of E. plana. Liming and fertilising native grasslands improve their potential to compete with E. plana. The wiper applicator, a device that allows glyphosate herbicide application selectively to E. plana, is an important component of the integrated weed management system, especially with very severe infestations. Establishing strategies to contain or manage E. plana should be a priority to preserve the biodiversity of the Pampa. In the future, innovative options could also help prevent new invasions. [ABSTRACT FROM AUTHOR]

In Germany, emissions from drained organic soils contributed approximately 53.7 Mio. t of carbon dioxide equivalents (CO2-eq) to the total national greenhouse gas (GHG) emissions in 2021. In addition to restoration measures, shifting management practices, rewetting, or using peatlands for paludiculture is expected to significantly reduce GHG emissions. The effects of climate change on these mitigation measures remains to be tested. In a 2017 experimental field study on agriculturally used grassland on organic soil, we assessed the effects of rewetting and of predicted climate warming on intensive grassland and on extensively managed sedge grassland (transplanted Carex acutiformis monoliths). The testing conditions of the two grassland types included drained versus rewetted conditions (annual mean water table of − 0.13 m below soil surface), ambient versus warming conditions (annual mean air temperature increase of + 0.8 to 1.3 °C; use of open top chambers), and the combination of rewetting and warming. We measured net ecosystem exchange of CO2, methane and nitrous oxide using the closed dynamic and static chamber method. Here, we report the results on the initial year of GHG measurements after transplanting adult Carex soil monoliths, including the controlled increase in water level and temperature. We observed higher N2O emissions than anticipated in all treatments. This was especially unexpected for the rewetted intensive grasslands and the Carex treatments, but largely attributable to the onset of rewetting coinciding with freeze–thaw cycles. However, this does not affect the overall outcomes on mitigation and adaptation trends. We found that warmer conditions increased total GHG emissions of the drained intensive grassland system from 48.4 to 66.9 t CO2-eq ha−1 year−1. The shift in grassland management towards Carex paludiculture resulted in the largest GHG reduction, producing a net cooling effect with an uptake of 11.1 t CO2-eq ha−1 year−1. Surprisingly, we found that this strong sink could be maintained under the simulated warming conditions ensuing an emission reduction potential of − 80 t CO2-eq ha−1 year−1. We emphasize that the results reflect a single initial measurement year and do not imply the permanence of the observed GHG sink function over time. Our findings affirm that rewetted peatlands with adapted plant species could sustain GHG mitigation and potentially promote ecosystem resilience, even under climate warming. In a warmer world, adaptation measures for organic soils should therefore include a change in management towards paludiculture. Multi-year studies are needed to support the findings of our one-year experiment. In general, the timing of rewetting should be considered carefully in mitigation measures. [ABSTRACT FROM AUTHOR]

More than 90% of grasslands in China are in a state of degradation or ongoing degradation. Some difficulties have posed on the sustainable supply and feed of animal husbandry. At the same time, the ever-increasing degree of ecological environment damage has seriously threatened sustainable animal husbandry and ecological environment. Therefore, it is crucial to improve the degraded grasslands at present. However, there is a great research gap among scientific theory, practice, technology, and machinery of grassland improvement in China. The overall promotion can be limited in the grassland improvement. In this review, 24 common technologies were summarized and then classified for grassland improvement. The characteristics and applicable conditions were given for the different technologies. A systematic analysis was implemented on the grassland improvement techniques. A classification framework was then established for a comprehensive process pipeline of grassland improvement. Four types of degraded grassland improvement were proposed, including less damage and improvement (improvement type I), the optimal growth environment of forage (improvement type II), the promoting development and improvement of forage (improvement type III), and the changing biological community and improvement (improvement type IV). The improvement techniques, processes, and machinery were analyzed within the framework of the four types of grassland improvement. The research and development direction of machinery and equipment were proposed after that. Four aspects were further determined in grassland improvement, including the intensive protection of grassland, the mechanized process of degraded grasslands, the new types of improvement machinery, as well as decision-making on grassland protection and improvement. The synergistic effect of these four aspects can bring positive promotion to the improvement of degraded grasslands. Since the current situation of grassland degradation cannot be fully curbed, the following work should be focused on the future grassland protection and mechanized improvement of degraded grasslands. 1) To strengthen grassland protection, the prevention of grassland degradation in the path of combining grass and land. 2) In grassland improvement, the existing no-till live broadcast can be optimized to develop compound machinery. 3) In grassland mechanization, the fundamental research should be strengthened for the technical improvement machinery, in order to fully leverage the technological advantages. 4) Grassland protection and improvement policies support and technical guidance to grassroots should be strengthened to enhance their enthusiasm for grassland protection and improvement. The technology schemes of degraded grassland improvement, machinery selection, and relevant policies can provide a strong reference for the research and development of grassland improvement machinery and equipment. [ABSTRACT FROM AUTHOR]

Nutrient enrichment often alters the biomass and species composition of plant communities, but the extent to which these changes are reversible after the cessation of nutrient addition is not well‐understood. Our 22‐year experiment (15 years for nutrient addition and 7 years for recovery), conducted in an alpine meadow, showed that soil nitrogen concentration and pH recovered rapidly after cessation of nutrient addition. However, this was not accompanied by a full recovery of plant community composition. An incomplete recovery in plant diversity and a directional shift in species composition from grass dominance to forb dominance were observed 7 years after the nutrient addition ended. Strikingy, the historically dominant sedges with low germination rate and slow growth rate and nitrogen‐fixing legumes with low germination rate were unable to re‐establish after nutrient addition ceased. By contrast, rapid recovery of aboveground biomass was observed after nutrient cessation as the increase in forb biomass only partially compensated for the decline in grass biomass. These results indicate that anthropogenic nutrient input can have long‐lasting effects on the structure, but not the soil chemistry and plant biomass, of grassland communities, and that the recovery of soil chemical properties and plant biomass does not necessarily guarantee the restoration of plant community structure. These findings have important implications for the management and recovery of grassland communities, many of which are experiencing alterations in resource input. [ABSTRACT FROM AUTHOR]

Elucidating factors that drive microhabitat selection in a species is important for informing the conservation management of the species. For species that use microhabitats as long-term refuge sites, selection pressures are likely to be strong because the microhabitat must fulfil their eco-physiological and life history requirements. Smaug giganteus (Sungazer) is a threatened (Vulnerable) cordylid lizard species in the highveld grasslands of South Africa – a key agricultural area in the country. Individuals dig burrows as refuges, which increases their sensitivity to habitat transformation. In addition, previous attempts to translocate populations have failed due to a lack of knowledge about their specific microhabitat requirements. We assessed microhabitat characteristics that may influence burrow site selection by measuring vegetation characteristics surrounding Sungazer burrows and comparing these to vegetation at randomly selected sites. We also recorded orientation, aspect, soil composition, and the presence of other animal dung. Sungazers selected sites with sparse vegetation cover, and where grass height was short, but had no preference for soil composition. There was no relationship between the presence of ungulate dung and the placement of Sungazer burrows. Most Sungazer burrows were orientated in a northerly direction on north-facing slopes, suggesting that burrow placement has thermoregulatory advantages. We recommend that to identify suitable sites for Sungazer translocations, landscapes are thoroughly surveyed with cognisance to the findings in this study, and that a soft-release translocation protocol follows to maximise translocation success. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is one of the main nutrients for all plants, including grasses. However, sources of P fertilizer are not renewable, are not evenly distributed and overfertilization can lead to serious environmental degradation. Smart combinations of grasses may be able to more efficiently take up P from soils through complementarity. In a two-year field mesocosm experiment, we compared the performance of Lolium perenne L. and Festuca arundinacea Schreb. in monocultures and in combination, as well as a mixture of both species with a tetraploid variety of Lolium perenne L and Phleum pratense L. Plants were grown in an unfertilized low P soil and in P fertilized soil for two growing seasons. We measured biomass production, root traits, nutrient uptake, microbial biomass and enzymatic activities. In the unfertilized plots the combination of Lolium perenne and Festuca arundinacea generated the highest cumulative yields (25,951 ± 4059 kg ha−1), relative total yield (> 1) and P nutrition index (0.79). We related this to the complementarity found in root traits and lower intraspecific competition of Festuca arundinacea and Lolium perenne diploid. Festuca arundinacea produced higher root biomass than Lolium perenne diploid at deeper soil layers (98 vs. 44 g m−2; p < 0.05). On the other hand, Lolium perenne diploid had significantly finer roots than Festuca arundinacea both at topsoil and bottom layers (0.19 vs. 0.22 mm and 0.19 vs. 0.23 mm at top and bottom layers respectively). The 4 species combination did not result in higher yields. Our results show that, in low P soils, combinations of grass species with contrasting root traits could lead to significantly higher yields than monocultures. [ABSTRACT FROM AUTHOR]

Grazing exclusion (GE) is considered an effective strategy for restoring the degradation of overgrazed grasslands on the global scale. Soil microbial diversity plays a crucial role in supporting multiple ecosystem functions (multifunctionality) in grassland ecosystems. However, the impact of grazing exclusion on soil microbial diversity remains uncertain. Here, we conducted a meta-analysis using a dataset comprising 246 paired observations from 46 peerreviewed papers to estimate how GE affects microbial diversity and how these effects vary with climatic regions, grassland types, and GE duration ranging from 1 to 64 years. Meanwhile, we explored the relationship between microbial diversity and its functionality under grazing exclusion. Overall, grazing exclusion significantly increased microbial Shannon (1.9%) and microbial richness (4.9%) compared to grazing group. For microbial groups, GE significantly increased fungal richness (8.6%) and bacterial richness (5.3%), but decreased specific microbial richness (-11.9%). The responses of microbial Shannon to GE varied among climatic regions, grassland types, and GE duration. Specifically, GE increased microbial diversity in in arid, semi-arid, and dry sub-humid regions, but decreased it in humid regions. Moreover, GE significantly increased microbial Shannon in semidesert grasslands (5.9%) and alpine grasslands (3.0%), but not in temperate grasslands. Long-term (>20 year) GE had greater effects on microbial diversity (8.0% for Shannon and 6.7% for richness) compared to short-term (<10 year) GE (-0.8% and 2.4%). Furthermore, grazing exclusion significantly increased multifunctionality, and both microbial and plant Shannon positively correlated with multifunctionality. Overall, our findings emphasize the importance of considering climate, GE duration, and grassland type for biodiversity conservation and sustainable grassland ecosystem functions. [ABSTRACT FROM AUTHOR]

To describe the composition of the penultimate glacial Brazilian Atlantic forest, we analyzed pollen, charcoal and diatoms deposited in the section from 871 to 1400 cm of core CO14 drilled in the Colônia basin in southeastern Brazil. The landscape was characterized by a cool grassland with three conifer genera: Araucaria, Podocarpus and Ephedra. Total arboreal pollen frequency did not change during the transition from glacial to interglacial conditions. Changes in Podocarpus frequency and concentration showed out‐of‐phase responses with austral summer insolation at an orbital scale while, at a millennial scale, both northern and southern hemisphere ice volume controlled the interplay between positions of the Inter‐Tropical Convergence Zone and South Tropical Front (STF), which in turn defined the latitudinal distribution of rainfall. The disappearance of Podocarpus and the decrease of Araucaria observed between ~167 and 160 ka were related to a dry interval which was not observed elsewhere. During Termination II a progressive decrease in conifer pollen taxa was in phase with a southward shift in the STF and increase in Atlantic sea surface temperatures. Our results show that southern hemisphere conifer distribution is strongly linked to austral summer insolation and winter precipitation and will be threatened by the southward expansion of the summer rainfall boundary. [ABSTRACT FROM AUTHOR]

This study aimed to assess soil organic carbon (SOC) concentration and stock in mineral soils in cropland and grassland in Latvia, considering soil groups and texture classes. It covered 197 sites across Latvia (152 in cropland, 45 in grassland). Soil profile description and sampling (at depths of 0–10 cm, 10–20 cm, and 20–40 cm) were conducted between 2021 and 2023. Laboratory analyses included soil bulk density (SBD), total carbon (TC), total nitrogen (TN), carbonate content, pH, and extractable phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). SOC stock was calculated, and correlations with other soil parameters were determined. In cropland sites, Arenosols and Stagnosols had the lowest SOC concentration and stock, while Gleysols and Phaeozems had the highest. In grassland sites, Retisols exhibited the lowest SOC concentration in the 0–20 cm layer, while Planosols had the highest SOC concentration in this layer. Conversely, in the 20–40 cm layer, Retisols showed the highest SOC concentration, while Gleysols had the lowest concentration. Regarding SOC stock in grassland sites, Planosols exhibited the highest values, while the lowest values were observed for Retisols and Umbrisols. Contrary to our hypothesis that grassland exhibits higher SOC stock than cropland, our results show the reverse for Phaeozems, the dominant WRB soil group in this study: a higher average SOC concentration and stock in cropland compared to grassland. However, very low occurrence of some soil groups and lack of some soil groups for grassland sites hinders the correct interpretation of these results, and further investigations are required in future studies. [ABSTRACT FROM AUTHOR]