Moderate Grazing Research Articles

The missing woodland story: Implications of 1700 years of stand‐scale change on ‘naturalness’ and managing remnant broadleaved woodlands

Abstract Longer‐term perspectives—equivalent to the lifespans of long‐lived trees—are required to fully inform perceptions of ‘naturalness’ used in woodland conservation and management. Stand‐scale dynamics of an old growth temperate woodland are reconstructed using palaeoecological data. The study site is Cambusurich Wood, Scotland, a woodland designated for conservation due to its ‘naturalness’. High temporal resolution palaeoecological records (pollen, plant macrofossils, non‐pollen palynomorphs and charcoal analyses) are used to explore long‐term human‐woodland interactions and the drivers of stand‐scale woodland dynamics. The results demonstrate stand‐scale woodland responses to climatic changes and human‐woodland interactions (increasingly) since 220 cal. BP (1730 CE). Periods of intense herbivore grazing and trampling altered the local vegetation composition and sediment accumulation. Greater vegetation diversity is associated with woodland disturbance through fire and moderate grazing. Subsequent cessation of localised burning and continued (long‐term) grazing have had legacy effects on woodland composition and diversity. Synthesis and applications: The current woodland is identified as being compositionally and structurally distinct from past woodland conditions, and its perceived ‘naturalness’ can be considered a ‘shifted baseline’, highlighting the importance of longer‐term perspectives to woodland management. Human‐woodland interactions are important in shaping modern woodlands and should not be overlooked in future management strategies as human‐induced disturbance can promote woodland diversity, resilience and valuable ecosystem characteristics. Read the free Plain Language Summary for this article on the Journal blog.

Light grazing increased but heavy grazing decreased the abundance and family richness of soil arthropods community in an alpine grassland in the Qinghai Lake Basin.

Soil arthropods are important biological components of the soil food web, which are highly sensitive to environmental disturbances and can rapidly respond to changes in the external environment, then reflect the stability and health of the soil ecosystem. We investigated the community structure of soil arthropod and their responses to grazing intensity along soil depth (from topsoil to subsoil) through a manipulated grazing treatment with four intensity levels (no grazing, light grazing, moderate grazing and heavy grazing) in an alpine grassland in the Qinghai Lake basin. The results showed that: (1) Collembola was the dominant group in the experimental site. (2) Nearly two-thirds of the individuals were distributed in the topsoil (0-10 cm), and grazing did not cause soil arthropods to migrate from the topsoil to deeper soil layers. (3) Light grazing had a positive effect on increasing the individual number, family richness and diversity of soil arthropods, while heavy grazing had the opposite effect, exerting a negative impact on the soil arthropod community. (4) When the grazing intensity did not exceed moderate grazing (i.e. stocking rate of 3.86 Tibetan sheep·hm-2), grazing would have a positive effect on the soil arthropod community. In summary, light grazing is the intensity of disturbance that has a positive effect on the soil arthropod community in this region. This study not only revealed the impact of grazing on the community structure of soil arthropods but also aided in assessing the potential effects of grazing activities on the stability of soil ecosystems, providing scientific evidence for the sustainable management of alpine grasslands.

Litter Removal Counteracts the Effects of Warming on Soil Bacterial Communities in the Qinghai–Tibet Plateau

Climate warming and high-intensity human activities threaten the stability of alpine meadow ecosystems. The stability of the soil microbial community is crucial for maintaining ecological service function. However, the effects of warming and litter removal on microbial interactions, community-building processes, and species coexistence strategies remain unclear. In this study, we used a fiberglass open-top chamber to simulate global change, and moderate grazing in winter was simulated by removing above-ground litter from all plants in the Qinghai–Tibet Plateau, China, to investigate the effects of warming, litter removal, and interactions on soil microbial communities. The treatments included (1) warming treatment (W); (2) litter removal treatment (L); (3) the combined treatment (WL); and (4) control (CK). The results show that compared with the control treatment, warming, litter removal, and the combined treatments increased bacterial Shannon diversity but reduced fungal Shannon diversity, and warming treatment significantly changed the bacterial community composition. Warming, litter removal, and the combined treatments reduced the colinear network connectivity among microorganisms but increased the modularity of the network, and the average path distance and average clustering coefficient were higher than those in the control group. Stochastic processes played a more important role in shaping the microbial community composition, and soil–available phosphorus and soil ammonium contributed more to the βNTI of the bacterial community, while total phosphorus and NAG enzyme in the soil contributed more to the βNTI of the fungal community. Notably, litter removal counteracts the effects of warming on bacterial communities. These results suggest that litter removal may enhance bacterial community stability under warming conditions, providing insights for managing alpine meadow ecosystems in the context of climate change.

Response of grassland greenhouse gas emissions to different human disturbances – A global Meta-analysis

Human disturbances have increased greenhouse gas (GHG) emissions from grassland, worsening global warming. However, the response of grassland GHG (CO2, N2O, and CH4) to human disturbances across various climatic zones requires further elucidation, as does the intricate relationship between GHG emissions and temperature and precipitation. A Meta-analysis of the effects of human disturbances on GHG in grassland over the past 40 years revealed that grazing, fertilization, mowing, and burning significantly influenced the total emissions of N2O, CH4, CO2, and GHG from grassland. However, the light and moderate grazing exerted no substantial impact on CO2 emission flux. In frigid zone grassland, the N2O emission flux was most significantly affected by grazing, the CH4 emission flux affected by fertilization was higher than grazing, and the CO2 emission flux was more sensitive to heavy grazing than severe fertilization. In temperate grassland and savanna, GHG emission flux was most sensitive to fertilization, with CO2 emission flux in savanna being particularly responsive to burning. The effect of increased temperature and precipitation on CO2e in fertilized grassland was approximately double that of grazed grassland and quadruple that of mowed grassland. This study emphasizes the increased effect of human disturbances on GHG emissions in the grassland, especially with the most significant impact of fertilization disturbances on GHG emissions in most grassland areas. Lowering the level of fertilization during grassland management could serve as a crucial step in mitigating GHG emissions from grassland. In summary, rigorous control of disturbance intensity represented an effective strategy for mitigating greenhouse gas emissions, albeit potentially impacting grassland productivity. Future endeavors should focus on determining the optimal disturbance intensity to strike a balance amidst these complex effects.

The Effect of Grazing on Central Anatolian Steppe Vegetation: A Modeling Approach Using Functional Traits.

Grazing is a major ecological driver that influences vegetation dynamics globally. We investigated the long-term effects of different grazing regimes on the vegetation structure of the Central Anatolian steppes, a region characterized by its unique convergence of biogeographical influences and historical land use. We employed the spatially explicit FATELAND model to simulate vegetation dynamics over a 50-year period under three distinct grazing scenarios: no grazing, moderate grazing, and overgrazing. Our simulations incorporated a range of plant functional traits to predict changes across five different vegetation types in Central Anatolia, including woodland steppes and treeless steppes. The simulations revealed that moderate grazing supports the diversity and abundance of various plant functional groups, excluding resprouter trees, which flourish under no grazing conditions. In contrast, overgrazing leads to significant reductions in the abundance of perennial forbs and both spiny and non-spiny subshrubs, often resulting in a shift toward grassland dominated by resprouter gramineae or an annual herb-dominated grassland, depending on the initial abundance of gramineae. Our findings highlight the critical role of grazing management in maintaining biodiversity and ecological stability in steppe ecosystems. While moderate grazing can enhance plant functional group diversity, overgrazing significantly threatens the ecological integrity of the Central Anatolian steppes. In conclusion, our modeling approach reveals that the grazing regime is a major driver in shaping the vegetation structure of Central Anatolian steppes. Grazing management strategies that are adjusted to the ecological characteristics and historical context of specific regions are required to prevent degradation and promote sustainable grassland vegetation.

Livestock grazing strengthens the effect of vole activity on the soil microbial community

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.

Moderate grazing intensity and pika disturbance can enhance plant diversity and soil nutrient cycling in the alpine grasslands of the Qinghai-Xizang Plateau

Grazing livestock and pikas, as the primary herbivores in grasslands, influence the health of grassland ecosystems through activities such as feeding, burrowing, and trampling. This study reviews 86 articles and examines the effects of varying grazing levels and pika activity on alpine grassland vegetation and soil in the Qinghai-Xizang Plateau, providing scientific insights to guide grassland conservation efforts. The research shows that: 1) Both grazing and pika disturbance significantly reduce aboveground biomass (AGB) in alpine grasslands (p < 0.05). Moderate grazing increases diversity indices, while pika disturbance has the opposite effect. 2) As grazing intensity increases, there is a significant decrease in total nitrogen (TN), total phosphorus (TP), and soil organic matter (SOM) content (p < 0.05). However, moderate pika disturbance leads to a significant increase in TP and TN content (p < 0.05). 3) In grazing trials, bulk density (BD) and the Shannon-Wiener index are significant positive drivers. Conversely, during pika disturbance, the Shannon-Wiener index and total nitrogen (TN) act as significant positive drivers, while BD is a significant negative driver. The study's findings indicate that moderate grazing intensity and pika disturbance can enhance plant diversity indices in grasslands, as well as improve soil structure and nutrient levels. Therefore, establishing a reasonable grazing system and controlling the pika population are effective methods for managing alpine grasslands.

Methane pulse spray and irrigation promote seed germination and seedling growth of common vetch

BackgroundGrazing 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.ResultsThe 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.ConclusionsThis 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.

Spatial distribution of shrubs and perennial plants under grazing disturbance in the desert steppe of Inner Mongolia

The desert steppe is unique as a transition zone from the steppe to the desert of the Eurasian Steppe. The spatial distribution of shrubs and perennial plants has changed due to long-term disturbance caused by overgrazing in the ecosystem. This study aimed to determine the degree of patchiness of shrubs and perennial plants under grazing disturbance, which is of great significance to better understand the succession mechanism of plant community in the desert steppe. This study investigated the spatial distribution of shrubs and perennial plants under four stocking rates (no grazing, CK, 0 sheep·hm−2·half year−1; light grazing, LG, 0.93 sheep·hm−2·half year−1; moderate grazing, MG, 1.82 sheep·hm−2·half year−1; heavy grazing, HG, 2.71 sheep·hm−2·half year−1) in the desert steppe of Inner Mongolia, primarily using geostatistical methods. The density of perennial grasses increased with increasing stocking rate, while its height decreased (except for HG). The density and height of the shrubs and the perennial forbs showed an exponential or gradual decline. The spatial distribution of shrubs and perennial plants is mainly affected by structural factors such as topography, soil parent material, and climate, and the density of shrubs and perennial plants is most sensitive to changes in stocking rate. An appropriate stocking rate increases the spatial heterogeneity of shrubs and perennial plants, but heavy grazing reduces the spatial heterogeneity of shrubs and perennial plants.

Livestock grazing modes induced the rapid differentiation of community recruitment in alpine meadow

Herbivores moderate grazing is a fundamental driver of plant diversity maintenance in grassland ecosystems. However, the effects of grazing with different herbivores on plant community composition and recruitment are still little known. Here, we conducted a field moderate grazing experiment to examine the effects of different grazing modes under moderate intensity in the cold season, including sheep grazing (SG), yak grazing (YG), and mixed grazing by sheep and yak (MG), on plant community composition and recruitment. Results showed that all grazing modes significantly decreased plant cover and average height of standing plant litter. Additionally, herbivores grazing significantly increased species richness but decreased community evenness (P < 0.05), with highest richness and evenness found in YG and SG plots, respectively. The trends of increasing aboveground biomass of common and rare species groups were most pronounced in the SG plots relative to the YG and MG plots. MG promoted the increasing of the common species group. From community recruitment, moderate grazing increased the sexual recruitment and decreased the asexual recruitment, and MG significantly inhibited the recruitment of asexual seedlings. Meanwhile, all grazing modes increased the species of poor palatability. These findings imply that the cold-season grazing with moderate intensity facilitated a rapid divergence succession of alpine meadow community by regulating the relative abundance of common and rare species, as well as the asexual seedlings recruitment induced by the removal of standing plant litter. Consequently, the cold-season grazing with different herbivores under moderate intensity can be used as a management tool to modulate grassland community structure and maintain species diversity in alpine grassland ecosystem.

Marandu palisade grass‐forage peanut mixed pastures: Forage intake, animal behaviour, and canopy structure as affected by grazing intensities

AbstractIntegrating forage legumes into grasslands offers numerous ecosystem services. However, the management of grass‐legume pastures is challenging because the interaction between the defoliation frequency and severity may affect the legume persistence and forage intake by grazing animals. This 2‐year study evaluated the most effective grazing intensity to increase forage intake while maintaining a balanced legume proportion in tropical pastures consisting of Brachiaria brizantha and Arachis pintoi. Three treatments (grazing intensities) were assessed: severe, moderate, and low, corresponding to stubble heights of 10, 15, and 20 cm, respectively, and a pre‐grazing height of 25 cm. Two purebred Tabapua heifers were used for each treatment, and additional put‐and‐take animals were introduced, as required. Canopy structure, grazing behaviour, nutritive value, and forage intake were evaluated. The legume proportion in herbage mass remained consistent across all intensities, averaging 35% pre‐ and 32% post‐grazing. The grazing duration remained consistent across treatments on the first and third days, with an average grazing time of 390 and 440 min, respectively. Under post‐grazing conditions, low‐intensity grazing had a 52% greater intake rate than severe‐intensity grazing, which was attributed to a greater biting rate (37.9 bites/min) and bite weight (0.9 g DM/bite). Moderate grazing intensity (stubble height of ~15 cm associated with a pre‐grazing height of ~25 cm) is recommended to manage a mixture of B. brizantha and A. pintoi when the objective is to couple high forage intake with a balanced legume proportion in the pasture.

Grazing and selenium influence community stability by increasing asynchrony and sedge, forbs stability in alpine meadow of Qinghai-Tibet Plateau

Grazing is a major driving force of biodiversity, functions and stability of alpine meadows. In selenium-deficient alpine meadows, moderate selenium supplementation can promote plant growth and increase selenium content within the food web. However, the combined effect of grazing and selenium (Se) addition on the stability of alpine meadow communities within selenium-deficient soil is still unclear. Therefore, we conducted a three-year experiment in an alpine meadow of Qinghai-Tibetan Plateau (QTP), with two stocking rates (0 and 6 sheep months ha−1) and six levels of Se addition (0, 5, 10, 20, 40 and 80 g ha−1) to explore how grazing and Se addition affect community stability and its relationship with species richness, species asynchrony and functional group stability. Results showed that the community stability, species richness and biomass response ratio of the community increased gradually with the increase in the selenium application under grazing and enclosure treatments, reaching the maximum values at 20 g ha−1. However, when the selenium addition exceeded 20 g ha−1, the above mentioned indexes were decreased gradually, especially under grazing. Structural equation model showed that grazing and selenium addition indirectly affected the temporal stability of sedges and forbs, thus influencing the temporal stability of the community. Results of this study indicated that the alpine meadow can maintain high species diversity and community temporal stability under moderate grazing combined with selenium addition, providing a scientific basis for selenium-enriched grazing management in alpine meadows.

Scale dependence and mechanisms of grazing‐induced biodiversity changes depend on herbivore type in semiarid grasslands

Abstract Grasslands support a variety of herbivores that profoundly impact biodiversity and ecosystem functioning at local and regional scales. Understanding how different herbivores influence plant diversity across multiple scales is crucial for effective biodiversity conservation. However, most studies have focussed on the effects of grazing intensity on plant diversity, neglecting the impacts and associated mechanisms of different herbivores across scales. Based on a 7‐year grazing experiment with 16 plots in Inner Mongolia's typical steppe, we compared the scale‐dependent effects of different herbivores (cattle, sheep and goats) on plant diversity at moderate grazing intensity. We used the species–area relationship (SAR) and linear mixed models to analyse the changes in species richness across multiple scales (1, 16, 32, 64, 128, 256, 512 and 1024 m2). To understand SAR slope changes, we examined four potential mechanisms: overall species richness, total number of individuals, species abundance distribution and species aggregation. We found that grazing had scale effects on plant diversity, as indicated by a significant decrease in the SAR slope. This decrease in slope suggests that the negative impacts of grazing were more pronounced at larger scales. Additionally, the scale effects of different herbivores on plant diversity varied. Cattle had stronger positive impacts on diversity than sheep and goats at both small (1 m2) and large (1024 m2) scales. Conversely, sheep and goats had stronger negative effects on diversity than did the control at the large scale (1024 m2). The decrease in the SAR slope was mainly caused by changes in overall species richness and species abundance distribution. This was primarily because cattle had a stronger impact on dominant species, whereas sheep and goats had a stronger impact on rare species. Synthesis: Our results demonstrate that even at the same intensity, the grazing effects on species diversity vary with the study scale, herbivore type and their interaction. This finding has important implications for the conservation of grassland biodiversity given that grazing typically occurs at larger scales than in studies with quadrats and involves various herbivores with distinct effects on plant diversity.

Linkage between soil stoichiometric imbalance and microbial carbon use efficiency in desert steppe under different grazing intensities.

Long-term grazing alters soil resource availability and microbial biomass stoichiometry in grassland ecosystems. Exploring the relationship between soil stoichiometric imbalance and microbial carbon use efficiency (CUE) in grazed desert steppe can help understand soil carbon dynamics from a microbial perspective. Based on a long-term grazing platform in Stipa breviflora desert steppe of Inner Mongolia established in 2004, taking heavy, moderate and light grazing intensities, using no grazing as a control, we measured soil available nutrients, microbial biomass and associated enzyme activities for their acquisition, and calculated soil microbial CUE using ecological stoichiometry. The results showed that grazing inhibited soil microbial CUE by 1.0%-10.3%. Soil C:N imbalance was significantly increased by 20.6% in the moderate grazing treatment, while both C:P imbalance and N:P imba-lance were significantly increased by 20.7% and 25.2% in the heavy grazing treatment, indicating that soil microbial communities were more susceptible to N and P limitation. Soil microbial communities maintained their stoichiometric balance by regulating the threshold of elemental stoichiometry ratios and the production of extracellular enzymes. Structural equation modelling (SEM) results indicated that stoichiometric imbalance indirectly affected microbial CUE by altering the threshold of elemental stoichiometry ratios, microbial biomass stoichiometry, and enzyme stoichiometry.

The impact of different grazing intensity and management measures on soil organic carbon density in Zhangye grassland

Studying the spatial and temporal changes of grassland soil organic carbon (SOC) is helpful in promote the management of regional ecosystem carbon sinks. Grazing is one of the main ways of rational utilization of grassland. Different grazing intensities will affect the change of SOC density. Under different grazing intensity and management measures in Zhangye grassland, this study uses the parameter localized CENTURY model to simulate the temporal and spatial variations of SOC density from 1970 to 2022. The results showed that long-term light grazing reduced the average SOC by 195.114 g·m−2 and 1.91%. Moderate and severe grazing, respectively, for a long time made the total SOC density loss of 5.21% and 17.69%. In a short period, mild and moderate grazing reduced total SOC first and then increased it. Under light grazing, total SOC density appeared higher relative changes in the southeast, and lower in the northwest and central. There was no significant difference in the relative changes of total SOC between steppe and desert grasslands under light grazing. The decrease range of steppe was gradually greater than that in desert grassland. Since different management measures were implemented in some sampling sites in 2017, we divided the study period into two periods, 1970–2016 and 2017–2022. The implementation of degraded grassland improvement, fallow grazing, and rotational grazing would increase the total SOC density and mild SOC density, rotational grazing > degraded grassland improvement > rest grazing. Rotational grazing and the improvement of degraded grassland increased the density of active and inert SOC, while resting grazing decreased the density of SOC.

Changes in soil bacterial community diversity and its network stability under different grazing intensities in plateau rangelands

Grassland degradation is a significant ecological challenge, it changes the grassland environment, including the structure of soil microbial communities. Grazing is a critical factor in this process, yet the impact of different grazing intensities on soil bacterial communities, particularly in unique environments like the Qinghai-Tibet Plateau, remains poorly understood. This study utilized a full-length 16 S rRNA gene sequencing technology combined with environmental factors to assess the impacts of the Holba sheep grazing on soil bacterial community diversity in Zhongba County, Shigatse City, Qinghai-Tibet Plateau. The specific aim was to explore the changes in soil bacterial community diversity and stability under contrasting grazing intensities: prohibited grazing, light grazing, moderate grazing, and heavy grazing. The results showed that grazing activities significantly altered the diversity of bacterial communities, particularly under light and heavy grazing. The spatial dissimilarity in soil bacterial communities was mainly driven by species turnover (i.e., species replacement), which was more pronounced under heavy grazing. The number of keystone species increased with the grazing intensity of the bacterial co-occurrence network. Under heavy grazing, bacterial communities showed the highest number of keystone species and the community stability. Environmental factors such as exchangeable magnesium (EM), soil available kalium (SAK), and soil pH were the most important environmental variables impacting changes in bacterial community structure by influencing community α-diversity and stability. This study enhances our understanding of the response mechanisms of soil microbial communities to grazing intensities and other environmental stresses in grassland ecosystems. In addition, this study also provides important references and guidance for microbial diversity research in extreme environments. These findings are crucial for promoting the sustainable management and conservation of grassland ecosystems in climatically harsh areas such as the Qinghai-Tibet Plateau.

Assessing the Impact of Sustainable Pasture Systems on Lamb Meat Quality

The global demand for sustainable lamb production is increasing due to the need for high-quality meat with minimal environmental impact, making the choice of feeding systems crucial. This study investigates the effects of supplemented pasture feeding during the last 60 days of rearing on the meat fatty acid profile, pH value, colour characteristics, and mineral composition of lambs, highlighting the benefits of such feeding systems. Ninety lambs (MIS sheep breed) were divided into three distinct feeding regimes: Group I (alfalfa and concentrate feeding), Group II (white clover [Trifolium repens] pasture with concentrate supplementation), and Group III (birds’ foot trefoil [Lotus corniculatus] pasture with concentrate supplementation). The results have shown that supplemented pasture feeding improves the fatty acid profile by increasing n-3 content and desirable fatty acids, while reducing the n-6/n-3 ratio and atherogenic index (p &lt; 0.05), particularly in lambs finished on an L. corniculatus diet. However, forage-supplemented feeding also reduces meat colour lightness and redness (p &lt; 0.05). On the other hand, it enhances the meat’s mineral profile, with higher calcium, selenium, and iron levels, especially in lambs fed L. corniculatus. These findings underscore the benefits of moderate grazing with supplemental concentrates in optimising lamb meat quality. Importantly, they also highlight the potential of forage legumes like T. repens and L. corniculatus to significantly enhance the nutritional profile of lamb meat, offering a promising outlook for the future of sustainable lamb production. Additionally, this research provides valuable insights that could guide the development of future agricultural practices, dietary guidelines, and environmental policies to advance sustainable and nutritious food systems.

Effects of grazing disturbances on soil seed bank diversity in two vegetation types

Soil seed bank (SSB) play an essential role in the restoration and regeneration of plant communities. Grazing is a common disturbance factor that exerts an important effect on the diversity and composition of the SSB community in forests. Here, we evaluated the structure and composition of SSB along a grazing disturbance gradient of two types of vegetation (broad-leaved forests and mixed coniferous broad-leaved forests) in southwest China. A comparison of the similarity of SSBs with the above-ground vegetation strata (tree, shrub and herb layers) was also analyzed. The experiment revealed the germination of 25 species that belonged to 14 families and 24 genera. The density of SSBs did not show significant differences along the grazing disturbance. The alpha diversity of SSBs was the highest at moderate grazing intensity in broad-leaved forests, and not significantly different along disturbance intensities in mixed coniferous broad-leaved forests. No significant changes were observed in the species composition of SSB along the grazing gradients. Nonmetric multidimensional scaling analyses revealed low similarities between SSBs and above-ground vegetation, with the lowest similarity occurring under medium grazing disturbance intensity. Overall, our research offers significant insight into the response of SSBs to grazing in different vegetation types. It serves as a guide for designing grazing management strategies tailored to natural forests.

Quantification of the provenance contribution and sedimentary mixing effect of sediments in the Yellow River Basin, China

Quantifying the source contributions of sediments in large fluvial systems with active wind erosion problems has crucial implications for understanding morphological evolution and ecological progression in the Earth system. Much effort have been focused on characterizing sediments of the Yellow River, but quantitation of the sediment source proportions at the basin-wide scale is lacking. To this end, the research aims to quantitatively elucidate the potential source contributions of sediments in the Yellow River based on geochemical characteristics and sediment fingerprinting technique, in order to identify sedimentary mixing effect and propose sustainable development strategies. In total, samples of four source groups (n = 107) and target floodplain sediments (n = 61) were collected and tested for elemental composition, grain size, magnetic susceptibility, and quartz grain microtextures. The results indicated that the optimal tracer combination was determined as P, Zn, and Ca. The average contributions of the “Tibetan Plateau”, “Sandy deserts-Loess Plateau”, “Loess Plateau”, and “Loess Plateau-Qinling Mountains” source groups to the target sediments were 23.0 %, 21.5 %, 31.6 %, and 23.9 %, respectively. The accuracy of source apportionments was supported by the goodness of fit (GOF) and virtual mixtures tests. Meanwhile, large amounts of debris from surrounding mountains was transported to the Loess Plateau through fluvial processes and ultimately mixed with aeolian deposits, leading to sedimentary mixing effect. To maintain water balance and minimize erosion risk, the drought-resistant perennial planting and moderate grazing were recommended. The findings are instrumental in promoting soil and water conservation and disclosing fluvial and aeolian interaction on a global scale.

Transcriptome and anatomical analysis of Stipa breviflora in response to different grazing intensities in desert steppe.

Stipa breviflora is a dominant species in the desert steppe of Northern China. Grazing is the main land use pattern of grassland, which could cause a variety of adaptive evolutionary mechanisms in plant community composition as well as individual plant growth and morphological characteristics. However, very little is known about the morphological structure and transcriptional regulation response to different grazing intensities in S. breviflora. In this study, transcriptome and anatomical analyses of S. breviflora under different grazing intensities, including no grazing, moderate grazing, and heavy grazing, were performed. The anatomical analysis results showed that epidermis cells and xylems significantly thicken with grazing intensity, suggesting that grazing results in increasing lignification. Furthermore, the components of cell walls such as lignin, cellulose, hemicellulose, and pectin were all increased dramatically and significantly under both moderate and heavy grazing. Transcriptome analysis showed that the differentially expressed genes related to different grazing intensities were also engaged in plant cell wall formation and in photosynthesis and respiration. In addition, the activities of ATP synthase and Rubisco-activating enzyme increased significantly with enhanced grazing intensity and differed significantly between moderate and heavy grazing intensities. The trends in transcriptome and plant phenotype changes are consistent. Taken together, these results indicated that S. breviflora has evolved a grazing tolerance strategy under long-term grazing conditions, influencing photosynthesis and respiration in terms of its own structure and enzyme activities in the body, to maintain normal life activities under different grazing conditions.