Search Results (632)

While methane emissions from cattle contribute to greenhouse gases, supplementing with red seaweed Asparagopsis taxiformis (AT) demonstrates an up to 90% methane reduction in controlled feeding studies. However, methods for delivery of AT in grazing systems remain unexplored. This study evaluated AT with mineral supplementation to 112 weaned steers grazing on annual rangeland over 157 days. Cattle were randomly assigned to access mineral with freeze-dried AT (targeting 150 mg bromoform/head/day) or mineral without AT. Methane emissions were measured using laser methane detection (LMD) and body weight, mineral consumption, and blood selenium levels were monitored. Average daily mineral consumption was lower than targeted, resulting in suboptimal bromoform intake (89.2 mg/head/day). No significant differences were observed between treatments for mineral consumption, weight gain, or blood selenium levels. Cattle with access to mineral with AT had lower peak emissions than control cattle when measured at day 25, but no differences in peak emissions were measured at day 115 or day 157. The lack of methane reduction was attributed to insufficient bromoform dosing, potential compound degradationduring field storage, and limitations of laser methane detection. Achieving consistent dosing and accurate methane assessment in extensive grazing systems requires improved delivery mechanisms, compound stabilization, and measurement techniques. Full article

The severe degradation of alpine grasslands on the Qinghai–Tibet Plateau poses a significant threat to regional ecological security. While insects are critical for ecosystem functions, their responses to restoration measures in these fragile habitats are poorly documented. This study assessed the initial impacts of four restoration approaches—grazing exclusion fencing (FE), no-till reseeding (FR), planting grass (GC), and grazing control (CK)—on insect trophic guilds (herbivores, predators, saprophagous, and omnivores) in the Qilian Mountains. Using a multi-dimensional indicator (alpha, zeta, and dark diversity), we systematically assessed community assembly and recovery potential. The results revealed the following: (1) FE supported the highest insect abundance, dominated by phytophagous insects. FR significantly enhanced species’ richness and diversity across multiple functional groups (p < 0.05). GC significantly increased the richness of omnivorous insects, but caused a significant decrease in the Shannon–Wiener index for saprophagous insects (p < 0.05). (2) Zeta diversity revealed stable, widespread-species-dominated communities under FR and FE, while CK and GC favored rare-species-driven succession. Dark diversity analysis indicated high recovery potential for phytophagous insects under FR and FE, while GC enhanced saprophagous latent diversity. However, we emphasize that mechanistic interpretations require further validation. Our findings highlight no-till reseeding as a promising initial strategy, though longer-term studies are essential to evaluate successional trajectories and establish definitive management protocols for alpine grassland restoration. Full article

In Eritrea, efforts are being made to tackle the widespread land degradation and promote natural resources and the agricultural sector. However, these efforts lack digital resources assessment, mapping, planning and monitoring. Thus, we developed soil organic carbon (SOC) predictor models for the Western Lowlands of the country, employing 6 machine learning models with different input variables (36, 27, 15, and 08) obtained following these variables selection strategies: (1) all proposed SOC predictor variables; (2) very high multicollinearity (≥0.900 **) reduction; (3) high multicollinearity (≥0.700 **) reduction; (4) the Boruta feature selection algorithm. The results revealed that SOC levels were generally low (mean = 0.43%). Grazing lands, rainfed croplands, and irrigated farmlands all exhibited similarly low SOC values, attributed to unsustainable land management practices that deplete soil nutrients. In contrast, natural forestlands exhibited significantly higher SOC concentrations, highlighting their potential for soil carbon sequestration. Among the tested models, the XGBoost algorithm using 27 covariates achieved the highest predictive performance (RMSE = 0.118, R² = 0.758, RPD = 2.252), whereas the multiple linear regression (MLR) model with 8 variables yielded the lowest performance (RMSE = 0.141, R² = 0.742, RPD = 1.883). Compared to the Boruta-based feature selection, the MLR, PLS, XGBoost, Cubist, and GB models showed performance improvements of 10.41%, 10.06%, 6.72%, 6.50%, and 3.15%, respectively. Rainfall emerged as the most influential predictor of SOC spatial variability in the study area. Other important predictors included temperature, soil taxonomy, SWIR2 and NIR bands from Landsat 8 imagery, as well as sand and clay contents. We conclude that reducing very high multicollinearity is essential for improving model performance across all tested algorithms, while reducing moderate multicollinearity is not consistently necessary. The developed SOC prediction models demonstrate robust predictive capabilities and can serve as effective tools for supporting soil fertility management, land restoration planning, and climate change mitigation strategies in the Western Lowlands of Eritrea. Full article

Accurate estimation of aboveground biomass (AGB) is essential for monitoring forage availability and guiding sustainable management in high-altitude pastures, where grazing sustains livelihoods but also drives ecological degradation. Although remote sensing has advanced biomass modeling in rangelands, applications in Andean–Amazonian ecosystems remain limited, particularly using UAV-based structural and spectral data. This study evaluated the potential of UAV LiDAR and multispectral imagery to estimate fresh and dry AGB in ryegrass (Lolium multiflorum Lam.) pastures of Amazonas, Peru. Field data were collected from subplots within 13 plots across two sites (Atuen and Molinopampa) and modeled using Random Forest (RF), Support Vector Machines, and Elastic Net. AGB maps were generated at 0.2 m and 1 m resolutions. Results revealed clear site- and month-specific contrasts, with Atuen yielding higher AGB than Molinopampa, linked to differences in climate, topography, and grazing intensity. RF achieved the best accuracy, with chlorophyll-sensitive indices dominating fresh biomass estimation, while LiDAR-derived height metrics contributed more to dry biomass prediction. Predicted maps captured grazing-induced heterogeneity at fine scales, while aggregated products retained broader gradients. Overall, this study shows the feasibility of UAV-based multi-sensor integration for biomass monitoring and supports adaptive grazing strategies for sustainable management in Andean–Amazonian ecosystems. Full article

Marine diatoms are an important group of phytoplankton that can shape marine ecosystems and global carbon cycling. When stressed, either physiologically or by grazing, diatoms release oxidized, lipid-derived signals known as oxylipins. Diatom-derived oxylipins are proposed to serve as defense and signaling chemicals that affect multiple components of marine ecosystems. Therefore, to elucidate the diversity of diatom-derived oxylipins produced during stress, we profiled the spectrum of dissolved lipids of five diatom species in culture under silicon limitation and across growth phases using ultra-high performance liquid chromatography coupled with high-resolution accurate mass spectrometry. In this study, we present evidence that physiological changes associated with Si-limitation elicit the extracellular release of linear oxygenated fatty acids (LOFAs) across five diatom species. For diatoms like Skeletonema japonicum and Pseudo-nitzschia multiseries, silicon limitation induced a distinct lipidomic signature driven by oxylipins known to be allelopathic. While their lipoxygenases were found to be different, S. japonicum and P. multiseries had the most similar dissolved lipidomes, suggesting alternative controls on oxylipin biosynthesis. Consequently, elevated oxylipin concentrations with silicon stress, estimated up to 5.91 µM, pose implications for diatoms at sea, potentially affecting ecosystems and biogeochemistry. Full article

Accurately quantifying grazing intensity (GI) is crucial for assessing grassland utilization and supporting sustainable management. Traditional livestock-based approaches cannot capture the spatial heterogeneity of grazing or its dynamic response to climate variability. The objective of this study was to develop a remote sensing-based quantitative framework for estimating GI across the Inner Mongolian grasslands. The framework integrates MODIS vegetation indices, ERA5-Land climate variables, topographic factors, and field-measured data and GI was quantified as the proportional difference between potential and satellite-derived aboveground biomass (AGB), providing a spatially explicit measure of forage utilization. In this framework, potential AGB (AGBp) represents the climate-driven growth capacity under ungrazed conditions reconstructed using machine learning models, whereas satellite-derived AGB (AGBs) denotes the standing AGB remaining under current grazing pressure. Validation using 324 paired grazed–ungrazed plots demonstrated strong agreement between modeled and observed GI (R² = 0.65, RMSE = 0.18). This AGB-difference-based approach provides an effective and scalable tool for large-scale rangeland monitoring, offering quantitative insights into grass–livestock balance, ecological restoration, and adaptive management in arid and semi-arid regions. Full article

Grassland ecosystems in arid regions are critical for ecological balance and human livelihoods but face threats from degradation and climate change. Weideverbot (grazing prohibition) is widely adopted for restoration, yet its impact on fire risk in extreme arid environments remains unclear. This study investigates how grazing prohibition affects fire risk in Turpan, China—a hyper-arid region with 16 mm annual precipitation—by analyzing vegetation dynamics (2000–2023) and fire records. To quantify changes in fuel properties and fire risk, we integrated remote sensing data (MODIS-derived Net Primary Productivity [NPP], Fractional Vegetation Cover [FVC], and Normalized Difference Moisture Index [NDMI]) and field observations, complemented by meteorological data (temperature, precipitation, potential evapotranspiration) and local fire records. We used paired-sample t-tests to compare vegetation metrics before (2000–2010) and after (2011–2023) Weideverbot, with Cohen’s d to assess effect sizes. The results show that Weideverbot significantly increases net primary productivity (NPP: 92 to 109 g C·m⁻²·yr⁻¹, Cohen’s d > 0.8) and fractional vegetation cover (FVC: 18% to 22%, Cohen’s d > 0.8), enhancing fuel load and connectivity. Vegetation water content shows no significant change (Cohen’s d < 0.2). Post-prohibition, fire frequency increased ~8-fold, driven by elevated fuel availability and regional warming/aridification. These findings indicate that Weideverbot exacerbates fire risk in hyper-arid grasslands by altering fuel dynamics. Balancing restoration and fire management requires adaptive strategies like moderate grazing, tailored to local aridity and vegetation traits. Full article

We adapt previous conceptual and numerical models of ciguateric food chains for the bioaccumulation of Pacific-ciguatoxin-1 (P-CTX-1) to a general model for bioaccumulation of P-CTX3C by parrotfish (Scarus frenatus, S. niger, and S. psittacus) that feed by scraping turf algae, and surgeonfish (Naso unicornis) that mostly feed on macroalgae. We also include the Indian Ocean parrotfish Chlorurus sordidus as a model for an excavator feeding parrotfish and include comparisons with the detritivorous surgeonfish Ctenochaetus striatus that brush-feeds on turf algae. Our food chain model suggests that, of the Gambierdiscus and Fukuyoa species so far analysed for ciguatoxin (CTX) production from the Pacific, only G. polynesiensis produces sufficient P-CTX3C to consistently produce parrotfish or N. unicornis with poisonous flesh. Our model suggests that insufficient CTX would accumulate into the flesh of parrotfish or N. unicornis to become poisonous from ingesting benthic dinoflagellates producing ≤0.03 pg P-CTX3C eq./cell, except from extended feeding times on high-density blooms and in the absence of significant depuration of CTX. Apart from G. polynesiensis, only G. belizeanus and possibly G. silvae and G. australes are thought to produce >0.03 pg P-CTX3C eq./cell in the Pacific. However, with relatively low maximum concentrations of ≤0.1 pg P-CTX3C eq./cell it is likely that their contribution is minimal. Our model also suggests that the differences between the area of turf algae grazed by parrotfish and similar sized C. striatus results in greater accumulation of CTX by this surgeonfish. This makes C. striatus a higher ciguatera risk than similar sized parrotfish, either directly for human consumption or as prey for higher trophic level fishes, consistent with poisoning data from Polynesia. It also suggests the possibility that C. striatus could bioaccumulate sufficient CTX to become mildly poisonous from feeding on lower toxicity Gambierdiscus or Fukuyoa species known to produce ≥0.02 P-CTX3C eq./cell. This indicates the potential for at least two food chain pathways to produce ciguateric herbivorous fishes, depending on the CTX concentrations produced by resident Gambierdiscus or Fukuyoa on a reef and the grazing capacity of herbivorous fish. However, only G. polynesiensis appears to produce sufficient P-CTX3C to consistently accumulate in food chains to produce higher trophic level fishes that cause ciguatera in the Pacific. We incorporate CTX depuration into our model to explore scenarios where mildly poisonous parrotfish or N. unicornis ingest CTX at a rate that is balanced by depuration to estimate the Gambierdiscus/Fukuyoa densities and CTX concentrations required for these fish to remain poisonous on a reef. Full article

Donkey milk is highly regarded for its nutritional, immunological and hypoallergenic properties. In this context, the global demand is increasing, and the challenges of low production and milk hygiene need to be addressed. This study evaluated the effects of dietary and phytogenic supplementation on milk yield, nutrient digestibility, and milk quality in lactating jennies (Equus asinus). All donkeys had unrestricted access to natural pasture during the study. In addition to grazing, animals were divided into three groups (n = 10 per group) that differed only in the type of supplemental feed. The control group (CG) received pasture grass with a corn-based supplement; Group 1 (G1) received the same basal feed enriched with sunflower meal and a phytogenic blend of medicinal plants; and Group 2 (G2) received the same compound feed as G1 but without the phytogenic additives. Over an eight-week period, milk production, apparent digestibility coefficients (dry matter, protein, fibre, and ether extract), and microbiological quality were assessed. G1 demonstrated the highest milk yield (p < 0.001), improved nutrient digestibility (e.g., crude protein digestibility: 57.89 ± 4.21%), and a significant reduction in total viable counts (TVC) from 2.848 ± 0.265 to 1.898 ± 0.404 log₁₀ CFU/mL (p < 0.001), compared to CG and G2. The latter maintained relatively stable TVC values (2.930 ± 0.260 → 2.838 ± 0.196; p = 0.356641), accompanied by reduced interindividual variability, whereas CG exhibited a slight increase (2.922 ± 0.253 → 2.949 ± 0.323; p = 0.792259) and greater variability, suggesting a negative trend. Crude protein digestibility was 55.86 ± 6.66% in G2 and 45.26 ± 9.85% in CG, further supporting the superior nutrient utilization efficiency observed in G1. The phytogenic supplement stabilized milk chemical composition, suggesting potential galactagogues, immunomodulatory, and antimicrobial effects. These findings support the use of functional feed additives as a promising strategy to enhance productive performance and milk hygiene in sustainable donkey farming systems. Full article

Rotational grazing and cover crops are conservation practices known to improve soil health, particularly soil organic carbon (SOC) and aggregate stability. Combining both practices may enhance these benefits more than either alone. With grazing lands covering 41% of U.S. agricultural land, adopting such methods could significantly impact the soil carbon cycle. A study near Koshkonong, Missouri, examined the effects of regenerative organic grazing with Bubalus bubalis (Linnaeus) on SOC, carbon sequestration, aggregate stability, and soil resistance. The 1620-hectare ranch tested four treatments: rotational grazing with cover crops (RGCC), grazing on native grasses (RGNCC), cover crops without grazing (NGCC), and orchards without cover crops or grazing (NGNCC). Cover crops were seeded twice yearly with diverse species. After three years, SOC increased most in NGNCC (28%), followed by RGCC (13%), NGCC (7%), and RGNCC (4%). Annual carbon gains in surface soils were highest in NGNCC (0.99 Mg ha⁻¹ yr⁻¹). Across all depths, NGCC led (4.88 Mg ha⁻¹ yr⁻¹). Aggregate stability was greatest in non-grazed systems, particularly in fine aggregates, and declined with soil disturbance. Overall, low-disturbance systems like orchards and no-grazing cover crop plots enhanced soil structure and carbon storage. Strategic management is key to improving soil function and ecosystem resilience. Full article

Concerns about potential negative impacts of human activity on macrofungal diversity are spreading globally, yet research on this topic remains scarce. This study focuses on forest grazing (silvopasture), a popular economic practice whose impacts on macrofungal diversity are underexplored. Through investigation and comparison of macrofungal diversity and selected environmental factors in three types of subtropical forests (secondary mixed forests, dense-tree plantations and sparse-tree plantations) before and after two years of grazing at an intensity of 10 goats per hectare in South China, three key findings emerged: (1) Macrofungal alpha-diversity increased significantly after grazing, associated with an increase in large plant remains and a decrease in litterfall thickness; (2) dominance was monopolized by few taxa before grazing but became more balanced among a number of taxa after grazing; and (3) dominance of endemic taxa decreased in two of the three types of forests after grazing. Such findings suggest that grazing may create additional niches through foraging, trampling and excretion by livestock and thus recruit diverse macrofungi but may also lead to homogenization of fungal florae across regions and thus result in recessive beta-diversity loss. As this study heavily relies on taxonomy, allied updates for ambiguous taxa recognized in analyses are additionally proposed. Full article

Agricultural land management is a major determinant of terrestrial carbon (C) fluxes and has substantial implications for greenhouse gas (GHG) mitigation strategies. This study evaluated the net ecosystem carbon balance (NECB) of an agricultural field in an organic integrated crop–livestock system (ICLS) with a ley-arable rotation in northern Germany over two years (2021–2023). Carbon dioxide (CO₂) fluxes were measured using the eddy covariance (EC) method to derive net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (RECO). This approach facilitated an assessment of the temporal dynamics of CO₂ exchange, alongside detailed monitoring of field-based C imports, exports, and management activities, of a crop sequence including grass-clover (GC) ley, spring wheat (SW), and a cover crop (CC). The GC ley acted as a consistent C sink (NECB: −1386 kg C ha⁻¹), driven by prolonged photosynthetic activity and moderate biomass removal. In contrast, the SW, despite high GPP, became a net source of C (NECB: 120 kg C ha⁻¹) due to substantial export via harvest. The CC contributed to C uptake during the winter period. However, cumulatively, it acted as a net CO₂ source, likely due to drought conditions following soil cultivation and CC sowing. Soil cultivation events contributed to short-term CO₂ pulses, with their magnitude modulated by soil water content (SWC) and soil temperature (TS). Overall, the site functioned as a net C sink, with an average NECB of −702 kg C ha⁻¹ yr⁻¹. This underscores the climate mitigation potential of management practices such as GC ley systems under moderate grazing, spring soil cultivation, and the application of organic fertilizers. To optimize CC benefits, their use should be combined with reduced soil disturbance during sowing or establishment as an understory. Additionally, C exports via harvests could be offset by retaining greater amounts of harvest residues onsite. Full article

Manure is a valuable organic resource for sustainable agriculture, enhancing soil fertility and promoting nutrient cycling; however, it also contributes significantly to methane and nitrous oxide emissions. The European Green Deal and Latvia’s National Energy and Climate Plan have set targets for reducing agricultural greenhouse gas (GHG) emissions, including those related to improved manure management. Therefore, this research aims to estimate the future manure production in Latvia to determine the potential for reducing GHG emissions by 2050. Using the LASAM model developed in Latvia, the number of farm animals, the amount of manure, and the associated GHG emissions were projected for the period up to 2050. The calculations followed the Intergovernmental Panel on Climate Change (IPCC) methodology and were based on national indicators and current national GHG inventory data covering the period of 2021–2050. Significant changes in the structure of manure in Latvia are predicted by 2050, with the proportion of liquid manure expected to increase while the amounts of solid manure and manure deposited by grazing animals are expected to decrease. The GHG emission projection results indicate that by 2050, total emissions from manure management will decrease by approximately 5%, primarily due to a decline in the number of farm animals and, consequently, a reduction in the amount of manure. In contrast, methane emissions are expected to increase by approximately 5% due to production intensification. The research results emphasise the need to introduce more effective methane emission reduction technologies and improved projection approaches. Full article

Epichloë endophytes are mutualistic associates with grasses, conferring host plants with enhanced competitiveness, improved stress tolerance, and increased ecological dominance. Epichloë can produce any of several classes of bioactive alkaloids, of which indole-diterpenes and ergot alkaloids are toxic to invertebrate and mammalian herbivores; peramine acts as an insect-feeding deterrent; and loline alkaloids possess potent insecticidal activity. Here, it was characterized as Epichloë endophytes inhibiting the Elymus species, El. cylindricus, and El. tangutorum from the Qinghai–Tibet Plateau, China. Based on the results of four types of alkaloid synthesis genes, the 30 isolates were divided into five types; they exhibited distinct alkaloid synthesis capabilities, highlighting intraspecific diversity within E. bromicola regarding its alkaloid-producing potential. Considering the toxicity of these isolates to the safety of herbivorous livestock, the above five types of isolates can be divided into two categories. Category I includes five animal-safe strains of type V, which do not produce alkaloids. Category II includes the remaining 25 strains, which could produce indole-diterpene (paspaline) and/or ergot alkaloids (chanoclavine I, D-lysergic acid, ergovaline) that are toxic to herbivorous livestock. Morphology and phylogenetic analysis confirmed all 30 isolates were Epichloë bromicola; mating type gene detection shows that all belonged to mating type A. Overall, this study has laid a solid foundation for the scientific and rational utilization of Epichloë endophyte resources. Furthermore, the presence of ergovaline in El. cylindricus and El. tangutorum poses a potential concern for livestock managers who conduct grazing. Full article

The Niokolo-Koba National Park (NKNP) was inscribed on the World Heritage List in 1981 for its exceptional biodiversity and unique ecosystem. However, due to poaching, livestock grazing, and dam construction projects in the Sambangalou area, the site was added to the List of World Heritage in Danger in 2007. Through regional and international cooperation, enhanced monitoring, and community engagement in conservation efforts, the site was removed from the List of World Heritage in Danger in 2024. As a typical case of the entire process from inscription on to removal from the World Heritage List in Danger, the NKNP’s threats and successful removal experience profoundly reveal complex internal and external challenges and governance needs in heritage conservation. Its successful experience can provide valuable lessons for World Heritage sites around the world facing similar threats. As part of our qualitative research, we reviewed the literature from UNESCO and IUCN, which annually assessed the state of conservation of the NKNP between 2007 and 2024. In 2024, a field mission assessed on-site conservation progress and discussed challenges and responses to the NKNP management with 30 stakeholders. Our results highlight the lengthy and potentially costly process of removal, such as Senegal’s EUR 4.57 million Emergency Plan, the threats to the park’s integrity by the State itself, and the value placed on World Heritage status, further emphasizing the need for long-term investment from both the national government and international partners. Therefore, ensuring returns on such investment, whether through increased ecotourism, international recognition, or strengthened ecosystem services, is essential for sustainable conservation financing. The case of the NKNP also illustrates the positive impact of improved national governance and partnerships involving international and local NGOs, as well as the private sector, on conservation efforts. It also highlights the importance of a new collaborative governance paradigm for heritage sites facing severe human interference (poaching, illegal development) and governance challenges, particularly in ecologically fragile or socio-economically pressured regions, by strengthening national responsibility, leveraging international mechanisms, and activating local participation. Full article