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Lake Van is T & uuml;rkiye's largest lake, and within it lies Akdamar, a small seven-hectare island. In 2008, eight feral European rabbits were introduced to the island to attract tourists. With no natural predators, their population had increased to 3,000 by 2016, causing severe ecological damage, destroying almond trees, accelerating soil erosion, and damaging historical buildings through burrowing. In response, local authorities launched a management programme from 2016 to 2017, removing 1,500 rabbits through physical control methods such as live trapping, net trapping, and night spotlighting. However, funding shortages halted further efforts, and the population surged to an estimated 4,000-5,000 by 2023. The rabbits now occupy the entire island, degrading vegetation, diminishing ecosystem services, and threatening tourism. According to the assessment conducted in this study, the situation is classified as causing major ecological impacts under the Environmental Impact Classification for Alien Taxa and minor cultural effects under the Socio-Economic Impact Classification of Alien Taxa. Therefore, urgent, long-term management solutions are essential to prevent further degradation, with public awareness campaigns, community involvement, and education can help reduce human-mediated spread and promote responsible behaviour. Coupled with sustainable, effective management strategies, these efforts are vital to preserving the island's ecosystem and cultural heritage.

期刊论文 2025-04-03 DOI: 10.1080/09397140.2025.2491145 ISSN: 0939-7140

With growing recognition of the ecological importance of grasslands, efforts to prevent their degradation, enhance the soil quality, and maintain ecological balance have become central to temperate grassland management. However, many temperate grasslands experience varying intensities and modes of grazing. Effective grazing management is crucial to avoid damage and promote the sustainable development of temperate grasslands. This study adopts a variety of research methods. Firstly, through the collection and sorting of data, it is clear that the research content mainly focuses on more than 70 response variables. Secondly, the comprehensive effects of different grazing intensity, grazing mode, and grazing history on these response variables were studied, and then detailed studies were conducted to analyze the effects of different grazing intensity and grazing mode under different temperate grassland types on these response variables. According to the analysis of the comprehensive effects and effects of different temperate grassland types, significant heterogeneity was found in 13 response variables (H, R, E, Height, Coverage, Density, TB, PB-PF, SWC, TK, OK, and N(20-60 cm)). Finally, in order to study the source of heterogeneity of these 13 response variables, subgroup analysis was carried out to analyze whether it was caused by environmental factors (MAP, MAT, MAP xMAT), and then publication bias test and Egger's test were carried out to prove the reliability of the research results. The results showed that the heterogeneity of 12 response variables (R, H, E, height, coverage, density, TB, PB, PF, SWC, OK and N (20-60 cm)) was attributed to environmental factors. However, due to insufficient data after subgroup analysis, the heterogeneity of TK cannot be determined.

期刊论文 2025-04-01 DOI: 10.1016/j.agee.2024.109452 ISSN: 0167-8809

Improving the quality of irrigated pastures can increase the profitability of ruminant production systems. Increasing pasture plant biodiversity is beneficial for ruminants, pollinators, and soil health, but it is challenging to manage weed incursion in seeded mixed-species pastures. This study assessed the weed incursion that resulted when forage legumes or grasses were seeded as binary mixtures with one of four non-legume forbs. Defoliation occurred at 6-week intervals as either mowing or mob grazing. Forbs were chicory, plantain, Lewis flax, or small burnet and forages were alfalfa, birdsfoot trefoil, creeping foxtail, intermediate wheatgrass, kura clover, meadow bromegrass, orchardgrass, perennial ryegrass, reed canarygrass, sainfoin, smooth bromegrass, tall fescue, and white clover. Four defoliations per year occurred between May and September for two years. Eight replications were grouped into four blocks and each pair in a block was randomly assigned to the two defoliation treatments, mob grazing or mowing. Plots were 1.5 m2 and were assessed visually before each defoliation for the percentage of forage, forb, and weed. Chicory was the most dominant of the four forbs, and relative to legumes, most grasses suppressed both forb establishment and weed incursion under both grazing and mowing. There were no statistically significant effects of defoliation treatment on weed incursion.

期刊论文 2025-01-01 DOI: 10.3390/agronomy15010025

Daurian Pika ( Ochotona dauurica) are steppe-dwelling burrowing mammals with the potential to have large effects on central Asian grasslands due to their extensive range, propensity to occur at extremely high density, and roles as ecosystem engineers and important prey species. The few studies that have been done are mostly from northern China and Russia, while little research has been done in the majority of their range in Mongolia. We studied a population of Daurian Pika in the Darhad Valley of northern Mongolia, near the southern edge of the permafrost, where climate change is progressing rapidly. We evaluated pika populations at 87 random plots across a large 40 x 125 km area and assessed the impact of factors related to vegetation cover, grazing, and soils that predicted their occupancy and an index of their density (number of active burrows). We found that pikas were more likely to occur in areas with taller grass and higher forb cover, and burrow densities were higher in areas with low or moderate grazing and lower soil moisture. In summer, pikas mainly foraged on grass compared with forbs-while in fall, forbs appeared to be selected for in haypiles. Dense pika burrow systems had taller grasses and forbs in their immediate vicinity, suggesting that in some cases, pika could help promote plant growth for other grazers. Long-tailed Ground Squirrel (Urocitellus undulatus) was the second most abundant small mammal in our study sight and selected for areas with high cover of overgrazing indicator species and for short forbs, providing little evidence for competition with Daurian Pika. Our results suggest that shorter grass (similar to 1 cm) can decrease pika occupancy by 75%, while heavy grazing may decrease burrow density by 66% in dry soils. With grazing pressure in Mongolia increasing dramatically since the 1990s, future research is strongly needed to assess the impacts of grazing on this keystone species.

期刊论文 2024-11-15 DOI: 10.1093/jmammal/gyae132 ISSN: 0022-2372

Biocrusts play an essential role in maintaining ecosystem stability, which is common in arid and semi-arid areas. Although there have been some previous studies on the stoichiometry of biocrust subsoil in grazing systems, further research is needed to assess the effects of varying grazing intensities. Four grazing gradients were established to investigate the change mechanism of biocrust subsoil stoichiometry under grazing conditions, considering its seasonal response. These findings revealed that biocrusts' coverage and their chlorophyll content showed a parabolic trend of increasing and then decreasing with the increase in grazing intensity. At the same time, their standard response thresholds to grazing intensity ranged from 2.67 to 5.33 sheep/ha. Moreover, the premise that the biocrust is damaged by grazing trampling has become a consensus; our study found that the biocrust still played an important role, although its structure was destroyed because of its greenness (BG) increased. The influence of grazing intensity on the biocrust subsoil stoichiometry is unquestionable; in addition, they are influenced by a combination of vegetation (10% and 19%) and environmental influences (6% and 18%). Furthermore, it was observed that these changes did not compensate for the reproduction and development of biocrusts in grazing-induced trampling damage. In this study, the integrated consideration of biocrusts into the grazing system fully affirmed its essential role. Additionally, it clarified the pathways and effect of grazing on biocrusts subsoil stoichiometry, providing a new perspective and reference for developing grazing strategy on the Loess Plateau.

期刊论文 2024-11-01 DOI: 10.1002/ldr.5280 ISSN: 1085-3278

Termite mounds are keystone structures in African savannas, affecting multiple ecosystem processes. Despite the large size of termite mounds having the potential to modify conditions around them, patterns of mound-induced ecosystem effects have been assumed to be isotropic, with little attention given to how effects might vary around mounds. We measured soil nitrogen content, grass species composition, and mammalian grazing on and off termite mounds in the four cardinal directions, and across wet and dry seasons at three savanna sites varying in mean annual rainfall in South Africa's Kruger National Park. Evidence of directional effects (anisotropy) on ecosystem properties around termite mounds varied with site. Grass species composition differed between north- and south-facing slopes at the two drier sites where mounds were taller. However, differences in grazing extent and soil nitrogen content around mounds were only present at the intermediate rainfall site where mammalian herbivore biomass was highest, and mounds were of medium height. Our results suggest that termite mound effects display significant variation with direction, but that the emergence of directional effects is context dependent. Our results further suggest that such context-dependent directional effects can lead to positive feedback loops between termites, abiotic conditions, and mammalian herbivores.

期刊论文 2024-09-01 DOI: 10.1002/ecs2.4978 ISSN: 2150-8925

Ecological stoichiometry serves as a valuable tool for comprehending biogeochemical cycles within grassland ecosystems. The impact of grazing time on the concentration and stoichiometric characteristics of carbon (C), nitrogen (N), and phosphorus (P) in desert steppe ecosystems remains ambiguous. This research was carried out in a desert grassland utilizing a completely randomized experimental design. Four distinct grazing time treatments were implemented: fenced grassland (FG, control), delay to start and early to end grazing grassland (DEG), delay to start grazing grassland (DG), and traditional grazing grassland (TG). The patterns of C, N, and P concentrations and their stoichiometry in various components of the ecosystem, as well as their driving factors under different grazing times were examined. The results showed that grazing time positively influenced C and N concentrations in leaves, while negatively affecting N concentrations in roots. TG had a significant positive effect on soil P concentrations but a negative effect on soil C:P and N:P ratios. Plant C:N, C:P, and N: P ratios were mainly influenced by N and P. The soil C:N ratio was primarily influenced by soil N, the soil C:P ratio was affected by both soil C and P, and the soil N:P ratio was influenced by both soil N and P. The growth of plants in desert steppes is mainly limited by P; however, as grazing time increased, P limitation gradually decreased and the N cycling rate increased. C -N, C -P, and N -P in various plant organs and soils demonstrated significant anisotropic growth relationships at different grazing times. Soil organic carbon, pH, and soil total phosphorus were the main driving factors that affected changes in ecological C:N:P stoichiometry. These results will help improve grassland management and anticipate the response of grassland systems to external disturbances with greater accuracy.

期刊论文 2024-09-01 DOI: 10.1016/j.scitotenv.2024.173664 ISSN: 0048-9697

As an important ecosystem, the wild fruit forest in the Tianshan Mountains is one of the origins of many fruit trees in the world. The wild fruit forest in Emin County, Xinjiang, China, was taken as the research area, the spatial and temporal distribution of the wild fruit forest was inverted using random forest and PLUS models, and the 2027 distribution pattern of the wild fruit forest was simulated and predicted. From 2007 to 2013, damage to the wild fruit forest from tourism and overgrazing was very serious, and the area occupied by the wild fruit forest decreased rapidly from 9.59 km2 to 7.66 km2. From 2013 to 2020, suitable temperatures and reasonable tourism management provided strong conditions for the rejuvenation of wild fruit forests. The distance of the center of gravity of the wild fruit forest increased, and the density of distribution of the wild fruit forest in the northwest direction of the study area also increased. It is predicted that the wild fruit forest in the study area will show a steady and slowly increasing trend in places far away from tourist areas and with more complex terrain. It is suggested that non-permanent fences be set up as buffer zones between wild fruit forests, ensuring basic maintenance of wild fruit forests, limiting human disturbance such as overgrazing, and reducing the risk of soil erosion.

期刊论文 2024-07-01 DOI: 10.3390/su16145925

Grasshopper disasters threaten grassland animal husbandry, and overgrazing is widely recognized as one of the main causes of locust infestation in grassland regions. However, the impact of overgrazing on grasshopper disasters remains unclear. To address this knowledge gap, this study interviewed 541 households living in locust-prone areas in Inner Mongolia, China. The generalized Poisson model and OLS regression examined the relationship between herders' production behavior and locust disasters. The results showed that 42% of the herders had suffered from locusts more than three times over the past 15 years, with an average of 49 ha of grassland damaged per household. In addition, with the increase in grazing rates, the scale of locust disasters decreased before it increased. The results also showed that operating grassland areas and feeding forage reduced locust disasters significantly, while renting grassland areas and grazing rates worked oppositely. These results suggest that grazing intensity can make a significant difference in the occurrence of locust disasters.

期刊论文 2024-04-01 DOI: 10.3390/agronomy14040820

Soil compaction is a regarded as a major environmental and economical hazard, degrading soils across the world. Changes in soil properties due to compaction are known to lead to decrease in biomass and increase in greenhouse gas emissions, nutrient leaching and soil erosion. Quantifying adverse impacts of soil compaction and developing strategies for amelioration relies on an understanding of soil compaction extent and temporal variability. The main indicators of soil compaction (i.e., reduction of pore space, increase in bulk density and decrease in soil transport properties) are relatively easy to quantify in laboratory conditions but such traditional point-based methods offer little information on soil compaction extent at the field scale. Recently, geophysical methods have been proposed to provide non-invasive information about soil compaction. In this work, we developed an agrogeophysical modelling framework to help address the challenges of characterizing soil compaction across grazing paddocks using electromagnetic induction (EMI) data. By integrative modelling of grazing, soil compaction, soil processes and EMI resistivity anomalies, we demonstrate how spatial patterns of EMI observations can be linked to management leading to soil compaction and concurrent modifications of soil functions. The model was tested in a dairy farm in the midlands of Ireland that has been grazed for decades and shows clear signatures of grazing-induced compaction. EMI data were collected in the summer of 2021 and autumn of 2022 under dry and wet soil moisture conditions, respectively. For both years, we observed decreases of apparent electrical resistivity at locations that with visible signatures of compaction such as decreased vegetation and water ponding (e.g., near the water troughs and gates). A machine learning algorithm was used to cluster EMI data with three unique cluster signatures assumed to be representative of heavy, moderately, and non-compacted field zones. We conducted 1D process-based simulations corresponding to non-compacted and compacted soils. The modelled EMI signatures agree qualitatively and quantitatively with the measured EMI data, linking decreased electrical resistivities to zones that were visibly compacted. By providing a theoretical framework based on mechanistic modelling of soil management and compaction, our work may provide a strategy for utilizing EMI data for detection of soil degradation due to compaction.

期刊论文 2024-04-01 DOI: 10.1111/sum.13039 ISSN: 0266-0032
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