Effects Of Grazing Research Articles

The effects of grazing and the meteorologic factors on wind-sand flux in the desert steppe

The effects of grazing and the meteorologic factors on wind-sand flux in the desert steppe

Effects of Grazing and Leaf Spot Disease on the Structure and Diversity of Phyllosphere Microbiome Communities in Leymus chinensis.

Leymus chinensis is a high-quality forage with wide distribution. Disease is an important factor affecting the yield and quality of L. chinensis. To investigate the effect of grazing on the phyllosphere microbiome community and leaf spot disease in L. chinensis, high-throughput sequencing technology was used to study the differences in the composition and structure of the phyllosphere fungal and bacterial communities of healthy and diseased leaves under different grazing intensities. The results showed that grazing significantly reduced leaf spot disease incidence and severity. There were significant differences in the phyllosphere microbiome composition between healthy and diseased leaves, and interestingly, diseased leaves showed more complex microbial activity. Grazing altered the relative abundance of micro-organisms and affected microbial dispersal and colonization either directly through behavior or indirectly by altering plant community structure. In this study, we found that the phyllosphere microbiome responded strongly to pathogen infection, and that plants recruited beneficial microbes to protect themselves after disease development. Grazing could regulate microbial community composition and structure, either directly or indirectly, and plays a crucial role in maintaining the health of L. chinensis.

Sheep rotational grazing strategy to improve soil organic carbon and reduce carbon dioxide emission from spring wheat in an arid region

Context Cultivating forage crops is crucial to improve feed production, and grazing is an important utilisation method to improve soil fertility. Aim Improving soil organic carbon (SOC) content and reducing carbon dioxide (CO2) emission through grazing management from a spring wheat field. Methods We compared sheep rotational grazing and control, and studied their effects on SOC and CO2 emission from a spring wheat field. Key results Sheep rotational grazing improved SOC content (by 23.5%) and soil easily oxidised organic carbon (EOC) content (by 7.7%) and reduces soil microbial biomass carbon (MBC) content (by 35.8%) compared with the control. Sheep rotational grazing reduced CO2 emission compared with the control. Sheep grazing reduced cumulative CO2 emission by 28.9% and 33.0% in May and June compared with the control. Conclusions Sheep grazing improved SOC content and reduce CO2 emission from a spring wheat field. Implications Based on our short-term study, sheep rotational grazing has a significant effect on SOC, EOC and MBC contents and CO2 emission from spring wheat fields in arid regions. For a large-scale assessment of sheep grazing on soil fertility and CO2 emission, more investigation for different soils and climates is necessary. Furthermore, a long-term study is also necessary to better understand the effect of sheep rotational grazing on soil fertility and CO2 emission from spring wheat fields in arid regions.

Beyond biomass: Resource effects on primary production and consumer nutrient assimilation in streams

Abstract Primary production in aquatic ecosystems is strongly controlled by resource availability (bottom‐up). At the same time, grazers exert top‐down pressure on algae. The effects of both resources and grazers on algal communities have been investigated extensively for both benthic and planktonic systems. However, most studies focus exclusively on net effects on algal standing stock, while the underlying ecological functions and processes often remain unknown. Here, we tested the effects of the two resources, light (L) and the limiting nutrient phosphorus (P), on both primary production (net oxygen production) by benthic algae (periphyton) and matter assimilation by the next trophic guild (particularly nitrogen assimilation by grazers). For this, we grew natural periphyton communities in stream mesocosm flumes together with two native grazer taxa and 15N as a tracer. Both resources resulted in an initial increase in net primary production, but this effect equalised after 36 days in the more mature communities. While both resources still showed strong positive effects on algal biovolume, the biovolume‐specific net primary production decreased with resource level and was lowest in the double elevated (+L, +P) treatment. The response of nitrogen assimilation by grazers was more closely related to the response of periphyton quality (stoichiometric and taxonomic composition) than to its biomass. In addition, light affected the nitrogen assimilation of both grazers negatively. These findings demonstrate that the responses of ecological functions, here primary production and assimilation by grazers, are not necessarily proportional to algal biomass and are thus not easily predictable from the common use of biomass as a proxy for functions.

Effects of livestock grazing on rangeland condition, plant species richness and wild ungulate population in a semi‐arid savannah

AbstractThis field study in a semi‐arid savannah at Senkelle Swayne's Hartebeest Sanctuary, Ethiopia, examined livestock grazing effects on rangeland condition, plant species composition and richness, and population of the endangered Swayne's hartebeest (Alcelaphus buselaphus swaynei). Rangeland condition was analysed using a common protocol for the assessment of semi‐arid rangelands. A total count method was used to estimate ungulate numbers. Grazing reduced all measures of range condition and productivity and affected the composition and richness of the herbaceous species. Grazing also induced an increase in the density and number of encroaching woody species Vachellia seyal and Senegalia senegal. The population of the Swayne's hartebeest significantly affected by livestock grazing (mean number of hartebeests observed under moderately and lightly grazed sites were 10.00 ± 2.49 and 6.75 ± 2.06, respectively). No individual hartebeest was observed roaming in the heavily grazed zone, which implies an effective reduction in the extent of habitat available for the hartebeest. The overall condition of the rangeland was poor. Measures to reduce livestock presence in areas from which the hartebeest has been displaced and controlled seasonal livestock grazing within non‐sensitive parts of the Sanctuary may benefit the hartebeest. Coupled with these, livestock exclusions for up to a year and interseeding may help improve rangeland condition and hartebeest's habitat.

Effects of livestock grazing on herbaceous species composition and biomass in the Simien Mountains National Park, Ethiopia

Abstract Simien Mountains National Park (SMNP) provides valuable ecosystem services. Despite its ecological values, the effect of livestock-free grazing on habitat quality has not been investigated. The present study aimed to examine how livestock grazing within the Simien Mountains National Park affects herbaceous plant diversity and biomass. The study was carried out from February 2019 to July 2019 in livestock-grazed and ungrazed sites. In each grazing site, ten transects with a length of 25 m were set monthly. Along each transect line, five temporary sample plots (1 m2) were established. For aboveground biomass estimation, grass and forbs were clipped from 0.25 m2 in every sample plot, whereas below-ground biomass was estimated from two soil core (diameter = 6.35 cm, depth =20 cm) samples in each transect. Species diversity and evenness were estimated using the Shannon-Wiener diversity and evenness index. A total of 43 plant species belonging to 20 families were identified. Aboveground biomass and below-ground biomass were significantly higher in ungrazed areas than in the grazed ones. Similarly, species diversity and richness were relatively lower in the grazed areas than in ungrazed areas. The study concluded that livestock grazing has affected the habitat by degrading the vegetation diversity and biomass production. Therefore, stakeholders should be encouraged to innovate appropriate grazing management technologies for the local livestock ranchers to support the conservation efforts of the park.

Grazing effects on vegetation: Biodiversity, management, and restoration

AbstractIn many regions, wild large herbivores have maintained open landscapes up to and including historic times, but, more recently, have been largely replaced by domestic livestock. By employing extensive and traditional grazing and browsing regimes, conservation actions support biodiversity and recovery in natural and degraded areas. However, grazing also plays other important ecological roles, for example, in the maintenance and/or recovery of important ecosystem services, such as biomass production and carbon sequestration. Understanding herbivore effects on plant composition and functional diversity, and ecosystem functioning and services, is essential for informing ecological theory and practice. The current Special Issue highlights that the effects of grazing on vegetation are strongly context‐dependent. The articles identify at least three major factors acting in concert, which are responsible for contrasting diversity and functional patterns of vegetation subjected to herbivores: (i) herbivore identity; (ii) grazing intensity; and (iii) vegetation type. Insights from this Special Issue imply that long‐term experiments across different habitat types and in underrepresented regions are needed to provide valuable information for grazing planning and management. They also demonstrate that integrating indigenous and traditional ecological knowledge, and considering socio‐economic contexts, can provide opportunities for improving sustainable grazing management.

Cover crop grazing effects on soil properties in no-tillage dryland cropping systems in the central Great Plains

Integrating ruminant livestock such as beef cattle (Bos taurus L.) to graze cover crops (CCs) could balance goals of short-term profitability and long-term environmental sustainability when CCs are grown in water-limited environments like the central Great Plains (CGP), USA. However, little information currently exists about the effects of CC grazing on soil properties in no-tillage (NT) dryland cropping systems, especially after multiple cycles of grazing. This study was conducted from 2018 to 2021 to evaluate the effects of beef cattle grazing CCs on residue return, soil bulk density (BD) and penetration resistance (PR), water stable aggregates (WSA) and wind-erodible fraction (WEF), as well as soil pH and nutrient concentrations on three producer fields in central and western Kansas. Across sites, CC biomass left as residue post-grazing was similar to pre-grazing and was 60 % of the ungrazed CCs (3704 kg ha−1) because of CC regrowth after the 30–40 day grazing period. Soil BD, PR, WSA, WEF, pH, particulate organic carbon, nitrate-nitrogen, and phosphorus concentration were not different between grazed and ungrazed CCs. However, soil organic carbon (SOC) stocks and potassium concentrations were greater with grazed CCs compared to ungrazed CCs possibly due to substantial CC residue retention following grazing coupled with manure and urine deposition. Regression and correlation analyses showed that increased SOC was associated with decreased soil BD and increased WSA, which suggests decreased soil erosion potential as well as possible improvements in water infiltration and underscores the importance of SOC for overall soil health in this water-limited environment. Based on these results, we conclude that grazing of CCs is a viable management option for producers to intensify NT dryland cropping systems to improve soil health and maintain or increase overall system profitability in the CGP. Longer (>3 years) grazing studies are needed, and results are likely to vary based on grazing animal stocking rate, categories, duration of grazing, and available CC biomass for grazing.

Grazing affects ecosystem traits by regulating plateau pika activities at the landscape scale

The mechanism underlying the effects of livestock grazing on grassland ecosystem traits has been greatly discussed. However, as a common small burrowing mammal on the Tibetan Plateau grasslands, the plateau pika's (Ochotona curzoniae) influence on alpine grassland ecosystem traits has rarely been investigated, especially beyond the plot scale. In this study, we flew an unmanned aerial vehicle (UAV) over a grassland landscape under grazing and nongrazing treatments. Mounted visible spectral remote sensing, in combination with field surveys, was utilized to explore how livestock and pika grazing modify grassland ecosystem traits at the landscape scale on the Tibetan Plateau (TP). Using object-oriented classification and partial least squares regression, we retrieved the pika burrow distribution and grassland ecosystem traits. Then, the relationships among livestock grazing, pika burrowing and ecosystem traits were evaluated. The results indicated that livestock grazing reduces the alpine meadow community height by 0.13 cm and the species number by 0.25 while increasing the vegetation coverage by 9.69 % and the aboveground biomass (AGB) by 10.07 g/m2. A lower statue grassland community with greater coverage caused by livestock grazing promotes pika burrowing. Pika burrow density increases 100/ha per 1.70 % increase in vegetation coverage, a 1.87 g/m2 increase in AGB or a 0.08 m decrease in community height. Under livestock grazing, both community structure and nutrients are more strongly associated with pika burrow density. The structural equation model demonstrated that livestock grazing regulates pika burrow density by moderating structural value and subsequently affecting nutritional value. Pika burrowing activity explains 40 % of the total variation in nutritional value. Our findings revealed an intrinsic linkage between mammal activities and alpine grassland ecosystems, which can provide guidelines for grassland management through pika population control by adjusting grazing intensity on the TP.

Effect of irrigation and grazing on the production of an alfalfa pasture (Medicago sativa L.)

La alfalfa es una especie forrajera muy utilizada en Uruguay en ganadería intensiva y lechería. El riego suplementario permite mitigar los efectos negativos del cambio climático, aumentando y estabilizando la productividad de las pasturas. Es necesario evaluar su efecto conjunto con el pastoreo. Se evaluaron dos umbrales de riego, con entrada de animales. Los tratamientos fueron: riego frecuente (30% agotamiento), riego espaciado (65% agotamiento) y secano. El diseño experimental fue de bloques completos al azar, 30 meses de evaluación. La productividad promedio anual de la alfalfa regada fue de 25333 y 23177 kg MS ha-1, primer y segundo año de evaluación, respectivamente. La producción acumulada (30 meses) no mostró diferencia significativa entre los tratamientos regados, pero sí entre regados y secano. En el último verano-otoño, la productividad de todos los tratamientos cae a 8660 kg MS ha-1 (regados) y 1756 kg MS ha-1 (secano). Las productividades estacionales indican la conveniencia de regar la alfalfa en verano, ya que el rendimiento aumentó 43% en el segundo año y 4,3 veces más en el último año. Además, luego de transcurrir la sequía extrema del verano, en el otoño siguiente los regados rindieron 7 veces más que el secano. El manejo con riegos espaciados y láminas de riego que no devuelven el suelo a su capacidad de campo aumenta la efectividad de las precipitaciones, ahorrando agua y energía destinada al riego. La densidad aparente aumentó hacia el final del experimento a consecuencia del pastoreo, sin embargo, no hubo diferencia entre los manejos de riego evaluados.

Defense against Paramecium predation via long filament morphology favors the survival of Raphidiopsis raciborskii populations

Raphidiopsis blooms are notorious for cyanotoxin formation and strong invasiveness, threatening the stability of aquatic ecosystems and human health. The protozoa Paramecium can potentially serve as an organism for controlling Raphidiopsis blooms owing to its grazing effect. However, the grazing ability of Paramecium is largely determined by the size of the prey, and the population of Raphidiopsis consists of filaments of varying lengths and sizes. The selective grazing behavior of Paramecium toward short-length or small-sized filaments in the Raphidiopsis population, as opposed to long filaments, remains unclear. Therefore, in this study, we co-cultured the predator Paramecium sp. with different initial abundances and the prey Raphidiopsis raciborskii to explore this knowledge gap. Our results suggested that: (1) the population of R. raciborskii declined under the selective grazing effect of Paramecium sp. on short filaments, whereas R. raciborskii with long filaments survived; (2) the growth of Paramecium sp. feeding on the same abundance of R. raciborskii was reduced at higher initial abundances, whereas its carrying capacity exhibited an opposite trend; (3) under ingestion by Paramecium sp., the morphology of R. raciborskii developed in the direction of becoming larger, and higher initial abundances of Paramecium sp. intensified this process; (4) increasing initial abundance of Paramecium sp. aggravated the decline of R. raciborskii photosynthetic activity. Therefore, the grazing effect of Paramecium sp. on R. raciborskii mainly affects filaments of short length or small size. Collectively, these results clarify the inter-species interaction between the protozoa Paramecium and filamentous cyanobacteria Raphidiopsis, including population dynamics and morphological and physiological changes in the predator and prey. Such insights into the interactions between Paramecium and R. raciborskii may have implications for the biological control of blooms caused by filamentous cyanobacteria.

Time budgets differ in horses during continuous and space-restricted rotational grazing

Horses can become obese and develop related health issues such as laminitis from excessive grazing on high-quality pasture grass; limiting pasture intake can allow weight loss to occur. The objective of this study was to determine the effect of space-restricted rotational grazing on body weight (BW) and time budgets in horses. Eight mature geldings and mares with maintenance-only requirements were randomly assigned to either a space-restricted rotational grazing group (SRG; BW 512 ± 6 kg; n = 4) or a continuous grazing group (CG; BW 517 ± 49 kg; n = 4) for 42 d SRG horses grazed an area with dimensions to provide 80–90 % of mean digestible energy requirement for the 4 horses over a 7-d grazing period; whereas, the CG horses continuously grazed similar non-toxic endophyte-infected tall fescue pasture providing greater than maintenance requirements for the 42 d Horses in the SRG group were moved to a new area every 7 d for 6 weeks. On d 7 at 1600 h of each week, horses were brought inside, and feed was withheld overnight. At 0700 h the next day, BWs were recorded prior to turnout. Observers recorded behaviors simultaneously on SRG and CG horses every six minutes throughout the day three days per week according to an ethogram. This included 30 s scans of all horses. Proportion of grazing and standing had an inverse relationship. Proportion of grazing was affected by the treatment by time interaction, which grazing was displayed more in SRG than CG during weeks 2 and 3, and then reversed weeks 4, 5 and 6.

Grazing herbivores reduce herbaceous biomass and fire activity across African savannas

AbstractFire and herbivory interact to alter ecosystems and carbon cycling. In savannas, herbivores can reduce fire activity by removing grass biomass, but the size of these effects and what regulates them remain uncertain. To examine grazing effects on fuels and fire regimes across African savannas, we combined data from herbivore exclosure experiments with remotely sensed data on fire activity and herbivore density. We show that, broadly across African savannas, grazing herbivores substantially reduce both herbaceous biomass and fire activity. The size of these effects was strongly associated with grazing herbivore densities, and surprisingly, was mostly consistent across different environments. A one‐zebra increase in herbivore biomass density (~100 kg/km2 of metabolic biomass) resulted in a ~53 kg/ha reduction in standing herbaceous biomass and a ~0.43 percentage point reduction in burned area. Our results indicate that fire models can be improved by incorporating grazing effects on grass biomass.

Effects of cattle grazing on young spruce trees in boreal production forest

The compatibility of forest livestock grazing with timber production is disputed, as livestock can damage young trees through browsing and trampling. At the same time, livestock grazing might reduce the growth of competing vegetation and thereby enhance conifer forest regeneration. We investigated the effects of cattle (Bos taurus) on young spruce (Picea abies) trees in boreal production forest. We compared data from young spruce plantations within and outside of the grazing area, and during and off the cattle grazing season. Overall, stocking rates were 0.01 cows per hectare across the grazing areas. Cattle did not distribute equally, but concentrated their area use to young spruce plantations, leading to locally high densities during periods of the grazing season. Cattle removed vegetation competing with young spruce trees: Within the grazing area, the sward height of the field layer vegetation was lower, and young willow (Salix spec.) and downy birch (Betula pubescens) trees were browsed more than outside the grazing area. The annual height growth of spruce increased once the spruce grew above sward height. Spruce trees surrounded by many competing trees grew slower than those surrounded by few trees. Bent spruce trees grew slower than undamaged spruce trees. Yet, no difference in annual spruce growth was found between inside and outside the cattle grazing area. In contrast, we found a higher spruce mortality risk inside than outside the cattle grazing area. This mortality risk was very low and positively correlated with a given spruce tree's bark being damaged. Cattle did not increase the risk of damaged stem bark. This study did not succeed in pointing out the mechanism by which cattle might increase spruce mortality risk. Interestingly, the probability of being browsed and the probability of being bent were higher after winter than after summer, indicating that wild ungulates and snow might have a stronger effect on young spruce trees than summer grazing cattle at these stocking rates. In conclusion, cattle had minor effects on young spruce trees. This study suggests that at low stocking rates, forestry and livestock production in boreal production systems are compatible.

Restorative pyric herbivory practices in shrub-encroached grasslands enhance nutrient resource availability and spatial heterogeneity

Pyric herbivory (PH), the combination of prescribed burnings and targeted herbivory, is a promising tool for landscape restoration that emulates historical disturbance regimes. Nitrogen (N) and phosphorus (P) are crucial nutrients for plant growth and although several studies have analysed the single effects of fire or grazers in their availability, the combined effect of both disturbances in the soil nutrient budgets have been rarely considered. This research was planned to analyse the 2-year impact of PH restoration practices on the availability of N and P in two Ulex gallii-encroached grasslands in the Pyrenees. We monitored available forms of N and P for two years using periodic replacements of ion exchange resins to test the hypothesis that mid-term effect of targeted grazing was more relevant than short-term effect of burning. Additionally, we investigated the role of temperature and precipitation on nutrients accumulation and compared its significance to management factors. Burning transformed vegetation and litter into a spatially heterogeneous layer of ash and charred material, which resulted in a variable availability of N and P at the rhizosphere level. After two periods of PH, nutrient availability was higher in soils from grazed plots compared to ungrazed, and the impacts of early burns were scarcely discernible. Nitrate was found to be the most rainfall-dependent nutrient, and grazing also affected its spatial distribution. Our results suggest that the heterogeneous nutrient enrichment enhanced by PH is important for promoting the establishment of a diverse pool of plant species, including both N2-fixing and non-fixing species. In these rainy areas, the use of burnings alone, without grazing, may perpetuate the dynamics of N2-fixing shrub encroachment.

Effects of Sheep Grazing and Nitrogen Addition on Dicotyledonous Seedling Abundance and Diversity in Alpine Meadows

Seedling is a crucial stage in the growth and development of plants, and the expansion and persistence of plant populations can be achieved through seed regeneration. Sheep grazing, fertilization, light, soil moisture, vegetation diversity and biomass, and litter all have potential impacts on species regeneration. We measured vegetation diversity, annual net primary productivity (ANPP), litter, ground photosynthetically active radiation (PAR), and soil moisture of alpine meadows under sheep grazing and nitrogen addition treatments, and studied their effects on the dicotyledonous seedling abundance and diversity using linear regression models (LMs) and structural equation models (SEMs). We found that sheep grazing reduced ANPP, increased vegetation diversity and PAR, and decreased soil moisture. Fertilization increased ANPP and litter, decreased vegetation diversity and PAR, but had no effect on soil moisture. Sheep grazing and fertilization both reduced the abundance of dicotyledonous seedlings, and simultaneously fertilization can reduce the diversity of dicotyledonous seedlings, while sheep grazing had no effect on the diversity of dicotyledonous seedlings. LMs showed that vegetation diversity, ANPP, and litter, rather than light and soil moisture, affected dicotyledonous seedling abundance and diversity. SEMs revealed that sheep grazing and fertilization indirectly influenced seedling regeneration through vegetation diversity rather than ANPP and litter. Our research will increase our understanding of the dicotyledonous plant regeneration process in alpine grasslands and facilitate the development of strategies for management and protection of alpine grassland.

Seasonal Grazing Does Not Significantly Alter the Particle Structure and Pore Characteristics of Grassland Soil

Seasonal grazing is a recognized and sustainable approach to livestock management, but there is still a lack of comprehensive research on its impact on soil structure. This study utilizes advanced scanning electron microscopy technology to quantitatively evaluate the long-term effects of seasonal grazing on grassland soil structure, focusing on soil pore distribution characteristics and particle size. The investigation offers a detailed visual representation of the arrangement of soil particles at a micro-level. In both grazed and ungrazed plots (NG), soil particles ranging from 0.005 to 0.05 mm and 0.075 to 0.25 mm in size were predominant, constituting 20% and 60%, respectively. In plots subjected to seasonal grazing (grazing in June and August, G68, and grazing in July and September, G79), micro-particles (0.002–0.005 mm) and particles sized 0.05–0.075 mm were significantly lower compared to NG. Scanning electron microscope (SEM) images demonstrate structural differences, with NG displaying a higher proportion of small to medium-sized particles, more small pores, and fewer large pores. Analysis of pore size and morphology reveals the prevalence of large pores in both grazed and ungrazed plots. Continuous grazing plots exhibit significantly higher proportions of large pores compared to NG, while seasonal grazing plots show no significant differences. Correlation analyses indicate associations between soil physicochemical properties, particle size, and pore structure. Total soil nitrogen (TN), total soil carbon (TC), and soil moisture positively correlate with 0.005–0.05 mm particle proportions, while EC is negatively correlated with 0.05–0.075 mm particles. This study enhances our understanding of the effects of grazing practices on soil structure and provides scientific evidence for sustainable land management.

Temporal niche partitioning among sympatric wild and domestic ungulates between warm and cold seasons

The coexistence of sympatric species with similar ecological niches has been a central issue in ecology. Clarifying the daily activity patterns of sympatric wild ungulates can help understand their temporal niche differentiation and the mechanisms of coexistence, providing information for their conservation. The Baotianman National Nature Reserve in northern China is rich in wild ungulates, but little is known about the daily activity patterns of wild ungulates in the area, making it difficult to develop effective conservation strategies. We studied five representative wild ungulates (i.e. forest musk deer, Chinese goral, Reeve’s muntjac, Siberian roe deer, and wild boar) of the region using camera-trapping data, focusing on the seasonal daily activity patterns and effects of seasonal grazing of domestic sheep, to reveal their coexistence based on temporal ecological niche differentiation. Comparative analyses of the seasonal daily activity showed that forest musk deer exhibited a single-peak activity in the warm season. Other ungulates exhibited multipeak activity. All five ungulates differed significantly in daily activity patterns. Notably, wild boar and Reeve’s muntjac showed high overlap coefficients between the cold and warm seasons. In both cold and warm seasons, the five wild ungulates and domestic sheep displayed low overlap in their daily activity rhythms potentially indicating temporal ecological niche differentiation. The results suggest that temporal isolation might be a strategy for wild ungulates to avoid domestic sheep and reduce interspecific competition, and that temporal ecological niche differentiation potentially promoted the coexistence among the studied sympatric ungulates. This understanding may provide new insights for the development of targeted conservation strategies.

A First Look at the Relationship Between Large Herbivore-Induced Landscape Modifications and Ixodes ricinus Tick Abundance in Rewilding Sites.

Background: While the influence of landscape and microclimatic conditions on tick populations is well-documented, there remains a gap in more specific data regarding their relationship to rewilding efforts with large herbivore activity. Objective: This pilot study, spanning from 2019 to 2021, explores the effects of naturalistic grazing by large semi-wild ungulates on tick abundance in the Milovice Reserve, Czechia. Methods: Tick collection was observed using flagging techniques at two distinct sites of rewilding area: one grazed, actively utilized by animals involved in the rewilding project, and one ungrazed, left fallow in neighboring areas utilized only by wild animals. Transects, each measuring 150 m in length and 5 m in width (750 m2), were established at these two sampling locations from March to September between 2019 and 2021. To minimize potential bias resulting from tick movement, a 300 m buffer zone separated the two sites. Data analysis employed a generalized estimating equations (GEE) model with negative binomial regression. The study assessed potential variations in tick abundance between selected transects, considering factors such as plant cover seasonality, temperature, and humidity. Results: During the collection periods, we gathered 586 live ticks, with 20% found in grazed areas and 80% in ungrazed areas. Notably, tick abundance was significantly higher in ungrazed areas. Peaks in tick abundance occurred in both grazed and ungrazed areas during spring, particularly in April. However, tick numbers declined more rapidly in grazed areas. Microclimatic variables like temperature and humidity did not significantly impact tick abundance compared to landscape management and seasonal factors. Conclusion: Rewilding efforts, particularly natural grazing by large ungulates, influence tick abundance and distribution. This study provides empirical data on tick ecology in rewilded areas, highlighting the importance of landscape management and environmental factors in tick management and conservation. Trophic rewilding plays a crucial role in shaping ecosystems and tick population dynamics in transformed landscapes.

Effects of macroalgae and sea urchin grazing pressure on zoantharians growth under laboratory conditions

In the context of ocean warming, thermophilic organisms such as zoantharians are expanding and altering shallow benthic habitats. Here, a four-month laboratory experiment was performed to examine the influence of three types of macroalgae morphotypes common in the Canary Islands (turf algae, Lobophora spp., and crustose coralline algae) on the growth of two zoantharian species, Palythoa caribaeorum and Zoanthus pulchellus. Additionally, the grazing effects of echinoids Diadema africanum and Paracentrotus lividus were assessed as facilitators of substrate colonization by means of controlling macroalgae cover. Colony and algal coverages were measured at the beginning, middle and end of the experiment, and increments were calculated. Results indicated a general decrease in zoantharian colony sizes in contact with different algal types in the absence of sea urchins. However, P. caribaeorum colonies showed significant growth in the presence of D. africanum, highlighting the ecological importance of sea urchins in zoantharian population proliferation and subsequent community modification. This study represents the first investigation into zoantharian-macroalgae interactions under controlled conditions.