Moderate Disturbance Research Articles

Winter Grazing, Not Fencing or Unicast, Promotes Stability of Microbial Community and Function in the Qilian Mountains of Qinghai‐Xizang Plateau

ABSTRACTIn alpine meadows, microorganisms are essential to sustain the stability of terrestrial geochemical processes and vegetation–soil–microbial systems. The present study in order investigate how various management measures impact the microbial communities' composition and functionality, we utilize metagenomic sequencing techniques to examinate the composition and function of soil microbial communities in the southern Qilian Mountains of the Qinghai‐Xizang Plateau in response to the management practices of fencing enclose (FE), winter grazing (WG), transition zone between natural and artificial grasslands (TZ), and artificial unicast oats (AU). Vegetation diversity and soil physicochemical characteristics were dramatically altered by the management measures. The prokaryotic community structure was considerably similar in FE and WG, as well as in TZ and AU. Near‐natural (FE) and artificial establishment (AU) disturbances changed the fungal community structure. Enzymes related to carbon metabolism did not respond significantly to the management measures, whereas those related to nitrogen metabolism did not respond significantly in TZ and AU. The relative abundance of enzymes participating in nitrogen metabolism was higher under TZ and AU than under FE and WG. We concluded that grassland management measures altered the structure of aboveground graminoid and leguminous vegetation communities and belowground biomass allocation, resulting in changes in K uptake, causing striking changes in the structure of fungal communities and nitrogen‐metabolizing enzymes; moderate disturbance (WG) was beneficial for maintaining the stability of microbial communities in alpine grasslands.

Multiple-Integrated Biomarker Indexes to Assess the Responses of the Flatfish Achirus lineatus during Exposure to Light Crude Oil Water Accommodated Fraction.

In the present study, we evaluated the biological response of Achirus lineatus to water accommodated fraction (WAF) of light crude oil (American Petroleum Institute gravity 35°) during a sub-chronic bioassay (14 and 28 days) at two different concentrations: 5% v/v (1.20µg∙L- 1 expressed as total polycyclic aromatic hydrocarbons [∑25 PAH]) and 10% v/v (6.61µg∙L- 1 [∑25 PAH]). The responses were evaluated through the biomarker response index (BRI), the integrated biomarker response (IBRv2) and the bioconcentration factor (BCF). The results showed an increase in biological response in relation to WAF concentration and exposure time, which resulted in a slight and moderate disturbance in the basal condition and bioconcentration level of metals (Pb > Ni > V > Cd) in fish tissue. Results in the present study denote that flatfish such as A. lineatus may be negatively influenced by spilled light crude oil.

Ecological Restoration Increases the Diversity of Understory Vegetation in Secondary Forests: An Evidence from 90 Years of Forest Closures

Ecological restoration and biodiversity are currently hot issues of global environmental concern. However, knowledge about the specific impacts of restoration duration on understory vegetation diversity remains limited. Therefore, this study comprehensive employed a spatial approach to compare the differences in understory plant diversity and species composition among secondary forests with varying ecological restoration ages (0, 10, 30, 60, and 90-year-old stands) in Huangfu Mountain National Forest Park. This methodology allowed us to clarify the key factors affecting the composition of the understory plant community and investigate the regulatory mechanisms influencing changes in understory plant diversity. The results showed that shrub Shannon’s index value, shrub evenness, herb Shannon’s index value, herb richness, and herb evenness were significantly affected by the years of restoration, with 10 years and 90 years being the highest and 60 years being the lowest. Substrate diversity was the main factor influencing plant diversity in the shrub layer. Overstory richness, soil C/N, soil C, soil N, soil bacterial Observed OTUs, soil bacterial Chao1, soil bacterial Pielou_e, and substrate diversity were the drivers of plant diversity in the herb layer. Overstory evenness had a direct effect (0.256) and an indirect effect (0.284) on herb evenness through light availability and fungal Simpson’s index value. Light availability directly negatively affected herb evenness (−0.360). In addition, 52.6% of the factors affecting the herb evenness index were from the arboreal layer evenness, light availability, and fungal Simpson’s index value. To sum up, moderate disturbance of the understory environment of natural secondary forests can be carried out after 10 years of restoration, which is more conducive to the increase of understory plant diversity. This comprehensive study provides a theoretical basis for formulating ecological restoration measures for secondary forests, particularly in understanding the optimal timing and nature of disturbance in the restoration process, reassuring the audience about the validity and reliability of the findings.

Elevation and Human Disturbance Interactively Influence the Patterns of Insect Diversity on the Southeastern Periphery of the Tibetan Plateau.

The maintenance of biodiversity and ecological balance heavily relies on the diversity of insects. In order to investigate the impacts of elevation and human disturbance, as well as their interactions on insect diversity, we conducted an intensive survey of insects in the Hengduan Mountain Range, which is situated on the southeastern periphery of the Tibetan Plateau in China. A total of 50 line transects were established in this study to investigate the impact of elevation and human disturbance on insect diversity and distribution patterns. Designed insect surveys were conducted at various elevations and levels of human disturbance, and statistical methods such as generalized linear modeling and redundancy analysis were employed for data analysis. The results of this study indicated a negative correlation between insect diversity and elevation. Additionally, moderate disturbance was found to have a positive impact on insect diversity to some extent. The explanatory power of the model for the distribution of insect diversity could be improved if elevation and human disturbance were included as an interaction effect into the model, and there were differences in the effects of human disturbances on insect diversity at different elevation levels. The highest insect diversity was observed under low disturbance conditions below elevation of ~2200 m, whereas above this threshold, insect diversity was the highest under moderate disturbance compared to low disturbance. The response of different insect taxa to the interactions of elevation and human disturbance varied. The findings imply that when formulating strategies for managing insect diversity, it is crucial to thoroughly consider the interaction of environmental factors and disturbance response of individual insect taxa.

Phyto-sociological changes in the Goima Forest, Gujarat due to human disturbances and their implications for conservation

Aim: The study aimed to understand the phytosociological changes by the impact of forest fringe human disturbance on the Goima forest of Valsad district in Gujarat. Methodology: The study area was classified into different tree canopy density and disturbance classes, and ecological indices were calculated for each class following the quadrate survey method. Results: A total of 772 individual plants of 141 species from 53 families were recorded during quadrate sampling, with variations in aspects being especially important predictors of biotic diversity. The study found that the maximum taxa of trees (30), herbs (24), and grasses (7) were reported in the high-disturbance class, while for shrubs (16) and climbers (10), it was in the middle-disturbance class. Dominance (D)was higher in the moderately dense forest as well as in the moderate disturbance class for trees (0.11, 0.13), shrubs (0.24, 0.21), herbs (0.13, 0.12), but for climbers, D was higher in dense forest (0.40) and in moderate disturbance class (0.22), and for grasses, it was higher in the moderately dense forest (0.69) and less disturbed class (0.58). Shannon's index (H) for trees (2.93), herbs (2.85), and grasses (1.68) was maximum in the higher disturbance class, while for shrubs (2.23) and climbers (2.10), it was highest in the low disturbance class. Interpretation: The study highlights that the phytosociology of the Goima forest changes due to human disturbances. The importance of understanding and conserving biodiversity in the Goima forest, especially given its unique flora and its critical role in supporting local communities. The research provides valuable scientific information that can aid in the better management and protection of the forest area. Key words: Canopy class, Goima forest, Human disturbance, Phytodiversity, Species distribution

Haymaking complemented by moderate disturbances can sustain and restore species-rich alpine to subalpine grasslands

AbstractThe high plant diversity in alpine to subalpine grasslands is threatened by the abandonment of land use. In addition, changing environmental conditions might lead to vegetation shifts even when traditional land use is maintained, as observed in grasslands in Switzerland during the last decades. Maintaining and restoring the diversity of such grasslands might therefore require modified management methods. We conducted a six-year experiment to assess the responses of plant species richness, mean ecological indicator values, and vegetation composition to five management treatments, including scraping as additional management measure: haymaking (in autumn), haymaking complemented by scraping (i.e. manual raking) in autumn, haymaking complemented by scraping in spring, only scraping in spring, and abandonment of land use. We hypothesized that haymaking complemented by scraping in either season would remove additional biomass and increase species richness by creating open patches that can reduce inter-specific competition and promote species establishment. We found positive effects of haymaking complemented by scraping on plant species richness and habitat quality, indicated by the increased mean indicator value for light. Abandonment showed the opposite effects and increased mean indicator values for nutrients. Interestingly, haymaking combined with scraping in autumn promoted the development of the vegetation towards the composition similar to the resident vegetation type. Our findings show that extensive land use is essential to maintain species-rich alpine to subalpine grasslands. Further, they imply that modified land use can compensate for the negative developments such as reduced habitat quality and species richness caused by environmental changes and help restore the vegetation.

Influence of nature reserve road traffic disturbance on soil carbon

PurposeRoad traffic has long been recognized as a considerable source of ecological disturbance, compromising the integrity of natural ecosystems from their pristine baseline state. Pollutant deposition from vehicular emissions significantly contributes to environmental contamination, while associated human activities exacerbate ecosystem disruptions. In designated conservation zones, including nature reserves, land-use practices such as pastoralism and agriculture are subject to regulation. Nevertheless, the influence of road traffic on ecosystem structure and processes, particularly concerning carbon (C) sequestration and its spatial heterogeneity, warrants further research. This consideration is critically relevant in the understanding the intricate C fractions and their dynamic interplay with environmental factors. Materials and methodsIn this study, we meticulously selected four distinct locations along a principal roadway within a national reserve. For each site, experimental measuring 2 m * 2 m were established at intervals of 2 m, 10 m, 20 m, 30 m, 40 m, and 50 m from the road's edge. Observational data were accrued during the peak of the vegetative growth seasons in August of both 2020 and 2021. Within each plot, soil and cut-ring samples were procured for comprehensive analysis of soil carbon fractions (Total Carbon, TC, g/kg; Carbon Density, g/m2; Readily Oxidizable Carbon, ROC, g/kg; Dissolved Organic Carbon, DOC, mg/kg; Microbial Biomass Carbon, MBC, mg/kg; Cumulative Mineralization Carbon, CMC, mg(CO2-C)*(kg*soil)−1; Soil Inorganic Carbon, SIC, g/kg), chemical properties (pH; Electrical Conductivity, EC, us/cm; Soil Organic Matter, SOM), and physical properties (Soil Water, SW, %; Bulk Density, BD, g/cm3; area conditions). Vegetation metrics, including above-ground biomass (AGB) and below-ground biomass (BGB), species composition, height, and coverage, were meticulously documented. The four sites were replicated, culminating in 24 uniformly oriented plots to mitigate wind influence. ResultsOur analysis revealed that C stock, as determined by TC and C density increased with distance from the road edge, reaching a peak at approximately 30 m (TC: 19.43 g/kg, C density: 39.26 g/m2, SOM: 27.57 g/kg), followed by a subsequent decline. At the 30 m distance, there was a 60.6 %, 41.2 %, and 38.7 % enhancement in TC, C density, and SOM, respectively, compared to the 2 m distance, and a 23.9 %, 25.9 %, and 19.8 % increase relative to the 50 m distance. Levels of DOC, MBC, and CMC exhibited an upward trend from the road edge to 50 m, suggesting more favorable microbiological conditions in less disturbed locales. SEM demonstrated that SIC is directly influenced by BGB (β = −0.31), pH (β = 0.46), and labile C components (β = 0.56), culminating in a reduction of total C storage (total effect, β = −0.28). The dynamic changes of soil C stocks were primarily explained directly by soil labile C (β = 0.475, p < 0.001), and indirectly by vegetation biomass (β = 0.460) and pH (β = −0.570), and were closely correlated with ROC (0.54, the highest eigenvalue among Labile_C). ConclusionThe findings suggest that the buffering effect of the roadside in these nature reserves up to a distance of 30 m has an signficant impact on C stock, and that C losses attributable to biochemical processes and laible soil C fractions may contribute to diminished C levels in less disturbed zones 50 m away from the road. Our findings also substantiate the moderate disturbance hypothesis, particularly in the milieu of road traffic within the Hulunbuir Nature Reserve, Mongolia. A moderate distance from roadways enhances soil C storage compared to areas near the road or undisturbed natural landscapes.

Functional diversity of avian communities in response to habitat fragmentation in human‐dominated landscapes of Tanzania miombo woodlands

AbstractBiodiversity conservation in human‐inhabited landscapes is increasingly gaining attention due to the global decline of species. Understanding the impact of human activities on avian functional ecology is becoming increasingly important as habitats are transformed. We assessed the influence of habitat fragmentation on avian functional diversity (FD), focusing on metrics like functional richness (FRic), evenness (FEve) and divergence (FDiv). We calculated the FRic, FEve and FDiv across habitats using ‘fundiversity’ R package. We also calculated the Enhanced Vegetation Index (EVI) and estimated land‐use cover of the study area from Landsat 8 images. We observed higher FD in minimally disturbed habitats, where among the habitats, woodland had high FD while human settlement had low. This supports the intermediate disturbance hypothesis, which suggests that moderate disturbance can increase species diversity. Our findings emphasise the pivotal role of fragmented habitats in shaping avian functional ecology, with environmental variables such as the EVI influencing diversity across habitats. Hence, we promote sustainable conservation connectivity, proper land management practices and conservation‐friendly agricultural practices for sustainable biodiversity conservation.

Effects of Great Gerbil Disturbance on Photosynthetic Characteristics and Nutrient Status of Haloxylon ammodendron.

Rodents, such as those that feed on plants and nest in plant roots, can significantly affect the growth and development of desert plants. The aim of this study was to investigate the effects of Rhombomys opimus disturbance on the photosynthetic characteristics and nutrient status of Haloxylon ammodendron at different growth stages in the Gurbantunggut Desert. The effects of great gerbil disturbance on the photosynthetic characteristics of H. ammodendron at different growth stages were investigated by measuring the gas exchange parameters, instantaneous water use efficiency, and chlorophyll fluorescence parameters of H. ammodendron at different ages (young, middle, and adult) under the disturbance of great gerbils. The soil nutrients in the assimilated branches and rhizosphere of H. ammodendron at different growth stages were tracked to reveal the relationship between the H. ammodendron nutrient content and gerbil disturbance. The results showed that great gerbil disturbance decreased the organic carbon content in the rhizosphere soil of adult H. ammodendron and increased the total nitrogen content in the rhizosphere soil and the nitrogen and potassium contents in the assimilated branches at each growth stage. The net photosynthetic rate and instantaneous water use efficiency of H. ammodendron decreased at each growth stage, and the maximum photochemical efficiency and non-photochemical quenching parameters of the young H. ammodendron decreased. However, the actual photochemical efficiency and photochemical parameters of the middle H. ammodendron increased. It was concluded that the disturbance of great gerbils decreased the photosynthetic capacity of H. ammodendron and increased the content of total nitrogen in the soil and nitrogen and potassium in the plant. This study revealed that the Gurbantunggut Desert great gerbil and H. ammodendron do not have a simple predation relationship. It laid a foundation for the study of the moderate disturbance threshold and better use of the mutually beneficial relationship between the two.

Multi‐level framework to assess social variation in response to ecological and social factors: modeled with coral gobies

Understanding variation in social organization that lacks a strong phylogenetic signal represents a key focus of research in behavioural ecology. Accordingly, we established a framework that identifies whether a range of ecological and social factors are affecting the social maintenance of taxa across multiple categories of social variation (ranging from large to fine‐scale): 1) forms of sociality, 2) degree of sociality, 3) social plasticity and 4) hierarchy maintenance. Each category of variation can then be assessed in combination to provide an outlook for social maintenance in light of predictor factors. We modelled this framework by quantifying each category over time, space and disturbance regime using multiple species of coral‐dwelling gobies, genus Gobiodon. Gobies are an interesting model system as they vary in social structure, have within‐group cooperation, and form mutualisms with coral hosts, which are vulnerable to climatic disturbances. We found that gobies varied in forms of sociality – from being more solitary or pair‐forming in high disturbance regimes, versus group‐forming in moderate disturbance regimes at some locations. Only low or moderate degrees of sociality were observed in gobies, with location or disturbance regime affecting some species. The size of coral hosts influenced the social plasticity of gobies, which was affected by climatic disturbances. Gobies did not exhibit direct changes to hierarchy maintenance, as location and disturbance regime did not affect their size‐based hierarchies. Lastly, by combining the four categories of variation, we found a high loss of sociality in coral‐dwelling gobies due to environmental disturbances, which likely affects overall goby survival as group‐forming can improve survival and fitness. By using our structured framework, we identified which categories of social variation were influenced by ecological factors like location and disturbance. This framework therefore provides an excellent tool for predicting future responses of animal societies to environmental stressors.

Anthropogenic disturbance produces divergent effects in the community structure and composition of tropical semi-evergreen forests in the Eastern Himalaya

Studies documenting anthropogenic disturbance-driven changes in forest communities of the Eastern Himalaya, a global biodiversity hot spot, are largely lacking. We studied six forest sites of tropical semi-evergreen forests in Arunachal Pradesh in the Eastern Himalaya to understand the effects of varying disturbance intensities on the forest community structure and composition. Based on the magnitude of disturbance, forest sites were classified as experiencing low, moderate and high disturbance. Mean species richness (SR) of trees and shrubs decreased from low disturbance to high disturbance. Mean SR of herbs was maximum in moderately disturbed forest sites. Maximum values of the Shannon-Wiener Diversity Index (SD) were recorded for trees at sites with low disturbance, for shrubs at sites with high disturbance and for herbs in moderately disturbed forests. Pilelou Evenness Index (EI) values were maximum for trees at sites with high disturbance, while maximum EI values for shrubs and herbs were recorded in the forest sites with low disturbance. The number of tree families decreased from 18 to 13 in the forests with low and high disturbance, respectively. Moderate disturbance led to increased herb species richness and diversity, while increasing disturbance produced contrasting effects on trees. High anthropogenic disturbance led to low species richness, but high diversity amongst shrubs. Our investigations suggest that the magnitude of disturbance elicits differential responses in different physiognomic classes in the forest ecosystems and further our understanding of the effects of disturbance in tropical forest ecosystems of a global biodiversity hotspot.

Disturbance and diversity: Lichen species richness decreases with increasing anthropogenic disturbance

Anthropogenic disturbance is rapidly increasing through habitat degradation, development, and deforestation. Gaps remain in understanding the effects of this disturbance on diverse and ecologically important organisms such as lichens. In North America, studies have focused on epiphytic macrolichens and catastrophic disturbance, largely ignoring microlichens and less severe disturbances. The Intermediate Disturbance Hypothesis predicts these moderate disturbances will lead to higher species richness. Here we examine the effects of anthropogenic disturbance in the form of land management on overall lichen richness, including microlichens, and on the species richness of eight lichen functional groups. The study draws on a comprehensive data set of 872 species, in 208 one-hectare plots throughout the Southern Appalachian Mountains, a global biodiversity hotspot in eastern North America. A habitat quality index based on an established forestry metric was used as a proxy for anthropogenic disturbance and was quantified using a 10-part score including categories such as percent native tree canopy cover and degree of fragmentation. Linear models were used to compare habitat quality scores to overall species richness and to species richness of functional groups. Rather than following the Intermediate Disturbance Hypothesis, all groups uniformly follow a negative linear relationship: as disturbance increases, species richness decreases. This pattern held even for widely variable functional groups such as morphotype. Effective conservation of lichen richness should prioritize the maintenance of existing older, less-disturbed stands within large, contiguously forested areas.

Effect of Forest Fires on the Alpha and Beta Diversity of Soil Bacteria in Taiga Forests: Proliferation of Rare Species as Successional Pioneers

Forest fires are among the most influential drivers of changes in forest soil bacterial diversity. Nevertheless, little is known regarding the effects of forest fires on maintaining the complex interactions that preserve forest ecosystem stability. Therefore, this study characterized alterations in soil bacterial community composition and diversity within taiga forests subjected to varying disturbance intensities. Particularly, this study examined the bacterial community within a Larix gmelinii fire-burnt site in Daxinganling, analyzing the changes in bacterial community structure and function across light, moderate, and heavy fire-burnt sites, as well as a control sample site, utilizing Illumina MiSeq technology. Through an assessment of bacterial community diversity and soil physicochemical properties (moisture content (MC), pH, microbial biomass carbon (MBC), organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), available phosphorus (AP), and available potassium (AP)), we explored the influence of the soil microenvironment on the soil bacterial community structure at the burnt site under different disturbance intensities. Our findings demonstrated that (1) there was no significant change in the Chao index of soil bacteria in the burnt site under different disturbance intensities, whereas the Shannon index decreased significantly (p &lt; 0.05) and the Simpson index increased significantly (p &lt; 0.05) in the burnt site under light and moderate disturbance. (2) The relative abundance of dominant phyla, such as Proteobacteria, Proteobacteria, and Actinobacteriota, did not change significantly in the fire-burnt site under different disturbance intensities, whereas rare species, such as Acidipila, Occallatibacter, and Acidibacter, experienced a significant increase in relative abundance at the genus level. (3) The results of principal coordinates analysis (PCoA) and canonical correlation analysis (CCA) revealed significant differences in the Beta diversity of soil bacteria in the fire-burnt site under varying interference intensities. The Beta diversity of soil bacteria exhibited significant differences (p = 0.001), with MC, pH, TN, AN, and AK identified as significant influencing factors. (4) FAPROTAX functional prediction analyses were conducted to assess the changes in soil bacteria involved in Cellulolysis, Chemoheterotrophy, and Aerobic_Chemoheterotrophy in the fire-burnt site, with the relative abundance of bacteria involved in Chemoheterotrophy being significantly increased (p &lt; 0.05) under different disturbance intensities. Collectively, our findings demonstrated that different disturbance intensities caused by fires significantly affected the Alpha diversity, Beta diversity, and functional abundance of soil bacterial communities in taiga forests, with MC, pH, TN, AN, and AK being identified as key influencing factors. Additionally, the presence of numerous rare species suggests their role as pioneer communities in the succession of soil bacterial communities.

Impacts of Spatio-Temporal Changes in Anthropogenic Disturbances on Landscape Patterns in the Nandu River Basin, China

We explored the characteristics of landscape pattern (LP) changes in the Nandu River Basin (NRB) and its dynamic response mechanism to anthropogenic disturbance (AD). This is important for ecological protection and for land use decision-making in the basin in the context of the construction of a free trade port. Land use and land cover change (LULCC) data of 1990, 2000, 2010, and 2020 were analyzed with the help of the LP index, moving window method, hemeroby index, geo-information atlas, and geographic information system (GIS) spatial analysis to reveal the dynamic changes in LP characteristics in the NRB. Furthermore, this paper discusses into the correlation between LP and AD. The results indicate that over the past three decades, the NRB showed a staggered LP, dominated by forestland and cropland, whose total area has decreased by 25.27 km2 and 62.75 km2, respectively. On the other hand, the built-up land increased by 91.37%. The overall landscape fragmentation, landscape patch homogeneity, and landscape diversity have increased in the NRB. AD is the main reason for the dramatic changes in the LP of urban agglomerations centered in Haikou city. The area of minor disturbance (over 34%) occupies the largest proportion of the land, followed by higher (about 13~25%) and moderate disturbances (about 17~22%). The area of minor and strong disturbances has increased significantly, whereas those of moderate and higher disturbances have significantly decreased. The spatial distribution pattern of AD is gradually increasing from the southwest (natural landscape) to the northeast (human landscape). A transition in areas of low disturbance levels to higher levels is obvious. The area of the atlas that has transitioned from “minor → lighter disturbance (12)” and “higher → minor disturbance (41)” changed changed most significantly during 2000 to 2010 and from 2010 to 2020, occupying 26.79% and 11.99% of the transfer atlas, respectively. All regions encountering disturbances were significantly correlated with the largest patch index (LPI) from 1990 to 2020. The overall AD in the NRB has increased, especially in Haikou. Urbanization is the main factor for an increase in AD. The ecological and environmental management and monitoring in the basin need to be strengthened.

Prevalence of Anxiety, Depression, and Sleep Disturbance Among Emergency Nurses in Oman

IntroductionAnxiety, depression, and sleep disturbances among accident and emergency nurses not only harm their well-being but also affect patient care and organizational outcomes. This study examines anxiety, depression, and sleep prevalence and associations among accident and emergency nurses. MethodsWe conducted a cross-sectional correlational survey with 331 accident and emergency nurses in 12 Omani governmental hospitals. ResultsResults showed that 28.7% of accident and emergency nurses reported symptoms indicative of anxiety, with 13.6% experiencing symptoms of depression, 16.6% reporting mild sleep disturbances, and 1.5% experiencing moderate disturbance. Those with symptoms of anxiety (r = 0.183, P = .001) or depression (r = 0.152, P = .005) were more likely to experience sleep disturbances. Being single (t [170.7] = 2.5, P = .015), childless (t [169.7] = −2.807, P = .008), Omani (t [215] = 7.201, P < .001), younger (r = −0.375, P < .001) and having less clinical experience (t [329] = 4.6, P < .001) were associated with a higher anxiety score. For depression, being of Omani nationality (t [215] = 7.201, P < .001), having less than 10 years of experience (t [329] = 3.2, P = .002), and being of younger age (r = −0.285, P < .001) were associated with a higher score. DiscussionAccident and emergency nurses commonly experience anxiety, depression, and sleep disturbances. Implementing interventions to promote their mental well-being or manage these issues is crucial. Organizational support is vital for ensuring their mental health, and individual-level interventions may also prove beneficial.

Consequences of plateau pika disturbance on plant-soil carbon and nitrogen in alpine meadows.

The presence of burrowing mammals can have extensive effects on plants and soils, creating bare soil patches in alpine meadows and potentially altering plant-soil carbon (C) and nitrogen (N). This study focuses on the plateau pika (Ochotona curzoniae) to examine the responses of plant-soil C and N to a small burrowing mammal from quadrat scale to plot scale. The density of active burrow entrances in disturbed plots was used as an indicator of the disturbance intensity of plateau pikas. The study found that the below-ground biomass (BGB) and its C and N, as well as soil C and N concentrations were significantly lower in bare soil areas than in vegetated areas and undisturbed plots. This shows that the quadrat scale limited the estimation of the C and N sequestration potential. Therefore, further research on the plot scale found that the disturbance by plateau pika significantly reduced plant biomass and BGB carbon stock. However, plateau pika did not affect soil C and N stocks or ecosystem C and N stocks. These findings suggest the bare soil patches formed by plateau pika caused plant and soil heterogeneity but had a trade-off effect on plant-soil C and N stocks at the plot scale. Nevertheless, moderate disturbance intensity increased the C and N sequestration potential in grassland ecosystems. These results provide a possible way to estimate how disturbance by small burrowing mammals affects C and N cycling in grassland ecosystems while accurately assessing the effects of small burrowing mammal densities on C and N in grassland ecosystems.

Effects of forest regeneration types on phosphorus fractions of soil aggregates in subtropical forest.

Soil aggregates are important for the storage and availability of phosphorus in the soil. However, how forest regeneration types affect phosphorus fractions of soil aggregates remains unclear. In this study, we examined the composition of aggregate particle size, phosphorus fractions, phosphorus sorption capacity index (PSOR), legacy phosphorus index (PLGC) and degree of phosphorus saturation by Mehlich 3 (DPSM3) in bulk soils and soil aggregates of Castanopsis carlesii secondary forest (slight disturbance), C. carlesii human-assisted regeneration forest (moderate disturbance), and Cunninghamia lanceolata plantation (severe disturbance), aiming to explore the impact of forest regeneration types on phosphorus availability and supply potential of bulk soils and soil aggregates. The results showed that forest regeneration types significantly influenced the composition of soil aggregates. The proportion of coarse macroaggregates (>2 mm) in the soil of C. carlesii secondary forest and human-assisted regeneration forest was significantly higher than that in the C. lanceolata plantation, while the proportion of silt and clay fraction (<0.053 mm) showed an opposite trend. The composition of soil aggregates significantly affected the contents of different phosphorus fractions. The contents of soil labile phosphorus fractions (PSOL and PM3) decreased as aggregate particle size decreased. The contents of soil total phosphorus (TP), total organic phosphorus (Po), mode-rately labile phosphorus fractions (PiOH and PoOH), and occluded phosphorus (POCL), as well as PSOR and PLGC, exhibited a trend of decreasing at the beginning and then increasing as particle size decreased. The contents of TP, Po, and PiOH in coarse and silt macroaggregates was significantly higher than that in fine macroaggregates (0.25-2 mm) and microaggregates (0.053-0.25 mm). Forest regeneration types significantly influenced the contents of phosphorus fractions of bulk soils and soil aggregates. The contents of TP, Po, PSOL, and PM3 in the soil of C. carlesii secondary forests was significantly higher than that in C. carlesii human-assisted regeneration forest and C. lanceolata plantation. The contents of PSOL and PM3 in different-sized aggregates of C. carlesii secondary forests were significantly higher than that in the C. lanceolata plantation. Forest regeneration types significantly influenced the composition and supply potential of phosphorus fractions in soil aggregates. The proportions of PSOL, and PM3 to TP in different-sized soil aggregates were significantly lower in C. carlesii human-assisted regeneration forest compared with C. carlesii secondary forest. PSOR and DPSM3 in different-sized soil aggregates were significantly lower in C. lanceolata plantation than that in C. carlesii secondary forest. Overall, our results indicated that natural regeneration is more favorable for maintaining soil phosphorus availability, and that forest regeneration affects soil phosphorus availa-bility and its supply potential by altering the composition of soil aggregates.

Toxinological profile and histopathological alterations induced by Bothrocophias campbelli venom from Colombia

Snakebite envenomings most frequently reported in Colombia are caused by snakes of the genera Bothrops, Bothriechis, Bothrocophias, and Porthidium. Their venoms induce local and systemic pathophysiological effects, sometimes leading to permanent sequelae such as reduced mobility of the limbs, amputations, besides the risk of death. The genus Bothrocophias includes nine species, among which B. campbelli has a distribution restricted to the department of Nariño in Colombia. In this work we determined the toxinological profile its venom, by performing assays for the lethal, hemorrhagic, edematogenic, and myotoxic activities in mouse models, as well as for in vitro coagulant activity on human plasma. The lethal toxicity of the venom was 142.7 µg venom/mouse (111.4–179.8 µg/mouse; 6.6–10.6 µg/g body weight) by intraperitoneal route. Its hemorrhagic activity (minimum hemorrhagic dose: 12.7 ± 2.3 µg) is generally weaker compared to other South American vipers, but edematogenic (minimum edematogenic dose 1.0 ± 0.3 µg), and myotoxic (minimum myotoxic dose 3.9 ± 2.5 µg) activities are very potent. Histopathological examination of the injected mouse gastrocnemius muscle showed prominent disorganization of the myofibrils, myonecrosis, and an intense inflammatory leukocyte infiltrate. In vitro, the minimal coagulant dose was 12.3 ± 0.5 µg. Overall, this toxinological profile would predict that the clinical picture of envenomings by B. campbelli might be characterized by moderate disturbances in the coagulation cascade, mild local hemorrhage, and, conversely, severe myonecrosis and edema, which could potentially lead to compartment syndrome and gangrene.

Plant compensatory growth: its mechanisms and implications to agricultural sustainability under global environmental changes

ABSTRACT Compensatory growth represents the ability of plants to counteract the negative consequences of herbivore damage, contributing to the sustainable development of agriculture. Minor changes in compensatory growth due to environmental changes may significantly impact the structure and functionality of ecosystems, especially for agriculture in a semiarid region. However, there is a lack of systematic quantitative summaries and reviews on compensatory growth mechanisms, especially regarding how they might respond to global environmental changes (e.g. climate warming, drought, nutrient variation, and elevated CO2). This paper summarizes the types of physio-ecological responses of plant compensatory growth to defoliation and their characteristics through a systematic review of existing literature. The review shows that damaged plants that undergo variations in morphological and physiological traits, such as enhanced photosynthesis, increased branching, and altered biomass allocation, may mitigate injury or produce overcompensatory growth. Moderate disturbance and arbuscular mycorrhizal fungus infection rates are beneficial for overcompensation. I further discuss how plant compensatory growth is affected by global change factors, concluding that adequate nutrients and water supply are crucial factors influencing overcompensation. This summary can advance our understanding of the response patterns and mechanisms underlying plant compensatory growth, which is vital for gaining insight into the regenerative capacity of plants and promoting sustainable agricultural development under global environmental changes.

Оценка геомеханического состояния массива пород в окрестности глубоких выработок рудника «Скалистый» комплексом натурных методов

In recent years, deep levels of exploited deposits have been a priority for the Polar Branch of MMC Norilsk Nickel. In the first half of 2023, KANEX SHAKHTOSTROY LLC has completed exploration workings EW-1 at the –1650 m level and EW-2 at the –1750 m level from the ventilation shaft VS-10 to the skip-cage shaft SCS-1 (2 km below the daytime surface). Comprehensive studies of mining-induced disturbance were carried out at 17 measuring stations in EW-1 and EW-2 sections driven in 2020–2022 (the length of about 1500 m). The rheometric, ultrasonic logging and seismic profiling methods were used as the principal in-situ methods to solve the task. It has been established that the size of the disturbed zone in the vicinity of EW-1 and EW-2 is characterized by longitudinal wave velocities, Vp, in the range of 2–4 km/s, averaging over the entire length of 1m from the contour of the working. The results of the seismic studies indicate moderate disturbance of the rock mass in the horizontal plane of the working's wall. The results of in-situ complex studies are qualitatively comparable with the results of visual inspection of the fixed surface of the working, thus indicating its satisfactory geomechanical condition.