Superior Competitor Research Articles

On the competition between Video OTT platforms vs Traditional TV: A niche case study in Greece

This paper examines the competition between Traditional TV and Video OTT platforms in Greece. Niche theory has been adopted to measure users’ gratification fulfilled by TV and Video OTTs, the competitive superiority of each medium, and the similarity between the two media across seven aspects of gratification. The results of an online survey conducted between February and October 2022, which collected a total of 508 responses, suggest that streaming TV exhibits a comparative advantage over Traditional TV in several dimensions of gratification, apart from information and financial benefits. Additionally, the survey revealed that Video OTTs and Traditional TV showed comparable levels of similarity concerning ease of use, convenience, and information, indicating that users perceived both media to be similarly accessible, user-friendly, and informative. Furthermore, the survey's findings suggest that Video OTT platforms are perceived to be superior to Traditional TV in terms of relaxation, where they scored the highest compared to all other dimensions.

Phenology mediates direct and indirect interactions among co-occurring invasive plant species.

Why nonnative invasive plant species commonly co-occur, despite their competitive superiority and propensity to displace native species, remains a paradox in invasion biology. Negative interactions among competitively dominant invaders are potentially alleviated by two understudied mechanisms: seasonal priority effects, where phenological separation weakens the effect of competition on species with early phenology; and indirect facilitation, where competition between two species is mitigated by a third species. Although phenological separation has been speculated as a mechanism for explaining co-occurrence patterns of invasive plants, it has never been directly tested. In a greenhouse experiment, we tested the effect of phenological separation on direct and indirect interactions between three co-occurring invasive plant species found in the riparian forests of North America. These species have distinct natural phenological separation with reproduction in early spring (Ficaria verna), mid-spring (Alliaria petiolata), and late summer (Microstegium vimineum). When phenology was experimentally synchronized, direct pairwise interactions among invasive species were overwhelmingly negative, asymmetric, and unlikely to promote co-occurrence. However, increasing phenological separation generated seasonal priority effects, which weakened the effect of competition on species with early phenology. Furthermore, the addition of a third species generated indirect facilitative effects, which balanced competitive outcomes among the two weakest competitors. Based on these findings, we conclude that phenological separation modulates the strength of both seasonal priority effects and indirect facilitation within species interaction networks and may promote the co-occurrence of three common invasive species within this study system. We articulate how future studies can test the external validity of these findings in more complex environmental conditions and with a larger range of invasive plants.

Inter- and Intraspecific Competition in Invasive Lactuca serriola and Co-Occurring Weedy Plant Species.

While invasive success of alien plant species is often attributed to their superior competitive abilities, it is also suggested that competitive ability depends on the target species of competition and resource availability. In addition, it remains unclear whether invaders and co-occurring plants in the introduced area exhibit distinctive inter- and intraspecific competitive intensities. This study aimed to evaluate the competitive ability of a successful invader, Lactuca serriola, through a combination of field surveys and a growth chamber experiment. First, we assessed biodiversity and the biomass of co-occurring plants in both L. serriola-invaded and uninvaded plots across nine sites in South Korea. Subsequently, a pairwise competition experiment was conducted between L. serriola and three weedy plant species commonly found in the invaded plots, Chenopodium album, Erigeron canadensis, and Oenothera biennis, under differential nutrient levels. Diversity indices of plant communities and the biomass of most co-occurring plants showed no significant difference between invaded and uninvaded plots. L. serriola and testing weedy plants exhibited mutually negative effects on biomass when grown together in the same pot, with the intensity of interspecific competition being comparable across nutrient treatments. Notably, intraspecific competition of L. serriola was weaker than testing weedy plants, particularly manifest in the high-nutrient treatment. The results of both field and growth-chamber studies demonstrated that L. serriola was not a particularly strong competitor compared to its neighboring weedy plants. Its successful invasion can be partially attributed to its weak intraspecific competition intensity, which potentially facilitate successful establishment with high density.

Asymmetric competition for habitats between the temperate Japanese eel Anguilla japonica and the tropical Indo-Pacific eel A. marmorata

Habitat segregation is a common phenomenon among anguillids in rivers where multiple species coexist. However, despite the growing need to conserve their river habitats, the mechanisms underlying such segregation remain unknown. Here, we conducted tank experiments to investigate the competitive superiority for habitats between the temperate Japanese eel Anguilla japonica and the tropical Indo-Pacific eel Anguilla marmorata, which co-occur in East Asian subtropical rivers. Using eight interspecific pairs of these two species of comparable total length, we compared the use of a single pipe shelter, recorded over a 24-h experimental period, between solitary and paired conditions. The changes in shelter use patterns between conditions indicated that in the paired condition, the shelter was occupied by A. marmorata in five pairs (62.5%) by the end of the experiment while A. japonica appeared to occupy the shelter in only one pair (12.5%). Furthermore, agonistic behaviors, which occurred mainly at night, such as biting and head-butting, were observed much more frequently for A. marmorata toward A. japonica (mean ± standard deviation: 23.2 ± 36.6 times per individual) than for A. japonica toward A. marmorata (0.4 ± 0.5 times per individual), indicating an asymmetry in aggressiveness. These results suggest that A. marmorata can negatively affect the diurnal habitat use and nocturnal activities of sympatric A. japonica. These findings, combined with those from previous field studies, suggest that A. marmorata may competitively exclude A. japonica from stream habitats with large substrate sizes. This asymmetric competition can contribute to shaping their riverine distribution and composition within rivers where they co-occur.

Temporal variability in host availability alters the outcome of competition between two parasitoid species.

Variability in the availability of resources through time is a common attribute in trophic interactions, but its effects on the fitness of different consumer species and on interspecific competition between them are not clearly understood. To investigate this, we allowed two parasitoid species, Trichopria drosophilae and Pachycrepoideus vindemiae, to exploit Drosophila host pupae under different temporal variability treatments, either on their own or simultaneously. When tested individually (in the absence of interspecific competition), both parasitoid species had lower fitness when hosts were exposed for a short duration at high density than when exposed for a long duration at low density. When both parasitoid species exploited hosts simultaneously, interspecific competition significantly decreased the number of offspring for both parasitoid species. The outcome of this interspecific competition depended on host temporal variability, with T. drosophilae or P. vindemiae dominating in short and long host exposure treatments, respectively. These results can be explained by the combination of host availability and egg load of female adult parasitoids. When abundant hosts are provided for a short period, the ample mature eggs of the proovigenic T. drosophilae enable them to exploit hosts more efficiently than P. vindemiae, which is synovigenic. However, P. vindemiae is an intrinsically superior competitor and dominates when multiparasitism occurs. Multiparasitism is more frequent when hosts are at low levels relative to the egg load of the parasitoids. Our results clearly demonstrate that resource temporal availability can alter the outcome of competition between consumers with different reproductive traits.

Self‐organised pattern formation promotes consumer coexistence by fluctuation‐dependent mechanisms

Abstract In spatially extended ecosystems, habitat heterogeneity facilitates coexistence of species if each competitor experiences environmental conditions in a particular habitat that provide a growth advantage compared to other species, thereby making it locally competitively superior. If the competitive hierarchy among species is the same everywhere, heterogeneity‐facilitated coexistence is possible provided that superior competitors disperse maladaptively towards unfavourable habitats or if they hedge insufficiently against fluctuating environmental conditions. We use a generic two‐patch metacommunity model to show that the latter mechanisms also operate in metacommunities with homogeneous habitat quality when heterogeneous biomass distributions emerge from self‐organised pattern formation. The model consists of an abiotic resource, an autotroph producer and two competing heterotroph consumer species of which one is always competitively inferior to the other, irrespective of resource availability. If the induced biomass patterns are static in time, a lower dispersal rate can allow the inferior competitor to avoid competitive exclusion by retaining most of its biomass in the patch with the higher resource density. However, if the biomass patterns fluctuate spatio‐temporally, the inferior competitor must adopt a higher dispersal rate than the superior competitor to persist. This increased movement enables the inferior competitor to effectively distribute its biomass across space, thereby achieving a higher growth rate during periods of recovery from local population minima. Strikingly, we find a novel coexistence mechanism that emerges if the competitors differ in their abilities to induce pattern formation. Similar to relative nonlinearity in resource use (based e.g. on a gleaner–opportunist trade‐off), the dominant species modifies the spatial or spatio‐temporal variation in the distribution of the resource in a way that favours its competitor. This prevents competitive exclusion due to differently effective dispersal strategies. We conclude that while temporal instabilities that cause, for example, predator–prey oscillations are usually regarded as jeopardising species' persistence, spatial instabilities that give rise to self‐organised pattern formation should be interpreted more positively, as they provide a generic mechanisms for maintaining diversity in metacommunities without requiring a priori habitat heterogeneity. Read the free Plain Language Summary for this article on the Journal blog.

Combined effects of food quality and temperature on competitive interactions between small- and large-bodied cladoceran species

Competition is one of the main drivers of population dynamics of cladoceran species. According to the Size Efficiency Hypothesis, large-bodied cladocerans are superior competitors over small-bodied species because they are more effective filter-feeders and can consume a wider size spectrum of food particles. However, we hypothesized that food quality in terms of phosphorus (P) and/or polyunsaturated fatty acid (PUFA) content can alter competitive interactions, and these potential effects can be modified by temperature. Since large-bodied cladocerans are more vulnerable to poor food quality and are regarded as less adaptive to high temperatures, we hypothesized that large-bodied species would be superior competitors at low temperature and/or high food quality, while small-bodied cladocerans would be competitively superior at enhanced temperature and/or poor food quality. To verify this hypothesis, we conducted laboratory experiments with the small-bodied D. longispina and large-bodied D. magna fed with three different types of food: (1) P-poor and PUFA-rich green algae (low phosphorus or LP-treatment), (2) PUFA-poor-cyanobacteria treatment (CYANO) and (3) P-rich and PUFA-rich green algae (high phosphorus or HP-treatment) at 18°C and 24°C. We found that D. magna had a stronger suppressive competitive effect on D. longispina in all food quality and temperature treatments. Nevertheless, food quality and temperature modified competitive interactions between the small- and large-bodied Daphnia. In HP and CYANO, both Daphnia species were more strongly suppressed by competitor presence at high than low temperatures, whereas in LP mutual suppression was relatively weaker at higher temperatures. This phenomenon was attributed to higher requirement for P at enhanced temperature which created constraints for population growth thus decreasing competitive interactions at higher temperatures. Mutual competitive suppression in CYANO was weaker than in the HP treatment although cyanobacteria had the greatest negative impact on the abundance of both Daphnia species. In general our results show that the outcome of competition between large and small-bodied cladoceran species was not affected by food quality and/or temperature, yet, these factors markedly altered competitive interactions between species.

Removal of nitrate and phosphate by aquatic plants during aquarium‐based ornamental fish production

AbstractObjectiveThe rising demand for ornamental fish and plants in aquariums is met through industrial production. However, higher production densities may negatively impact water quality (such as ammonia, nitrate, nitrite, and dissolved oxygen levels), thus impacting production. This can be mitigated by utilizing specific aquatic plants to promote sustainable ornamental fish production. This study aimed to determine how the water quality in ornamental fish tanks can be improved using two floating aquarium plant species: Najas grass Najas guadalupensis and Java moss Taxiphyllum barbieri.MethodsThe efficiency of nitrate and phosphate filtration by the two plant species was determined in aquariums containing Endler Guppies Poecilia wingei. The duration of the study was 4 weeks, and the water quality parameters were measured weekly. The growth rates of the two plants were measured at the beginning and end of the study period.ResultNajas grass effectively maintained lower nitrate and phosphate levels while showing robust growth. By week 4, nitrate levels in control tanks rose to 33.75 and 35.00 mg/L in the two independent experiments, while nitrate in tanks with Najas grass only reached 8.75 and 11.50 mg/L. Phosphate levels in control tanks increased to 2.42 and 2.40 mg/L compared to 1.075 and 1.05 mg/L in tanks with Najas grass. In single‐species tanks, Najas grass showed a 1.6‐fold biomass increase, while Java moss showed a 1.2‐fold increase. In tanks with both species, Najas grass biomass increased significantly, whereas Java moss biomass decreased.ConclusionThe superior competitive ability of Najas grass (allelopathy and increased nutrient uptake) underlies the findings of this study and indicates that this species is a better option for maintaining low levels of nitrate and phosphate in aquarium water. This finding can contribute to creating a cleaner and healthier environment for fish species involved in industrial ornamental fish production and trade.

Extrinsic and Intrinsic Competition between Chouioa cunea Yang and Tetrastichus septentrionalis (Hymenoptera: Eulophidae), Two Pupal Parasitoids of the Fall Webworm, Hyphantria cunea (Lepidoptera: Erebidae).

The endoparasitoids Chouioa cunea Yang and Tetrastichus septentrionalis Yang (Hymenoptera: Eulophidae) are both gregarious pupal parasitoids of the fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Erebidae). In order to analyze the competitive interactions between both parasitoids exploiting H. cunea, we assessed both extrinsic and intrinsic competition. The search time, oviposition duration, and oviposition frequency were used as evaluation criteria for extrinsic competition. The number of survival days, female ratio, and number of parasitoids emerging from the host were used as evaluation criteria for intrinsic competition. The results indicated that both parasitoid species were able to parasitize hosts that were already parasitized by competitors. The first released species consistently emerged as the superior competitor in multiparasitized hosts. Both parasitoid release orders and time intervals between oviposition affect the competition of parasitoids and the parasitic efficiency. The results emphasize the parasitic abilities of both parasitoid species and provide a basis for future research on competition mechanisms and biological control of H. cunea.

Study on Associations between Root and Aboveground Growth of Mixed-Planting Seedlings of Populus tomentosa and Pinus tabuliformis under Soil Nutrient Heterogeneity

Near-natural transformation can convert artificial monoculture forests into mixed forests with diverse ages, multi-layered structures, and enhanced ecological functions. This transformation optimizes stand structure, improves soil physical and chemical properties, and enhances stand productivity and species diversity. This study aimed to explore the relationship between the underground roots and aboveground growth of Pinus tabuliformis and Populus tomentosa under conditions of nutrient heterogeneity, with the goal of advancing plantation transformation. This research focused on 1-year-old Populus tomentosa and 5-year-old Pinus tabuliformis, employing two planting densities (25 cm and 50 cm) and three fertilization levels, low (50 g·m−2), medium (100 g·m−2), and high (200 g·m−2), using Stanley Potassium sulfate complex fertilizer (N:P:K = 15:15:15). Each treatment had three replicates, resulting in a total of nine experimental groups, all planted in circular plots with a radius of 1 m. Standard major axis (SMA) regression was used to analyze the allometric relationship between underground fine root biomass and aboveground organ biomass. This study further explored correlations between fine root length, root surface area, volume, biomass, and aboveground biomass, culminating in a mixed-effects model. The mixed-effects model quantified the relationships between underground roots and aboveground growth in varying soil nutrient environments. The results indicated optimal root growth in Populus tomentosa and Pinus tabuliformis, characterized by maximum root length, surface area, and volume, under conditions of 200 g·m−2 soil nutrient concentration and 50 cm planting distance; Populus tomentosa fine roots had a vertical center at a depth of 8.5 cm, whereas Pinus tabuliformis roots were centered at depths of 5–7.5 cm, indicating differing competitive strategies. Pinus tabuliformis exhibited competitive superiority in the soil’s surface layer, in contrast to Populus tomentosa, which thrived in deeper layers. The study of the allometric growth model revealed that under conditions where the nutrient gradient was 200 g·m−2 and the planting distance was 25 cm, Populus tomentosa demonstrated its highest allometric growth index (2.801), indicative of positive allometric growth. Furthermore, there was a notable inclination of resource allocation towards the aboveground, which enhances the accumulation of aboveground biomass. The mixed-effects model equation showed a clear linear relationship between underground roots and aboveground biomass. The final fitting coefficient of the model was high, providing a robust theoretical basis for future management practices. The mixed-effects model revealed the following hierarchy of fixed-effect coefficients for root system characteristics affecting aboveground biomass: fine root volume (132.11) > fine root biomass (6.462) > root surface area (−4.053) > fine root length (0.201). In subsequent plantation reconstruction and forest management, increasing soil fertility and planting distance can promote the growth of underground roots and biomass accumulation. Appropriately increasing soil fertility and reducing planting distance can effectively promote aboveground biomass accumulation, achieving sustainable forest development.

Evolution of "invasion syndrome" in invasive goldenrod is not constrained by genetic trade-offs.

A suite of plant traits is thought to make weed populations highly invasive, including vigorous growth and reproduction, superior competitive ability, and high dispersal ability. Using a breeding design and a common garden experiment, we tested whether such an "invasion syndrome" has evolved in an invasive range of Solidago altissima, and whether the evolution is likely to be genetically constrained. We found an overall shift in invasive phenotypes between native North American and invasive Japanese populations. The invasive populations were taller and produced more leaves, suggesting a superior ability to exploit limited resources. The populations also produced more allelopathic compounds that can suppress competitor growth. Finally, invasive populations produced more seeds, which are smaller and are released from a greater height, indicating a potential for superior dispersal ability than the native populations. Quantitative genetics analyses found a large amount of additive genetic variation in most focal traits across native and invasive populations, with no systematic differences in its magnitude between the ranges. Genetic covariances among three traits representing invasion strategies (leaf mass, polyacetylene concentration and seed size) were small. The R metric, which measures the effect of genetic covariances on the rate of adaptation, indicated that the covariance neither constrains nor accelerates concerted evolution of these traits. The results suggest that the invasion syndrome in S. altissima has evolved in the novel range due to ample additive genetic variation, and relatively free from genetic trade-offs.

CDTFAFN: A novel coarse-to-fine dual-scale time-frequency attention fusion network for machinery vibro-acoustic fault diagnosis

When the machinery device operates abnormally, it is not sufficient for fault detection only via extracting fault features from a single sensor due to the latent fault information may be scattered across multiple sensors. Multi-sensory fusion techniques with deep learning framework have attracted increasing attention from researchers due to the exploiting and integration of fault information between multiple sensors. Nevertheless, there are two remaining shortcomings in most existing multi-sensory fusion technologies. (1) Most existing fusion methods merely concentrate on conducting multi-sensory information fusion from time-domain or frequency-domain to achieve fault diagnosis, which are often unsatisfactory in the face of strong noise environments. (2) The collaborative fusion between several vibration sensors is generally considered in the past works, whereas the complementary information fusion between multi-sensory vibro-acoustic heterogeneous data are rarely studied. To address these deficiencies, this paper proposes a novel coarse-to-fine dual-scale time-frequency attention fusion network (CDTFAFN) for machinery fault diagnosis, which not only adequately considers the complementary information fusion of vibro-acoustic signal, but also has robust feature learning capabilities in a noisy scenario. Firstly, the signal-to-image encoding unit (SIEU) containing the improved constant-Q non-stationary Gabor transform (ICQ-NSGT) is introduced to convert the collected raw vibro-acoustic heterogeneous signal into time-frequency representation (TFR) and achieve the coarse-grained feature fusion. Secondly, the time-frequency attention feature fusion unit (TFA-FFU) is designed to concurrently learn the fine-grained features at two scales from the low-level fused features which are meaningful for fault diagnosis. Finally, the coarse-to-fine features are sequentially concatenated and fed into softmax classifier to preferably promote the network learning performance and automatically implement fault classification. The performance of the proposed approach is validated against those state-of-the-art results on two groups of multi-sensory vibro-acoustic data in different experimental platforms. Experiment results show that the proposed method with the diagnosis accuracy of 99 % above outperforms other several representative fusion technologies (i.e., 2MNet, MFF-GBFD, MSCNN-BiLSTM, MFAN-VAF, 1D-CNN-VAF, MI-CNN-TFT and TFFN-VAF) in the raw noise-free addition scenario. Moreover, the average testing accuracy of the proposed method can still reach 97 % above in the noisy scenarios with Gaussian white noises, which shows its competitive superiority and strong robustness against noises in machinery fault diagnosis. According to the five ensemble macro-average performance evaluation metrics (i.e., accuracy, precision, sensitivity, specificity and F1-score) and the receiver operator characteristic (ROC) analysis, our findings also emphasize the superiority of applying our method for machinery fault diagnosis under the colored noises compared with other fusion technologies (i.e., 2MNet, MFF-GBFD, MSCNN-BiLSTM, MFAN-VAF, 1D-CNN-VAF, MI-CNN-TFT and TFFN-VAF) reported in this paper.

Habitat amount modulates biodiversity responses to fragmentation.

Anthropogenic habitat destruction leads to habitat loss and fragmentation, both of which interact to determine how biodiversity changes at the landscape level. While the detrimental effects of habitat loss are clear, there is a long-standing debate about the role of habitat fragmentation per se. We identify the influence of the total habitat amount lost as a modulator of the relationship between habitat fragmentation and biodiversity. Using a simple metacommunity model characterized by colonization-competition (C-C) trade-offs, we show that the magnitude of habitat loss can induce a unimodal response of biodiversity to habitat fragmentation. When habitat loss is low, habitat fragmentation promotes coexistence by suppressing competitively dominant species, while habitat fragmentation at high levels of habitat loss can shape many smaller isolated patches that drive extinctions of superior competitors. While the C-C trade-off is not the only mechanism for biodiversity maintenance, the modulation of habitat fragmentation effects by habitat loss is probably common. Reanalysis of a globally distributed dataset of fragmented animal and plant metacommunities shows an overall pattern that supports this hypothesis, suggesting a resolution to the debate regarding the relative importance of positive versus negative fragmentation effects.

Unpacking the relationship between ethical leadership and innovative work behavior: A moderated mediation model

This study delves into the significant role of innovative work behavior among bankers in achieving competitive superiority and addressing contemporary business needs. It uncovers a research gap in understanding the influence of bankers’ innovative work behaviors and the factors driving these behaviors. This study proposes to examine ethical leadership’s direct and indirect effects on innovative work behavior through the mediating role of bankers’ resilience and the moderating role of a manager’s gender. The study collected perceptual cross-sectional data from employees across Thailand’s ten largest commercial banks via self-administered questionnaires, analyzing 960 responses using structural equation modeling. Anchored in social learning theory, the study’s regression analysis found significant positive effects of ethical leadership on bankers’ innovative work behavior (B = 0.197, p < 0.001), ethical leadership on bankers’ resilience (B = 0.388, p < 0.001), and bankers’ resilience on their innovative work behavior (B = 0.649, p < 0.001). Furthermore, it identified that bankers’ resilience mediates the relationship between ethical leadership and innovative work behavior (B = 0.240, p < 0.05), with the gender of leaders moderating the impact of ethical leadership on innovation. These findings suggest that banks can enhance their competitive edge by fostering ethical leadership and resilience, highlighting the strategic importance of these factors in promoting innovation within the banking sector.

The Role of Strategic Monitoring In Achieving Competitive Superiority " An Analytical Study of The Opinions of A Sample of Working in The Iraqi Insurance Company"

This This research attempts to diagnose the nature of the role that strategic monitoring contributes to the competitive superiority of the Iraqi insurance company, as strategic monitoring represents an important resource in the company and the main driver of other resources, so it is necessary to strengthen the special competencies of strategic monitoring to achieve competitive superiority that ensures the survival and continuity of the company in operation, as The research problem indicated that there is a clear lack of attention to the two research variables in the researched company, so the importance of the research emerges in the researcher’s attempt to provide solutions to address this problem, and to achieve the research objectives, so the researcher adopted the descriptive analytical approach in its applied aspect, as the questionnaire was used in collecting data. Which was distributed to a sample of (70) employees of the surveyed company, which was adapted to suit the purposes of the current research, and after processing and interpreting the results of the data analysis that was carried out using a number of statistical tools found in the ready-made program (SPSS V.28), the validity of the main and subsidiary hypotheses that were confirmed was confirmed. Included in the research, which emphasized the importance of the moral role that strategic monitoring contributes to achieving competitive superiority, and therefore it is necessary to activate the dimensions of strategic monitoring and invest in them in the best possible way to achieve competitive superiority for the Iraqi insurance company in light of the highly competitive environment in which it operates.

Invasive-plant traits, native-plant traits, and their divergences as invasion factors.

Invasive plants exert significant ecological impacts on native plants, communities, and ecosystems. However, consistent conclusions regarding how traits of invasive plants, native plants, and their divergences affect invasion dynamics are still lacking. Here, we conducted a pairwise common garden experiment to investigate how invasion was influenced not only by invasive plants but also by native plants, aiming to elucidate the role of invasive-plant traits, native-plant traits, and their divergences in invasion processes. Our findings revealed variations in invasive stage depending on the combinations of invasive and native plants. Specifically, native plants such as A. argyi, A. lavandulifolia, and C. album exhibited competitive superiority when co-occurring with the three invasive plants. S. viridis, A. vestita, and A. annua had competitive superiority when they co-occurred with E. canadensis, G. quadriradiata, and E. annuus respectively. Furthermore, our results demonstrated that the competitive abilities of invasive plants were primarily influenced by factors such as height, diameter, and biomass allocation, while native plants' competitive abilities were mainly affected by diameter, biomass allocation, and function group differences. Moreover, our analysis revealed that invasive-plant traits, native-plant traits, their divergences, and their interactions together explained 36.88% of the variation in invasion dynamics, with invasive-plant traits and the native-plant traits explaining 10.19% and 6.88%, respectively. In conclusion, the traits of invasive and native plants, along with their divergences, significantly influence interspecific relationships, and influencing the invasive stages. Divergences in competitive strategies between the native plants and invasive plants facilitated invasion processes. Our study not only contributes to understanding the mechanisms underlying invasion, but also provides a scientific foundation for predicting and managing the negative effects of invasive plants.

Анализ современных методов профессиональной подготовки управленческих кадров

This article examines the issues of professional training and development of managerial personnel as an important object of management in modern organizations. The author substantiates the need to apply a systematic approach to the development of managerial competencies to improve management effectiveness. It is noted that professional training of managerial personnel is one of the objects of management, which aims to develop and train specialists in the field of management. The research area includes acquiring practical skills and specific knowledge necessary for the effective performance of managerial functions in organizations of various scales and business orientations. Existing problems and barriers in the field of managerial personnel training are analyzed, and ways to overcome them are proposed. Advanced practices of leading companies in in the field of human resource development and managerial potential are examined. To summarize, this research highlights the critical role of ongoing professional development for managerial staff within contemporary organizational contexts. By confronting current obstacles and embracing progressive training approaches, organizations can nurture a proficient and adaptable leadership cohort primed to propel sustainable expansion and competitive superiority.

Effect of invasive species on forest composition in tropical dry forest: a case study of invasion by Gliricidia sepium

Ecological concerns caused by biological invasion have been considered an inevitable threat to global sustainability. The superior competitive ability of invasive plant species (IPS) has an impact on vegetation composition and loss of native flora. Recognising IPS at an early stage would significantly contribute to controlling invasive plants, protecting biodiversity and formulating appropriate strategies. Most of the studies available on invasive plants are descriptive and largely confined to non-woody species. The present study focused on the alien Gliricidia sepium, a tree species, to determine the invasive potential of its distribution in tropical dry deciduous forests of Central India. Forty square plots (25 × 25 m) were laid out at each uninvaded and invaded forest to enumerate phytosociological attributes to determine the impact of G. sepium on vegetation composition and community structure. Higher density (37.2 individuals ha−1), basal area (6.32 m2 ha−1) and importance value index (95.8) contributed by G. sepium clearly showed the suppression of seedlings, saplings and trees of native forest species at the invaded sites in terms of species richness, cover and other attributes as compared to at the uninvaded sites. Further, other invasive attributes such as higher seed production, dieback phenomenon, higher coppicing power and higher growth rate as observed during the study clearly affirmed the early speculation that the species might be invasive. The species has a strong potential to spread vigorously and may gradually become invasive throughout the country as already reported from various parts of India. In the present study area, G. sepium was introduced due to restoration and plantation programmes and our findings indicate its negative impact on the native vegetation. Thus, we strongly recommend the avoidance of this species for both plantation and restoration programmes, especially for Indian forests. The study helps in early recognition and rapid monitoring of G. sepium to control its spread throughout the country.

Evolutionary adaptation to steady or changing environments affects competitive outcomes in marine phytoplankton

AbstractThe interplay of phytoplankton competition and adaptation affects how phytoplankton, and ultimately marine ecosystems, respond to global warming. However, current ecosystem models that are run under global warming scenarios do not include both processes simultaneously. To fill this gap, we developed an innovative ecosystem model for the Baltic Sea that simulates competition between three phytoplankton functional groups and allows for adaptation to changing temperatures. As adaptation can be affected by the resuspension of dormant resting cells from the sediment, we explicitly implemented this mechanism. We found that resuspension tends to slow down adaptation, and that competition and adaptation influence each other. The outcome of the competition‐adaptation interplay depends on environmental conditions. In a steady environment, competition drives adaptation to individual temperature niches to reduce competition pressure. In a changing environment, adaptation allows inferior competitors to mitigate the dominance of preadapted superior competitors. Our results demonstrate that by neglecting adaptation, models can systematically overestimate warming‐related changes in taxa dominance. Ecosystem models should include both competition and adaptation to accurately simulate phytoplankton responses to global warming. Our model is ideally suited to integrate emerging evolutionary data based on long‐term data series (e.g., from sediment archives) to further improve projections of future ecosystem change.

Inverse relationship between species competitiveness and intraspecific trait variability may enable species coexistence in experimental seedling communities

Theory suggests that intraspecific trait variability may promote species coexistence when competitively inferior species have higher intraspecific trait variability than their superior competitors. Here, we provide empirical evidence for this phenomenon in tree seedlings. We evaluated intraspecific variability and plastic response of ten traits in 6750 seedlings of ten species in a three-year greenhouse experiment. While we observed no relationship between intraspecific trait variability and species competitiveness in competition-free homogeneous environments, an inverse relationship emerged under interspecific competition and in spatially heterogeneous environments. We showed that this relationship is driven by the plastic response of the competitively inferior species: Compared to their competitively superior counterparts, they exhibited a greater increase in trait variability, particularly in fine-root traits, in response to competition, environmental heterogeneity and their combination. Our findings contribute to understanding how interspecific competition and intraspecific trait variability together structure plant communities.