Competition For Resources Research Articles

Biomass allocation and growth of young Black spruce (Picea mariana (Mill.) B.S.P.) trees

Accurately predicting biomass allocation to below- versus above-ground tree parts is crucial in estimating carbon stocks in forest ecosystems. A nine-year outdoor experiment was conducted to analyze the variations in C allocation in below- and above-ground parts in black spruce trees growing at the edge or at the center of a raised garden bed. Dry biomass, length and radial growth of stems, branches and roots were measured as well as the annual above-ground growth for the five most recent years prior to harvesting. We found that more than 90% of dry biomass was allocated to the above-ground tree parts whereas less than 10% was allocated to the root system. Strong correlations were found between the different tree parts regardless of the tree’s position in the delimited growth area. Annual growth variables declined from 2018 to 2022, likely due to increased competition for resources. Basal area and stem height were good predictors for the production of stem dry biomass (88%), and to a lesser extent for the total tree biomass (65%). The dry biomass of the woody root and the root surface close to the stem were well correlated to the above-ground tree parts (varying between 45% to 95%). Thus, the strong link between the root system and the above tree parts is confirmed.

Effect of Deficit Irrigation on Agronomic and Physiological Performance of Pomegranate (Punica granatum L.).

Agriculture accounts for over 70% of global freshwater consumption, with increasing competition for water resources due to climate change and rising urban and industrial demands. This study analyzes the effect of deficit irrigation (DI) on the agronomic and physiological performance of pomegranate (Punica granatum L.) in a Mediterranean climate. Deficit irrigation strategies, including sustained deficit irrigation (SDI) and regulated deficit irrigation (RDI), were evaluated against a control with full irrigation. The research was conducted over two growing seasons (2022-2023) at the Cajamar Experimental Centre in Paiporta, Valencia, Spain. RDI strategies achieved approximately 10% water savings without compromising marketable yield or fruit weight, while SDI resulted in significant water savings (~50%) but with a notable reduction in marketable yield, particularly in hot and dry conditions. SDI also reduced tree growth in height and trunk diameter compared to RDI and control strategies. The study concludes that RDI is a viable irrigation strategy for pomegranate cultivation under water-limited conditions, whereas SDI should be reserved for situations of severe water scarcity.

Linking Juvenile Chum Salmon (Oncorhynchus keta) Nutritional Condition and Trophic Status to Genetic-Based Stock Assignments

In the high seas, Pacific salmon (Oncorhynchus spp.) stocks exhibit considerable mixing across the North Pacific, which increases the potential for inter- and intra-species resource competition. Stock origin and potential stock-specific phenotypic differences in feeding may therefore be an important factor in understanding density dependence and other drivers of nutritional quality. Evidence of stock-specific differences in feeding of north Pacific salmon have been shown from stable isotope analysis of sockeye salmon returns (Welch and Parsons 1993; Johnson and Schindler 2012), and stock-specific growth rates (Tucker et al. 2009). Here we assess stock specific differences in stable isotopes and measures of nutritional condition (lipid and protein) in chum salmon (O. keta) collected from the North Pacific during the 2022 International Year of the Salmon Pan Pacific Winter Survey. We discuss the importance of incorporating genetic stock identification, life history stage and growth when applying biochemical measures to understanding trophic processes from winter months in high latitude systems.

Observation of offspring sex ratio in quenda, Isoodon fusciventer

Sex ratios in wild populations of mammals often differ from parity. Here, we describe variation in offspring sex ratios in a population of quenda (Isoodon fusciventer, Marsupialia: Peramelidae), along with observations of maternal body mass and home range size. We evaluate whether the Local Resource Competition (LRC) or Trivers–Willard hypothesis best explains the observed patterns in offspring sex ratio. During the study period, young (small) females over-produced sons, whereas older (larger) females tended to produce more daughters, providing evidence consistent with the LRC hypothesis in this species. There were, however, observed shifts in adult sex ratios compared to previous years. We further discuss the possibility of adaptive sex-ratio adjustment by female quenda to reduce competition with their kin.

Balancing limited resources in actin network competition.

In cells, multiple actin networks coexist in a dynamic manner. These networks compete for a common pool of actin monomers and actin-binding proteins. Interestingly, all of these networks manage to coexist despite the strong competition for resources. Moreover, the coexistence of networks with various strengths is key to cell adaptation to external changes. However, a comprehensive view of how these networks coexist in this competitive environment, where resources are limited, is still lacking. To address this question, we used a reconstituted system, in closed microwells, consisting of beads propelled by actin polymerization or micropatterns functionalized with lipids capable of initiating polymerization close to a membrane. This system enabled us to build dynamic actin architectures, competing for a limited pool of proteins, over a period of hours. We demonstrated the importance of protein turnover for the coexistence of actin networks, showing that it ensures resource distribution between weak and strong networks. However, when competition becomes too intense, turnover alone is insufficient, leading to a selection process that favors the strongest networks. Consequently, we emphasize the importance of competition strength, which is defined by the turnover rate, the amount of available protein, and the number of competing structures. More generally, this work illustrates how turnover allows biological populations with various competition strengths to coexist despite resource constraints.

Metabolic Signaling in the Tumor Microenvironment.

Cancer cells must reprogram their metabolism to sustain rapid growth. This is accomplished in part by switching to aerobic glycolysis, uncoupling glucose from mitochondrial metabolism, and performing anaplerosis via alternative carbon sources to replenish intermediates of the tricarboxylic acid (TCA) cycle and sustain oxidative phosphorylation (OXPHOS). While this metabolic program produces adequate biosynthetic intermediates, reducing agents, ATP, and epigenetic remodeling cofactors necessary to sustain growth, it also produces large amounts of byproducts that can generate a hostile tumor microenvironment (TME) characterized by low pH, redox stress, and poor oxygenation. In recent years, the focus of cancer metabolic research has shifted from the regulation and utilization of cancer cell-intrinsic pathways to studying how the metabolic landscape of the tumor affects the anti-tumor immune response. Recent discoveries point to the role that secreted metabolites within the TME play in crosstalk between tumor cell types to promote tumorigenesis and hinder the anti-tumor immune response. In this review, we will explore how crosstalk between metabolites of cancer cells, immune cells, and stromal cells drives tumorigenesis and what effects the competition for resources and metabolic crosstalk has on immune cell function.

Swarming bacteria exhibit developmental phase transitions to establish scattered colonies in new regions.

The collective surface motility and swarming behavior of microbes play a crucial role in the formation of polymicrobial communities, shaping ecosystems as diverse as animal and human microbiota, plant rhizospheres, and various aquatic environments. In the human oral microbiota, T9SS-driven gliding bacteria transport non-motile microbes and bacteriophages as cargo, thereby influencing the spatial organization and structural complexity of these polymicrobial communities. However, the physical rules governing the dispersal of T9SS-driven bacterial swarms are barely understood. Here, we collected time-lapse images, under anaerobic conditions, of developing swarms of a T9SS-driven microbe common to the human oral microbiota. Tracking of swarms revealed that small peripheral flares emerging from a colony develop structures that resemble fireworks displaying a chrysanthemum effect and flower-like patterns that convert to wave-like patterns and which further evolve into scattered microcolonies. Particle-image velocimetry showed density-dependent phase transitions and initial vorticity within these emerging patterns. Numerical simulations demonstrate that these patterns arise due to changes in swarm speed and alignment strength. Our data reveal a strategy used by an anaerobic swarming bacterium to control swarm behavior, resulting in scattered microcolonies distant from the mother colony, thus reducing competition for resources among colony members. This might ensure species survival even if conditions change drastically in one location of the human oral cavity.

Kajian Dampak Penerapan Pendidikan Kewirausahaan dan Edupreneurship kepada Peserta Didik Tingkat SMA Sederajat

Indonesia is an archipelagic country with a lot of potential that can be developed. Ironically, with all the natural wealth it possesses, it has yet to produce anything meaningful, especially for the advancement of the economic sector. Unfortunately, that progress has not been felt evenly by the Indonesian people. A study conducted by the International Institute for Management Development (IMD) states that Indonesia still has significant deficiencies in investment levels and talent development. This is also considered one of the reasons for the lack of competitiveness of human resources in Indonesia. Schools, as educational institutions, are required to provide education that can enhance the quality of their graduates so that they can become high-quality future employees. The method in the research uses a systematic literature review, which involves a systematic literature review aimed at collecting secondary data in the form of scientific works, journals, and other relevant sources. The research results show that edupreneurship is important to implement because it has a positive impact on the development of students, particularly their skills as entrepreneurs. The development includes progress in activity, enthusiasm in participating in learning activities, and presenting innovative and creative ideas in entrepreneurship. Students also experience an increase in self-confidence, followed by the emergence of task- and result-oriented skills, a willingness to take risks, and the development of leadership qualities in students.

Narrow Dietary Niche With High Overlap Between Snow Leopards and Himalayan Wolves Indicates Potential for Resource Competition in Shey Phoksundo National Park, Nepal.

Understanding species' dietary ecology and interspecific interactions is crucial for multi-species conservation planning. In Central Asia and the Himalayas, wolves have recolonized snow leopard habitats, raising considerable concern about resource competition between these apex predators. Using micro-histological analysis of prey species remains (e.g., hair) in their fecal samples, we determined the prey composition, dietary niche breadth, and the extent of diet overlap between these two apex predators in Shey Phoksundo National Park, Nepal. We analyzed 152 scat samples collected along 89 survey transects from April to June 2021. Our findings reveal a significant overlap in their diets (Pianka's index = 0.93), with snow leopard and wolf scats containing the remains of 11 and 10 prey species, respectively. However, the interspecific difference in prey selection was apparent, with significant deviations between observed and expected prey use indicating non-random prey selection relative to availability: Snow leopards exhibited a higher occurrence of wild prey items in their diet (55.28%), primarily blue sheep (Pseudois nayaur) (24.83%), whereas wolves relied predominantly on domestic livestock (67.89%), with goats (Capra hircus) accounting for over one-fourth of their diet (29.15%). Yaks (Bos grunniens) comprised a significant portion of the biomass consumed by both predators, with higher for wolves (43.68%) than snow leopards (36.47%). Overall, the narrow dietary niche breadth with high overlap indicates potential resource competition between snow leopards and wolves. However, a comprehensive understanding of resource competition will require further study on other axes of niche partitioning, including habitat and time. Nevertheless, the region's low prey richness means that, with increasing human influence, any reduction in wild prey or increase in livestock could intensify competition between snow leopards and wolves, which could have implications for livestock depredation.

Reproductive Interference Alters Species Coexistence in Nematodes due to Asymmetric Sperm-Induced Harm.

Species coexistence is shaped by a range of biotic and abiotic factors. Beyond predation, parasitism and competition, one species may interfere with another's reproduction to induce sexual exclusion from a habitat. Here, we test for reproductive interference from inter-species mating between sympatric nematodes Caenorhabditis macrosperma and C. nouraguensis. Higher intrinsic population growth of C. nouraguensis arises from greater reproductive output by both sexes, predicting it to be superior in resource competition. Mate discrimination between species is incomplete, however, with inter-species mating errors reducing lifespan and reproductive fitness of female C. nouraguensis only. These asymmetric costs arise within hours, due to ectopic migration of C. macrosperma's giant sperm cells. We modelled the population dynamic impacts of reproductive interference, then confirmed rapid sexual exclusion in mixed-species communities with multi-generation experiments. These findings demonstrate the profound ecological implications of reproductive interference for demographic parameters and species coexistence through a cell-mediated mechanism of inter-species harm.

Contrasting Seasonal Distribution Patterns of Two Boreal Aerial Hawking Bat Species in Finland.

Climate change poses significant consequences for temperate bat species, potentially altering their distribution ranges and generating novel interactions among species sharing similar ecological niches. Recent observations suggest distribution range expansion in the Palearctic aerial hawking bat, Pipistrellus nathusii, prompting an investigation into its interaction with Eptesicus nilssonii, a northern Palearctic species overlapping with the previous in many ecological characteristics. This study examines the spatiotemporal variations between the two boreal bat species to form an evidence-based background onto which future research on, e.g., resource competition, can be built. A comprehensive community science project engaged over 470 participants from 45 high schools to collect acoustic data on bat echolocation calls across Finland, in northern Europe, during the summers of 2019-2020. Our modelling approach reveals distinct spatiotemporal patterns for each species. In early summer, E. nilssonii activity is concentrated in the southern region, whereas by late summer, observations are distributed across our study area, though predominantly in the south. This pattern suggests that E. nilssonii could exhibit post-breeding vagrant behaviour, an observation only recently evidenced in bats. Conversely, the activity of P. nathusii remains notably low throughout the season, with observations concentrated along the south coast during both early and late seasons, making it challenging to fully model its distribution. Despite initial expectations of overlap given their similar foraging behaviour and habitat preferences, the limited activity and coastal association of P. nathusii suggest low competitive interaction with E. nilssonii. These findings contribute to our understanding of bat spatial ecology amid changing environmental conditions, emphasising the necessity for ongoing monitoring to ascertain the long-term implications of shifting species distributions.

Resource availability and competition shape pollinator trophic specialization in longleaf pine savannas

Resource availability and competition shape pollinator trophic specialization in longleaf pine savannas

Ecomorphology of South American Penguins.

A major goal of evolutionary ecology is to understand the interaction between ecological differences and the functional morphology of organisms. Studies of this type are common among flying birds but less so in penguins. Penguins (Spheniscidae) are the most derived extant underwater flying birds using their wings for swimming and beak when foraging. The Humboldt Penguin (Spheniscus humboldti) and Magellanic Penguin (S. magellanicus) occur along the coast of South America and their morphology was compared in allopatry and sympatry throughout their ranges. Measurements included: mass, tarsus length, four beak/head dimensions, bite force, wing loading, and aspect ratio. A thin-plate spline/relative warp analysis was also used to detect subtle differences in wing shape. Both species generally overlapped in trait morphology, but Magellanic Penguins showed greater trait diversity. Wing morphology was more homogenous between species than beak morphology indicating a similar mode of locomotion but potential differences in prey procurement. Morphological character displacement in sympatry was only evident in beak length. Local adaptation was common in other traits, and Punta Norte (Argentina) was often distinct in having high variation, notably in beak depth, wing loading, and wing shape (relative warp 1). This may be attributed to the fact that penguins here dive deep and forage farther from their colony; they also have a greater colony size that may contribute to greater intraspecific competition for resources. These results support a potentially optimal wing design for aquatic movement, which likely applies to other penguin species. Differences in morphology may also be related to differences between Atlantic and Pacific ecosystems.

Kin discrimination causes plastic responses in floral and clonal allocation.

The composition of a plant's neighbourhood shapes its competitive interactions. Neighbours may be related individuals due to limited seed dispersal or clonal growth, so that the ability to recognize and respond to the presence of kin is beneficial. Here, we ask whether plants plastically adjust their floral and clonal allocation in response to their neighbour's identity. In a species that reproduces both sexually and clonally, we test the following predictions in response to neighbouring kin: (i) a reduction in floral display will occur to minimize costly floral structures and pollinator competition, as well as to mitigate inbreeding; and (ii) a decrease in clonality will occur to minimize resource competition and overcrowding among kin. We grew focal individuals of Mimulus guttatus (syn. Erythranthe guttata) surrounded by neighbours of varying relatedness (non-kin, outcross siblings or self siblings) and measured a suite of vegetative, floral and clonal traits. Consistent with our predictions, focal plants reduced floral and clonal allocation in the presence of kin. Moreover, focal plants increased their floral and clonal allocation when surrounded by non-kin neighbours that were high-performing. Together, we demonstrate a clear and predictable response to kin, which has general implications for the structure and function of plant neighbourhoods.

Diversity of ectoparasitic bat flies (Diptera, Hippoboscoidea) in inter-Andean valleys: evaluating interactions in the largest inter-Andean basin of Colombia.

Flies belonging to the families Streblidae and Nycteribiidae are highly specialized arthropods that feed on the blood of bats. Their morphology varies and has adapted throughout their coevolutionary history with hosts. Bat flies are often associated with specific bat species and can establish distinct infracommunities. Interaction networks have been used to better understand these associations, revealing interaction modules between bats and their parasites. The Magdalena River basin is the largest in Colombia, encompassing a wide variety of climatic and ecological conditions, with up to 98 bat species reported. We conducted field trips to capture bats and bat flies in different locations along the basin and reviewed literature records and biological collections to gather additional data on interactions between bats and bat flies in this region. We found a high diversity of bats and bat flies in the Magdalena River basin, revealing a medium specialization and modularity in these interactions. We identified bat fly infracommunities and negative associations between certain bat fly species, suggesting competition for resources within hosts. The specialization is similar to that reported in degraded and fragmented habitats where the availability of shelters decreases, favoring the overcrowding of bats, forming multi-species colonies. In conclusion, our study provides important information on the interactions between bats and bat flies in the Magdalena River basin, expanding knowledge about the diversity and structure of these communities in inter-Andean landscapes.

Water Resources and Geopolitical Tensions in the Himalayas: Analysing Nepal’s Mediating Role

The Himalayan region, often regarded as the 'water tower' of Asia, is crucial for sustaining millions of people across Asia. As climate change exacerbates water scarcity, competition over shared water resources has intensified geopolitical tensions between India and China, particularly concerning the Indus and Brahmaputra river basins. This research posits that the escalating competition over shared water resources in the Himalayan region, intensified by climate change and nationalistic narratives from India and China, necessitates an exploration of Nepal's mediating role, cooperative frameworks from other regions, and sustainable practices to alleviate tensions and promote regional stability, ultimately informing policymakers on effective strategies for conflict resolution and governance amid growing geopolitical challenges. Furthermore, it examines Nepal's diplomatic strategies aimed at balancing its relationships with both powers while asserting its own interests. By analysing successful frameworks for mediation and cooperation from other regions, such the Mekong River basin, this study proposes actionable strategies for enhancing collaborative water management among India, China, and Nepal. This article is based on both secondary information as well as primary data sources. Under primary sources, in-depth interview has been taken from the three selective experts. Such experts were selected purposively on the basis of their fields of expertise. Similarly, for the secondary information, previously published articles and journals of the scholars from the diverse background has been reviewed and critically analysed. Their views are compared and contrasted to come to the logical conclusion regarding this field. The findings of this research suggest that the regional disputes in the twenty first century is an established fact, and one of the reasons of this tension is, of course, not other than the water resources and geopolitical strategies. Fostering sustainable practices and establishing transparent data-sharing mechanisms can alleviate such tensions and promote regional stability between and among the countries. Ultimately, this research emphasizes the importance of cooperative frameworks in addressing the challenges posed by water resource competition in the Himalayas and calls for further exploration of Nepal's role in facilitating peace and conflict management in the region. This study contributes to the understanding of the intersection between water resources and geopolitics, providing insights that are critical for policymakers and stakeholders invested in the sustainable management of shared water resources in the Himalayas.

Exploring the Social-Economic Approach on the Production Level of Rice: Panel Data Analysis from 34 Province in Indonesia

The social-economic approach in rice production emphasizes the importance of understanding and solving social and economic problems related to the agricultural sector. The Ongoing economic changes, competition for resources from other sectors, environmental changes and the increasing commercialization of rice farming mean that the way rice is produced in the future will be very different. The aim of this research is to determine the influence of the relationship between rice productivity and economic indicators on maintaining sustainable food security. This research uses the HDI variable instrument as an intervening variable using panel data from 34 provinces in Indonesia in 2018-2023, which was tested using the REM, CEM, and FEM models. It is known that simultaneously, economic indicators, namely land area, productivity, inflation, poverty index, rice consumption, and population, have an effect on the amount of rice production; however, in partial testing through sub structural model 1 testing, it was found that productivity and rice consumption had no impact on the intervening variables HDI and sub structural test 2 found that partial inflation, poverty index, rice consumption, and population had no effect on the amount of rice production. Despite a series of tests, the results remained consistent. In the future, it is necessary to develop a new vision for rice farming, such as exploring food security and technology, and drafting strategic policy reforms, considering global trends and the unstable economic scenario.

Metabolic enhancement contributed by horizontal gene transfer is essential for dietary specialization in leaf beetles

Horizontal gene transfer (HGT) from bacteria to insects is widely reported and often associated with the adaptation and diversification of insects. However, compelling evidence demonstrating how HGT-conferred metabolic adjustments enable species to adapt to surrounding environment remains scarce. Dietary specialization is an important ecological strategy adopted by animals to reduce inter- and intraspecific competition for limited resources. Adults of the leaf beetle Plagiodera versicolora (Coleoptera) preferentially consume new leaves; nevertheless, we found that they selectively oviposit on mature leaves, thereby establishing a distinct dietary niche separation between adults and larvae. Based on the de novo assembled chromosome-level genome, we identified two horizontally transferred genes with cellulose degradation potential, belonging to the glycosyl hydrolase 48 family (GH48-1 and GH48-2). Prokaryotic expression of the HGTs confirmed the cellulose degradation capability of the two genes. Knockdown of GH48 significantly hampered the growth and survival rate of larvae feeding on mature leaves compared to wild-type larvae, with no similar effect observed in adults. Replenishing the GH48-expressing bacteria compensated for the knockdown of these two genes and recurred larval adaptability to mature leaves. Taken together, our results highlight the advantage and metabolic enhancement conferred by the two cellulose-degrading HGTs in P. versicolora larvae, enabling their development on cellulose-enriched mature leaves and underscoring the indispensable role of HGTs in facilitating the adaptation of leaf beetles to plants.

Competition for human edible feed resources in aquaculture - looking at tilapia farming

Competition for human edible feed resources in aquaculture - looking at tilapia farming

Phage-mediated intercellular CRISPRi for biocomputation in bacterial consortia.

Coordinated actions of cells in microbial communities and multicellular organisms enable them to perform complex tasks otherwise difficult for single cells. This has inspired biological engineers to build cellular consortia for larger circuits with improved functionalities while implementing communication systems for coordination among cells. Here, we investigate the signalling dynamics of a phage-mediated synthetic DNA messaging system and couple it with CRISPR interference to build distributed circuits that perform logic gate operations in multicellular bacterial consortia. We find that growth phases of both sender and receiver cells, as well as resource competition between them, shape communication outcomes. Leveraging the easy programmability of DNA messages, we build eight orthogonal signals and demonstrate that intercellular CRISPRi (i-CRISPRi) regulates gene expression across cells. Finally, we multiplex the i-CRISPRi system to implement several multicellular logic gates that involve up to seven cells and take up to three inputs simultaneously, with single- and dual-rail encoding: NOT, YES, AND and AND-AND-NOT. The communication system developed here lays the groundwork for implementing complex biological circuits in engineered bacterial communities, using phage signals for communication.