High Resource Availability Research Articles

Allometric equations for biomass and carbon pool estimation in short rotation Pinus radiata stands of the Western Cape, South Africa

AbstractThe quantification of tree growth and carbon storage over time is an important task for sustainable forest management and carbon sequestration projects. For the South African short-rotation Pinus radiata (D. Don) forests, this knowledge is lacking. We developed allometric equations and compared the estimated weights to previously published biomass studies and we used Dirichlet Regression (DR) modelling to ensure additivity of the component proportions. The biomass components and their contribution to carbon storage depend strongly on forest structure and mean tree size but also on-site conditions and tree architecture. Our first two hypotheses were that the (1) best model for stemwood (SW), bark and total mass will include the combined variable DBH2H and (2) that the DR will yield statistically similar estimates for all components when compared to the best models. Our third hypothesis was that allometric equations developed for sites with high resource availability (e.g. wet, fertile sites) will yield biased estimates when extrapolated to sites with lower levels of resource availability (drier and/or infertile sites). The results indicated that DBH2H was the best variable to describe SW, bark and total mass and the DR yield similar estimates for all component proportions when compared to the best models. There were strong similarities in the SW and total mass of independent test sites in comparison to the SW and total mass of this study but greater variability in the bark, needle and branch mass. This can be associated to site and seasonal differences as well as variability in tree architecture brought about by different silvicultural operations on individual sites. Previously developed equations by other authors for sites with high resource availability overpredicted the SW and total mass of the models developed in this study. Our set of additive component equations performed well even when applied to sites of similar productivity over a climate gradient. The presented new equations bridge the gap in knowledge where allometric equations for short rotation Radiata pine stands are lacking.

Universal Prevention Strategies to Prevent Opioid Misuse on a U.S. College Campus.

Opioid misuse and risk of death due to overdose are critical public health issues and young adults are at risk. College campus communities are ideal settings for the prevention of opioid misuse among young adults due to high enrollment rates, the diversity and availability of resources within the campus community, and the range of risk and protective factors that can be targeted. This practitioner narrative describes a grant-funded three-year opioid misuse prevention project implemented on a U.S. college campus. In keeping with the focus of the grant, the project involved a range of universal prevention activities implemented across the campus community. Lessons learned regarding factors that facilitated implementation in this community context are discussed and may be useful for others interested in implementing prevention activities to help prevent opioid misuse among young adults in their campus communities. Additionally, a reflection on the project and the efficacy of universal prevention to prevent opioid misuse among college students are offered for consideration.

Hydration characteristics of calcium sulfoaluminate cements synthesized using an industrial symbiosis framework

Calcium sulfoaluminate (CSA) cement offers a sustainable alternative to ordinary portland cement by using less energy and producing fewer CO2 emissions. However, the high cost and limited availability of alumina-rich resources like bauxite pose significant challenges for CSA cement production. This study addresses these issues by synthesizing CSA cement through an industrial symbiosis framework, incorporating natural materials (limestone and gypsum) with industrial wastes and by-products (Serox, ladle furnace slag, ceramic waste, and glass waste). This approach aims to minimize these challenges to CSA production while promoting environmental sustainability in the construction industry. Laboratory studies have resulted in the successful synthesis of three distinct CSA cements with at least 40 % recovered material content. Ye'elimite, anhydrite, merwinite, and fluorellestadite were identified as major compounds of the CSA cements. Hydration studies revealed ettringite as the primary hydration product, contributing to rapid strength gains with compressive strengths over 30 MPa within a day. In addition, a tendency to ettringite carbonation was observed over the long term, the adverse effects of which need to be further investigated. These results demonstrate the feasibility of producing environmentally friendly CSA cements through industrial symbiosis and highlight their potential for scalable and sustainable construction applications.

Social Support at School for Students with Sensory Disabilities.

Social support is the gratification of basic social needs (affection, belonging, esteem or approval, security, identity) through interaction with others. Social support at school allows students to perceive themselves as competent during learning and to enjoy school in general. Little is known about social support at school for students with sensory disabilities. This review aims to synthesize findings from studies examining social support at school for students with hearing and visual impairments. A search of computerized databases was supplemented by a manual search of the bibliographies of the main publications. The synthesis of the literature suggests that all students need adequate support devices in class and properly trained support teachers. However, visually impaired students are more likely to have access to resources compared to those with hearing impairments. Students with visual impairments attending regular schools are more positive about the availability of resources than those with hearing impairments attending special schools. Overall, senior secondary school students indicate higher resource availability than junior secondary school ones. Still, very few studies have investigated social support for students with sensory disabilities. Thus, further research is needed to confirm these results.

Recent Advances and Prospects in Manganese‐Catalyzed C‐H Activation

C–H activation represents an interesting alternative to conventional cross‐coupling methods, avoiding the requirement of additional steps to introduce activating groups. Generally, Pd‐catalyzed reactions have been extensively employed for C–H activation. The high cost and limited availability of resources of Pd have prompted us to explore alternative transition metals. In this context, researchers are turning to Earth Abundant Metals (EAMs) like manganese and iron for their potential in C–H activation.Significant progress has been made in manganese‐catalyzed C–H activation in recent years, showcasing excellent specificity, environmental compatibility, and versatility across different substrates. This review summarizes approximately 50 recent publications highlighting significant advancements in this field from 2020 to 2023.

Winter wheat response to plant density in yield contest fields

AbstractSeeding rate recommendations for wheat (Triticum aestivum L.) are often 150–450 seeds m−2. However, we hypothesize that wheat grown with high resource availability (i.e., fertility and moisture) can maximize yield under considerably lower rates. Our objectives were to explore winter wheat response to low populations under high resource availability using yield‐contest fields as a case study. A factorial experiment evaluated four wheat varieties (i.e., Joe, WB‐Grainfield, Langin, and LCS Revere) exposed to five seeding rates (50, 100, 150, 200, and 250 seeds m−2) during five seasons in commercial wheat fields managed by yield‐contest winning producers near Leoti, KS. Fields were silt‐loam soils with high available water‐holding capacity, long‐term history of manure application with non‐limiting fertility, and adopted a sorghum [Sorghum bicolor (L.) Moench]–fallow–wheat rotation. Plant density ranged from 26 to 341 plants m−2 and yield ranged from 3.2 to 6.8 Mg ha−1. Water use efficiency of 19.5 kg ha−1 mm−1 suggested no management limitations to yield. Quadratic models portrayed the grain yield–plant density relation well, with 95% of the maximum yield reached at 68 to 91 plants m−2 for crops sown at the optimum date (4 out of 5 years), and at 312 plants m−2 for a late‐sown crop. Greater fall temperature accumulation reduced the relative yield between the maximum and minimum seeding rates. There was no variety × plant density interaction and Langin was the most consistent yielding variety across environments. Optimum plant density for winter wheat in environments with high resource availability may be considerably lower than current recommendations.

Habitat use by a bird community in a Caatinga area: habitat seasonality and overlap

Habitat degradation is one of the main drivers of biodiversity loss, a phenomenon that significantly manifests in the Caatinga domain, where extensive habitat areas undergo modifications. Therefore, understanding how organisms select their habitats becomes crucial for effective conservation management. In this context, the present study aims to analyze habitat use, seasonality, and overlap within a bird community in an area located within the Caatinga domain, specifically at Fazenda Aba. Twelve monthly expeditions were conducted using the point-count method to estimate usage areas, habitat intensity, and overlap during both dry and rainy periods. Usage areas were measured using the Minimum Convex Polygon (MCP 100%) method, while the Kernel 95% estimator was employed to assess habitat intensity. Overlap was calculated using the Utilization Distribution Overlap Index (UDOI). The results revealed comprehensive use of the study area by the bird community, with more pronounced usage intensity in riparian forest environments. Additionally, an increase in usage areas was observed during the rainy period compared to the dry season, reflecting greater overlap during the scarcity season. It is suggested that riparian forest habitats play a fundamental role in maintaining avifauna, especially during droughts, promoting seasonal movements of species that tend to shift to areas with higher resource availability, resulting in convergence of utilized areas.

Monographs on invasive plants in Europe N°8: Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn

ABSTRACT Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn. (Pampas grass) is a perennial grass native to temperate and subtropical regions of South America. The species was introduced to western Europe for ornamental purposes during the nineteenth century, where it has become naturalized in anthropogenic and natural habitats, especially in sandy, open, and disturbed areas. Female plants of C. selloana produce thousands of seeds that are dispersed over long distances by wind and germinate readily. Its invasive success is also attributed to its ability to adapt and tolerate a wide range of environmental conditions, such as high salinity levels, long droughts, and soil chemical pollution. Cortaderia selloana usually invades human-disturbed habitats where it encounters little competition with other plants and high resource availability. However, the species can invade natural habitats, especially those with high light availability, causing biodiversity loss and changes in ecosystem functioning (e.g. alteration of succession and nutrient dynamics). The species may cause negative socio-economic impacts by reducing productivity of tree plantations, causing respiratory allergies, and decreasing the recreational value of invaded areas. Control costs are high due to the extensive root system that C. selloana develops and the high resprouting ability following physical damage. Although herbicides are effective control measures, their use is not allowed or is undesirable in all situations where the plant occurs (e.g. near riverbanks, natural protected sites). No biological control agents have been released on C. selloana to date, but the planthopper Sacchasydne subandina and the gall midge Spanolepis selloanae are promising targets.

In situ nanoscale insights into the interfacial degradation of Zn metal anodes

Zn metal batteries are highly attractive because of their high theoretical specific capacity, intrinsic safety and resource availability. However, further development is significantly hindered by low Coulomb efficiency, which is closely linked to reaction processes occurring at electrode/electrolyte interfaces. Herein, we have achieved a real-time visualization and comprehensive analysis of the interfacial evolution of Zn metal anode via in situ AFM in organic and aqueous electrolytes, respectively. The processes of uneven nucleation, dendrite growth, the ZnO formation and the dissolution of Zn substrate are directly probed in aqueous electrolyte, which induces interfacial deterioration and ultimately results in battery failure. In organic electrolyte, the in situ observations show that the homogeneous nuclei form on the Zn surface to induce the dendrite-free deposition, however, exhibiting poor Zn plating/stripping reversibility. This work delves into the dynamic evolution and electrochemical behaviors regulated by solvents, which provides in-depth understanding of structure-reactivity correlations and further interfacial engineering.

Individual diet variability shapes the architecture of Antarctic benthic food webs

Antarctic biodiversity is affected by seasonal sea-ice dynamics driving basal resource availability. To (1) determine the role of intraspecific dietary variability in structuring benthic food webs sustaining Antarctic biodiversity, and (2) understand how food webs and the position of topologically central species vary with sea-ice cover, single benthic individuals’ diets were studied by isotopic analysis before sea-ice breakup and afterwards. Isotopic trophospecies (or Isotopic Trophic Units) were investigated and food webs reconstructed using Bayesian Mixing Models. As nodes, these webs used either ITUs regardless of their taxonomic membership (ITU-webs) or ITUs assigned to species (population-webs). Both were compared to taxonomic-webs based on taxa and their mean isotopic values. Higher resource availability after sea-ice breakup led to simpler community structure, with lower connectance and linkage density. Intra-population diet variability and compartmentalisation were crucial in determining community structure, showing population-webs to be more complex, stable and robust to biodiversity loss than taxonomic-webs. The core web, representing the minimal community ‘skeleton’ that expands opportunistically while maintaining web stability with changing resource availability, was also identified. Central nodes included the sea-urchin Sterechinus neumayeri and the bivalve Adamussium colbecki, whose diet is described in unprecedented detail. The core web, compartmentalisation and topologically central nodes represent crucial factors underlying Antarctica’s rich benthic food web persistence.

Emergence of structure in plant–pollinator networks: low floral resource constrains network specialisation

Specialisation enhances the efficiency of plant–pollinator networks through the exchange of conspecific pollen transfer for floral resources. Floral resources form the currency of plant–pollinator interactions, but the understanding of how floral resources affect the structure of plant–pollinator networks remains modest. Previous theory predicts that optimally foraging animal species will specialise to improve resource acquisition under high resource availability. Although floral resource availability depends on both the plant production and animal consumption of the resources, previous work has assumed that production and availability are equivalent. This potentially may have led to erroneous inferences on the effect of resource availability on specialisation. We develop a mutualistic Lotka–Volterra consumer‐resource model to investigate the influence of floral resource availability on plant–pollinator network structure. The model incorporates animal adaptive foraging behaviour, floral resource dynamics, and density‐dependent dynamics. Specialisation, nestedness and modularity of simulated networks generated from the model under a wide range of parameters were explained using the generalised linear model. We found that the distinction between floral resource dynamics and plant density dynamics was necessary for partial specialisation of plant–pollinator networks. This is because floral resource dynamics constrained animal preference due to its depletion by animal species. Floral resource abundance had a positive effect on network specialisation, but animal density had a negative effect on network specialisation. Floral resource dynamics thus play key roles in the structure of plant–pollinator networks, distinctive from plant species density dynamics.

Spatial and Ontogenetic Trophic Dynamics of Co-occurring Predatory Fishes in a Northern Gulf of Mexico Estuary

AbstractCo-occurring predators often exhibit ecological niche partitioning, resulting from competition over evolutionary time. However, in productive estuarine ecosystems with high resource availability, predators may occupy similar niches without conflict. Determining the degree of niche partitioning and overlap among co-occurring predators can provide insights into a food web’s function and its potential resiliency to perturbations. This study used stable isotope analysis to assess the trophic ecology of four predators in Galveston Bay, Texas, USA: spotted seatrout, black drum, bull shark, and alligator gar. Spatially distinct primary producer isotopic ratios emerged for both δ13C and δ15N following salinity regimes, which translated to similar patterns in predator tissue. The volume and overlap among species’ trophic niches also varied spatially, with species-specific expansion and contraction of niches across the freshwater-marine continuum. The observed niche patterns were likely related to movements, with implications for trophic coupling across the estuarine landscape. Using regional delineations for baseline values yielded trophic position estimates that were validated by compound-specific stable isotopes and were similar (3.77 to 3.96) for all species but black drum (3.25). Trophic position increased with body length for all species but black drum, and these relationships differed when using estuary-wide versus regionally distinct baselines. Alligator gar gut contents were examined, which primarily aligned with piscivory but also included previously unreported taxa (insect, mammal). Collectively, these results provide evidence for spatial and ontogenetic shifts in trophic ecology within this predator assemblage and highlight the importance of spatial scale when using stable isotopes to examine estuarine food webs.

Effects of leaf herbivory and autumn seasonality on plant secondary metabolites: A meta-analysis.

Plant secondary metabolites (PSMs) are produced by plants to overcome environmental challenges, both biotic and abiotic. We were interested in characterizing how autumn seasonality in temperate and subtropical climates affects overall PSM production in comparison to herbivory. Herbivory is commonly measured between spring to summer when plants have high resource availability and prioritize growth and reproduction. However, autumn seasonality also challenges plants as they cope with limited resources and prepare survival for winter. This suggests a potential gap in our understanding of how herbivory affects PSM production in autumn compared to spring/summer. Using meta-analysis, we recorded overall production of 22 different PSM subgroups from 58 published papers to calculate effect sizes from herbivory studies (absence to presence) and temperate to subtropical seasonal studies (summer to autumn), while considering other variables (e.g., plant type, increase in time since herbivory, temperature, and precipitation). We also compared production of five phenolic PSM subgroups - hydroxybenzoic acids, flavan-3-ols, flavonols, hydrolysable tannins, and condensed tannins. We wanted to detect a shared response across all PSMs and found that herbivory increased overall PSM production in herbaceous plants. Herbivory was also found to have a positive effect on individual PSM subgroups, such as flavonol production, while autumn seasonality was found to have a positive effect on flavan-3-ol and condensed tannin production. We discuss how these responses might stem from plants producing some PSMs constitutively, whereas others are induced only after herbivory, and how plants produce metabolites with higher costs only during seasons when other resources for growth and reproduction are less available, while other phenolic PSM subgroups serve more than one function for plants and such functions can be season dependent. The outcome of our meta-analysis is that autumn seasonality changes some PSM production differently from herbivory, and we see value in further investigating seasonality-herbivory interactions with plant chemical defense.

Selective method for invasive plant removal enhances restoration

Effective and sustainable restoration of habitats invaded by non‐native plant species requires both invader removal and recovery of native species. However, efficacy of removal methods and native species responses commonly depend on site conditions, spatial scale, and time, indicating invader removal and restoration approaches must consider environmental context. To better understand how selectivity of invader control methods and site conditions determine invader removal efficacy and resident community responses, we conducted an experiment with a widespread plant invader in the southeast United States (cogongrass, Imperata cylindrica) and co‐occurring resident species across nine sites that varied widely in environmental context. We found that three applications of the commonly used broad‐spectrum herbicide glyphosate reduced invader cover by 97%, on average, across the sites over 2 years. Fluazifop‐P‐butyl, a selective grass‐specific herbicide was equally effective (95% reduction in cover) in removing the invader when only two additional treatments were applied (five treatments total over 2 years) but it also helped preserve or allow for recovery of resident plant cover. Furthermore, removal efficacy was similar across sites regardless of differences in environmental conditions. Higher resource availability, as estimated by initial invader biomass at the sites, resulted in greater resident species recovery, but only under the grass‐specific herbicide treatment. Our results suggest that refocusing invasive plant management efforts from removal alone to community‐wide native species preservation and recovery, in part by using more selective invader removal strategies, has higher initial management costs but could simultaneously ease invader impacts and enhance ecosystem restoration.

Viruses, microsporidia and glyphosate residues in Africanized honey bees Apis mellifera, under field conditions

Bees are affected by several factors, including pathogens and pesticides, which may cause mortality and consequent population decline. Considering the ecological and economic importance of these pollinators, this study evaluated the occurrence of the microsporidia Nosema apis and Nosema ceranae, the viruses ABVP, DWV, BQCV, KBV, IAPV and CBPV and residues of the pesticides atrazine, chlorantraniliprole, deltamethrin, fipronil and glyphosate in workers from field colonies of Africanized honey bee Apis mellifera across one year. The presence of pesticide residues was also evaluated in honey and pollen samples. All tested viruses were found in the workers, with BQCV showing the highest copy number. BQCV levels were correlated with relative humidity. Nosema ceranae was the only microsporidian with higher intensities of infection during summer and autumn; seasons with high availability of food resources, which can act as dispersers of this pathogen. Small amounts of glyphosate and its metabolite were detected in the bees tested. These data show that honey bees are contaminated with pathogens and pesticides in the field and present correlative data for these threats.

Strategies for developing layered oxide cathodes, carbon-based anodes, and electrolytes for potassium ion batteries.

Lithium-ion batteries (LIBs) have become the most popular portable secondary energy storage facilities. However, the limited lithium resource results in possible unsustainable development. Potassium-ion batteries (PIBs) are considered promising alternatives to LIBs because of their high resource availability, low cost, and environmentally friendly features. In this field, high energy density layered cathodes and carbon-based anodes are also the main research objectives. However, compared to the most appealing alternative sodium-ion batteries (SIBs), despite having various theoretical advantages, PIBs exhibit poorer electrochemical performance in practice. Their poor capacity retention and narrow working voltage range seriously limit their applications. The performance of the electrodes is usually considered an important factor for battery performance, life, and safety. To solve these problems, many significant research studies have been carried out in the last decade, achieving numerous breakthroughs. Nevertheless, there are still many drawbacks and unclear mechanisms. In this comprehensive review, we examine the current state of high-performance layered oxide cathodes, electrolytes, and carbon-based anodes, to identify potential candidates for PIBs. Our focus lies on their structural characteristics, interface properties, underlying mechanisms, and modification techniques. The viewpoints of these advanced strategies are integrated, and concise development suggestions and strategies are subsequently proposed.

Organic electrodes based on redox-active covalent organic frameworks for lithium batteries.

Electroactive organic materials have received much attention as alternative electrodes for metal-ion batteries due to their high theoretical capacity, resource availability, and environmental friendliness. In particular, redox-active covalent organic frameworks (COFs) have recently emerged as promising electrodes due to their tunable electrochemical properties, insolubility in electrolytes, and structural versatility. In this Highlight, we review some recent strategies to improve the energy density and power density of COF electrodes for lithium batteries from the perspective of molecular design and electrode optimisation. Some other aspects such as stability and scalability are also discussed. Finally, the main challenges to improve their performance and future prospects for COF-based organic batteries are highlighted.

Cell wall epitope distribution in the functional compartments of galls induced by Palaeomystella oligophaga (Lepidoptera) in Macairea radula (Melastomataceae)

Context The parasitic interaction between the galling insect Palaeomystella oligophaga (Lepidoptera) and the host plant tissues of Macairea radula (Melastomataceae) leads to the formation of globoid galls. These galls have storage and typical nutritive tissues (outer and inner compartments, respectively), whose functions may be related to differential cell wall component distributions and to the stage of development of the gall inducer. Aims We evaluated whether the cell wall composition of the gall compartments (storage and nutritive tissues) changes according to the developmental stage of the gall inducer P. oligophaga. Methods The galls occupied by the gall inducer in different stages of development (i.e. larval and pupal stages, as well as empty galls) were collected and submitted to histological examination, immunocytochemical analyses using monoclonal antibodies for pectins, hemicelluloses, and glycoproteins, and histochemical analyses using phloroglucinol for lignins. Key results The histological results showed that nutritive tissues have smaller cells compared with storage ones when the galling insect is in the larval stage. Immunocytochemical analyses also showed the occurrence of both methyl-esterified and unesterified pectins, as well hemicelluloses in the nutritive tissue during the larval stage. The dynamic of some cell wall components changes when the gall inducer is in the pupal stage, or the galls are empty. Conclusions The changes in the composition of the cell walls, especially regarding homogalacturonans and xyloglucans, support the high metabolism and resource availability in cell walls of nutritive tissue for the gall inducer. Implications The cell wall composition may indicate important metabolic steps during gall formation and galling insect diet.

Testing intra-species variation in allocation to growth and defense in rubber tree (Hevea brasiliensis).

Plants allocate resources to growth, defense, and stress resistance, and resource availability can affect the balance between these allocations. Allocation patterns are well-known to differ among species, but what controls possible intra-specific trade-offs and if variation in growth vs. defense potentially evolves in adaptation to resource availability. We measured growth and defense in a provenance trial of rubber trees (Hevea brasiliensis) with clones originating from the Amazon basin. To test hypotheses on the allocation to growth vs. defense, we relate biomass growth and latex production to wood and leaf traits, to climate and soil variables from the location of origin, and to the genetic relatedness of the Hevea clones. Contrary to expectations, there was no trade-off between growth and defense, but latex yield and biomass growth were positively correlated, and both increased with tree size. The absence of a trade-off may be attributed to the high resource availability in a plantation, allowing trees to allocate resources to both growth and defense. Growth was weakly correlated with leaf traits, such as leaf mass per area, intrinsic water use efficiency, and leaf nitrogen content, but the relative investment in growth vs. defense was not associated with specific traits or environmental variables. Wood and leaf traits showed clinal correlations to the rainfall and soil variables of the places of origin. These traits exhibited strong phylogenetic signals, highlighting the role of genetic factors in trait variation and adaptation. The study provides insights into the interplay between resource allocation, environmental adaptations, and genetic factors in trees. However, the underlying drivers for the high variation of latex production in one of the commercially most important tree species remains unexplained.

Nutrient status changes bacterial interactions in a synthetic community.

Microbial interactions affect community stability and niche spaces in all ecosystems. However, it is not clear what factors influence these interactions, leading to changes in species fitness and ecological niches. Here, we utilized 16 monocultures and their corresponding pairwise co-cultures to measure niche changes among 16 cultivable bacterial species in a wide range of carbon sources, and we used resource availability as a parameter to alter the interactions of the synthetic bacterial community. Our results suggest that metabolic similarity drives niche deformation between bacterial species. We further found that resource limitation resulted in increased microbial inhibition and more negative interactions. At high resource availability, bacteria exhibited little inhibitory potential and stronger facilitation (in 71% of cases), promoting niche expansion. Overall, our results show that metabolic similarity induces different degrees of resource competition, altering pairwise interactions within the synthetic community and potentially modulating bacterial niches. This framework may lay the basis for understanding complex niche deformation and microbial interactions as modulated by metabolic similarity and resource availability.IMPORTANCEUnderstanding the intricate dynamics of microbial interactions is crucial for unraveling the stability and ecological roles of diverse ecosystems. However, the factors driving these interactions, leading to shifts in species fitness and ecological niches, remain inadequately explored. We demonstrate that metabolic similarity serves as a key driver of niche deformation between bacterial species. Resource availability emerges as a pivotal parameter, affecting interactions within the community. Our findings reveal heightened microbial inhibition and more negative interactions under resource-limited conditions. The prevalent facilitation is observed under conditions of high resource availability, underscoring the potential for niche expansion in such contexts. These findings emphasize that metabolic similarity induces varying degrees of resource competition, thereby altering pairwise interactions within the synthetic community and potentially modulating bacterial niches. Our workflow has broad implications for understanding the roles of metabolic similarity and resource availability in microbial interactions and for designing synthetic microbial communities.