Research in Ecology

Effects of Tillandsia recurvata Colonization on Vegetative Reserve Compounds in Neltuma laevigata

José Luis Escobar-De Luna — 2026-09-09

Mesquite species are widely distributed across arid and semi-arid regions and provide important ecological and socioeconomic benefits, including timber, livestock forage, fuelwood, and food for human consumption. However, mesquite woodlands are threatened by several biotic factors, including insect pests, parasitic plants, and epiphytes. The abundance of the atmospheric epiphyte Tillandsia recurvata has been associated with the mineral characteristics of potential host-tree canopies. This study evaluated whether colonization by T. recurvata was associated with changes in nitrogenous compounds and carbohydrate reserves in natural stands of Neltuma laevigata in northern Mexico. Total soluble proteins were quantified using the Bradford method, total free amino acids using the Yemm and Cocking method, starch using a colorimetric iodine-based procedure, and total soluble sugars using the Van Handel method. Roots, stems, leaves, and fruits were compared between trees growing at a site colonized by T. recurvata and trees at a site where the epiphyte was absent. Total soluble protein concentrations did not differ significantly between sites in any of the evaluated organs. In contrast, significant differences in total free amino acid and starch concentrations were detected in all organs. Total soluble sugars concentrations did not differ significantly in roots or fruits, whereas significant differences were observed in stems and leaves. These findings indicate that T. recurvata colonization was associated with organ-specific variation in the nitrogen and carbon reserve compounds of N. laevigata, although total soluble protein concentrations remained unchanged.

Genetic Diversity and Population Structure of Hilacha Mango (Mangifera indica L.) in Montería, Colombia Based on SSR Markers

Luisa Causil — 2026-09-07

Understanding the distribution of genetic diversity within cultivated plant populations is essential for developing effective conservation and sustainable management strategies. Hilacha mango (Mangifera indica L.) is one of the most important traditional landraces cultivated in the Colombian Caribbean; however, information on its genetic diversity and population structure remains limited. This study assessed the genetic diversity and population structure of five Hilacha mango populations from Montería, Córdoba, Colombia, using eight Simple Sequence Repeats (SSR) loci. A total of 47 accessions were genotyped, and genetic diversity indices, Wright's F-statistics, gene flow, analysis of molecular variance (AMOVA), Bayesian clustering, and principal coordinates analysis were performed. The SSR loci revealed substantial allelic variation, with pronounced differences in allele distribution among populations. Florida and San Anterito exhibited the highest levels of allelic richness and genetic diversity, whereas all populations showed lower observed than expected heterozygosity, indicating a generalized heterozygote deficit. Wright's statistics revealed moderate genetic differentiation, mean Fixation Index (F_ST) = 0.109 and relatively high number of migrants per generation (Nm) of 2.464, suggesting that historical germplasm exchange has contributed to maintaining genetic connectivity among populations. AMOVA further showed that most genetic variation was distributed among individuals within populations rather than among populations. These findings demonstrate that Hilacha mango populations in Montería constitute a valuable reservoir of genetic diversity and provide a robust molecular foundation for germplasm conservation, sustainable management, and future breeding programs aimed at preserving this traditional mango landrace.

Evolutionary Game Analysis of Construction Suspension Supervision under Persistent Disasters in the Greater Bay Area

Hanxiang Gong — 2026-09-03

This study aims to provide a methodological contribution by demonstrating how to incorporate exogenous environmental temporal dynamics into evolutionary game models. Unlike existing adaptive Evolutionary Game Theory (EGT) models that primarily capture endogenous behavioral feedback (e.g., adjusting penalties based on violation rates), this framework mathematically formalizes how external environmental duration structurally alters the payoff matrix over time. Using the persistent typhoons in the Greater Bay Area (GBA) purely as a narrative device, this study examines how disaster duration alters the cost-benefit structure of suspension supervision and identifies conditions to prevent regulatory failure. We built a tripartite evolutionary game model among government regulatory departments, construction units, and third-party subjects. A disaster persistence index (D) was explicitly embedded into compliance costs, accident losses, and governance benefits. We also treated detection probability as a dynamic variable. Replicator dynamics and numerical simulations were used to analyze equilibrium stability and parameter sensitivity. The system reaches an ideal safety equilibrium (compliant suspension, diligent performance, strict supervision) when compliance returns and diligence benefits outweigh violation and collusion gains. However, as disaster duration (D) extends, accumulating compliance costs quickly erode compliance incentives. This shift can drive the system into a dangerous state of "violation and dereliction" despite strict supervision. Sensitivity analysis reveals that compliance costs have a critical threshold effect. While higher fines promote compliance, their marginal utility diminishes. Furthermore, excessive collusion rent induces third-party dereliction, and rising regulatory costs threaten supervision sustainability. The model theoretically supports a shift toward dynamic governance. While mechanisms like duration-linked penalties or targeted compensation align with the mathematical conditions for safety equilibrium, these remain theoretical pathways requiring empirical validation before practical application.

Environmental Drivers and Group Defense Strategies in Diffusive and Non-Diffusive Predator-Prey Dynamics

Muhammad Shoaib Arif — 2026-09-18

Predator-prey dynamics are strongly influenced by environmental factors, such as the availability of resources, habitat quality and climatic conditions, which determine species survival, species reproduction and aggregate defensive behaviour. Using these ecological processes, a three-species predator-prey model is formulated and analysed, with prey group defence dependent on an environmental logistic function. Predation intensity, influenced by environmental conditions, is examined, and the long-term dynamics of interacting populations under these conditions are explored. Biologically plausible equilibrium points are verified, and their local and global stability is thoroughly investigated by the Routh-Hurwitz criterion and Lyapunov function methods, respectively. The governing equations are modified to include diffusion terms to describe the dispersal of species in space, leading to a reaction-diffusion system that describes the spread of species in heterogeneous habitats. A three-level finite difference scheme is developed to approximate the diffusive model, and its numerical stability is examined through Von Neumann analysis. Furthermore, the stability of the reaction-diffusion system is investigated using a Fourier series expansion and the Routh-Hurwitz criterion. Increased effective predation, larger population oscillations, and less stable coexistence between species are shown to result from a reduction in the strength of environmentally regulated group defence. In contrast, diffusion can help smooth spatial population gradients, making the ecosystem more resilient to effective predation and promoting species redistribution. The mathematical model proposed here can contribute to a better understanding of the complex interplay between environmental drivers, collective defense, and spatial dispersion in predator-prey dynamics and is potentially applicable to ecological modelling, biodiversity conservation, habitat management, and the analysis of spatially structured ecosystems.