Publications
Evolutionary history reveals spatial concentration of threatened evolutionary diversity in Agave across the Americas
A groundbreaking study reveals that the Tehuacán–Cuicatlán Valley and other arid regions in Mexico, the USA, and Guatemala are critical hotspots for threatened evolutionary diversity in Agave, hosting a disproportionate share of evolutionarily unique and endangered species. Using a time-calibrated phylogenomic framework analyzing 207 taxa and 286 nuclear genes, researchers traced Agave's origins to Aridoamerica during the late Miocene (∼7 Ma), highlighting how dispersal and macroevolutionary processes shaped its biodiversity. The study identifies 70 Evolutionarily Distinct and Globally Endangered (EDGE) taxa, with species like Agave montium-sancticaroli and A. aurea var. promontorii facing extreme conservation risks. These findings underscore the urgent need to prioritize spatial conservation efforts in these regions, where anthropogenic pressures exacerbate threats to unique evolutionary lineages.
In Vitro Antibacterial and Antioxidant Activities of Extracts of Turnera diffusa Willd. Ex Schult and Its Polyphenol Profile
Research confirms the antibacterial and antioxidant properties of Turnera diffusa, a plant traditionally used in Mexico's Tehuacán-Cuicatlán Valley for treating infections. The study found that acetone extracts of T. diffusa exhibited strong bactericidal effects against Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, S. epidermidis), with minimal inhibitory concentrations as low as 2.0 mg/mL. Methanol extracts showed significant antioxidant activity, particularly in scavenging DPPH and ABTS radicals, and reducing ferric ions, likely due to their high polyphenol content (6.052%). The study used diffusion and agar dilution assays for antibacterial testing, microbial survival curves, and colorimetric/HPLC analyses for chemical profiling. These findings validate the plant's medicinal use and highlight its potential in treating infectious diseases and oxidative stress.
Novelties in the genus Stylosanthes (Leguminosae, Papilionoideae, Dalbergieae) for Mexico
A taxonomic and molecular study identifies three new species of the genus Stylosanthes (Leguminosae) endemic to Mexico, expanding the country's botanical diversity. These discoveries—Stylosanthes leticiana, S. rosalindae, and S. gretheriae—are supported by detailed morphological descriptions, distribution maps, and comparative scanning electron microscope (SEM) images of their fruits. Stylosanthes leticiana exhibits a broad distribution in Mexico with affinities to S. humilis, while S. rosalindae is primarily found in the central-southern region, particularly within the UNESCO-listed Tehuacán-Cuicatlán Valley, showing morphological similarities to S. subsericea and S. viscosa. Meanwhile, S. gretheriae occurs in western Mexico and shares traits with S. guianensis. This research contributes critical insights into the biodiversity of Mesoamerica's originary habitat, highlighting the region's ecological significance.
Spatial phylogenetics of the genus Melampodium (Millerieae: Asteraceae)
Research on the genus Melampodium (Asteraceae) reveals Mexico as a primary center for its diversification and endemism, with distinct phyloregions characterized by phylogenetic clustering. The study identified four types of phylogenetic endemism—neo-, palaeo-, mixed-, and super-endemism—with palaeo-endemisms linked to higher elevations and greater environmental stability since the Pliocene. Phylogenetic overdispersion was notably found in the Tehuacán–Cuicatlán Valley suggesting unique evolutionary dynamics. The research used spatial phylogenetics, including categorical analysis of endemism, Wilcoxon tests for environmental variables, and phylogenetic Sorensen dissimilarity to map phyloregions. Chromosomal evidence supported some findings, reinforcing Mexico's significance in the genus' evolutionary history.
Arid and Semi-Arid Zones of Mexico: A Comprehensive Exploration of Biodiversity, Ecology, and Conservation
Mexico's arid and semi-arid zones, including the Tehuacán-Cuicatlán Valley, are revealed as ecologically distinctive and biologically rich landscapes through a multidisciplinary examination. This comprehensive study highlights the unique climatic, physical, and biological characteristics of these regions, focusing on emblematic plant and animal species, ecological processes, and human impacts. The research emphasizes conservation priorities, particularly in protected natural areas and germplasm resources, with cacti serving as umbrella taxa. Additionally, it documents the medicinal and biologically active products derived from arid-zone flora, underscoring their ecological and cultural significance. By integrating case studies across four major arid regions—Baja California Peninsula, Chihuahuan Desert, Sonoran Desert, and Tehuacán-Cuicatlán Valley—the study provides integrative analyses of biodiversity trends and conservation strategies.
Axantismo en el Sapo de Espuelas Mexicano, Spea multiplicata (Scaphiopodidae)
A rare case of axanthism, characterized by partial loss of pigmentation, has been documented in the Mexican spadefoot toad (Spea multiplicata) from a dam in the Tehuacán-Cuicatlán Valley, Puebla, Mexico. This observation represents the first record of this chromatic anomaly in the species and contributes to the growing list of amphibians in Mexico exhibiting such traits. While axanthism is uncommon, its documentation provides valuable insights into the biology of S. multiplicata, raising questions about its ecological implications and potential effects on individual survival. The study highlights the importance of monitoring and understanding such anomalies to deepen our knowledge of species' adaptations and vulnerabilities.
Ex situ Conservation of Mexican Flora from Arid Regions: How Well is it Represented in the FESIUNAM Seed Bank?
The FESI-UNAM Seed Bank (SB) holds over 5,200 accessions of approximately 2,500 species from Mexico's arid regions, with a notable concentration of endemic and threatened flora. The SB's collection includes 2,135 accessions from these zones, representing 1,182 species across 547 genera and 108 families. Regions like the Tehuacán-Cuicatlán Valley and central Mexico dominate the collection, with Asteraceae, Fabaceae, and Cactaceae comprising nearly half of the samples. However, significant gaps remain in representation, particularly for endangered or endemic species in underrepresented regions. The study identifies these gaps to guide future conservation efforts, emphasizing the need to bolster seed collections from arid zones to safeguard Mexico's unique biodiversity.
Fungi and Myxomycetes of the Tehuacán‐Cuicatlán Biosphere Reserve, Mexico: A Comprehensive Review and Future Perspectives
The Tehuacán-Cuicatlán Biosphere Reserve in Mexico hosts 436 taxa of fungi and myxomycetes, including 266 fungal species and 170 myxomycete taxa, many adapted to arid conditions. This first comprehensive inventory highlights their role as bioindicators for ecosystem health and climate resilience, with potential applications in drug discovery and agricultural sustainability. The study combines mycological literature reviews and biodiversity databases to document these organisms' variability and adaptive strategies under environmental stress. Interdisciplinary research is proposed to leverage fungi's polyextremotolerant traits for conservation and climate mitigation efforts.
Restoration implications of the germination ecology of six dry-forest woody Fabaceae species in Mexico
Seed germination responses to temperature and light vary significantly among six dry-forest woody Fabaceae species, offering critical insights for ecological restoration and climate change adaptation. The study found that mechanical scarification substantially increases germination rates, while higher temperatures generally accelerate germination in dark conditions, though responses in germination synchrony differ among species. These findings highlight the importance of understanding not just germination percentage and time but also synchrony to guide effective management actions. The research involved a multifactorial experiment with five temperature ranges (10–40 °C), two light regimes, and scarification conditions for species such as Mimosa luisana and Vachellia constricta, which are ecologically, culturally, or economically significant in the Tehuacán-Cuicatlán Valley, Mexico. The study underscores potential threats to natural recruitment due to warmer, drier conditions and deforestation, emphasizing the need for targeted restoration strategies.
The “milpa-chichipera” ethno-agroforestry system as a buffer against land-use change impacting arbuscular mycorrhizal fungi in a semiarid Mexican ecosystem
Research reveals that the traditional 'milpa-chichipera' ethno-agroforestry system in Mexico's Tehuacán-Cuicatlán Valley acts as a critical buffer against land-use change, preserving arbuscular mycorrhizal fungi (AMF) diversity and abundance. Unlike intensive monocropping agriculture, which significantly depletes AMF communities, this system—rooted in native plant conservation—mirrors the biodiversity hotspots found in preserved scrub lands. The study identified 58 AMF species across 17 genera, with higher spore abundance, richness, and diversity in vegetation patches within the 'milpa-chichipera' system compared to open areas or agricultural fields. Seasonal variations further shaped AMF composition, tied to native host plants and soil features. This suggests that integrating traditional agroforestry practices can mitigate the ecological impacts of land-use intensification on mycorrhizal fungi.
Viability and Morphometry in Agave Seeds as an Initial Study for Sustainable Management and Genetic Preservation
A. marmorata seeds exhibit the highest viability (78.49% at 72 hours), indicating robust physiological adaptations, while A. potatorum shows the lowest (57.99%), suggesting potential reproductive challenges. Morphometric analysis revealed significant interspecific differences, with A. angustifolia seeds being the largest and A. marmorata the smallest. This study highlights critical variability in seed viability and morphometric traits among Agave species in the Tehuacán-Cuicatlán Valley (TCV), a biodiversity hotspot. Researchers collected seeds from five Agave species, subjected them to controlled dehydration and storage, then assessed viability using the tetrazolium chloride (TTC) test while measuring length, width, weight, and volume. These findings provide key insights for conservation strategies and sustainable management of Agave populations, influencing regeneration efforts and breeding programs.
Agrosilviculturas tradicionales que mantienen la diversidad vegetal nativa del Valle de Tehuacán-Cuicatlán: un panorama regional
Traditional agroforestry systems (AFS) in the Tehuacán-Cuicatlán Valley, Mexico, can preserve 68% of native perennial plant species and 34% of individuals found in surrounding wild vegetation. A redundancy analysis and generalized linear models revealed that while AFS maintain similar species composition and diversity to wild vegetation across most forest types, thorn forests showed a notable reduction in species richness and altered composition. Despite lower individual abundance in AFS, these systems emerge as a viable strategy for biodiversity conservation, underscoring the need for fair valuation and promotion of peasant agroecological management practices in regional conservation policies.
Federated Learning Based Enhanced FedBA with MobileNet Convolutional Neural Network for the Identification of Columnar Cactus
A novel federated learning (FL) framework, enhanced FedBA with MobileNet CNN, achieves 97% accuracy in identifying columnar cactus species from UAV-collected images in the UNESCO-listed Tehuacán-Cuicatlán Valley. This approach addresses key challenges in FL for non-IID data, including slow convergence and high communication costs, by integrating momentum for faster learning, adaptive learning rates, and model aggregation clipping. Evaluated on a dataset of over 20,000 remote sensing images, the proposed method outperforms traditional models like InceptionV3 and modified MobileNet CNN, offering a privacy-preserving solution that mitigates data sharing risks while maintaining high accuracy.
The evolution of paleo- and neo-endemic species of Cactaceae in the isolated Valley of Tehuacán-Cuicatlán, Mexico
Research reveals that the Tehuacán-Cuicatlán Valley has served as a stable refuge for cactus species throughout Pleistocene climatic shifts. Most endemic Cactaceae emerged during this period, with a mix of paleo- and neo-endemics concentrated in topographically rugged and ecologically complex zones. The study used dated molecular phylogeny to classify endemism, finding that the valley's high climatic stability and diverse habitats likely fostered speciation, particularly of neo-endemics, while also preserving ancient paleo-endemic species. This highlights the valley's role as a biodiversity hotspot with distinct evolutionary patterns.
Pollen morphology of columnar cacti from Tehuacán-Cuicatlán Valley, Mexico
A detailed analysis of pollen morphology reveals that the 19 species of columnar cacti found in the Tehuacán-Cuicatlán Valley, Mexico—a biodiversity hotspot—share highly similar pollen structures. Despite this similarity, combined microscopy techniques allowed researchers to distinguish each species based on subtle differences in spinule dimensions and columellae distribution patterns. The study provides a synoptic table differentiating these species, offering new insights into their taxonomic relationships and evolutionary history.
Biogeographic units in the Chihuahuan Desert: Implications for regionalization and area nomenclature
Researchers have identified eight distinct biogeographic units within the Chihuahuan Desert, including subprovinces and districts that represent natural biotic regions. These units, such as the Trans-Pecos and Mapimian districts in the Chihuahuan subprovince, along with the Tehuacán-Cuicatlán Valley district in the Mexican Plateau subprovince, are characterized by unique assemblages of endemic taxa. The study compared existing regionalizations to uncover similarities and differences, providing a framework for understanding biodiversity patterns in this arid region. This classification offers critical insights for conservation efforts and regional nomenclature.
Mitochondrial DNA sequences and nuclear microsatellites reveal population genetic structure of the range-restricted hummingbirdPhaeoptila sordidain the Balsas Basin
A new genetic analysis of the Dusky Hummingbird (Phaeoptila sordida) challenges the traditional view of the Balsas Basin as a distinct biogeographical unit. Using mitochondrial DNA (mtDNA) and nuclear microsatellites, researchers found discordant population structures: mtDNA grouped samples from the Balsas Basin separately from those in the Tehuacán-Cuicatlán Valley and Valles Centrales, while nuclear markers revealed two habitat-specific clusters within the region. Ecological niche modeling suggested historical range instability, with contractions during interglacial periods and expansions at glacial maxima, supporting the interglacial refugia hypothesis. The study highlights the impact of ecological and climatic factors on species diversification and underscores the need for conservation efforts in these endemic-rich areas.
SEM Pollen Morphology of Columnar Cacti Polaskia from Tehuacán-Cuicatlán Valley, Mexico
Scanning Electron Microscopy (SEM) analysis of Polaskia columnar cacti from the Tehuacán-Cuicatlán Valley reveals distinct pollen morphological traits that contribute to understanding the species' reproductive biology and taxonomic relationships. The study identified key features such as pollen grain size, exine structure, and surface ornamentation, which vary among Polaskia taxa. These findings provide insights into the evolutionary adaptations of columnar cacti in this region, known for its high biodiversity and cultural significance. The research employed SEM to examine pollen samples, offering a detailed characterization that enhances our knowledge of Mesoamerica's native flora.
An Enhanced Randomly Initialized Convolutional Neural Network for Columnar Cactus Recognition in Unmanned Aerial Vehicle imagery
A new deep learning model, the Enhanced Randomly Initialized Convolutional Neural Network (ERI-CNN), achieves high accuracy in recognizing columnar cacti from unmanned aerial vehicle (UAV) imagery. With 98% accuracy, 97% precision and recall, and an F1-score of 97.5%, the model outperforms existing architectures like InceptionV3 and modified LeNet-5 when tested on a dataset of over 20,000 remote sensing images from Mexico's Tehuacán-Cuicatlán Valley. This advancement in plant recognition technology supports environmental conservation efforts by improving surveillance and monitoring of protected ecosystems.
Biocrusts inside and outside of Mimosa luisana resource islands as reservoirs of arbuscular mycorrhizal fungi in a Mexican semiarid ecosystem
Biocrusts (BC) inside and outside Mimosa luisana resource islands (M. luisana-RI) act as reservoirs for arbuscular mycorrhizal fungi (AMF), harboring 12 species compared to just five in open areas, while also protecting AMF from environmental stressors. Seasonal variations suggest water availability drives AMF assemblages. The study found that BC, particularly outside M. luisana-RI, buffer soil AMF loss, forming potential mycorrhizal inocula. Researchers analyzed spore abundance, species richness, and propagation potential in both rainy and dry seasons using laboratory and greenhouse experiments.
Evaluation of the Antimicrobial Activity of Some Components of the Essential Oils of Plants Used in the Traditional Medicine of the Tehuacán-Cuicatlán Valley, Puebla, México
Research on the Tehuacán-Cuicatlán Valley reveals that essential oils from medicinal plants used in traditional medicine contain antimicrobial compounds like eugenol and carvacrol. These compounds exhibit strong antibacterial and fungicidal effects against Gram-positive and Gram-negative bacteria, as well as certain yeasts. Eugenol, carvacrol, and thymol demonstrated the lowest minimum inhibitory concentrations (MIC) and bactericidal activity at MIC levels for specific strains, including S. aureus, E. coli, and C. albicans. The study used Kirby-Baüer agar diffusion and agar dilution methods to assess antimicrobial efficacy, highlighting the potential of these plant-derived compounds as natural alternatives in medicine.
Peasants’ Motivations to Maintain Vegetation of Tropical Dry Forests in Traditional Agroforestry Systems from Cuicatlán, Oaxaca, Mexico
Traditional agroforestry systems (TAFS) in the Tehuacán-Cuicatlán Valley, Mexico, play a critical role in biodiversity conservation and ecosystem resilience. Peasants maintain wild vegetation in these systems primarily for material benefits such as edible fruits, medicinal plants, fodder, and firewood, which account for 62% of their motivations. These TAFS also provide regulating services like shade, soil fertility, and humidity retention, as well as non-material contributions such as regional flavors and ritual uses. The study found that higher forest cover in these systems correlates with greater species diversity and a broader range of socio-ecological benefits, meeting fundamental human needs for subsistence, identity, and protection. While peasant agriculture supports biodiversity, its potential is hindered by inefficiencies and lack of profitability, necessitating revitalization to ensure environmental sustainability and people’s well-being.
Unraveling Reticulate Evolution in Opuntia (Cactaceae) From Southern Mexico
A study challenges the hybrid origin of Opuntia tehuacana, revealing instead introgression involving O. decumbens and O. huajuapensis, while confirming hybridization in O. pilifera with O. decumbens as a probable parent. Using two nuclear intron markers, researchers constructed phylogenetic networks to analyze reticulate evolution in southern Mexican Opuntia species from the Tehuacán-Cuicatlán Valley, a biodiversity hotspot. The findings suggest new cases of hybridization and introgression among these species, including O. tehuantepecana and O. depressa as parental species for O. velutina and O. decumbens. This research advances understanding of genetic exchange patterns in this taxonomically complex cactus genus.
Adiciones a la familia Bromeliaceae en Veracruz, México
A recent study has uncovered three previously unrecorded bromeliad species in Veracruz, Mexico: two Tillandsia species (T. bourgaei and T. roseoscapa) and one Pitcairnia (P. xanthocalyx), alongside the rediscovery of Tillandsia prodigiosa. This research, conducted through botanical expeditions and herbarium reviews, highlights the understudied flora of Veracruz's central and northern regions, particularly the xerophytic vegetation shared with the Tehuacán-Cuicatlán Valley—a UNESCO World Heritage Site. The findings underscore the region's biodiversity significance, revealing new insights into its unique plant communities.
Phylogeography and Genetic Diversity in a Southern North American Desert: Agave kerchovei From the Tehuacán-Cuicatlán Valley, Mexico
High genetic diversity and strong population structuring in the endemic Agave kerchovei suggest that Pleistocene glacial cycles shaped its distribution within the Tehuacán-Cuicatlán Valley. The study sequenced three non-coding chloroplast regions from 128 individuals across eight populations, revealing total chloroplast genetic variation (Hd = 0.718) despite restricted distribution, with low intrapopulation diversity and high genetic structure (FST = 0.928). Ecological niche models indicated stable potential distribution since the middle Holocene (6 kya), while core valley populations appear distinct from peripheral ones, hinting at incipient speciation outside the Tehuacán Valley.
Traditional Agroforestry Systems and Conservation of Native Plant Diversity of Seasonally Dry Tropical Forests
Traditional agroforestry systems (TAFS) in the Tehuacán-Cuicatlán Valley, Mexico, demonstrate significant potential for conserving native plant diversity in seasonally dry tropical forests. These systems maintain 68% of species and 53% of individual abundance found in adjacent tropical dry forests (TDF), including 30% of Mexico's endemic plants. Despite similar species richness between TAFS and TDF, the high species turnover (74%) in both suggests that multiple sites are necessary to preserve regional diversity. Peasants' motivations for maintaining native vegetation include material, non-material, and regulatory factors, highlighting the socio-ecological benefits of TAFS. This study underscores the importance of integrating traditional practices with conservation efforts to balance biodiversity protection and social well-being.
Use and management of wild fauna by people of the Tehuacán-Cuicatlán Valley and surrounding areas, Mexico
The Tehuacán-Cuicatlán Valley (TCV) in Mexico, recognized for its high biodiversity and ancient agricultural significance, supports 652 vertebrate species and 765 insect species. A study reveals that 107 wild animal species are used by local communities—primarily Nahua, Cuicatec, Popolocan, Ixcatec, Mazatec, and Mestizo—for food (65.42%), ornamental (27.52%), and medicinal (21.10%) purposes. These practices include manual capture, hunting, trapping, relocation, and captivity care, with some involving temporal or spatial planning and communal regulations. The research, based on a review of 38 documents and case studies from 1967 to 2018, highlights the valley's biocultural significance while identifying gaps in ethnozoological knowledge for Mixtec, Chinantec, and Chocholtec groups. Nearly 178 species used elsewhere in Mesoamerica remain undocumented in this region.
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