Efraín Tovar-Sánchez

• PhD
• Senior Professor-Researcher at Universidad Autónoma del Estado de Morelos

Hybridization is frequent in oaks and may drive various evolutionary and ecological effects on involved plant populations and their associated species. Quercus castanea is a species of Mexican red oak that has served as a valuable model for examining the effects of hybridization events. We used a multimarker approach to characterize the morphologic...

Widespread use of pesticides in agriculture causes adverse impacts on non-target organisms and environmental pollution. Efficient and sustainable pesticide removal alternatives must be developed to reduce pesticide environmental impacts. Recently, bioremediation based on immobilized microorganisms has been proposed as an environmentally friendly an...

Herbicides are the most employed pesticides in agriculture worldwide; among them, glyphosate is the most successful herbicide molecule in history. The extensive use of glyphosate has been related to environmental pollution and toxic effects on non-target organisms. Effective remediation and treatment alternatives must be developed to reduce the env...

Lichens are organisms whose dynamics take place on terrestrial substrates such as rock, dead wood, living plants, and soil. Living trees are used for lichens as structural support to access light. However, little is known about how the genetic traits of a host tree influence which lichen species grow on it and, consequently, the community structure...

Heavy metals are among the most toxic environmental pollutants. They are a group of chemical elements broadly distributed in different environments. Anthropogenic activities such as agriculture, livestock farming, and mining release large amounts of waste that contain toxic heavy metals into the environment. Bacteria are organisms that present a wi...

The hybridization phenomenon increases genetic diversity and modifies recombinant individuals’ secondary metabolite (SMs) content, affecting the canopy-dependent community. Hybridization events occur when Quercus rugosa and Q. glabrescens oaks converge in sympatry. Here, we analyzed the effect of the genetic diversity (He) and SMs of Q. rugosa, Q....

Water pollution by metals is a global environmental problem. In riparian ecosystems, metal pollution generates adverse effects on organisms and reduces water quality. The Cuautla River is of great ecological relevance and an important water supplier. However, it is polluted by multiple wastewater discharges from different origins, with toxic metals...

The waste generated during metal mining activities contains mixtures of heavy metals (HM) that are not biodegradable and can accumulate in the surrounding biota, increasing risk to human and environmental health. Plant species with the capacity to grow and develop on mine tailings can be used as a model system in phytoremediation studies. Dodonaea...

La selva tropical estacionalmente seca (STES) o bosque tropical caducifolio, es un tipo de vegetación que se desarrolla en áreas cálidas y semicálidas; su comunidad vegetal está conformada por árboles de baja altura, entre 8 y 12 m, con copas extendidas y con un estrato arbustivo muy denso. La característica particular de este tipo de vegetación es...

Medicines are pharmaceutical substances used to treat, prevent, or relieve symptoms of different diseases in animals and humans. However, their large-scale production and use worldwide cause their release to the environment. Pharmaceutical molecules are currently considered emerging pollutants that enter water bodies due to inadequate management, a...

En las últimas décadas, se ha incrementado considerablemente el deterioro del planeta por actividades antropogénicas a través de la liberación de sustancias tóxicas al ambiente. Uno de los contaminantes de interés ambiental son los desechos producidos por la actividad minera, principalmente porque produce el 65 % del total de los residuos industria...

The increasing demand for mineral resources has generated mine tailings with heavy metals (HM) that negatively impact human and ecosystem health. Therefore, it is necessary to implement strategies that promote the immobilization or elimination of HM, like phytoremediation. However, the toxic effect of metals may affect plant establishment, growth,...

The steadily increasing presence of both natural and anthropogenic pollutants in our environment poses a considerable challenge, given the recalcitrance of many of these pollutants. Microbial bioremediation presents a promising and sustainable strategy that harnesses a diverse array of microorganisms, operating either concurrently or sequentially,...

The steadily increasing presence of both natural and anthropogenic pollutants in our environment poses a considerable challenge, given the recalcitrance of many of these pollutants. Microbial bioremediation presents a promising and sustainable strategy that harnesses a diverse array of microorganisms, operating either concurrently or sequentially,...

El Grupo Intergubernamental de Expertos sobre el Cambio Climático (Intergovernmental Panel on Climate Change o IPCC, por sus siglas en inglés) ha definido el cambio climático como “cualquier cambio en el clima a través del tiempo, ya sea debido a su variabilidad natural o como resultado de la actividad humana”. A nivel internacional se reconoce al...

La influencia del clima sobre la salud humana fue reconocida por Hipócrates desde el siglo IV o V A.C. Actualmente, hay un renovado interés en este tema debido a la preocupación de los efectos negativos particularmente del calentamiento global (CG) sobre la salud humana. La evidencia científica indica que el cambio climático global (CCG) ya ha afec...

Phytoremediation is a useful, low-cost, and environmentally friendly alternative for the rehabilitation of heavy-metal-contaminated (HM) soils. This technology takes advantage of the ability of certain plant species to accumulate HMs in their tissues. Crotalaria pumila is a herbaceous plant with a wide geographical distribution that grows naturally...

Citation: Santoyo-Martínez, M.; Mussali-Galante, P.; Hernández-Plata, I.; Valencia-Cuevas, L.; Rodríguez, A.; Castrejón-Godínez, M.L.; Tovar-Sánchez, E. Phytoremediation Potential of Crotalaria pumila (Fabaceae) in Soils Polluted with Heavy Metals: Evidence from Field and Controlled Experiments. Plants 2024, 13, 1947. https://doi. Abstract: Phytore...

Mining is a major economic activity in many developing countries. However, it disturbs the environment, producing enormous quantities of waste, known as mine tailings, which can have deleterious environmental impact, due to their high heavy metals (HM) content. Often, foundation species that establish on mine tailings are good candidates to study t...

Glyphosate is a broad spectrum and non-selective herbicide employed to control different weeds in agricultural and urban zones and to facilitate the harvest of various crops. Currently, glyphosate-based formulations are the most employed herbicides in agriculture worldwide. Extensive use of glyphosate has been related to environmental pollution eve...

Background and Research Aims: Morphological and physiological effects of anthropogenic metals have been the focus of several studies in the Sierra de Huautla Biosphere Reserve (REBIOSH, Mexico) but little is known about how they affect anurans in the area. We evaluated metal bioaccumulation in anurans from streams in the REBIOSH and examined anuran...

With the aim of exploring the source of the high variability observed in the production of perezone, in Acourtia cordata wild plants, we analyze the influence of soil parameters and phenotypic characteristics on its perezone content. Perezone is a sesquiterpene quinone responsible for several pharmacological effects and the A . cordata plants are t...

Mexico is a major center of evolutionary radiation for the genus Quercus , with oak species occurring across different habitat types and showing a wide variation in morphology and growth form. Despite representing about 20% of Mexican species, scrub oaks have received little attention and even basic aspects of their taxonomy and geographic distribu...

The hybridization phenomenon is recognized as an important evolutionary force that influences the diversification and evolution of different vascular plant groups. Hence, it is important to identify hybrid individuals. In Mexico, the dry tropical forest (DTF) is considered as the main center of diversification and endemism of the Bursera genus, con...

Pesticides are chemical molecules employed to protect crops from pests in agriculture. The use of pesticides significantly enhances crop yields and helps to guarantee the quality of farm products; due to this, each year, millions of tons of pesticides are employed in crop fields worldwide. However, the extensive use of pesticides has been related t...

Heavy metal pollution is a worldwide environmental and human health problem. Prosopis laevigata is a hyperaccumulator legume that bioaccumulates Pb, Cu and Zn. With interest in designing phytoremediation strategies for sites contaminated with heavy metals, we isolated and characterized endophytic fungi from the roots of P. laevigata growing on mine...

The pollution generated by the heavy metals (HM) contained in mining wastes (tailings) is a worldwide recognized environmental concern. Due to the persistence, toxicity, bioaccumulation, and biomagnification capacity through the food chains, the release of HM into the environment causes negative effects on human health and the ecosystems. Wigandia...

As a result of mining activities, waste of different types is generated. One example is mine tailings that contain potentially toxic elements such as heavy metals that negatively impact the environment and human health. Hence, developing treatments to guarantee its efficient elimination from the environment is necessary. Among these treatments, phy...

Phytoremediation is a cost-effective technique to remediate heavy metal (HM) polluted sites. However, the toxic effects of HM can limit plant establishment and development, reducing phytoremediation effectiveness. Therefore, the addition of organic amendments to mine wastes, such as biochar, improves the establishment of plants and reduces the bioa...

Mexico is considered one of the main regions of diversification of the genus Quercus (oaks). Oak species are one of the most important tree groups, particularly in temperate forests, due to its diversity and abundance. Some studies have shown that oak contains specialized metabolites with medicinal importance. In this work, the acetonic extract fro...

The galls induced by cynipids in host oaks have been proposed as biodiversity hotspots. They constitute support for the development of arthropod communities of great diversity and functional complexity that find in them nutrition and protection from external abiotic and biotic elements which change according to environmental gradients. We character...

Dodonaea viscosa (L.) Jacq. is a plant with a wide distribution that expands throughout almost all Mexican territory and is used in traditional medicine to treat many ailments. This species has been found associated with polluted areas, including mine tailings. Huautla, Morelos, Mexico, was a metallurgic district where mining activities generated 7...

Methyl parathion is an organophosphorus pesticide widely employed worldwide to control pests in agricultural and domestic environments. However, due to its intensive use, high toxicity, and environmental persistence, methyl parathion is recognized as an important ecosystem and human health threat, causing severe environmental pollution events and n...

The use of pesticides in agriculture worldwide significantly offers crop protection from pests, enhances crop yields, and guarantees the quality of the agricultural products during storage, which generates economic benefits for farmers. Due to this, millions of tons of pesticides are released into crop fields each year. However, only a small propor...

The presence of different Persistent Organic Pollutants (POPs), such as organochlorine pesticides, polybrominated diphenyl ethers, polychlorinated aromatic compounds, polychlorinated dibenzofurans, polychlorinated dibenzo-p-dioxins, among others, has been reported in agricultural and industrial areas across different regions worldwide. POPs are hig...

Zephyranthes (Amaryllidaceae) is a taxonomically complex genus due to the frequent overlap of interspecific morphological variation. In Mexico, Z. alba and Z. fosteri are herbaceous plants that, when distributed in sympatry, generate individuals with complex patterns of morphological variation, leading to taxonomic confusion. Therefore, it is neces...

Background and Aims: The species Ulex europaeus (Fabaceae, Faboideae) has been listed as one of the 100 most harmful invasive species worldwide. It is native to western Europe and northwestern Africa and has become naturalized throughout Europe and the Middle East. Its environmental and economic impact in America is documented in Canada, Chile, Col...

Unlike organic contaminants, metals cannot be degraded and tend to bioaccumulate in the organism promoting their biomagnification along the food chains; therefore, sanitation of heavy metals (HMs) contaminated sites is a priority because HMs can affect all levels of biological organization—from molecules to ecosystems—including human health. Phytor...

Differentiation among populations, sometimes despite ongoing gene exchange, is a key step in speciation. Therefore, comparison of intra- and interspecific differentiation patterns is of great significance to understanding speciation. The genus Quercus is an interesting system to test speciation models in the presence of gene flow, due to its weak i...

Glyphosate is a broad-spectrum herbicide extensively used worldwide to eliminate weeds in agricultural areas. Since its market introduction in the 70's, the levels of glyphosate agricultural use have increased, mainly due to the introduction of glyphosate-resistant transgenic crops in the 90's. Glyphosate presence in the environment causes pollutio...

Wild animals that inhabit inside mine tailings which contain heavy metals are an excellent study model to conduct ecotoxicological studies that analyze chronic metal exposures at low doses (realistic exposures). This study was conducted in Huautla, Morelos, Mexico, in a mining district where 780,000 tons of wastes were deposited in open air. Liomys...

Mining activities have more than 450 years of tradition in Mexico. This extractive activity has great relevance in the country’s economy and development. However, mining activity and the processes used for the extraction of metallic minerals of economic interest generate a large amount of wastes, called mine-tailings, which contain a complex mixtur...

Mining is one of the most important extractive activities worldwide. It has a significant impact on the economic development of different regions in many countries and supplies the growing demand for mineral resources, for various industries. However, this economic activity is well recognized as an environmental hazard due to the release of several...

• Historical climate changes and interspecific gene flow have played an important role in shaping the distribution and genetic diversity of the biota in the Neotropics. In this study, we explored the role of both the Pleistocene climate changes and hybridization on the contemporary geographic structure of two Neotropical weedy species: Tithonia tub...

Methyl parathion (MP) is a highly toxic organophosphorus pesticide associated with water, soil, and air pollution events. The identification and characterization of microorganisms capable of biodegrading pollutants are an important environmental task for bioremediation of pesticide impacted sites. The strain Burkholderia cenocepacia CEIB S5-2 is a...

Models based on multifactorial interactions are needed to deal with the dynamics taking place in the eutrophication processes of coastal lagoons. However, as the number of indirect drivers stemming from anthropogenic factors increases, temporal disorders between anthropogenic activities may increase, thus hindering the understanding of their dynami...

Citese: Comisión Nacional de Áreas Naturales Protegidas (CONANP) - Centro de Investigación en Biodiversidad y Conservación, UAEM (CIByC-UAEM). 2013. Valenzuela, D.V. et al. / Estudio Previo Justificativo para el establecimiento del área natural protegida de competencia de la Federación con la categoría de Reserva de la Biosfera “Mixteca Baja Poblan...

Mining industry generates large volumes of waste known as mine tailings, which contain heavy metals (HMs) that generate a risk to environmental health. Thus, remediation of HM pollution requires attention. In this study, HM bioaccumulation, genotoxic damage, and morphological and physiological changes in the tree species Prosopis laevigata were eva...

El conocimiento sobre la variación genética es fundamental para distinguir especies, así como para la conservación de la diversidad genética y, en consecuencia, de la biodiversidad. Sin embargo, su estudio y entendimiento tiene otros beneficios al brindar la posibilidad de complementar estrategias de aprovechamiento de lo que ahora se reconoce como...

Las especies invasoras se consideran como la segunda causa de la pérdida de biodiversidad, sólo después de la destrucción del hábitat. Las invasiones inician con la presencia de especies no nativas, que son aquellas que se establecen fuera de su área de distribución natural. Dichas especies son introducidas por actividades humanas de manera intenci...

Durante la última década, el análisis de los efectos de los metales sobre la estructura y diversidad genética en poblaciones naturales se ha convertido en un tema prioritario en estudios de ecotoxicología . En términos generales, se ha documentado el efecto significativo que la exposición a contaminantes ambientales tiene sobre los cambios en la es...

Ecotoxicological studies are necessary in order to evaluate the effects of environmental exposure of chemicals on wild animals and their ecological consequences. Particularly, neurobehavioral effects of heavy metal elements on wild rodents have been scarcely investigated. In the present study, we analyzed the effect of metal bioaccumulation (Pb, As...

Elevational gradients can serve as natural experiments to study how species are restricted spatially according to environmental conditions. The variation in resources and conditions that habitats experience in relation to the seasons can be useful for understanding why the abundance and distribution of the species change temporarily. In this study,...

A review of the inquiline oak gall wasp species of the genus Synergus Hartig that are known to be associated with Cynipini woolly galls on oaks (Quercus L.) from the New World is conducted for the first time. Redescriptions, remarks, pictures and/or new location and biological data for the species previously known from the New World are given. Comm...

Theory ecology is applied to comprehend how genetic variation within tree dominant species may be an important driver of ecological processes. In this sense, studies performed suggest that the genetic diversity of the foundation species can have robust organizational influence at the population, community and ecosystem levels. Foundation species ar...

The exploitation and utilization of metallurgical resources promote the production of dangerous residues, known as mine tailings. These residues contain potentially toxic elements (PTE) that produce alterations and adverse effects in the environment affecting the surrounding biota. Heavy metals (HM) may induce different alterations in organisms (e....

In this work, Opuntia fuliginosa and Agave angustifolia fibers were used as an alternative for the removal of heavy metals from water, through a biosorption process. Both species of plant are widely available in Mexico, particularly A. angustifolia as waste material from the production of tequila. First, both fibers were characterized by scanning e...

Vachellia campechiana (Mill Seigler & Ebinger) is widely distributed in Mexico and is a dominant species of tailings in Huautla, in the state of Morelos, Mexico. Mining activities carried out in this region generated about 780 thousand tons of bioavailable heavy metal waste (HMs) that were deposited in the environment without any treatment. This st...

Pesticides are xenobiotic molecules necessary to control pests in agriculture, home, and industry. However, water and soil can become contaminated as a consequence of their extensive use. Therefore, because of its eco-friendly characteristics and efficiency, bioremediation of contaminated sites is a powerful tool with advantages over other kinds of...

Heavy metal pollution has become an environmental and health problem worldwide. With the aim of finding novel strategies for metal bioremediation, endophytic fungi from the heavy metal hyperaccumulator plant Vachellia farnesiana were isolated and characterized. The plants were growing in mine tailings, rich in Zn, Pb, and Cu. Morphological and phyl...

This paper proposes a hybrid method integrating case-based reasoning (CBR) and analytic hierarchy process (AHP) methods to reinforce the sustainable performance of an environmental management system. The CBR–AHP method aims to support the decision-making process to select environmental management actions (EMAs) aimed at reducing risky trends of the...

Burkholderia zhejiangensis CEIB S4-3 has the ability to degrade methyl parathion (MP) and its main hydrolysis byproduct p-nitrophenol (PNP). According to genomic data, several genes related with metabolism of MP and PNP were identified in this strain. However, the metabolic state of the strain during the MP degradation has not been evaluated. In th...

Multiple interactions between population increase-as driving force- and pressure factors can cause damage to human-nature interactions. In this paper, we aim to identify, understand, and assess those interactions that exert effects on environment quality. The assessments of multiple interactions will allow selecting management actions to reduce neg...

The impacts of the historical geologic and climatic events on the diversity and genetic structure of Neotropical taxa have recently become a subject of study. However, annual plants associated to tropical dry forests remain understudied. The exploration of additional taxa in contrasting environments will improve the current understanding of respons...

Background The analysis of the negative effects of environmental metal pollution is complex and difficult to assess, because the great number of variables and levels of biological organization involved. Therefore, an integral interpretation of the structure of ecological interactions from the multifactorial toxicological vision can be achieved by t...

Heavy metals present in mine tailings pollute agroecosystems, put the integrity of the environment at risk and become a major route of exposure to humans. The present study was carried out in Taxco, Guerrero, Mexico, where millions of tons of mine tailings have been deposited. Soils from this region are used for agricultural activities. Maize (Zea...

Natural hybridization has significant ecological, genetic and evolutionary consequences altering morphological and chemical characters of individuals. Quercus glabrescens, Q. rugosa and Q. obtusata are white oak species well separated by their morphological characters when they occur in allopatry in Mexican temperate forests. However, in sympatry,...

Plant-insect interaction has maintained stable for more than 300 million years, a fact that has been related with these groups capacity to escape or associate with their counterparts for reproduction, protection and feeding, among others. Arthropod communities are influenced by various factors; however, some studies suggest that genetic, chemical...

Heavy metals exert their toxic effects through different mechanisms. Lately, increasing attention has been focused on understanding the long-term ecological effects of chronically exposed populations and communities and their consequences to the ecosystem. The long-term exposure to heavy metals in the environment represents a threat to wild populat...

After agriculture, mining is traditionally regarded as the oldest and the most important activity of the world. Throughout history, mining has had important contributions to the people and has become one of the most important economic primary activities in several countries. It is oriented to the search, exploitation, and use of the various mineral...

Hybridization has a number of ecological and evolutionary consequences by either increasing intraspecific genetic diversity or by altering morphological characters and secondary chemical content of recombinant individuals. In this paper, we reanalyzed through nSSR and secondary metabolites four mixed stands between Tithonia tubaeformis and T. rotun...

p> Background: Hybridization leads to individuals with atypical phenotypes, leading to taxonomic confusion when hybridizing populations are studied. Micromorphological characters may enable taxonomists to discriminate between parental and hybrid categories due to their simple genetic inheritance. Species study: Three oak taxa distributed in the mo...

Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with c...

Polymeric materials have had a boom in the global industry over the past two decades, because of its adaptability, durability, and price so much so that now we cannot imagine a product that does not contain it. However, many synthetic polymers that have been developed are mainly derived from petroleum and coal as raw material, which make them incom...

Arsenic (As) contaminated drinking water is a well-known problem that still affects millions of people worldwide. Therefore, biomonitoring studies of human populations exposed to arsenic via drinking water along with the search for new biomarkers become important. Huautla, Morelos, Mexico, is a mining district where 780 000 tons of toxic wastes hav...

Quercus crassifolia is an oak species with characteristics of foundation species, which is a canopy dominant element of different forest types that supports a wide diversity of associated species. Therefore, it is an excellent system to address important ecological questions. We analyzed the effect of individual genetic relatedness of the host plan...

Recently it has been proposed that the genetic diversity of foundation species influences the structure and function of the community by creating locally stable conditions for other species and modulating ecosystem dynamics. Oak species are an ideal system to test this hypothesis because many of them have a wide geographical distribution, and they...

Background: Morphological variability can lead to serious taxonomic problems in species with wide distribution ranges. Although morphological variability is partly due to ontogenetic programming, abiotic variables can also exert a significant effect on micro- and macromorphological characters. In this paper, we studied the morphological variability...

Canopy of forest ecosystems has been recognized as a habitat that supports a wide variety of plants, vertebrates, invertebrates, and microbes. Within the invertebrate group, arthropods are characterized by their great abundance, diversity, and functional importance. Particularly in temperate forests, species of the genus Quercus (oaks) are one of t...

Natural hybridization between an insular endemic species and a widely distributed congener may endanger the endemic through genetic assimilation or outbreeding depression. Furthermore, hybrids can exhibit complex morphological variation, causing taxonomic problems in the identification of the involved taxa. In this work, we used a combination of le...

Endosulfan is an organochloride and persistent pesticide that has caused concern because of its impact in the environment and its toxicity to and bioaccumulation in living organisms. In this study, we isolated an endosulfan-degrading fungus from the activated sludge from an industrial wastewater treatment plant. Through repetitive enrichment and su...

Abstract Natural hybridization is a frequent phenomenon among vascular plants. Hybridization is considered an important evolutionary force since it may lead to (1) an increase of the intraspecific genetic diversity of the participating populations, (2) the creation of new species, (3) species extinction through genetic assimilation, and (4) the gen...

Abstract Incipient reproductive barriers are a common characteristic of oak species. Disruption of these barriers promotes changes in diversity and genetic structure of the species involved. Quercus castanea is a red oak with wide geographic distribution in Mexico, which presents atypically high morphological variability when it occurs in sympatry...