Potentially toxic elements in soil-plant-water-animal continuum in a mining area from Northwestern Mexico: animal exposure pathways and health risks for children.

Mining increases environmental concentrations of potentially toxic elements (PTEs) accumulating in organisms and spreading in the human food chain-their presence in milk is of great human health concern. Pathways were identified by which these elements reach raw milk from farms within a mining area in Northwestern Mexico; health risks for dairy cattle and children were also evaluated. Water from river and cattle waterers, as well as, soils showed that PTE concentrations generally below the Mexican and international limits; cattle forage concentrations were above the World Health Organization limits.

Geographic isolation and long-distance gene flow influence the genetic structure of the blue fan palm Brahea armata (Arecaceae).

The formation of the Baja California Peninsula (BCP) has impacted the microevolutionary dynamics of different species in ways that depend on biological traits such as dispersal capacity. Plants with relatively low levels of vagility have exhibited high genetic divergence between the BCP and Continental mainland. Brahea armata (Arecaceae) is a palm species inhabiting the northern part of the BCP and Sonora; its distribution occurs in isolated oases of vegetation.

Genomic Analyses of Wild and Cultivated Bacanora Agave ( var. ) Reveal Inbreeding, Few Signs of Cultivation History and Shallow Population Structure.

Due to the recent increase in demand for agave-based beverages, many wild agave populations have experienced rapid decline and fragmentation, whereas cultivated plants are now managed at monocultural plantations, in some cases involving clonal propagation. We examined the relative effect of migration, genetic drift, natural selection and human activities on the genetic repertoire of var. , an agave used for bacanora (an alcoholic spirit similar to tequila) production in northwestern Mexico.

Microstructure and Hydrophobicity of the External Surface of a Sonoran Desert Beetle.

We have studied the external surface (elytra) of the Sonoran Desert beetle (). Our aim was to assess whether this species has similar traits to some beetles from the Namibian Desert that are known to have hierarchical micropatterns that allow for water harvesting. We have conducted scanning electron microscopy (SEM) and apparent contact angle experiments on specimens collected at two sampling sites with different ambient humidity.

A Change in Conservation Status of (Crassulaceae), a Threatened Species from Central Mexico Based on Genetic Studies.

Genetic studies in rare species are important to determine their patterns of genetic diversity among populations and implement conservation plans aimed to reduce extinction risks. is an endemic species with extremely small populations in central Mexico. This work analyzes the diversity and genetic structure of (Crassulaceae) to change the conservation status and propose conservation strategies.

Speciation along a latitudinal gradient: The origin of the Neotropical cycad sister pair - (Zamiaceae).

Latitude is correlated with environmental components that determine the distribution of biodiversity. In combination with geographic factors, latitude-associated environmental variables are expected to influence speciation, but empirical evidence on how those factors interplay is scarce. We evaluated the genetic and environmental variation among populations in the pair of sister species , two cycads distributed along a latitudinal environmental gradient in northwestern Mexico, to reveal their demographic histories and the environmental factors involved in their divergence.

Water resources affected by potentially toxic elements in an area under current and historical mining in northwestern Mexico.

Rio Sonora watershed and its aquifer-located in northwest Mexico-have been influenced by mining operations for 140 years, possibly causing emissions of potentially toxic elements (PTE) and affecting health of exposed populations. On the basis of available data from governmental surveys (2014-2017) and recent sampling (2018), this study constructed reliable PTE total concentration database that allowed us to report temporal/spatial variations in surface and groundwater and their associated health risks to the population living in the central part of the Rio Sonora basin. The data clearly showed that a mining spill that took place in 2014 has had an adverse impact on total PTE concentrations in surface water.

Stabilization of potentially toxic elements contained in mine waste: A microbiological approach for the environmental management of mine tailings.

Metals are key materials extensively employed in several industries to produce technological and daily-life products. The mining industry that produces such commodities generates Tons of waste that if not remediated can be transferred to the surrounding environment, thus representing a water, air, and soil pollution threat. In this work, we evaluated the feasibility of microbial sulfate reduction (SR) as a management strategy for this waste.

Barriers for plant establishment in the abandoned tailings of Nacozari, Sonora, Mexico: the influence of compost addition on seedling performance and tailing properties.

Past mining activities have left a legacy of abandoned mine tailing deposits whose metal contaminants poses serious risks to ecosystems and human health. While the development of a vegetated cover in mine tailings can help in mitigating these risks, the local factors limiting plant establishment in these sites are not well understood, restricting phytostabilization efforts. Here, we explore some of the barriers that limit seedling establishment of two species (Vachellia farnesiana and Prosopis velutina) in a mine tailing deposit located in Nacozari, Sonora, Mexico, and assess whether compost addition can help in overcoming these barriers in pot and field experiments.

Niche conservatism promotes speciation in cycads: the case of Dioon merolae (Zamiaceae) in Mexico.

Niche conservatism is the tendency of lineages to retain the same niche as their ancestors. It constrains biological groups and prevents ecological divergence. However, theory predicts that niche conservatism can hinder gene flow, strengthen drift and increase local adaptation: does it mean that it also can facilitate speciation? Why does this happen? We aim to answer these questions.

Mobility and accessibility of Zn, Pb, and As in abandoned mine tailings of northwestern Mexico.

Generation, storage, and management of waste coming from industrial processes are a growing worldwide problem. One of the main contributors is the mining industry, in particular tailings generated by historical mining, which are barely maintained, especially in developing countries. Assessing the impact of a mining site to surrounding soils and ecosystems can be complex, especially when determining mobility and accessibility of the contaminants is required to perform ecological and human health risk assessment.

Environmental assessment and historic erosion calculation of abandoned mine tailings from a semi-arid zone of northwestern Mexico: insights from geochemistry and unmanned aerial vehicles.

Mining is known as one of the primary economic activities where exploitation of minerals and other materials have become essential for human development. However, this activity may represent a risk to the environment, starting from deforestation and ending with production of residues that might contain potentially toxic elements. Tailing deposits from historical mining are an example of waste that may represent an environmental concern when abandoned and exposed to environmental conditions.

Different patterns of colonization of in the Sky Islands of the Sonoran desert via pollen and seed flow.

Historical factors such as climatic oscillations during the Pleistocene epoch have dramatically impacted species distributions. Studies of the patterns of genetic structure in angiosperm species using molecular markers with different modes of inheritance contribute to a better understanding of potential differences in colonization and patterns of gene flow via pollen and seeds. These markers may also provide insights into the evolution of reproductive systems in plants.

The role of hybridization during ecological divergence of southwestern white pine (Pinus strobiformis) and limber pine (P. flexilis).

Interactions between extrinsic factors, such as disruptive selection and intrinsic factors, such as genetic incompatibilities among loci, often contribute to the maintenance of species boundaries. The relative roles of these factors in the establishment of reproductive isolation can be examined using species pairs characterized by gene flow throughout their divergence history. We investigated the process of speciation and the maintenance of species boundaries between Pinus strobiformis and Pinus flexilis.

The phylogeography of the cycad genus Dioon (Zamiaceae) clarifies its Cenozoic expansion and diversification in the Mexican transition zone.

Background And Aims: Biogeographic transition zones are promising areas to study processes of biogeographic evolution and its influence on biological groups. The Mexican transition zone originated due to the overlap of Nearctic and Neotropical biota, which promoted great biological diversification. However, since most previous studies in this area were focused on revealing the phylogeography of Nearctic plants, how historical biogeographic configuration influenced the expansion and diversification of the Neotropical flora remains almost unknown.

Aridification as a driver of biodiversity: a case study for the cycad genus Dioon (Zamiaceae).

Background And Aims: Aridification is considered a selective pressure that might have influenced plant diversification. It is suggested that plants adapted to aridity diversified during the Miocene, an epoch of global aridification (≈15 million years ago). However, evidence supporting diversification being a direct response to aridity is scarce, and multidisciplinary evidence, besides just phylogenetic estimations, is necessary to support the idea that aridification has driven diversification.

Plants from the abandoned Nacozari mine tailings: evaluation of their phytostabilization potential.

Phytostabilization is a remediation technology that uses plants for in-situ stabilization of contamination in soils and mine tailings. The objective of this study was to identify native plant species with potential for phytostabilization of the abandoned mine tailings in Nacozari, Sonora in northern Mexico. A flora of 42 species in 16 families of angiosperms was recorded on the tailings site and the abundance of the most common perennial species was estimated.

Unique haplotypes of cacao trees as revealed by trnH-psbA chloroplast DNA.

Cacao trees have been cultivated in Mesoamerica for at least 4,000 years. In this study, we analyzed sequence variation in the chloroplast DNA trnH-psbA intergenic spacer from 28 cacao trees from different farms in the Soconusco region in southern Mexico. Genetic relationships were established by two analysis approaches based on geographic origin (five populations) and genetic origin (based on a previous study).

Variation in heterostylous breeding systems in neighbouring populations of Oxalis alpina (Oxalidaceae).

Unlabelled: The heterostylous reproductive system of Oxalis alpina in the Galiuro Mts. of Arizona was investigated using field surveys, controlled crosses in the greenhouse and measurements of reproductive morphs. Although populations in the Pinaleño Mts.

Genetic identification of Theobroma cacao L. trees with high Criollo ancestry in Soconusco, Chiapas, Mexico.

Criollo-type cacao trees are an important pool of genes with potential to be used in cacao breeding and selection programs. For that reason, we assessed the diversity and population structure of Criollo-type trees (108 cultivars with Criollo phenotypic characteristics and 10 Criollo references) using 12 simple sequence repeat (SSR) markers. Cultivars were selected from 7 demes in the Soconusco region of southern Mexico.

The role of inbreeding depression and mating system in the evolution of heterostyly.

We investigated the role of morph-based differences in the expression of inbreeding depression in loss of the mid-styled morph from populations of tristylous Oxalis alpina. The extent of self-compatibility (SC) of reproductive morphs, the degree of self-fertilization, and the magnitude of inbreeding depression were investigated in three populations of O. alpina differing in their tristylous incompatibility relationships.