Publications

@article{delaBarrera2022,

title = {The role of CAM ecophysiology in the Anthropocene},

author = {E. de la Barrera},

url = {http://agro.mx/wp-content/uploads/2022/09/071-delaB-CAM-Anthropocene.pdf},

doi = {10.17660/ActaHortic.2022.1343.35},

year  = {2022},

date = {2022-09-19},

urldate = {2022-09-19},

journal = {Acta Horticulturae},

volume = {1343},

pages = {267-281},

abstract = {Human impact on the planet is such that geologists have acknowledged the start of a new geological epoch, the Anthropocene, which is characterized by an environmental emergency with multiple open fronts such as climate change, biodiversity loss, decreased fresh water availability, alterations to the nitrogen cycle, and chemical pollution. Activities such as food production and the increasing aggregation of people in urban areas are simultaneously major drivers and vulnerable points of such environmental change. For example, climate change represents a major threat to food production, considering that a reduction of annual precipitation, in addition to temperature increases, is likely to occur especially in tropical agricultural regions. The use of CAM crops has been recognized as a useful strategy for climate change adaptation, owing to their tolerance of high temperatures and their inherently high water use efficiency. The potential performance of Opuntia ficus-indica and Agave tequilana is modeled as an application of the Environmental Productivity Index for identifying potential areas for cultivation under climate change. Regarding alterations to the nitrogen biogeochemical cycle, CAM epiphytes can be useful to characterize environmental pollution in tropical environments, especially when electrochemical monitoring networks are lacking. Indeed, CAM epiphytes are particularly promising to characterize the prevalent levels of heavy metals, persistent organic pollutants and, especially, nitrogen deposition. This is illustrated with the use of the orchid Laelia speciosa and the bromeliad Tillandsia recurvata as biomonitors of atmospheric nitrogen deposition. From fundamental research on the mechanisms behind plant responses to environmental change to applications in agriculture and biomonitoring, CAM ecophysiology will be essential in the Anthropocene.},

keywords = {anthropocene, arid, arid agriculture, atmospheric pollution, biomonitors, climate change, environmental productivity index, food security, nitrogen, nitrogen deposition, planetary boundaries},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2020b,

title = {Isotopic biomonitoring of anthropic carbon emissions in a megalopolis},

author = {E. A. Díaz-Álvarez and E. de la Barrera},

doi = {10.7717/peerj.9283},

issn = {2167-8359},

year  = {2020},

date = {2020-05-29},

journal = {PeerJ},

volume = {8},

pages = {e9283},

abstract = {Atmospheric pollution has become a serious threat for human health and the environment. However, the deployment, operation, and maintenance of monitoring networks can represent a high cost for local governments. In certain locations, the use of naturally occurring plants for monitoring pollution can be a useful supplement of existing monitoring networks, and even provide information when other types of monitoring are lacking. In this work, we i) determined the tissue carbon content and the δ13C values for the epiphytic CAM bromeliad Tillandsia recurvata and the relationship of both parameters with the existing CO concentrations in the Valley of Mexico basin, and ii) mapped the spatial distribution of such elemental and isotopic composition for this plant within the basin, in order to assess its potential as an atmospheric biomonitor of carbon monoxide, a pollutant with important repercussions on public health. The CO concentrations in the basin ranged from 0.41 ppm at rural locations to 0.81 ppm at urban sites. The carbon content of T. recurvata which averaged 42.9 ± 0.34% (dry weight), was not influenced by the surrounding CO concentration. In contrast, the δ13C depended on the sites where the plants were collected. For example, the values were ‒13.21‰ in rural areas and as low as –17.47‰ in an urban site. Indeed, the isotopic values had a positive linear relationship with the atmospheric CO concentrations. Given the close relationship observed between the isotopic composition of T. recurvata with the CO concentrations in the Valley of Mexico, the δ13C values can be useful for the detection of atmospheric carbonaceous emissions.},

keywords = {atmospheric pollution, biomonitoring, biomonitors, stable isotopes, Tillandsia, urban ecology},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2019b,

title = {Bryophyte enzymatic responses to atmospheric nitrogen deposition: A field validation for potential biomonitors},

author = {E. A. Díaz-Álvarez and E. de la Barrera and A. Arciga-Pedraza and M. Arróniz-Crespo},

doi = {10.1639/0007-2745-122.3.396},

year  = {2019},

date = {2019-08-19},

journal = {The Bryologist},

volume = {122},

number = {3},

pages = {396-403},

abstract = {The monitoring of atmospheric nitrogen deposition is necessary considering that this kind of environmental pollution is among the leading causes of global biodiversity loss. However, deploying and operating monitoring networks can be cost-prohibitive; the use of naturally occurring biomonitors can be a viable alternative for characterizing such nitrogenous pollution, with bryophytes being of particular promise. For instance, a previous dose-response greenhouse experiment evaluating potential biomonitors of different life-forms revealed that the activities of the enzymes phosphomonoesterase and nitrate reductase respond linearly to simulated nitrogen deposition for the generalist neotropical moss Braunia secunda. The present work is the field validation of B. secunda and Leptodontium pungens, a specialist of oak forests, as biomonitors of nitrogen deposition. Moss samples were collected during the 2009 dry and rainy seasons from fir and oak forests at ‘‘low-pollution’’ or ‘‘high-pollution’’ sites within the Valley of Mexico, where the megalopolis of Mexico City is located, and transported to the laboratory for colorimetric determinations of enzymatic activity. The phosphomonoesterase activity was consistently higher for both mosses from the high-pollution sites than for the low-pollution sites, while the nitrate reductase had a lower activity for the plants collected from the high-pollution sites. These results suggest that the proposed biomonitors are appropriate for the region of study.},

keywords = {atmospheric pollution, biomonitors, moss, pollution, urban ecology},

pubstate = {published},

tppubtype = {article}

}

@article{Osuna-Vallejo2019,

title = {Total mercury in plant tissue from a mining landscape in Western Mexico},

author = {V. Osuna-Vallejo and C. Sáenz-Romero and L. Escalera-Vázquez and E. de la Barrera and R. Lindig-Cisneros},

doi = {10.1007/s00128-018-2488-0},

year  = {2019},

date = {2019-01-15},

journal = {Bulletin of Environmental Contamination & Toxicology},

volume = {102},

number = {1},

pages = {19-24},

abstract = {Environmental impacts of mining activities are well known, particularly on-site degradation, but long term effects are less known. Mercury content from vegetation samples from a mine dump and surrounding forests was quantified for understanding the fate of this element in the local the environment. The study area, Tlalpujahua, Michoacán, México, has a mining history going back more than 400 years. Including gold and silver extraction by means of mercury amalgamation for 352 years (1554–1906). Mercury was present in all sampled materials. The highest values correspond to wood samples from the mine dump (13.84 ± 3.88 ppm), while wood samples from adjacent forests had 4.3 ± 2.4 ppm, almost twice as much as coniferous needles, shrub leaves and corn seeds (2.2 ± 0.34 ppm). The highest concentration was found for J. deppeana wood (16.05 ± 2.3 ppm). The capacity of accumulating mercury by Juniperus trees when growing on the mine dumps suggests that this species has a potential to be used for biosequestration purposes.},

keywords = {agriculture, biomonitors, conifers, pollution, temperate forest, tropical forest},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2018b,

title = {Characterization of nitrogen deposition in a megalopolis by means of atmospheric biomonitors},

author = {E. A. Díaz-Álvarez and E. de la Barrera },

url = {https://rdcu.be/6jWU},

doi = {10.1038/s41598-018-32000-5},

year  = {2018},

date = {2018-09-11},

journal = {Scientific Reports},

volume = {8},

pages = {13569},

abstract = {An increase of nitrogen deposition resulting from human activities is not only a major threat for global biodiversity, but also for human health, especially in highly populated regions. It is thus important and in some instances legally mandated to monitor reactive nitrogen species in the atmosphere. The utilization of widely distributed biological species suitable for biomonitoring may be a good alternative. We assessed the suitability of an ensemble of atmospheric biomonitors of nitrogen deposition by means of an extensive sampling of a lichen, two mosses, and a bromeliad throughout the Valley of Mexico, whose population reaches 30 million, and subsequent measurements of nitrogen metabolism parameters. In all cases we found significant responses of nitrogen content, C:N ratio and the δ15N to season and site. In turn, the δ15N for the mosses responded linearly to the wet deposition. Also, the nitrogen content (R2 = 0.7), the C:N ratio (R2 = 0.6), and δ15N (R2 = 0.5) for the bromeliad had a linear response to NOx. However, the bromeliad was not found in sites with NOx concentrations exceeding 80 ppb, apparently of as a consequence of exceeding nitrogen. These biomonitors can be utilized in tandem to determine the status of atmospheric nitrogenous pollution in regions without monitoring networks for avoiding health problems for ecosystems and humans.},

keywords = {biomonitors, epiphytes, Mexico, mosses, nitrogen, pollution, stable isotopes, Tillandsia, urban ecology},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2018,

title = {Biomonitors of atmospheric nitrogen deposition: potential uses and limitations},

author = {E. A. Díaz-Álvarez and R. Lindig-Cisneros and E. de la Barrera },

doi = {10.1093/conphys/coy011},

year  = {2018},

date = {2018-03-13},

journal = {Conservation Physiology},

volume = {6},

pages = {coy011},

abstract = {Atmospheric nitrogen deposition is the third largest cause of global biodiversity loss, with rates that have more than doubled over the past century. This is especially threatening for tropical regions where the deposition may soon exceed 25 kg of N ha–1 year–1, well above the threshold for physiological damage of 12-20 kg of N ha–1 year–1, depending on plant species and nitrogenous compound. It is thus urgent to monitor these regions where the most diverse biotas occur. However, most studies have been conducted in Europe, the USA, and recently in China. This review presents the case for the potential use of biological organisms to monitor nitrogen deposition, with emphasis on tropical plants. We first present an overview of atmospheric chemistry and the nitrogen metabolism of potential biomonitors, followed by a framework for monitoring nitrogen deposition based on the simultaneous use of various functional groups. In particular, the tissue nitrogen content responds to the rate of deposition, especially for mosses, whose nitrogen content increases by 1% per kilogram of N ha-1 year-1. The isotopic signature, δ15N, is a useful indicator of the nitrogen source, as the slightly negative values (e.g., 5‰) of plants from natural environments can become very negative (–11.2‰) in sites with agricultural and husbandry activities, but very positive (13.3‰) in urban environments with high vehicular activity. Mosses are good biomonitors for wet deposition and atmospheric epiphytes for dry deposition. In turn, the nitrogen saturation of ecosystems can be monitored with trees whose isotopic values increase with saturation. Although given ecophysiological limitations of different organisms, particular studies should be conducted in each area of interest to determine the most suitable biomonitors. Overall, biomonitors can provide an integrative approach for characterizing nitrogen deposition in regions where the deployment of automated instruments or passive monitoring is not feasible or can be complementary. 

},

keywords = {biomonitors, ecosystem saturation, epiphytes, nitrogen, pollution, stable isotopes, urban ecology},

pubstate = {published},

tppubtype = {article}

}