Publications

@article{Martínez2024,

title = {Malezas ruderales como biomonitores del depósito de nitrógeno urbano},

author = {D. N. Martínez and H. Vibrans and F.J. Espinosa-García and M. Camacho-Cervantes and E. de la Barrera},

url = {https://www.revistaecosistemas.net/index.php/ecosistemas/article/view/2672

http://agro.mx/wp-content/uploads/2024/07/075-Martinezetal-Ecosistemas-Malezas-biomonitoras.pdf},

doi = {10.7818/ECOS.2672},

issn = {1697-2473},

year  = {2024},

date = {2024-07-17},

urldate = {2024-07-17},

journal = {Ecosistemas},

volume = {33},

number = {2672},

issue = {2},

abstract = {The production of reactive forms of nitrogen has surpassed safe planetary boundaries, jeopardizing the proper functioning of ecosystems. Their deposition is a threat to both biodiversity and public health. Monitoring systems to quantify nitrogen deposition are often lacking, making biomonitoring a potential alternative. In biomonitoring, physiological variables responsive to nitrogen availability are identified, along with organisms tolerant to high nitrogen availability. Although epiphytic organisms are frequently used as biomonitors, many are confined to humid climates and areas with minimal anthropogenic disturbance. The aim of this review is to identify potential nitrogen deposition biomonitors for sites under anthropic disturbance. Ruderal weeds persist and thrive in urban areas, where disturbance, pollutant emissions, and nitrogen deposition rates are often high. Moreover, several weeds are identified as nitrophilic, and within a well-represented group among them, grasses, tolerance to high nitrogen deposition rates has been documented. The use of these organisms has allowed for the identification of contributions from nitrogen sources and the increase of nitrogen in environments that are restrictive for other plants.},

keywords = {anthropocene, biomonitoring, invasive species, nitrogen, nitrogen deposition, plant nutrition, pollution, urban ecology},

pubstate = {published},

tppubtype = {article}

}

@article{Espinosa-García2024,

title = {The conceptual babel of agroecologies is related to their diverse origins and objectives},

author = {F.J. Espinosa-García and E. de la Barrera and A. González-Jácome},

url = {http://agro.mx/wp-content/uploads/2023/11/074-Espinosa-et-al-babel-agroecologies.pdf},

doi = {10.1080/21683565.2023.2270938},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Agroecology and Sustainable Food Systems},

volume = {48},

issue = {1},

pages = {4-16},

abstract = {The term agroecology has undergone broad diversification since it was first conceived as the study of the ecology of agricultural systems. In addition to the “tripartite” definition, which includes science, practice, and social movement, political and “emancipatory” agroecologies, among others, are included. There is no consensus on the meaning of “agroecology” and “agroecological,” nor the objectives and uses associated with those concepts. Thus, despite the concept of “agroecology” not being consolidated nor unisemic, its meaning and application continue to diversify according to the interests and perspectives of the users. That diversification encompasses different ways of looking at agriculture’s role in human societies and the environment in which they are based and function. Agroecology, too, has been seen as an activity whose objectives include issues as diverse as mythical, ceremonial, dogmatic, political, or religious. Moreover, this unrestricted diversification also devalues and trivializes the term and hinders the mutual understanding among academics, practitioners, promoters, decision-makers, the public, and government agencies. We begin a series of reflections on the various agroecologies in Mexico that we hope will promote the formation of clear, well-defined, and documented concepts to contribute to synergies among agroecologies and the advancement of their objectives.},

keywords = {agriculture, agroecology, food security, sustainable agriculture, sustainable development goals},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2021b,

title = {Climate change can trigger fall armyworm outbreaks: a developmental response experiment with two Mexican maice landraces},

author = {E. A. Díaz-Álvarez and J. P. Martínez-Zavaleta and E. E. López-Santis and E. de la Barrera and J. Larsen and E. del-Val},

doi = {10.1080/09670874.2020.1869347},

year  = {2023},

date = {2023-03-26},

urldate = {2023-03-26},

journal = {International Journal of Pest Management},

volume = {69},

issue = {2},

pages = {184-192},

abstract = {Maize is one of the most important crops in the world, particularly in Mexico where it was domesticated and is central to traditional cultures. The fall armyworm (Spodoptera frugiperda [J.E. Smith]), is a major pest that can greatly reduce production of this crop. Climate change also threatens maize production, as projections estimate an increase of fall armyworm outbreaks. For these reasons, (1) we assessed the changes in the S. frugiperda life cycle along a temperature gradient ranging from 23 °C to 31 °C, and (2) assessed the development of larvae feeding on two Mexican landraces and the responses of each landrace to herbivory under current and predicted climatic conditions; both assessments were conducted under laboratory conditions. Development was faster and each life cycle stage was shorter at higher temperatures. The effect of herbivory differed between the landraces; herbivory was more harmful for White Ranchero than for Yellow. As warmer and drier conditions are expected during this century, sowing appropriate maize landraces that can cope with herbivores under climate change could mitigate potential economic losses.},

keywords = {agricultural pests, agriculture, food security, herbivory, larvae},

pubstate = {published},

tppubtype = {article}

}

@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{Contreras-Negrete2021,

title = {Differences in germination response to temperature, salinity, and water potential among Prosopis laevigata populations are guided by the tolerance-exploitation trade-off},

author = {G. Contreras-Negrete and F. Pineda-García and S. Nicasio-Arzeta and E. de la Barrera and A. González-Rodríguez },

url = {https://www.sciencedirect.com/science/article/abs/pii/S0367253021002024},

doi = {10.1016/j.flora.2021.151963},

year  = {2021},

date = {2021-11-06},

journal = {Flora},

volume = {285},

pages = {151963},

abstract = {Highlights

• Germination of P. laevigata seeds from populations across its distribution range was very sensitive to the reduction in water potential but not to variation in temperature or salinity.



• Differentiation in the germination response of P. laevigata populations was constrained by the exploitation–tolerance trade-off.



• Variation in the germination response among P. laevigata populations was related with aridity and salinity gradients across its distribution.



Abstract

Exploring the mechanisms that promote population divergence represents a central point in evolutionary ecology. Along their distribution, species commonly experience contrasting environmental conditions, which impose local selection pressures to which populations tend to adapt resulting, for example, in ways to deal with resource shortage or abundance. In this study, we explored if germination performance varies under different levels of temperature, water potential and salinity among populations of Prosopis laevigata, a widespread mesquite species from the arid and semi-arid zones of Mexico. Given the wide distribution of P. laevigata and the sensitivity of the germination phase to environmental conditions, we hypothesized the existence of differential responses during this crucial stage of plant development. Thus, we expected germination in populations of P. laevigata from more arid zones to be less sensitive to high temperatures, salinity, and water deficit. Also, we explored if the exploitation–tolerance trade-off guides the differentiation of P. laevigata populations in germination performance under varying conditions. Germination of all populations was very sensitive to water scarcity but not to variation in temperature or salinity. We identified two major axes of trait covariation in germination physiology: one defined by tolerance of germination to water and saline stress versus germination velocity, and the other defined by the tolerance to extreme temperatures. We found evidence that variation in tolerance among the populations was related with their distribution along environmental gradients. Overall, populations with a higher capacity to germinate under water deficit stress, salinity, and extreme temperatures inhabit warmer and more saline areas. Our study provides strong evidence of existing local adaptations during germination of P. laevigata from across its distribution in the arid lands of Mexico.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Martínez2021c,

title = {Ephemeral visitors or permanent residents? — Decadal change in the ruderal vegetation from a periurban university campus},

author = {D. N. Martínez and L. López-Toledo and F. Espinosa-García and M. Camacho-Cervantes and E. de la Barrera},

url = {https://www.sciencedirect.com/science/article/pii/S161886672100399X},

doi = {10.1016/j.ufug.2021.127372},

year  = {2021},

date = {2021-10-11},

urldate = {2021-10-11},

journal = {Urban Forestry and Urban Greening},

volume = {65},

pages = {127372},

abstract = {Highlights

• Anthropogenic disturbance (built area) increased in the study site over the years.

• Species richness and the proportion of exotic species increased with disturbance.

• The most diverse families of ruderal flora were Asteraceae, Fabaceae, and Poaceae.

• The 16 species that disappeared after 2008 were native.

• Thirteen of the exotic species found in the study site are invasive in Mexico.



Abstract

Urbanization creates environmental conditions that hinder the growth of natural vegetation. We surveyed the ruderal vegetation from a periurban university campus in west-central Mexico during the rainy seasons of 2008 and 2016–2018, time during which the campus underwent intensive construction. The built area grew from 4 ha in 2009 to 12.6 ha in 2017. We identified 234 different Angiosperms belonging to 165 genera and 43 families and the community composition changed over time. For example, Asteraceae was replaced by Poaceae as the richest family in 2018. Also, 16 native species found in 2008 disappeared from the study site, 9 of which have been related with low disturbance. In contrast, 98 new species were observed in the latter years, including some that are commonly found in cities. Overall, species richness increased with time, including that of exotic species that increased from 16 % of the total species in 2008 to 24 % in 2018. Thirteen of such exotic species are invasive in Mexico, including Digitaria velutina, Asphodelus fistulosus, Mercurialis annua, and Senecio inaequidens, for which this was their first record in the city of Morelia (population 849,053), where the campus is located. These results suggest that environmental conditions imposed by disturbance can favor the proliferation of various species, especially grasses and several exotic species of different families.},

keywords = {anthropocene, biodiversity, biodiversity threats, Bioindicator, disturbance, invasive species, land-use change, urban ecology, urban sprawl},

pubstate = {published},

tppubtype = {article}

}

@article{González-Salvatierra2021,

title = {Seasonal changes in photosynthesis for the epiphytic bromeliad Tillandsia brachycaulos in a tropical deciduous forest.},

author = {C. González-Salvatierra and L. M. Peña-Rodríguez and C. Reyes-García and E. de la Barrera and J. L. Andrade },

url = {https://botanicalsciences.com.mx/index.php/botanicalSciences/article/view/2842},

doi = {10.17129/botsci.2842},

year  = {2021},

date = {2021-10-01},

journal = {Botanical Sciences},

volume = {99},

pages = {850-862},

abstract = {Background: Sunlight stress and drought affect plants by inducing various biochemical and physiological responses, which reduce growth. Seasonal changes in light and water availability that occur in forest canopies, where epiphytes occur, are extreme.

Questions: What are the seasonal changes in photosynthesis for an abundant epiphytic bromeliad in contrasting microenvironments? Is Crassulacean acid metabolism (CAM) an important feature of photoprotection for this epiphyte?

Studied species: Tillandsia brachycaulos Schltdl. (Bromeliaceae)

Study site and dates: Canopy of the tropical dry deciduous forest of Dzibilchaltún National Park, Yucatan, Mexico during the rainy season 2008 and dry season 2009.

Methods: Diurnal measurements of photosystem II efficiency, titratable acidity, leaf water potential, and photosynthetic pigment concentration were measured during the dry and rainy seasons in adult plants of T. brachycaulos in shaded and exposed microenvironments. The prevailing environmental conditions (photon flux density, precipitation, air temperature and relative humidity) were also seasonally characterized.

Results: The highest irradiance occurred during the dry season, caused photo-inactivation, a decrease of the quantum efficiency of photosystem II, and a reduction in CAM activity of about 40% in leaves of exposed plants of T. brachycaulos. During the rainy season, the leaf water potential of exposed and shaded plants of T. brachycaulos was lower at midday than at predawn, indicating water loss during the day. 

Conclusions: Individuals of T. brachycaulos reduced CAM activity during the dry season; and, during the rainy season, increased carbon gain by stomata opening during phase II and IV of CAM.

},

keywords = {CAM, chlorophyll, chlorophyll fluorescence, Crassulacean acid metabolism, ecophysiology, epiphytes, microenvironment, pigments, shade, tropical dry forest, water, water relations},

pubstate = {published},

tppubtype = {article}

}

@article{Alcántara-Plazola2021,

title = {Quantification of embedded phosphorus in Mexican agriculture},

author = {J. J. Alcántara-Plazola and E. de la Barrera},

url = {https://www.sciencedirect.com/science/article/abs/pii/S2352550921002104},

doi = {10.1016/j.spc.2021.07.011},

issn = {2352-5509},

year  = {2021},

date = {2021-07-14},

journal = {Sustainable Production and Consumption},

volume = {28C},

pages = {824-828},

abstract = {Phosphorus is an essential element for agricultural production, and for life in general, whose availability as a mineral is geographically restricted. Considering that Mexico is a major contributor to the global flow of water embedded in agricultural commodities, it is likely that this country is also a major exporter of embedded phosphorus. Thus, we quantified the embedded phosphorus for the 38 major crops produced in Mexico from 1980 to 2015, which were grouped into forages, fruits and vegetables, cereals, legumes, and cash crops. The total phosphorus extracted was 4.4 × 106 tonnes for an agricultural production of 5,844 × 106 tonnes, which respectively increased by 86% and 145% over 35 years. Food crops, i.e., cereals, fruits and vegetables, and legumes, accounted for 44% of the total phosphorus extracted, forages for 38%, and cash crops for 18%. Forage production exhibited a substantial increase since 1995, becoming the largest phosphorus extractor by 2000. Our estimation of embedded phosphorus is susceptible of utilization in other countries and is a first step to estimate a country's phosphorus balance, which is necessary to understand the magnitude of the anthropogenic alteration of a biogeochemical cycle that is essential for the maintenance of life on earth.},

keywords = {agriculture, embedded phosphorus, food security, phosphorus, planetary boundaries, telecoupling},

pubstate = {published},

tppubtype = {article}

}

@article{Martínez2021b,

title = {Selecting biomonitors of atmospheric nitrogen deposition: guidelines for practitioners and decision makers},

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

url = {https://www.mdpi.com/2504-3129/2/3/21},

doi = {10.3390/nitrogen2030021},

issn = {2504-3129},

year  = {2021},

date = {2021-07-12},

journal = {Nitrogen},

volume = {2},

number = {3},

pages = {308-320},

abstract = {Environmental pollution is a major threat to public health and is the cause of important economic losses worldwide. Atmospheric nitrogen deposition is one of the most significant components of environmental pollution, which, in addition to being a health risk, is one of the leading drivers of global biodiversity loss. However, monitoring pollution is not possible in many regions of the world because the instrumentation, deployment, operation, and maintenance of automated systems is onerous. An affordable alternative is the use of biomonitors, naturally occurring or transplanted organisms that respond to environmental pollution with a consistent and measurable ecophysiological response. This policy brief advocates for the use of biomonitors of atmospheric nitrogen deposition. Descriptions of the biological and monitoring particularities of commonly utilized biomonitor lichens, bryophytes, vascular epiphytes, herbs, and woody plants, are followed by a discussion of the principal ecophysiological parameters that have been shown to respond to the different nitrogen emissions and their rate of deposition.},

keywords = {atmospheric pollution, environmental indicators, environmental management, planetary boundaries, public health, public policy},

pubstate = {published},

tppubtype = {article}

}

@article{Martínez2021,

title = {Physiological screening of ruderal weed biomonitors of atmospheric nitrogen deposition},

author = {D. N. Martínez and E. de la Barrera },

url = {https://botanicalsciences.com.mx/index.php/botanicalSciences/article/view/2789},

doi = {10.17129/botsci.2789},

year  = {2021},

date = {2021-05-18},

journal = {Botanical Sciences},

volume = {99},

number = {3},

pages = {573-587},

abstract = {Background: Plants take up various species of reactive nitrogen and their different physiological responses to the increase of nitrogen availability can be useful in biomonitoring. 

Questions: Does atmospheric nitrogen deposition affect the physiology of ruderal weeds? Which species are most responsive to the nitrogen deposition?

Studied species: Eleven ruderal weeds.

Study site and dates: Morelia, Michoacán, Mexico. 2019.

Methods: Under scenarios of 10, 20, 40 and 80 kg N ha-1year-1, we quantified plant responses of biomass production, nitrate reductase activity, chlorophyll content, fluorescence, δ15N, nitrogen and carbon content. 

Results: Total biomass production increased with the rate of nitrogen deposition for Bidens pilosa, Chloris gayana, Lepidium virginicum, and Pennisetum setaceum, as chlorophyll content in B. pilosa, C. gayana, and L. virginicum. In turn, the below- to above-ground biomass ratio decreased for B. pilosa and C. gayana, as photosynthetic efficiency in C. gayana, L. virginicum, and Chloris pycnothrix. Nitrate reductase activity was only affected in L. virginicumm, C. gayana, and T. officinale.

   With the exception of C. pycnothrix, the nitrogen content increased, while the carbon augmented in C. gayana, C. pycnothrix, and P. setaceum. The C/N ratio was reduced in B. pilosa, C. gayana, Chloris virgata, P. setaceum, and T. officinale. The δ15N was increased in B. pilosa, C. gayana, C. virgata and P. setaceum.

Conclusions: Bidens pilosa, C. gayana, L. virginicum, and P. setaceum were the species with more affected variables to nitrogen deposition, which could be useful in the biomonitoring. 

},

keywords = {atmospheric pollution, biomass, chlorophyll, invasive species, nitrate reductase, nitrogen, plant nutrition, stable isotopes},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2021bb,

title = {Influence of land-use on the C and N status of a C4 invasive grass in a semi-arid region: implications for biomonitoring},

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

url = {https://www.mdpi.com/2223-7747/10/5/942},

doi = {10.3390/plants10050942},

year  = {2021},

date = {2021-05-09},

journal = {Plants},

volume = {10},

pages = {942},

abstract = {Biomonitoring of atmospheric pollution is an increasingly accepted practice. However, most existing biomonitors are usually epiphytic species from mesic environments. This work assessed the suitability of buffelgrass (Cenchrus ciliaris), an invasive C4 grass in northwestern Mexico, as a biomonitor, by means of the spatial distribution of the carbon and nitrogen content and isotopic signatures for grass samples collected from urban, agricultural, and natural areas throughout the state of Sonora. We found the highest tissue carbon content of 45.6% (on a dry weight basis) and highest nitrogen content of 3.31% for buffelgrass from the Yaqui Valley. We also found the lowest δ13C of −15.9‰, and the highest δ15N of 16.7‰ in the same region. In contrast, the lowest carbon and nitrogen content of 39.4 and 1.49% were found for Bahía de Kino and Río Sonora mountains, respectively. The lowest δ15N of 2.18‰ and the highest δ13C of −13.7‰ were measured for two remote locations. These results show the influence that pollutant emissions, including agriculture and transportation, have on elemental and isotopic composition of vegetation. Buffelgrass is most adequate for tracking carbon and nitrogen emissions in arid environments and for determining alterations on nitrogen soil reactions, as a first approximation for saturation.},

keywords = {atmospheric pollution, biomonitoring, buffel grass, carbon, global ecology, invasive species, nitrogen, pollution, Sonora, stable isotopes},

pubstate = {published},

tppubtype = {article}

}

@article{Cooke2021,

title = {One hundred questions in conservation physiology for generating actionable evidence to inform conservation policy and practice},

author = {S. J. Cooke and J. N. Bergman and C. L. Madliger and R. L. Cramp and J. Beardall and G. P. Burness and T. D. Clark and B. Dantzer and E. de la Barrera and N. A. Fangue and C. F. Franklin and A. Fuller and L. A. Hawkes and K. R. Hultine and K. E. Hunt and O. P. Love and H. A. MacMillan and J. W. Mandelman and F. C. Mark and L. B. Martin and A. E. M. Newmann and A. B. Nicotra and G. D. Raby and S. A. Robinson and Y. Ropert-Courdet and J. L. Rummer and F. Seebacher and A.E. Todgham and S. Tomlinson and S. L. Chown },

url = {https://academic.oup.com/conphys/article/9/1/coab009/6214572},

doi = {10.1093/conphys/coab009},

year  = {2021},

date = {2021-04-07},

journal = {Conservation Physiology},

volume = {9},

pages = {coab009},

abstract = {Environmental change and biodiversity loss are but two of the complex challenges facing conservation practitioners and policy makers. Relevant and robust scientific knowledge is critical for providing decision-makers with the actionable evidence needed to inform conservation decisions. In the Anthropocene, science that leads to meaningful improvements in biodiversity conservation, restoration and management is desperately needed. Conservation Physiology has emerged as a discipline that is well-positioned to identify the mechanisms underpinning population declines, predict responses to environmental change and test different in situ and ex situ conservation interventions for diverse taxa and ecosystems. Here we present a consensus list of 10 priority research themes. Within each theme we identify specific research questions (100 in total), answers to which will address conservation problems and should improve the management of biological resources. The themes frame a set of research questions related to the following: (i) adaptation and phenotypic plasticity; (ii) human–induced environmental change; (iii) human–wildlife interactions; (iv) invasive species; (v) methods, biomarkers and monitoring; (vi) policy, engagement and communication; (vii) pollution; (viii) restoration actions; (ix) threatened species; and (x) urban systems. The themes and questions will hopefully guide and inspire researchers while also helping to demonstrate to practitioners and policy makers the many ways in which physiology can help to support their decisions.},

keywords = {anthropocene, biodiversity, biodiversity threats, conservation decisions, conservation physiology, ecophysiology},

pubstate = {published},

tppubtype = {article}

}

@article{Paredes-García2020,

title = {Biomasa y carbono almacenado en un humedal continental en Cuitzeo, Michoacán, México},

author = {S. Paredes-García and P. Moreno-Casasola and E. de la Barrera and F. García-Oliva and R. Lindig-Cisneros},

url = {http://revistatyca.org.mx/index.php/tyca/article/view/2582/2307},

doi = {10.24850/j-tyca-2021-02-09},

issn = {2007-2422},

year  = {2021},

date = {2021-03-02},

journal = {Tecnología y Ciencias del Agua},

volume = {12},

pages = {416-441},

abstract = {Wetlands provide multiple ecosystem services, such as carbon sequestration both in living biomass and in the soil. In México, most studies have been done in coastal wetlands, and for this reason

information on continental wetlands is scarce. Two research questions were answered: how much carbon is stored in the biomass and in the soil of a continental wetland?; and, which is the spatial structure and distribution of the dominant plant species? The study site is a floating wetland in the eastern part of lake Cuitzeo where field work was carried out during 2’17 and 2018. Following a

transect six points were selected and aerial biomass was harvested in one square meter plots, and a soil profile was excavated. Carbon content was analyzed from samples of the dominant species and

aparent density and carbon stored in the soil determined. Satellite imagery was analized to obtain the total area of the wetland in the period 2003- 2017 and the area damaged by fires was calculated.

Aerial biomass was 173.1 ± 61.1 kg/ha -1 , with a carbon storage of 70.4 ± 25.4 kg-C ha -1 . The wetland substrate contains 168 ± 10 Mg C ha -1 . It was detected that the invasive species Phragmites australis has increased its cover in 10 % of the toal wetland area from 2010 a 2017. Two major fires were detected, the largest in 2016 that covered 242 ha of a total of 535 ha.},

keywords = {carbon, carbon sequestration, ecosystem services, fire, hydrophyte, wetland},

pubstate = {published},

tppubtype = {article}

}

@article{Cruzado-Vargas2021,

title = {Reciprocal common garden altitudinal transplants reveal potential negative impacts of climate change on Abies religiosa populations in the Monarch Butterfly Biosphere Reserve overwintering sites},

author = {A. L. Cruzado-Vargas and A. Blanco-García and R. Lindig-Cisneros and M. Gómez-Romero and L. López-Toledo and E. de la Barrera and C. Sáenz-Romero },

url = {https://www.mdpi.com/1999-4907/12/1/69},

doi = {10.3390/f12010069},

year  = {2021},

date = {2021-01-09},

journal = {Forests},

volume = {21},

pages = {69},

abstract = {Highlights: Reciprocal altitudinal transplants of Abies religiosa seedlings within the Monarch Butterfly Biosphere Reserve (MBBR) allow prediction of the impacts of climatic change, because they grow in sites with a climate that differs from that of their origin. Background and Objectives: Climatic change is generating a mismatch between the sites currently occupied by forest populations and the climate to which they have adapted. This study determined the effect on the survival and growth of A. religiosa seedlings of transfer to sites that were warmer or colder than that of the origin of their seeds. Materials and Methods: Eleven provenances of A. religiosa, collected along an altitudinal gradient (3000 to 3550 m a.s.l.), were assayed in common gardens in three sites of contrasting altitude: 3400, 3000 and 2600 m a.s.l. The results were evaluated by fitting a response curve with a mixed model. Results: The climate transfer distance for the seasonal balance between the temperature conducive to growth (degree days above 5 °C) and the available precipitation (a ratio expressed as dryness index) dominated the shape of the response function curve. The rainy season (June–October) dryness index transfer distance was critical for survival, while that of the cold and dry season (November–February) was critical for aerial biomass, and the annual index was critical for the increase in basal diameter. The effect of climatic transfer distance is much more negative (triggering about 45% mortality) when transfer is toward warmer and dryer sites (at 400 m lower in altitude, +1.9 °C warmer and 16% less precipitation), than when shifting toward colder and wetter sites (400 m higher in altitude, resulting in 95% survival). Conclusions: The projected higher temperatures and lower precipitation due to climatic change will undoubtedly cause severe mortality in young A. religiosa seedlings. A 400 m shift upwards in altitude to compensate for climatic change (assisted migration) appears to be a feasible management action.},

keywords = {assisted migration, biomass, climate change, climate transfer distance, dryness, index},

pubstate = {published},

tppubtype = {article}

}

@article{Hernández2020,

title = {Cooperation between Sporobolus airodes and associated arbuscular mycorrhizal fungi for phosphorus acquisition under drought conditions in an oligotrophic desert ecosystem},

author = {D. Hernández-y-Hernández and J. Larsen and A. González-Rodríguez and Y. Tapia-Torres and E. de la Barrera and L.E. Eguiarte and F. García-Oliva},

doi = {10.1016/j.rhisph.2020.100225},

year  = {2020},

date = {2020-07-04},

journal = {Rhizosphere},

volume = {15},

number = {100225},

pages = {1-11},

abstract = {Plants from phosphorus (P) limited environments have developed various strategies for acquiring P from the soil , and for maintaining P homeostasis within the plant. We analyzed the mechanisms of phosphorus acquisition used by the grass Sporobolus airoides -rhizosphere microbiota during two years with contrasting annual rainfall in an extreme P-oligotrophic ecosystem. We determined arbuscular mycorrhizal fungi (AMF) root and soil colonization , and the activity of three P-related eco-enzymes over two consecutive years. We also determined C, N, and P concentrations and ratios in plant biomass, microbial biomass and soil for assessing nutrient homeostasis of soil microbial community and plants. S. airoides invested more carbon in the AMF symbiosis in the drought year in the site more limited by P (Pozas Azules site). Additionally, the specific activity of phosphomonoesterases was higher in this site, suggesting that the microbial community invests more energy to produce this enzyme to release P from organic molecules. In conclusion, our results show evidence of the importance of AMF symbiosis for S. airoides to cope with P and water limitations in a highly oligotrophic ecosystem.},

keywords = {arid, desert, mycorrhiza, nutrients, phosphorus},

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{Cooke2020,

title = {Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan},

author = {S. J. Cooke and C. L. Madliger and R. L. Cramp and J. Beardall and G. P. Burness and S. L. Chown and T. D. Clark and B. Dantzer and E. de la Barrera and N. A. Fangue and C. F. Franklin and A. Fuller and L. A. Hawkes and K. R. Hultine and K. E. Hunt and O. P. Love and H. A. MacMillan and J. W. Mandelman and F. C. Mark and L. B. Martin and A. E. M. Newmann and A. B. Nicotra and S. A. Robinson and Y. Ropert-Courdet and J. L. Rummer and F. Seebacher and A.E. Todgham},

url = {https://academic.oup.com/conphys/article/8/1/coaa016/5815645},

doi = {10.1093/conphys/coaa016},

year  = {2020},

date = {2020-04-04},

journal = {Conservation Physiology},

volume = {8},

number = {1},

pages = {coaa016},

abstract = {Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of ‘success stories’ is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a ‘horizon scan’, we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users.},

keywords = {conservation physiology, ecophysiology, evidence, horizon scan, sustainability, sustainable development goals},

pubstate = {published},

tppubtype = {article}

}

@article{Briones2020,

title = {A few islands of preliminary research among a sea of unknown: moving plant ecophysiology forward in megadiverse countries},

author = {O. Briones and C. Reyes-García and E. A. Díaz-Álvarez and C. Tinoco-Ojanguren and E. de la Barrera and J. L. Andrade},

url = {http://botanicalsciences.com.mx/index.php/botanicalSciences/article/view/2546},

doi = {10.17129/botsci.2546},

year  = {2020},

date = {2020-03-11},

journal = {Botanical Sciences},

volume = {98},

number = {98},

pages = {212-216},

abstract = {A principal intention of ecological sciences is to explain biodiversity: why are some species and not others found in certain places. As an experimental science, plant ecophysiology focuses on the interactions among plants, the environment, and other biological species. In this context, the VII Mexican Ecology Congress focused on "addressing the complexity of nature." Some examples of how ecophysiology can address said complexity were discussed during the symposium.},

keywords = {atmospheric pollution, climate change, drought, ecophysiology, environmental productivity index, epiphytes, food security},

pubstate = {published},

tppubtype = {article}

}

@article{Martínez2020,

title = {Germination ecophysiology for three peri-urban ephemeral weeds},

author = {D. N. Martínez and E. de la Barrera },

url = {https://lagranja.ups.edu.ec/index.php/granja/article/view/31.2020.03},

doi = {10.17163/lgr.n31.2020.03},

year  = {2020},

date = {2020-02-28},

journal = {La Granja (Revista de Ciencias de la Vida)},

volume = {31},

pages = {03},

abstract = {The environmental requirements leading to germination were determined by three common species found during the June-October 2009 rainy season in a peri-urban site from Morelia, Michoacán, Mexico, where the construction of a campus of Universidad Nacional Autónoma de México (UNAM) was underway. In particular, the responses were evaluated in the laboratory to low-temperature stratification, as well as day/night air temperature, and water potential for the native Onagraceae Lopezia racemosa and Ludwigia octovalvis, and the exotic Polygonaceae Rumex crispus. Low-temperature stratification had no effect on germination by L. racemosa, for which maximum germination averaging 88% was optimal at 25/15 and 30/20 ºC. Germination at 21 d was halved at –0.5 MPa and completely inhibited at –1.0 MPa. The seeds of L. octovalvis were also insensitive to low temperature stratification and their germination never exceeded 70%, with the two highest temperatures of 30/20 and 35/25 ºC being the optimum. For this species germination was maximal at 0.0 MPa, decreasing significantly under every treatment with a minimum germination of 21% for seeds incubated at –0.1 MPa. Germination for the exotic R. crispus was delayed by low-temperature stratification, although all its seeds germinated regardless of the temperature or water potential treatment. While the environmental requirements for germination of ephemeral species often match the typical climate of their growing season, the differential responses found for the species considered in the present study provide some insight into the mechanisms leading to changes in species composition for communities from disturbed environments, including the displacement of native species and the proliferation of exotic, potentially invasive plants. },

keywords = {invasive species, reproductive ecophysiology, temperature, urban ecology, water relations},

pubstate = {published},

tppubtype = {article}

}

@article{Rosado-Calderón2018,

title = {High resilience to extreme climatic changes in the CAM epiphyte Tillandsia utriculata L. (Bromeliaceae)},

author = {A.T. Rosado-Calderón and M. Tamayo-Chim and E. de la Barrera and I.M. Ramírez-Morillo and J. L. Andrade and O. Briones and C. Reyes-García },

doi = {10.1111/ppl.12805},

year  = {2020},

date = {2020-02-27},

journal = {Physiologia Plantarum},

volume = {168},

pages = {547-562},

abstract = {Climate change is expected to increase the frequency of extreme climatic events, yet few studies have addressed the capacity of plant species to deal with such events. Species that are widespread are predicted to be highly plastic and able to acclimate to highly changing conditions. To study the plasticity in physiological responses of the widely distributed epiphyte Tillandsia utriculata, we transplanted individuals from a coastal scrub and broadleaf evergreen forest to a similar coastal scrub site and forest. After a 45‐day acclimation, the plants were moved to a semicontrolled greenhouse at each site, and then subjected to a 20‐day drought. Physiological variables were measured during the acclimation and the drought. The individuals of scrub and forest populations had similar relative water content and carbon assimilation in the contrasting conditions of the two transplantation sites despite the high discrepancy between the environments at their original site. Electron transport rates were higher in individuals from the scrub population. Electron transport rates were also higher than estimated from carbon assimilation, suggesting that photorespiration was present. The individuals of the coastal scrub population had a higher capacity to dissipate excess energy this way. The relative distance index of plasticity was high overall, indicating that some traits are highly plastic (titratable acidity, carbon assimilation) in order to maintain the stability of others (maximum quantum yield Fv/Fm and relative water content). We conclude that T. utriculata is a highly plastic species with a high capacity to tolerate extreme environmental changes over a short time.},

keywords = {CAM, climate change, drought, epiphytes, reaction norms, Tillandsia},

pubstate = {published},

tppubtype = {article}

}

@article{delaBarrera2020b,

title = {No country for new seeds: Food and environmental security implications of Mexico's  intended ban on GM crops},

author = {E. de la Barrera and I. A. Aguirre-Pérez and B. A. Ibarra-Otero and E. A. Villalvazo-Figueroa and E. A. Díaz-Álvarez},

url = {https://link.springer.com/article/10.1007/s11248-019-00186-7},

doi = {10.1007/s11248-019-00186-7},

year  = {2020},

date = {2020-02-03},

journal = {Transgenic Research},

volume = {29},

number = {1},

pages = {156-170},

abstract = {An intended generalized ban on the "introduction and use of transgenic seeds" has been announced by the Mexican government, which, unlike the other agricultural programs under this administration, lacks a budget and rules of operation. In this policy brief we consider scenarios of implementing such an intended ban, de-regulating the use of genetically modified crops, or an intermediate scenario under the existing biosafety regulations. We recommend maintaining the status quo given its potential contributions to food and environmental security, in addition to a better economic outlook. However, a greater impulse needs to be given by the federal government to foment the domestic development of GM crops that are pertinent for Mexican agri-food needs, in addition to funding the development and implementation of various agro-ecological practices that increase biodiversity in food production units.},

keywords = {agroecology, biodiversity, biosafety, climate change, public policy, science policy},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2020,

title = {Morphophysiological screening of potential organisms for biomonitoring nitrogen deposition},

author = {E. A. Díaz-Álvarez and E. de la Barrera and E. Y. Barrios-Hernández and M. Arróniz-Crespo},

url = {https://www.sciencedirect.com/science/article/pii/S1470160X19307228},

doi = {10.1016/j.ecolind.2019.105729},

issn = {1470-160X},

year  = {2020},

date = {2020-01-06},

journal = {Ecological Indicators},

volume = {108},

pages = {105729},

abstract = {The intensification of different anthropic activities has led to a doubling of the emitted reactive nitrogen species since the second half of the XX century, resulting in the increase of nitrogen deposition. This poses a major threat to global biodiversity. However, in developing countries the monitoring of atmospheric deposition has shown to be difficult. For these reasons, the aim of this study was to assess, by means of a greenhouse dose-response experiment, the biomonitoring potential of two mosses, Braunia secunda and Thuidium delicatulum, and two epiphytic bromeliads, Tillandsia recurvata and Tillandsia usneoides, which are widely distributed in Latin America. A significant increase of the phosphomonoesterase activity was observed for the mosses, particularly under a High-nitrogen treatment, a parameter that decreased for the bromeliads. In turn, the nitrate reductase activity decreased over the course of the experiment for the mosses, but it remained almost unchanged for both tillandsias. While the nitrogen content for the mosses increased, it fluctuated for the bromeliads. Braunia secunda became greener under the Low-nitrogen than under the other treatments, while the coloration for T. delicatulum turned to brown under all treatments. The tillandsias remained visually unchanged under all treatments. The mosses had a clear response to the simulated nitrogen deposition, with B. secunda being more tolerant than T. delicatulum. Neither tillandsia presented a clear response to the treatments. Thus, the moss B. secunda is a very suitable species for biomonitoring nitrogen deposition, while the other species evaluated were deemed unsuitable.},

keywords = {atmospheric pollution, CAM, global change, Latin America, Mexico, neotropical, nitrogen},

pubstate = {published},

tppubtype = {article}

}

@article{delaBarrera2019b,

title = {4T don't stand for tacos: An analysis of food and environmental security considerations in the new Mexican government's agricultural agenda},

author = {E. de la Barrera and E. A. Villalvazo-Figueroa and E. A. Díaz-Álvarez and C. SegAlim},

doi = {10.12688/f1000research.20934.1},

issn = {2046-1402},

year  = {2019},

date = {2019-10-17},

journal = {F1000 Research},

volume = {8},

pages = {1768},

abstract = {On his first day in office, on 1 December 2018, freshman President of Mexico, Andrés Manuel López Obrador (AMLO) delivered a speech outlining 100 policy priorities of his administration. The present study analyzed the contributions of this government’s program relating to food security and their environmental implications, and whether they contributed to strengthen the state or improved human security, considering that the poor and marginalized were at the center of AMLO's campaign. In total 45 policy priorities were geared to consolidate the state, while 55 contributed to improving human security. Only six were related to food security, including stipends to food producers and purchasing grains at guaranteed prices, a fertilizer distribution program and subsidies for cattle husbandry and fisheries/aquaculture. These programs contributed to advancing 10 of the 17 Sustainable Development Goals, especially those related to Zero Hunger and Reduced Inequalities. Various policy programs had explicit considerations towards climate change and land degradation, including the exclusion of natural protected areas from agricultural subsidies, and recognized that food production is vulnerable to climate change. The four agricultural programs analyzed may advance AMLO’s goal of avoiding food imports, while curbing rural poverty. However, available evidence is mixed regarding animal acquisition loans, which are likely to have adverse environmental outcomes. Finally, the program for developing agroforestry operations is already contributing to deforestation, and further ecosystem degradation is most likely to occur from the introduction of timber and fruit species to natural forests as this program does not preclude the inclusion of recently cleared plots. If human development goals are to be reached, along with fulfilling the international commitments on sustainable development and environmental conservation, policies need to be implemented that simultaneously tend to a booming transnational industry, while bringing forward the rural poor, who amount to nearly half of the country's population.

},

keywords = {agricultural policy, evidence-based policy, food security, human security, public policy, socioecological systems, sustainability, sustainable development goals},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2019c,

title = {Drying protocol does not alter plant δ13C and δ15N: a baseline survey for ecological studies},

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

doi = {10.1080/10256016.2019.1673747},

year  = {2019},

date = {2019-10-09},

journal = {Isotopes in Environmental & Health Studies},

volume = {55},

pages = {526-531},

abstract = {The use of stable isotopes in plant ecological studies has become widespread over the past few decades, given the potential of this tool for integrating physiological processes within an individual and allowing to track ecosystem-wide processes at various scales, with applications ranging from determining past meteorological conditions and potential adaptations of ecosystems to climate change, to biomonitoring studies of atmospheric pollution. However, the drying protocol might alter the isotopic signatures of plant samples given that high temperatures can volatilize various organic compounds or delay the halting of physiological processes at lower drying temperatures. We thus evaluated the effect of four drying protocols on the carbon and nitrogen isotopic signatures for 23 species of plants. In particular, leaves were either freeze dried, placed in a herbarium drying stove (ca. 50 ºC), in a gravity convection oven (80 ºC), or microwaved (900 Watts) in 2-minute pulses, until constant weight. For each species, neither treatment led to significantly different δ13C values, which ranged from ‒31.7‰ to ‒12.4‰. The δ15N values of 21 of the species considered were not affected by the drying protocols, ranging from ‒11.6‰ to ‒8.8‰. For Tillandsia makoyana, significant differences were observed between the freeze dried and the microwaved samples and between the freeze dried samples and those dried at 50 ºC for Macroptilium gibbosifolium. },

keywords = {atmospheric pollution, biomonitoring, ecophysiology, microwave, stable isotopes},

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{Díaz-Álvarez2019,

title = {Elemental and isotopic assessment for Colombian orchids from a montane cloud forest: a baseline for global environmental change},

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

url = {https://rdcu.be/bCRG6},

doi = {10.1007/s11738-019-2893-y},

year  = {2019},

date = {2019-05-16},

journal = {Acta Physiologiae Plantarum},

volume = {41},

number = {6},

pages = {99},

abstract = {Orchidaceae is the largest family of plants, reaching its maximum diversity in Colombia where 4000 species have been registered. One particular ecosystem with high diversity of orchids is the tropical montane cloud forest characterized by high humidity and low air temperatures. However, due to anthropic pressure such as land use change its area has been reduced. This is not the only anthropic disturbance that can affect the continuity of this forest and orchids, climate change and nitrogen deposition also become threats. By means of elemental composition and isotopic measurements of carbon and nitrogen, we determined the photosynthetic pathway for orchids from a tropical cloud forest in Colombia, for which, we also evaluated the nutritional status of nitrogen and its relationship with atmospheric deposition. We found 46 species from 18 genera; of these, 19 species were epiphytic, 9 lithophytic and 18 terrestrials. The carbon content was not significantly different among the species evaluated, averaging 46.4 ± 0.41% (dry weight). In turn, only one terrestrial orchid had a nitrogen content above 2.2%, averaged 1.4 ± 0.07% for the remaining 45 species. The δ13C that averaged − 28.1 ± 0.4‰ for 45 species was typical of C3 plants, while only one species, whose δ13C of 18.8‰ can be considered CAM. The δ15N values for 44 orchids were negative, in total they ranged from − 8.1 to 4.5‰. It can be concluded that the temperatures in this area are not yet high enough to produce a noticeable change in photosynthesis as evidenced by the carbon content of orchids, however, the expected rise would bring harmful consequences for these populations of orchids, especially when considering that these orchids were collected at the highest altitudinal range of the region. Moreover, the rates of nitrogen deposition are not high enough yet to leave a significant signal in the vegetation.},

keywords = {biodiversity, CAM, ecophysiology, epiphytes, global change, nitrogen, orchid, photosynthesis, stable isotopes},

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{Gudiño2018,

title = {Estructura de los nectarios florales y el néctar en la familia Cactaceae},

author = {W. Gudiño and E. de la Barrera and J. Márquez-Guzmán},

url = {http://web.ecologia.unam.mx/cactsucmex/csm2018_63_4.pdf},

year  = {2018},

date = {2018-11-01},

journal = {Cactáceas y suculentas mexicanas},

volume = {64},

pages = {100-126},

abstract = {Los nectarios son estructuras glandulares o tejidos especializados encargados de sintetizar y secretar el néctar. El néctar, por su parte, es una solución compuesta por azúcares y proteínas que las plantas usan como recompensa para los polinizadores o para los insectos que las protegen de la herbivoría. Por más de 200 años los nectarios y el néctar han sido objeto de la atención de numerosos investigadores, debido al rol central que juegan en la interacción planta-polinizador. Sin embargo, la mayoría de los trabajos se enfocan solo en la interacción ecológica y pocos en la forma, función y ubicación. Los pocos trabajos acerca de nectarios en la familia de las Cactaceae son un claro ejemplo de que a pesar de que, las cactáceas son uno de los grupos más importantes

en las zonas áridas del país aún falta mucho por conocer de esta familia. El objetivo de este trabajo es reunir, sintetizar y analizar la información disponible a la fecha sobre los nectarios florales y el néctar en la familia Cactaceae, con el propósito de ofrecer a los interesados un documento con información actualizada. },

keywords = {ecophysiology, nectar, nectary, reproductive ecophysiology},

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{Orozco-Martínez2018,

title = {Can germination requirements predict tolerance to extreme weather? — An assessment for heirloom maize from the P'urhépecha Plateau},

author = {R. Orozco-Martínez and E. de la Barrera },

url = {http://www.fspublishers.org/Issue.php?categoryID=158

http://agro.mx/wp-content/uploads/2018/07/045-OrozcoMtz-delaBarrera-maize-germination.pdf},

doi = {10.17957/IJAB/15.0727},

year  = {2018},

date = {2018-07-27},

journal = {International Journal of Agriculture and Biology},

volume = {20},

number = {9},

pages = {2039-2044},

abstract = {The temperature and water potential requirements for seed germination were determined for five heirloom maizes from three different agroclimatological regions from the P'urhépecha community of San Francisco Pichátaro, Michoacán, Mexico. Germination experiments were conducted in environmental controlled chambers exposing seeds to day/night air temperatures (12 h photoperiod) of 15/5, 20/10, or 35/25ºC, and to water potentials of 0, –0.01, –0.05, –0.1, or –0.5 MPa, which were created with aqueous solutions of polyethylene glycol (molecular weight 20,000). Germination was maximal and occurred at a faster rate for seeds incubated at 35/25ºC. In turn, a high water potential of 0.0 or –0.01 MPa was necessary to achieve maximum germination, which decreased under more negative water potentials until germination was completely inhibited for seeds incubated under –0.5 MPa failed. Although an environmental specialization for germination was not observed among the heirloom maize evaluated, their ability to germinate maximally under high temperatures is indicative of their cultivation potential under the increasing air temperatures expected to occur during the present century. In contrast, germination sensitivity to relatively mild water potentials may be a conservative ecophysiological trait of drought-escape for this tropical annual plant.},

keywords = {agriculture, cereal, climate change, domestication, drought, ecophysiology, food security, germination, maize},

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}

}

@article{Díaz-Álvarez2017,

title = {Acumulación nocturna de acidez titulable por Tillandsia makoyana (Bromeliaceae), epífita de la selva baja caducifolia},

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

url = {http://agro.mx/wp-content/uploads/2017/12/043-Diaz_Alvarez-2017-Phyton.pdf

http://www.revistaphyton.fund-romuloraggio.org.ar/vol86.html},

year  = {2017},

date = {2017-12-20},

journal = {Phyton – International Journal of Experimental Botany},

volume = {86},

pages = {278-281},

abstract = {The epiphytic bromeliad \textit{Tillandsia makoyana} was studied to assess the contribution of the environmental factors, water, temperature, and light, to the expression of the Crassulacean acid metabolism. In particular, nocturnal titratable acidity accumulation and maximum leaf temperature were measured in response to watering and incident light. Plants that were watered and exposed to direct sunlight had the highest nocturnal accumulation of titratable acidity of 25.52 ± 0.34 H+/m^2, while the plants without irrigation and kept in the shade had a 59% reduction in their titratable acidity. Our results illustrate a rapid response of the photosynthetic activity to water availability for \textit{Tillandsia makoyana}, native from an ecosystem where this environmental factor greatly fluctuates.},

keywords = {CAM, Chamela, epiphyte, Jova, shade, Tillandsia, water relations},

pubstate = {published},

tppubtype = {article}

}

@article{Martínez2017,

title = {PREPRINT: Germination ecophysiology for three peri-urban ephemeral weeds},

author = {D. N. Martínez and E. de la Barrera},

url = {https://peerj.com/preprints/2950/},

doi = {10.7287/peerj.preprints.2950v1},

issn = { 2167-9843},

year  = {2017},

date = {2017-04-27},

journal = {PeerJ Preprints},

volume = {5},

pages = {e2950v1},

abstract = {We determined the environmental requirements leading to germination by three common species found during the summer rainy season in a peri-urban site where construction of a university campus was underway. In particular, we evaluated laboratory responses to low-temperature stratification, day/night air temperature, and water potential for the native Onagraceae Lopezia racemosa and Ludwigia octovalvis, and the exotic Polygonaceae Rumex crispus. Low-temperature stratification had no effect on germination by L. racemosa, for which maximum germination averaging 88% was optimal at 25/15 and 30/20 ºC. Germination at 21 d was halved at –0.5 MPa and completely inhibited at –1.0 MPa. The seeds of L. octovalvis were also insensitive to low temperature stratification and their germination never exceeded 70%, with the two highest temperatures of 30/20 and 35/25 ºC being the optimum. For this species germination was maximal at 0.0 MPa, decreasing significantly under every treatment with a minimum germination of 21% for seeds incubated at –0.1 MPa. Germination for the exotic R. crispus was delayed by low-temperature stratification, although all of its seeds germinated regardless of the temperature or water potential treatment. While the environmental requirements for germination of ephemeral species often match the typical climate of their growing season, the differential responses found for the species considered in the present study provide some insight into the mechanisms leading to changes in species composition for communities from disturbed environments, including the displacement of native species and the proliferation of exotic, potentially invasive, plants.},

note = {NOT Peer reviewed. This is an early communication for feedback before peer review},

keywords = {disturbance, invasive species, land-use change, reproductive ecophysiology, seed bank, temperature, urban ecology, water relations},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2017b,

title = {PREPRINT: Mapping pollution in a megalopolis: the case for atmospheric biomonitors of nitrogen deposition},

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

url = {https://doi.org/10.1101/118257

},

doi = {10.1101/118257},

year  = {2017},

date = {2017-03-19},

journal = {BioRxiv},

volume = {doi: 10.1101/118257},

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. However, deployment of automated networks can be excessively costly for most cities so the utilization of widely distributed biological species suitable for biomonitoring may be a good alternative. The aim of this work was thus to assess the suitability of different atmospheric organisms as biomonitors of nitrogen deposition, by means of an extensive sampling of a lichen, two mosses, and one bromeliad throughout the Valley of Mexico, the basin where the megalopolis of Mexico City (population 20 million) is located, and subsequent measurements of nitrogen metabolism parameters. In all cases significant responses of nitrogen content, C:N ratio and 15N were found for the lichen Anaptychia sp. the mosses Grimmia sp. and Fabronia sp., and the bromeliad Tillandsia recurvata in response to season and collected site. In turn, 15N for the mosses responded linearly to the wet deposition (R2= 0.7 for Grimmia sp. and R2=0.2 for Fabronia sp.). Also, the nitrogen content (R2=0.7), the C:N ratio (R2=0.6), and 15N (R2=0.5) for the bromeliad had a linear response to NOx. However, latter species was not found in sites with NOx concentrations above 212 ppm. These biomonitors can be utilized in tandem to determine the status of nitrogenous pollution in regions without monitoring networks.},

note = {This article is a preprint and has not been peer reviewed. },

keywords = {biomonitoring, ecophysiology, global change, lichen, megacities, mosses, nitrogen, Tillandsia, urban ecology},

pubstate = {published},

tppubtype = {article}

}

@article{delaBarrera2016b,

title = {COP-eration for global food security},

author = {E. de la Barrera},

url = {https://f1000research.com/articles/5-2814},

year  = {2016},

date = {2016-12-05},

journal = {F1000Research},

volume = {5},

pages = {2814},

abstract = {Mexico is hosting the 13th Conference of the Parts (COP-13) on the Convention on Biological Diversity. Participants will have another opportunity to "integrate biodiversity for wellbeing." Considering that food production is a major driver for the loss of biological diversity, despite the fact that ample genetic reservoirs are crucial for the persistence of agriculture in a changing world, food can be a conduit for bringing biodiversity into people's minds and government agendas. If this generation is going to "live in harmony with nature," as the Aichi Biodiversity Targets indicate, such an integration needs to be developed between the agricultural and environmental sectors throughout the world, especially as an increasingly urban civilization severs its cultural connections to food origin.},

keywords = {agriculture, biodiversity, food security, public policy, science communication},

pubstate = {published},

tppubtype = {article}

}

@article{delaBarrera2016,

title = {Socio-ecological considerations on the persistence of Mexican heirloom maize},

author = {E. de la Barrera and R. Orozco-Martínez},

url = {http://agro.mx/wp-content/uploads/2017/01/61_4_36.pdf

http://www.maydica.org/articles/61_4_36.pdf

http://agro.mx/wp-content/uploads/2017/01/Maydica-61-4-M36-Apendix-1.pdf},

year  = {2016},

date = {2016-12-02},

journal = {Maydica},

volume = {61},

number = {4},

pages = {M36},

abstract = {The vulnerability of 59 Mexican landraces of maize was assessed in relation to five socio-ecological factors, namely, social and economic marginalization, association with indigenous peoples, high biodiversity regions, environmental suitability for cultivation, and climate change effects. The most marginalized states had the highest number of landraces, 80% of which were found in predominantly or substantially indigenous municipalities. While only one third of 152 regions of high biodiversity had collection records, 47 landraces had at least one collection record in these regions. Eleven races can be cultivated in at least 10% of the Mexican territory, while 13 can occupy less than 1% under current environmental conditions. Given a projected temperature increase of 0.5 oC and a 5% reduction in annual precipitation, 66% of the landraces could disappear during the current decade. A normalized Vulnerability Index was constructed (can have values from 0.00 for non-threatened landraces to 1.00 for the most vulnerable) that averaged 0.76 ± 0.02 for the 59 landraces. The most vulnerable third of the landraces were threatened by being from a region of low marginalization combined with a limited potential distribution both under current conditions and under the climate change scenario considered.},

keywords = {climate change, food security, maize, orphan crops, risk assessment},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2016b,

title = {A δ15N assessment of nitrogen deposition for the endangered epiphytic orchid Laelia speciosa from a city and an oak forest in Mexico},

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

url = {http://rdcu.be/npd1

http://agro.mx/wp-content/uploads/2016/06/039-Diaz-Alvarez-laelia-rv3.pdf

http://link.springer.com/article/10.1007/s10265-016-0843-y},

doi = {10.1007/s10265-016-0843-y},

year  = {2016},

date = {2016-06-09},

journal = {Journal of Plant Research},

volume = {129},

pages = {863–872},

abstract = {Atmospheric nitrogen deposition poses a major threat to global biodiversity. Tropical epiphytic plants are especially at risk given their reliance on atmospheric sources of nutrients. The leaf, pseudobulb, and root carbon and nitrogen content, C:N ratio, as well as the nitrogen isotopic composition were studied for individuals of Laelia speciosa from a city and from an oak forest in Mexico. The nitrogen content of leaves was similar between the city and the oak forest, reaching 1.3 ± 0.2 % (dry mass). The δ15N of leaves, pseudobulbs, and roots reached 5.6 ± 0.2 ‰ in the city, values found in sites exposed to industrial and vehicular activities. The δ15N for plant from the oak forest amounted to –3.1 ± 0.3 ‰, which is similar to values measured from sites with low industrial activities. Some orchids such as Laelia speciosa produce a single pseudobulb per year, i.e., a water and nutrient storage organ, so the interannual nitrogen deposition was studied by considering the ten most recent pseudobulbs for plants from either site formed between 2003 and 2012. The C:N ratio of the ten most recent pseudobulbs from the oak forest, as well as that of the pseudobulbs formed before 2010 for plants in the city were indistinguishable from each other, averaging 132.4 ± 6.5, while it was lower for the two most recent pseudobulbs in the city. The δ15N values of pseudobulbs from the oak forest averaged ‒4.4 ± 0.1 ‰ for the entire series. The δ15N ranged from 0.1 ± 1.6 ‰ for the oldest pseudobulb to 4.7 ± 0.2 ‰ for the pseudobulb formed in the city from 2008 onwards. Isotopic analysis and the C:N ratio for L. speciosa revealed that rates of nitrogen deposition were higher in the city than in the forest. The δ15N values of series of pseudobulbs showed that it is possible to track nitrogen deposition over multiple years.},

keywords = {conservation physiology, global change, moss, Neo-volcanic axis, nitrogen, orchid, pollution, stable isotopes, urban ecology},

pubstate = {published},

tppubtype = {article}

}

@article{Villa-Reyes2016,

title = {Environmental cues for germination of the invasive bunch grass Pennisetum ciliare (L.) Link},

author = {F. Villa-Reyes and E. de la Barrera},

url = {http://rdcu.be/noeu



http://link.springer.com/article/10.1007/s11738-016-2175-x},

doi = {10.1007/s11738-016-2175-x},

year  = {2016},

date = {2016-05-28},

journal = {Acta Physiologiae Plantarum},

volume = {38},

pages = {156},

abstract = {Responses of seed germination to air temperature, water potential, light, and smoke were studied in the laboratory for seeds of the invasive bunch grass Pennisetum ciliare (L.) Link (syn. Cenchrus ciliare L.; buffel grass). First introduced to North America during the mid-20th Century for establishing pastures, this African bunch grass has become an invasive species of concern. Across all the experiments conducted, a low germination was observed for P. ciliare fascicles that never exceeded 30% at 21 days after sowing. Optimal day/night air temperatures for germination, controlled with an environmental chamber, were 25/15 and 30/20 ºC, while extreme temperatures of 15/5 and 45/35 ºC inhibited germination. By sowing seeds of P. ciliare under different water potentials, created with aqueous solutions of polyethylene glycol, an optimum of -0.03 MPa led to the highest germination, while no germination was observed at -1.0 MPa. Monochromatic optical filters were utilized to germinate seeds under various wavelengths, of which red (650 nm) and far red (730 nm) led to the highest germination. In addition, seeds that were incubated in the dark had higher germination than those incubated under white light. Incubation in smoke water, which can stimulate germination of phyrophytic species, resulted in a marginal inhibition of germination compared with imbibition with distilled water.},

keywords = {buffel grass, Cenchrus ciliaris, ecophysiology, germination, global change, invasive species, Pennisetum ciliare, zacate buffel},

pubstate = {published},

tppubtype = {article}

}

@article{Gómez-Ruiz2016,

title = {Potassium enhances frost tolerance in young individuals of three tropical dry forest species from Mexico},

author = {P. A. Gómez-Ruiz and R. Lindig-Cisneros and E. de la Barrera and C. Martorell},

url = {http://www.publish.csiro.au/?paper=FP15329},

doi = {10.1071/FP15329},

year  = {2016},

date = {2016-02-24},

journal = {Functional Plant Biology},

volume = {43},

pages = {461-467},

abstract = {Movement of species outside their range of distribution could be a strategy for conservation purposes, but before implementation, it is necessary to evaluate plants responses to the conditions that they will experience in new locations. We evaluated the effect of potassium fertilisation to enhance the frost tolerance of young individuals of Albizia plurijuga (Standley) Britton & Rose, Cedrela dugesii S.Watson and Ceiba aesculifolia (Kunth) Britten & Baker f., which are all common species from tropical dry forests in Mexico. Plants were propagated in a shade-house and fertilised during 9 months with different concentrations of potassium (39, 189 and 528 ppm). In frost simulations, plants were exposed to temperatures below 0°C during different time periods and frost injury was assessed by electrolyte leakage of leaf discs from young and old leaves. We observed that potassium fertilisation enhanced frost tolerance by reducing electrolyte leakage mainly in young leaves. We recorded plant re-sprouting ability after exposure to subzero temperatures over 45 days, finding notable differences among species: all individuals of C. dugesii sprouted, followed by some of A. plurijuga and finally just one of C. aesculifolia. Also, high potassium levels increased re-sprouting response. These species have a low frost tolerance, but potassium fertilisation seemed to be effective to enhance it for young individuals, increasing the probability of survival if plants are moved to colder areas than current habitats.},

keywords = {dry forest, frost, potassium, tree, tropical, woody species},

pubstate = {published},

tppubtype = {article}

}

@article{delaBarrera2015,

title = {Short-term drought responses by seedlings of three maizes along an environmental gradient in Michoacán, Mexico},

author = {Z. D. Guerrero-Jiménez and E. de la Barrera},

url = {http://agro.mx/wp-content/uploads/2016/07/036-Guerrero-dlB-Maydica-html.pdf

},

year  = {2015},

date = {2015-12-17},

journal = {Maydica},

volume = {60},

number = {2},

pages = {M017},

keywords = {climate change, drought, ecophysiology, food security, maize},

pubstate = {published},

tppubtype = {article}

}

@article{Gudiño2015b,

title = {High-temperature tolerance by the endangered Mexican orchid \textit{Laelia speciosa}},

author = {W. Gudiño and I. Ávila-Díaz and K. Oyama and E. de la Barrera },

url = {http://tropicalconservationscience.mongabay.com/content/v8/tcs_v8i4_983-991_Gudino.pdf},

year  = {2015},

date = {2015-12-13},

journal = {Tropical Conservation Science},

volume = {8},

number = {4},

pages = {983-991},

keywords = {assisted migration, climate change, conservation physiology, ecological niche, global warming, Laelia, orchid, temperature, tissue culture},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2015,

title = {In vitro germination and development of two endangered endemic Colombian orchids Cattleya mendelii and Cattleya quadricolor},

author = {E. A. Díaz-Álvarez and C. Torres-Galeano and A. P. Rojas-Cortés and E. de la Barrera },

url = {http://www.gayanabotanica.cl/pdfs/2015/2/05_Diaz-Alvarez_etal_2015.pdf},

year  = {2015},

date = {2015-11-26},

journal = {Gayana Botánica},

volume = {72},

pages = {213-220},

keywords = {auxin, biotechnology, CAM, Cattleya, culture media, development, gibberellin, orchid, phytohormones},

pubstate = {published},

tppubtype = {article}

}

@article{Montejo-Mayo2015,

title = {Interactions between dominant hydrophytic species of the wetlands of western Mexico mediated by fire and nitrite concentration},

author = {W. Montejo-Mayo and E. del-Val and M. Gómez-Romero and E. de la Barrera and R. Lindig-Cisneros},

url = {http://agro.mx/wp-content/uploads/2015/10/MontejoetalPolibotanica.pdf



http://www.polibotanica.mx/esp/num40/tema10esp.htm



},

year  = {2015},

date = {2015-09-29},

journal = {Polibotánica},

volume = {40},

pages = {53-161},

keywords = {fire, nitrogen, Typha, wetland},

pubstate = {published},

tppubtype = {article}

}

@article{Báez-Pérez2015,

title = {Inoculación con hongos micorrízicos y fertilización con urea de plantas de Fraxinus uhdei en acrisoles provenientes de sitios degradados},

author = {A. L. Báez-Pérez and M. Gómez-Romero and J. Villegas and E. de la Barrera and L. Carreto-Montoya and R. Lindig-Cisneros},

url = {http://agro.mx/wp-content/uploads/2015/09/032-Baez-Pérez-2015-BotSci-micorrizas.pdf



http://www.botanicalsciences.com.mx/index.php/botanicalSciences/article/view/207/pdf_138



},

doi = {10.17129/botsci.207},

year  = {2015},

date = {2015-09-15},

journal = {Botanical Sciences},

volume = {93},

number = {3},

pages = {501-508},

keywords = {erosion, Fraxinus, micorrhizae, nitrogen, Pisolitus, restoration, Rhizophagus},

pubstate = {published},

tppubtype = {article}

}

@article{Díaz-Álvarez2015,

title = {Responses to simulated nitrogen deposition by the neotropical epiphytic orchid Laelia speciosa},

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

url = {https://peerj.com/articles/1021/

http://agro.mx/wp-content/uploads/2015/06/031-Díaz-Alvarez-et-al-2015-PeerJ-Laelia.pdf},

doi = {10.7717/peerj.1021},

year  = {2015},

date = {2015-06-18},

journal = {PeerJ},

volume = {3},

pages = {e1021},

abstract = {Potential ecophysiological responses to nitrogen deposition, which is considered to be one of the leading causes for global biodiversity loss, were studied for the endangered endemic Mexican epiphytic orchid, Laelia speciosa, via a shadehouse dose-response experiment (doses were 2.5, 5, 10, 20, 40, and 80 kg N ha-1 yr-1) in order to assess the potential risk facing this orchid given impending scenarios of nitrogen deposition. Lower doses of nitrogen of up to 20 kg N ha yr–1, the dose that led to optimal plant performance, acted as fertilizer. For instance, the production of leaves and pseudobulbs were respectively 35% and 36% greater for plants receiving 20 kg N ha yr–1 than under any other dose. Also, the chlorophyll content and quantum yield peaked at 0.66 ± 0.03 g m-2 and 0.85 ± 0.01, respectively, for plants growing under the optimum dose. In contrast, toxic effects were observed at the higher doses of 40 and 80 kg N ha yr–1. The δ13C for leaves averaged –14.7 ± 0.2‰ regardless of the nitrogen dose. In turn, δ15N decreased as the nitrogen dose increased from 0.9 ±0.1‰ under 2.5 kg N ha-1 yr-1 to – 3.1 ± 0.2 ‰ under 80 kg N ha-1 yr-1, indicating that orchids preferentially assimilate NH4+ rather than NO3– of the solution under higher doses of nitrogen. Laelia speciosa showed a clear response to inputs of nitrogen, thus, increasing rates of atmospheric nitrogen deposition can pose an important threat for this species.},

keywords = {acid rain, biodiversity, CAM, conservation physiology, d15N, global change, Laelia, neotropical, nitrogen, orchid, plant nutrition, pollution, stable isotopes},

pubstate = {published},

tppubtype = {article}

}

@article{Gudiño2015,

title = {Structural implications for nectar secretion by floral nectaries  of three columnar cacti},

author = {W. Gudiño and J. Márquez-Guzmán and E. de la Barrera },

url = {http://agro.mx/wp-content/uploads/2015/06/30-MIJST.pdf

http://www.mijst.mju.ac.th/vol9/156-164.pdf

},

year  = {2015},

date = {2015-06-06},

journal = {Maejo International Journal of Science and Technology},

volume = {9},

number = {2},

pages = {156-164},

abstract = {Floral nectaries are essential for plant reproduction. Their position and shape are

important because these factors determine the amount of nectar secreted and therefore the

pollinators that are attracted. The main objective of this study is to determine the position,

shape and macromorphology of floral nectaries for three columnar cacti, namely Polaskia

chende, P. chichipe and Stenocereus quevedonis. By means of light microscopy, scanning

electron microscopy and histochemical tests, the floral nectar-secreting structures were

investigated. Different secreting structures were found for the three species, with S.

quevedonis having the largest nectar secreting area consisting of stomates located at the base

of the stem filaments (1.9 mm2

). The nectar secretory pores of P. chichipe measured 0.93

mm2

, while the cuticular fissures of P. chende measured 0.8 mm2

. For the case of these three

species, the surface available for nectar secretion appears to determine the volume of nectar

secretion. The relationships between nectarial chamber size, total nectar volume secreted and

size of secreting structure found for the three species suggest that the surface area available is

the central influential variable that determines the volume of secreted nectar.},

keywords = {flower, morphology, nectar, nectary, Polaskia, reproductive ecophysiology, Stenocereus},

pubstate = {published},

tppubtype = {article}

}