2019
Díaz-Álvarez, E. A.; de la Barrera, E.; Arciga-Pedraza, A.; Arróniz-Crespo, M.
Bryophyte enzymatic responses to atmospheric nitrogen deposition: A field validation for potential biomonitors Journal Article
In: The Bryologist, vol. 122, no. 3, pp. 396-403, 2019.
Abstract | Links | BibTeX | Tags: atmospheric pollution, biomonitors, moss, pollution, urban ecology
@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}
}
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.
2016
Díaz-Álvarez, E. A.; Reyes-García, C.; de la Barrera, E.
A δ15N assessment of nitrogen deposition for the endangered epiphytic orchid Laelia speciosa from a city and an oak forest in Mexico Journal Article
In: Journal of Plant Research, vol. 129, pp. 863–872, 2016.
Abstract | Links | BibTeX | Tags: conservation physiology, global change, moss, Neo-volcanic axis, nitrogen, orchid, pollution, stable isotopes, urban ecology
@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}
}
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.