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.
2015
Díaz-Álvarez, E. A.; Lindig-Cisneros, R.; de la Barrera, E.
Responses to simulated nitrogen deposition by the neotropical epiphytic orchid Laelia speciosa Journal Article
In: PeerJ, vol. 3, pp. e1021, 2015.
Abstract | Links | BibTeX | Tags: acid rain, biodiversity, CAM, conservation physiology, d15N, global change, Laelia, neotropical, nitrogen, orchid, plant nutrition, pollution, stable isotopes
@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}
}
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.