2021
González-Salvatierra, C.; Peña-Rodríguez, L. M.; Reyes-García, C.; de la Barrera, E.; Andrade, J. L.
Seasonal changes in photosynthesis for the epiphytic bromeliad Tillandsia brachycaulos in a tropical deciduous forest. Journal Article
In: Botanical Sciences, vol. 99, pp. 850-862, 2021.
Abstract | Links | BibTeX | Tags: CAM, chlorophyll, chlorophyll fluorescence, Crassulacean acid metabolism, ecophysiology, epiphytes, microenvironment, pigments, shade, tropical dry forest, water, water relations
@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}
}
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.
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.
2020
Martínez, D. N.; de la Barrera, E.
Germination ecophysiology for three peri-urban ephemeral weeds Journal Article
In: La Granja (Revista de Ciencias de la Vida), vol. 31, pp. 03, 2020.
Abstract | Links | BibTeX | Tags: invasive species, reproductive ecophysiology, temperature, urban ecology, water relations
@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}
}
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.
2017
Díaz-Álvarez, E. A.; Rojas-Cortés, A. P.; de la Barrera, E.
Acumulación nocturna de acidez titulable por Tillandsia makoyana (Bromeliaceae), epífita de la selva baja caducifolia Journal Article
In: Phyton – International Journal of Experimental Botany, vol. 86, pp. 278-281, 2017.
Abstract | Links | BibTeX | Tags: CAM, Chamela, epiphyte, Jova, shade, Tillandsia, water relations
@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}
}
The epiphytic bromeliad 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 Tillandsia makoyana, native from an ecosystem where this environmental factor greatly fluctuates.
Martínez, D. N.; de la Barrera, E.
PREPRINT: Germination ecophysiology for three peri-urban ephemeral weeds Journal Article
In: PeerJ Preprints, vol. 5, pp. e2950v1, 2017, ISSN: 2167-9843, (NOT Peer reviewed. This is an early communication for feedback before peer review).
Abstract | Links | BibTeX | Tags: disturbance, invasive species, land-use change, reproductive ecophysiology, seed bank, temperature, urban ecology, water relations
@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}
}
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.